//
//   Copyright 2013 Pixar
//
//   Licensed under the Apache License, Version 2.0 (the "Apache License")
//   with the following modification; you may not use this file except in
//   compliance with the Apache License and the following modification to it:
//   Section 6. Trademarks. is deleted and replaced with:
//
//   6. Trademarks. This License does not grant permission to use the trade
//      names, trademarks, service marks, or product names of the Licensor
//      and its affiliates, except as required to comply with Section 4(c) of
//      the License and to reproduce the content of the NOTICE file.
//
//   You may obtain a copy of the Apache License at
//
//       http://www.apache.org/licenses/LICENSE-2.0
//
//   Unless required by applicable law or agreed to in writing, software
//   distributed under the Apache License with the above modification is
//   distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
//   KIND, either express or implied. See the Apache License for the specific
//   language governing permissions and limitations under the Apache License.
//

#if defined(__APPLE__)
    #if defined(OSD_USES_GLEW)
        #include <GL/glew.h>
    #else
        #include <OpenGL/gl3.h>
    #endif
    #define GLFW_INCLUDE_GL3
    #define GLFW_NO_GLU
#else
    #include <stdlib.h>
    #include <GL/glew.h>
    #if defined(WIN32)
        #include <GL/wglew.h>
    #endif
#endif

#include <GLFW/glfw3.h>
GLFWwindow* g_window = 0;
GLFWmonitor* g_primary = 0;

#include <vector>
#include <sstream>
#include <iostream>
#include <fstream>
#include <string>
#include <utility>
#include <algorithm>

#include <osd/glDrawContext.h>
#include <osd/glDrawRegistry.h>
#include <far/error.h>

#include <osd/cpuEvaluator.h>
#include <osd/cpuGLVertexBuffer.h>

#ifdef OPENSUBDIV_HAS_OPENMP
    #include <osd/ompEvaluator.h>
#endif

#ifdef OPENSUBDIV_HAS_TBB
    #include <osd/tbbEvaluator.h>
#endif

#ifdef OPENSUBDIV_HAS_OPENCL
    #include <osd/clEvaluator.h>
    #include <osd/clGLVertexBuffer.h>
    #include "../common/clDeviceContext.h"
    CLDeviceContext g_clDeviceContext;
#endif

#ifdef OPENSUBDIV_HAS_CUDA
    #include <osd/cudaEvaluator.h>
    #include <osd/cudaGLVertexBuffer.h>
    #include "../common/cudaDeviceContext.h"
    CudaDeviceContext g_cudaDeviceContext;
#endif

#ifdef OPENSUBDIV_HAS_GLSL_TRANSFORM_FEEDBACK
    #include <osd/glXFBEvaluator.h>
    #include <osd/glVertexBuffer.h>
#endif

#ifdef OPENSUBDIV_HAS_GLSL_COMPUTE
    #include <osd/glComputeEvaluator.h>
    #include <osd/glVertexBuffer.h>
#endif

#include <osd/glMesh.h>
OpenSubdiv::Osd::GLMeshInterface *g_mesh;

#include "Ptexture.h"
#include "PtexUtils.h"

#include <common/vtr_utils.h>
#include "../common/stopwatch.h"
#include "../common/simple_math.h"
#include "../common/gl_hud.h"
#include "../common/patchColors.h"
#include "../common/hdr_reader.h"
#include "../common/stb_image_write.h"
#include "../common/glPtexMipmapTexture.h"

static const char *g_defaultShaderSource =
#if defined(GL_ARB_tessellation_shader) || defined(GL_VERSION_4_0)
    #include "shader.gen.h"
#else
    #include "shader_gl3.gen.h"
#endif
;
static const char *g_skyShaderSource =
#include "skyshader.gen.h"
;
static const char *g_imageShaderSource =
#include "imageshader.gen.h"
;
static std::string g_shaderSource;
static const char *g_shaderFilename = NULL;

enum KernelType { kCPU = 0,
                  kOPENMP = 1,
                  kTBB = 2,
                  kCUDA = 3,
                  kCL = 4,
                  kGLSL = 5,
                  kGLSLCompute = 6 };

enum HudCheckBox { HUD_CB_ADAPTIVE,
                   HUD_CB_DISPLAY_OCCLUSION,
                   HUD_CB_DISPLAY_NORMALMAP,
                   HUD_CB_DISPLAY_SPECULAR,
                   HUD_CB_CAGE_EDGES,
                   HUD_CB_ANIMATE_VERTICES,
                   HUD_CB_VIEW_LOD,
                   HUD_CB_FRACTIONAL_SPACING,
                   HUD_CB_PATCH_CULL,
                   HUD_CB_IBL,
                   HUD_CB_BLOOM,
                   HUD_CB_SEAMLESS_MIPMAP,
                   HUD_CB_FREEZE };

enum HudRadioGroup { HUD_RB_KERNEL,
                     HUD_RB_LEVEL,
                     HUD_RB_SCHEME,
                     HUD_RB_WIRE,
                     HUD_RB_COLOR,
                     HUD_RB_DISPLACEMENT,
                     HUD_RB_NORMAL };

enum DisplayType { DISPLAY_WIRE,
                   DISPLAY_SHADED,
                   DISPLAY_WIRE_ON_SHADED };

enum ColorType { COLOR_NONE,
                 COLOR_PTEX_NEAREST,
                 COLOR_PTEX_HW_BILINEAR,
                 COLOR_PTEX_BILINEAR,
                 COLOR_PTEX_BIQUADRATIC,
                 COLOR_PATCHTYPE,
                 COLOR_PATCHCOORD,
                 COLOR_NORMAL };

enum DisplacementType { DISPLACEMENT_NONE,
                        DISPLACEMENT_HW_BILINEAR,
                        DISPLACEMENT_BILINEAR,
                        DISPLACEMENT_BIQUADRATIC };

enum NormalType { NORMAL_SURFACE,
                  NORMAL_FACET,
                  NORMAL_HW_SCREENSPACE,
                  NORMAL_SCREENSPACE,
                  NORMAL_BIQUADRATIC,
                  NORMAL_BIQUADRATIC_WG };

//-----------------------------------------------------------------------------
int   g_frame = 0,
      g_repeatCount = 0;

// GUI variables
int   g_fullscreen = 0,
      g_wire = DISPLAY_SHADED,
      g_drawNormals = 0,
      g_drawCageEdges = 0,
      g_mbutton[3] = {0, 0, 0},
      g_level = 1,
      g_tessLevel = 2,
      g_kernel = kCPU,
      g_scheme = 0,
      g_running = 1,
      g_maxMipmapLevels = 10,
      g_color = COLOR_PTEX_BILINEAR,
      g_displacement = DISPLACEMENT_NONE,
      g_normal = NORMAL_SURFACE;


float g_moveScale = 0.0f,
      g_displacementScale = 1.0f,
      g_mipmapBias = 0.0;

bool  g_adaptive = false,
      g_yup = false,
      g_patchCull = true,
      g_screenSpaceTess = true,
      g_fractionalSpacing = true,
      g_ibl = false,
      g_bloom = false,
      g_freeze = false;

GLuint g_transformUB = 0,
       g_transformBinding = 0,
       g_tessellationUB = 0,
       g_tessellationBinding = 0,
       g_lightingUB = 0,
       g_lightingBinding = 0;

struct Transform {
    float ModelViewMatrix[16];
    float ProjectionMatrix[16];
    float ModelViewProjectionMatrix[16];
    float ModelViewInverseMatrix[16];
} transformData;

// ptex switch
bool  g_occlusion = false,
      g_specular = false;

bool g_seamless = true;

// camera
float g_rotate[2] = {0, 0},
      g_dolly = 5,
      g_pan[2] = {0, 0},
      g_center[3] = {0, 0, 0},
      g_size = 0;

int   g_prev_x = 0,
      g_prev_y = 0;

// viewport
int   g_width = 1024,
      g_height = 1024;

GLhud g_hud;

// performance
float g_cpuTime = 0;
float g_gpuTime = 0;
#define NUM_FPS_TIME_SAMPLES 6
float g_fpsTimeSamples[NUM_FPS_TIME_SAMPLES] = {0, 0, 0, 0, 0, 0};
int   g_currentFpsTimeSample = 0;
Stopwatch g_fpsTimer;
float g_animTime = 0;

// geometry
std::vector<float> g_positions,
                   g_normals;

std::vector<std::vector<float> > g_animPositions;

GLuint g_queries[2] = {0, 0};
GLuint g_vao = 0;
GLuint g_cageEdgeVAO = 0;
GLuint g_skyVAO = 0;
GLuint g_edgeIndexBuffer = 0;
GLuint g_numCageEdges = 0;

GLuint g_diffuseEnvironmentMap = 0;
GLuint g_specularEnvironmentMap = 0;

//------------------------------------------------------------------------------

struct Sky {
    int numIndices;
    GLuint vertexBuffer;
    GLuint elementBuffer;
    GLuint mvpMatrix;
    GLuint program;

    Sky() : numIndices(0), vertexBuffer(0), elementBuffer(0), mvpMatrix(0),
            program(0) {}
} g_sky;

//------------------------------------------------------------------------------

struct ImageShader {
    GLuint blurProgram;
    GLuint hipassProgram;
    GLuint compositeProgram;

    GLuint frameBuffer;
    GLuint frameBufferTexture;
    GLuint frameBufferDepthTexture;

    GLuint smallFrameBuffer[2];
    GLuint smallFrameBufferTexture[2];

    GLuint smallWidth, smallHeight;

    GLuint vao;
    GLuint vbo;

    ImageShader() : blurProgram(0), hipassProgram(0), compositeProgram(0),
                    frameBuffer(0), frameBufferTexture(0), frameBufferDepthTexture(0) {
        smallFrameBuffer[0] = smallFrameBuffer[1] = 0;
        smallFrameBufferTexture[0] = smallFrameBufferTexture[1] = 0;
    }
} g_imageShader;

//------------------------------------------------------------------------------

GLPtexMipmapTexture * g_osdPTexImage = 0;
GLPtexMipmapTexture * g_osdPTexDisplacement = 0;
GLPtexMipmapTexture * g_osdPTexOcclusion = 0;
GLPtexMipmapTexture * g_osdPTexSpecular = 0;
const char * g_ptexColorFilename;
size_t g_ptexMemoryUsage = 0;


static void
checkGLErrors(std::string const & where = "") {
    GLuint err;
    while ((err = glGetError()) != GL_NO_ERROR) {
        std::cerr << "GL error: "
                  << (where.empty() ? "" : where + " ")
                  << err << "\n";
    }
}

//------------------------------------------------------------------------------
static void
calcNormals(OpenSubdiv::Far::TopologyRefiner * refiner,
    std::vector<float> const & pos, std::vector<float> & result ) {

    typedef OpenSubdiv::Far::ConstIndexArray IndexArray;

    // calc normal vectors
    int nverts = refiner->GetNumVertices(0),
        nfaces = refiner->GetNumFaces(0);

    for (int face = 0; face < nfaces; ++face) {

        IndexArray fverts = refiner->GetFaceVertices(0, face);

        float const * p0 = &pos[fverts[0]*3],
                    * p1 = &pos[fverts[1]*3],
                    * p2 = &pos[fverts[2]*3];

        float n[3];
        cross(n, p0, p1, p2);

        for (int vert = 0; vert < fverts.size(); ++vert) {
            int idx = fverts[vert] * 3;
            result[idx  ] += n[0];
            result[idx+1] += n[1];
            result[idx+2] += n[2];
        }
    }
    for (int i = 0; i < nverts; ++i)
        normalize(&result[i*3]);
}

//------------------------------------------------------------------------------
void
updateGeom() {

    int nverts = (int)g_positions.size() / 3;

    if (g_moveScale and g_adaptive and not g_animPositions.empty()) {
        // baked animation only works with adaptive for now
        // (since non-adaptive requires normals)
        int nkey = (int)g_animPositions.size();
        const float fps = 24.0f;

        float p = fmodf(g_animTime * fps, (float)nkey);
        int key = (int)p;
        float b = p - key;

        std::vector<float> vertex;
        vertex.reserve(nverts*3);
        for (int i = 0; i < nverts*3; ++i) {
            float p0 = g_animPositions[key][i];
            float p1 = g_animPositions[(key+1)%nkey][i];
            vertex.push_back(p0*(1-b) + p1*b);
        }
        g_mesh->UpdateVertexBuffer(&vertex[0], 0, nverts);

    } else {
        std::vector<float> vertex;
        vertex.reserve(nverts*6);

        const float *p = &g_positions[0];
        const float *n = &g_normals[0];

        for (int i = 0; i < nverts; ++i) {
            float move = g_size*0.005f*cosf(p[0]*100/g_size+g_frame*0.01f);
            vertex.push_back(p[0]);
            vertex.push_back(p[1]+g_moveScale*move);
            vertex.push_back(p[2]);
            p += 3;
            if (g_adaptive == false) {
                vertex.push_back(n[0]);
                vertex.push_back(n[1]);
                vertex.push_back(n[2]);
                n += 3;
            }
        }

        g_mesh->UpdateVertexBuffer(&vertex[0], 0, nverts);
    }

    Stopwatch s;
    s.Start();

    g_mesh->Refine();

    s.Stop();
    g_cpuTime = float(s.GetElapsed() * 1000.0f);
    s.Start();

    g_mesh->Synchronize();

    s.Stop();
    g_gpuTime = float(s.GetElapsed() * 1000.0f);
}

//-------------------------------------------------------------------------------
void
fitFrame() {
    g_pan[0] = g_pan[1] = 0;
    g_dolly = g_size;
}

//-------------------------------------------------------------------------------
Shape *
createPTexGeo(PtexTexture * r) {

    PtexMetaData* meta = r->getMetaData();

    if (meta->numKeys() < 3) {
        return NULL;
    }

    float const * vp;
    int const *vi, *vc;
    int nvp, nvi, nvc;

    meta->getValue("PtexFaceVertCounts", vc, nvc);
    if (nvc == 0) {
        return NULL;
    }
    meta->getValue("PtexVertPositions", vp, nvp);
    if (nvp == 0) {
        return NULL;
    }
    meta->getValue("PtexFaceVertIndices", vi, nvi);
    if (nvi == 0) {
        return NULL;
    }

    Shape * shape = new Shape;

    shape->scheme = kCatmark;

    shape->verts.resize(nvp);
    for (int i=0; i<nvp; ++i) {
        shape->verts[i] = vp[i];
    }

    shape->nvertsPerFace.resize(nvc);
    for (int i=0; i<nvc; ++i) {
        shape->nvertsPerFace[i] = vc[i];
    }

    shape->faceverts.resize(nvi);
    for (int i=0; i<nvi; ++i) {
        shape->faceverts[i] = vi[i];
    }

    // compute model bounding
    float min[3] = {vp[0], vp[1], vp[2]};
    float max[3] = {vp[0], vp[1], vp[2]};
    for (int i = 0; i < nvp/3; ++i) {
        for (int j = 0; j < 3; ++j) {
            float v = vp[i*3+j];
            min[j] = std::min(min[j], v);
            max[j] = std::max(max[j], v);
        }
    }

    for (int j = 0; j < 3; ++j) {
        g_center[j] = (min[j] + max[j]) * 0.5f;
        g_size += (max[j]-min[j])*(max[j]-min[j]);
    }
    g_size = sqrtf(g_size);

    return shape;
}

//------------------------------------------------------------------------------

void
reshape(GLFWwindow *, int width, int height) {

    g_width = width;
    g_height = height;

    int windowWidth = g_width, windowHeight = g_height;

    // window size might not match framebuffer size on a high DPI display
    glfwGetWindowSize(g_window, &windowWidth, &windowHeight);

    g_hud.Rebuild(windowWidth, windowHeight, width, height);

    // resize framebuffers
    glBindTexture(GL_TEXTURE_2D, g_imageShader.frameBufferTexture);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0,
                 GL_RGBA, GL_UNSIGNED_BYTE, 0);

    glBindTexture(GL_TEXTURE_2D, g_imageShader.frameBufferDepthTexture);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT32F, width, height, 0,
                 GL_DEPTH_COMPONENT, GL_FLOAT, 0);

    glBindFramebuffer(GL_FRAMEBUFFER, g_imageShader.frameBuffer);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
                           GL_TEXTURE_2D, g_imageShader.frameBufferTexture, 0);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
                           GL_TEXTURE_2D, g_imageShader.frameBufferDepthTexture, 0);

    const int d = 4;
    g_imageShader.smallWidth = width/d;
    g_imageShader.smallHeight = height/d;
    for (int i = 0; i < 2; ++i) {
        glBindTexture(GL_TEXTURE_2D, g_imageShader.smallFrameBufferTexture[i]);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width/d, height/d, 0,
                     GL_RGBA, GL_UNSIGNED_BYTE, 0);

        glBindFramebuffer(GL_FRAMEBUFFER, g_imageShader.smallFrameBuffer[i]);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
                               GL_TEXTURE_2D, g_imageShader.smallFrameBufferTexture[i], 0);
    }

    GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
    if (status != GL_FRAMEBUFFER_COMPLETE)
        assert(false);

    glBindTexture(GL_TEXTURE_2D, 0);
    glBindFramebuffer(GL_FRAMEBUFFER, 0);

    checkGLErrors("Reshape");
}

void reshape() {
    reshape(g_window, g_width, g_height);
}

void windowClose(GLFWwindow*) {
    g_running = false;
}

//------------------------------------------------------------------------------
const char *getKernelName(int kernel) {

         if (kernel == kCPU)
        return "CPU";
    else if (kernel == kOPENMP)
        return "OpenMP";
    else if (kernel == kCUDA)
        return "Cuda";
    else if (kernel == kGLSL)
        return "GLSL";
    else if (kernel == kCL)
        return "OpenCL";
    return "Unknown";
}

//------------------------------------------------------------------------------
static GLuint compileShader(GLenum shaderType,
                            OpenSubdiv::Osd::DrawShaderSource const & common,
                            OpenSubdiv::Osd::DrawShaderSource const & source) {

    const char *sources[4];
    std::stringstream definitions;
    for (int i = 0; i < (int)common.defines.size(); ++i) {
        definitions << "#define "
                    << common.defines[i].first << " "
                    << common.defines[i].second << "\n";
    }
    for (int i = 0; i < (int)source.defines.size(); ++i) {
        definitions << "#define "
                    << source.defines[i].first << " "
                    << source.defines[i].second << "\n";
    }
    std::string defString = definitions.str();

    sources[0] = source.version.c_str();
    sources[1] = defString.c_str();
    sources[2] = common.source.c_str();
    sources[3] = source.source.c_str();

    GLuint shader = glCreateShader(shaderType);
    glShaderSource(shader, 4, sources, NULL);
    glCompileShader(shader);

    GLint status;
    glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
    if (status == GL_FALSE) {
        GLchar emsg[40960];
        glGetShaderInfoLog(shader, sizeof(emsg), 0, emsg);
        fprintf(stderr, "Error compiling GLSL shader: %s\n", emsg);
        fprintf(stderr, "Defines: %s\n", defString.c_str());
        return 0;
    }

    return shader;
}

//------------------------------------------------------------------------------

int bindPTexture(GLint program, GLPtexMipmapTexture *osdPTex,
                 GLuint data, GLuint packing, int samplerUnit) {

#if defined(GL_ARB_separate_shader_objects) || defined(GL_VERSION_4_1)
    glProgramUniform1i(program, data, samplerUnit + 0);
    glProgramUniform1i(program, packing, samplerUnit + 1);
#else
    glUniform1i(data, samplerUnit + 0);
    glUniform1i(packing, samplerUnit + 1);
#endif

    glActiveTexture(GL_TEXTURE0 + samplerUnit + 0);
    glBindTexture(GL_TEXTURE_2D_ARRAY, osdPTex->GetTexelsTexture());

    glActiveTexture(GL_TEXTURE0 + samplerUnit + 1);
    glBindTexture(GL_TEXTURE_BUFFER, osdPTex->GetLayoutTextureBuffer());

    glActiveTexture(GL_TEXTURE0);

    return samplerUnit + 2;
}

//------------------------------------------------------------------------------

union Effect {
    struct {
        unsigned int wire:2;
        unsigned int color:3;
        unsigned int displacement:2;
        unsigned int normal:3;
        int occlusion:1;
        int specular:1;
        int patchCull:1;
        int screenSpaceTess:1;
        int fractionalSpacing:1;
        int ibl:1;
        int seamless:1;
    };
    int value;

    bool operator < (const Effect &e) const {
        return value < e.value;
    }
};

typedef std::pair<OpenSubdiv::Osd::DrawContext::PatchDescriptor, Effect> EffectDesc;

class EffectDrawRegistry : public OpenSubdiv::Osd::GLDrawRegistry<EffectDesc> {

protected:

    virtual ConfigType *
    _CreateDrawConfig(DescType const & desc, SourceConfigType const * sconfig);

    virtual SourceConfigType *
    _CreateDrawSourceConfig(DescType const & desc);
};

//------------------------------------------------------------------------------
EffectDrawRegistry::SourceConfigType *
EffectDrawRegistry::_CreateDrawSourceConfig(DescType const & desc) {

    Effect effect = desc.second;

    SourceConfigType * sconfig =
        BaseRegistry::_CreateDrawSourceConfig(desc.first);

    // add ptex functions
    sconfig->commonShader.source += GLPtexMipmapTexture::GetShaderSource();

    if (effect.patchCull)
        sconfig->commonShader.AddDefine("OSD_ENABLE_PATCH_CULL");
    if (effect.screenSpaceTess)
        sconfig->commonShader.AddDefine("OSD_ENABLE_SCREENSPACE_TESSELLATION");
    if (effect.fractionalSpacing)
        sconfig->commonShader.AddDefine("OSD_FRACTIONAL_ODD_SPACING");

#if defined(GL_ARB_tessellation_shader) || defined(GL_VERSION_4_0)
    const char *glslVersion = "#version 400\n";
#else
    const char *glslVersion = "#version 330\n";
#endif

    int nverts = 4;
    if (desc.first.GetType() == OpenSubdiv::Far::PatchDescriptor::QUADS) {
        sconfig->vertexShader.source = g_shaderSource;
        sconfig->vertexShader.version = glslVersion;
        sconfig->vertexShader.AddDefine("VERTEX_SHADER");
        if (effect.displacement) {
            sconfig->geometryShader.AddDefine("FLAT_NORMALS");
        }
    } else if (desc.first.GetType() == OpenSubdiv::Far::PatchDescriptor::LINES) {
        nverts = 2;
        sconfig->vertexShader.source = g_shaderSource;
        sconfig->vertexShader.version = glslVersion;
        sconfig->vertexShader.AddDefine("VERTEX_SHADER");
    } else {
        nverts = 3;
        sconfig->vertexShader.source = g_shaderSource + sconfig->vertexShader.source;
        sconfig->tessControlShader.source = g_shaderSource + sconfig->tessControlShader.source;
        sconfig->tessEvalShader.source = g_shaderSource + sconfig->tessEvalShader.source;
        sconfig->tessEvalShader.version = glslVersion;
        if (effect.displacement and (not effect.normal))
            sconfig->geometryShader.AddDefine("FLAT_NORMALS");
    }
    assert(sconfig);

    sconfig->geometryShader.source = g_shaderSource;
    sconfig->geometryShader.version = glslVersion;
    sconfig->geometryShader.AddDefine("GEOMETRY_SHADER");

    sconfig->fragmentShader.source = g_shaderSource;
    sconfig->fragmentShader.version = glslVersion;
    sconfig->fragmentShader.AddDefine("FRAGMENT_SHADER");

    switch (effect.color) {
        case COLOR_NONE:
            break;
        case COLOR_PTEX_NEAREST:
            sconfig->fragmentShader.AddDefine("COLOR_PTEX_NEAREST");
            break;
        case COLOR_PTEX_HW_BILINEAR:
            sconfig->fragmentShader.AddDefine("COLOR_PTEX_HW_BILINEAR");
            break;
        case COLOR_PTEX_BILINEAR:
            sconfig->fragmentShader.AddDefine("COLOR_PTEX_BILINEAR");
            break;
        case COLOR_PTEX_BIQUADRATIC:
            sconfig->fragmentShader.AddDefine("COLOR_PTEX_BIQUADRATIC");
            break;
        case COLOR_PATCHTYPE:
            sconfig->fragmentShader.AddDefine("COLOR_PATCHTYPE");
            break;
        case COLOR_PATCHCOORD:
            sconfig->fragmentShader.AddDefine("COLOR_PATCHCOORD");
            break;
        case COLOR_NORMAL:
            sconfig->fragmentShader.AddDefine("COLOR_NORMAL");
            break;
    }

    switch (effect.displacement) {
        case DISPLACEMENT_NONE:
            break;
        case DISPLACEMENT_HW_BILINEAR:
            sconfig->commonShader.AddDefine("DISPLACEMENT_HW_BILINEAR");
            break;
        case DISPLACEMENT_BILINEAR:
            sconfig->commonShader.AddDefine("DISPLACEMENT_BILINEAR");
            break;
        case DISPLACEMENT_BIQUADRATIC:
            sconfig->commonShader.AddDefine("DISPLACEMENT_BIQUADRATIC");
            break;
    }

    switch (effect.normal) {
        case NORMAL_FACET:
            sconfig->commonShader.AddDefine("NORMAL_FACET");
            break;
        case NORMAL_HW_SCREENSPACE:
            sconfig->commonShader.AddDefine("NORMAL_HW_SCREENSPACE");
            break;
        case NORMAL_SCREENSPACE:
            sconfig->commonShader.AddDefine("NORMAL_SCREENSPACE");
            break;
        case NORMAL_BIQUADRATIC:
            sconfig->commonShader.AddDefine("NORMAL_BIQUADRATIC");
            break;
        case NORMAL_BIQUADRATIC_WG:
            sconfig->commonShader.AddDefine("OSD_COMPUTE_NORMAL_DERIVATIVES");
            sconfig->commonShader.AddDefine("NORMAL_BIQUADRATIC_WG");
            break;
    }

    if (effect.occlusion)
        sconfig->fragmentShader.AddDefine("USE_PTEX_OCCLUSION");
    if (effect.specular)
        sconfig->fragmentShader.AddDefine("USE_PTEX_SPECULAR");
    if (effect.ibl)
        sconfig->fragmentShader.AddDefine("USE_IBL");

    if (nverts == 4) {
        sconfig->geometryShader.AddDefine("PRIM_QUAD");
        sconfig->fragmentShader.AddDefine("PRIM_QUAD");
    } else if (nverts == 3) {
        sconfig->geometryShader.AddDefine("PRIM_TRI");
        sconfig->fragmentShader.AddDefine("PRIM_TRI");
    } else {
        sconfig->geometryShader.AddDefine("PRIM_LINE");
        sconfig->fragmentShader.AddDefine("PRIM_LINE");
    }

    if (effect.seamless) {
        sconfig->commonShader.AddDefine("SEAMLESS_MIPMAP");
    }

    if (effect.wire == 0) {
        sconfig->geometryShader.AddDefine("GEOMETRY_OUT_WIRE");
        sconfig->fragmentShader.AddDefine("GEOMETRY_OUT_WIRE");
    } else if (effect.wire == 1) {
        sconfig->geometryShader.AddDefine("GEOMETRY_OUT_FILL");
        sconfig->fragmentShader.AddDefine("GEOMETRY_OUT_FILL");
    } else if (effect.wire == 2) {
        sconfig->geometryShader.AddDefine("GEOMETRY_OUT_LINE");
        sconfig->fragmentShader.AddDefine("GEOMETRY_OUT_LINE");
    }

    return sconfig;
}

EffectDrawRegistry::ConfigType *
EffectDrawRegistry::_CreateDrawConfig(
        DescType const & desc,
        SourceConfigType const * sconfig) {

    ConfigType * config = BaseRegistry::_CreateDrawConfig(desc.first, sconfig);
    assert(config);

    // XXXdyu can use layout(binding=) with GLSL 4.20 and beyond
    g_transformBinding = 0;
    GLint transformIndex = glGetUniformBlockIndex(config->program, "Transform");
    if (transformIndex != -1)
        glUniformBlockBinding(config->program, transformIndex, g_transformBinding);

    g_tessellationBinding = 1;

#if defined(GL_ARB_tessellation_shader) || defined(GL_VERSION_4_0)
    GLint tessellationIndex = glGetUniformBlockIndex(config->program, "Tessellation");
    if (tessellationIndex != -1)
        glUniformBlockBinding(config->program, tessellationIndex, g_tessellationBinding);
#endif

    g_lightingBinding = 2;
    GLint lightingIndex = glGetUniformBlockIndex(config->program, "Lighting");
    if (lightingIndex != -1)
        glUniformBlockBinding(config->program, lightingIndex, g_lightingBinding);

    GLint loc;
#if defined(GL_ARB_separate_shader_objects) || defined(GL_VERSION_4_1)
    if ((loc = glGetUniformLocation(config->program, "OsdVertexBuffer")) != -1) {
        glProgramUniform1i(config->program, loc, 0);  // GL_TEXTURE0
    }
    if ((loc = glGetUniformLocation(config->program, "OsdValenceBuffer")) != -1) {
        glProgramUniform1i(config->program, loc, 1);  // GL_TEXTURE1
    }
    if ((loc = glGetUniformLocation(config->program, "OsdQuadOffsetBuffer")) != -1) {
        glProgramUniform1i(config->program, loc, 2);  // GL_TEXTURE2
    }
    if ((loc = glGetUniformLocation(config->program, "OsdPatchParamBuffer")) != -1) {
        glProgramUniform1i(config->program, loc, 3);  // GL_TEXTURE3
    }
#else
    glUseProgram(config->program);
    if ((loc = glGetUniformLocation(config->program, "OsdVertexBuffer")) != -1) {
        glUniform1i(loc, 0);  // GL_TEXTURE0
    }
    if ((loc = glGetUniformLocation(config->program, "OsdValenceBuffer")) != -1) {
        glUniform1i(loc, 1);  // GL_TEXTURE1
    }
    if ((loc = glGetUniformLocation(config->program, "OsdQuadOffsetBuffer")) != -1) {
        glUniform1i(loc, 2);  // GL_TEXTURE2
    }
    if ((loc = glGetUniformLocation(config->program, "OsdPatchParamBuffer")) != -1) {
        glUniform1i(loc, 3);  // GL_TEXTURE3
    }
#endif

    return config;
}

EffectDrawRegistry effectRegistry;

EffectDrawRegistry::ConfigType *
getInstance(Effect effect,
    OpenSubdiv::Osd::DrawContext::PatchDescriptor const & patchDesc) {

    EffectDesc desc(patchDesc, effect);

    EffectDrawRegistry::ConfigType * config =
        effectRegistry.GetDrawConfig(desc);
    assert(config);

    return config;
}

//------------------------------------------------------------------------------
GLPtexMipmapTexture *
createPtex(const char *filename, int memLimit) {

    Ptex::String ptexError;
    printf("Loading ptex : %s\n", filename);

#define USE_PTEX_CACHE
#define PTEX_CACHE_SIZE (512*1024*1024)

#ifdef USE_PTEX_CACHE
    PtexCache *cache = PtexCache::create(1, PTEX_CACHE_SIZE);
    PtexTexture *ptex = cache->get(filename, ptexError);
#else
    PtexTexture *ptex = PtexTexture::open(filename, ptexError, true);
#endif

    if (ptex == NULL) {
        printf("Error in reading %s\n", filename);
        exit(1);
    }

    size_t targetMemory = memLimit * 1024 * 1024; // MB

    GLPtexMipmapTexture *osdPtex = GLPtexMipmapTexture::Create(
        ptex, g_maxMipmapLevels, targetMemory);

    GLuint texture = osdPtex->GetTexelsTexture();
    glBindTexture(GL_TEXTURE_2D_ARRAY, texture);
    GLint w, h, d;
    glGetTexLevelParameteriv(GL_TEXTURE_2D_ARRAY, 0, GL_TEXTURE_WIDTH, &w);
    glGetTexLevelParameteriv(GL_TEXTURE_2D_ARRAY, 0, GL_TEXTURE_HEIGHT, &h);
    glGetTexLevelParameteriv(GL_TEXTURE_2D_ARRAY, 0, GL_TEXTURE_DEPTH, &d);
    printf("PageSize = %d x %d x %d\n", w, h, d);
    glBindTexture(GL_TEXTURE_2D_ARRAY, 0);

    ptex->release();

#ifdef USE_PTEX_CACHE
    cache->release();
#endif

    return osdPtex;
}

//------------------------------------------------------------------------------

void
createOsdMesh(int level, int kernel) {

    checkGLErrors("createOsdMesh");

    Ptex::String ptexError;
    PtexTexture *ptexColor = PtexTexture::open(g_ptexColorFilename, ptexError, true);
    if (ptexColor == NULL) {
        printf("Error in reading %s\n", g_ptexColorFilename);
        exit(1);
    }

    // generate Shape representation from ptex
    Shape * shape = createPTexGeo(ptexColor);
    if (not shape) {
        return;
    }

    g_positions=shape->verts;

    typedef OpenSubdiv::Far::ConstIndexArray IndexArray;

    // create Vtr mesh (topology)
    OpenSubdiv::Sdc::SchemeType sdctype = GetSdcType(*shape);
    OpenSubdiv::Sdc::Options sdcoptions = GetSdcOptions(*shape);

    OpenSubdiv::Far::TopologyRefiner * refiner =
        OpenSubdiv::Far::TopologyRefinerFactory<Shape>::Create(*shape,
            OpenSubdiv::Far::TopologyRefinerFactory<Shape>::Options(sdctype, sdcoptions));

    // save coarse topology (used for coarse mesh drawing)

    // create cage edge index
    int nedges = refiner->GetNumEdges(0);
    std::vector<int> edgeIndices(nedges*2);
    for(int i=0; i<nedges; ++i) {
        IndexArray verts = refiner->GetEdgeVertices(0, i);
        edgeIndices[i*2  ]=verts[0];
        edgeIndices[i*2+1]=verts[1];
    }

    delete shape;

    g_normals.resize(g_positions.size(), 0.0f);
    calcNormals(refiner, g_positions, g_normals);

    delete g_mesh;
    g_mesh = NULL;

    // Adaptive refinement currently supported only for catmull-clark scheme
    bool doAdaptive = (g_adaptive != 0 and g_scheme == 0);

    OpenSubdiv::Osd::MeshBitset bits;
    bits.set(OpenSubdiv::Osd::MeshAdaptive, doAdaptive);
    bits.set(OpenSubdiv::Osd::MeshPtexData, true);
    bits.set(OpenSubdiv::Osd::MeshEndCapGregoryBasis, true);

    int numVertexElements = g_adaptive ? 3 : 6;
    int numVaryingElements = 0;

    if (kernel == kCPU) {
        g_mesh = new OpenSubdiv::Osd::Mesh<OpenSubdiv::Osd::CpuGLVertexBuffer,
                                           OpenSubdiv::Far::StencilTables,
                                           OpenSubdiv::Osd::CpuEvaluator,
                                           OpenSubdiv::Osd::GLDrawContext>(
                                                refiner,
                                                numVertexElements,
                                                numVaryingElements,
                                                level, bits);
#ifdef OPENSUBDIV_HAS_OPENMP
    } else if (kernel == kOPENMP) {
        g_mesh = new OpenSubdiv::Osd::Mesh<OpenSubdiv::Osd::CpuGLVertexBuffer,
                                           OpenSubdiv::Far::StencilTables,
                                           OpenSubdiv::Osd::OmpEvaluator,
                                           OpenSubdiv::Osd::GLDrawContext>(
                                                refiner,
                                                numVertexElements,
                                                numVaryingElements,
                                                level, bits);
#endif
#ifdef OPENSUBDIV_HAS_TBB
    } else if (kernel == kTBB) {
        g_mesh = new OpenSubdiv::Osd::Mesh<OpenSubdiv::Osd::CpuGLVertexBuffer,
                                           OpenSubdiv::Far::StencilTables,
                                           OpenSubdiv::Osd::TbbEvaluator,
                                           OpenSubdiv::Osd::GLDrawContext>(
                                                refiner,
                                                numVertexElements,
                                                numVaryingElements,
                                                level, bits);
#endif
#ifdef OPENSUBDIV_HAS_OPENCL
    } else if (kernel == kCL) {
        static OpenSubdiv::Osd::EvaluatorCacheT<OpenSubdiv::Osd::CLEvaluator> clEvaluatorCache;
        g_mesh = new OpenSubdiv::Osd::Mesh<OpenSubdiv::Osd::CLGLVertexBuffer,
                                           OpenSubdiv::Osd::CLStencilTables,
                                           OpenSubdiv::Osd::CLEvaluator,
                                           OpenSubdiv::Osd::GLDrawContext,
                                           CLDeviceContext>(
                                                refiner,
                                                numVertexElements,
                                                numVaryingElements,
                                                level, bits,
                                                &clEvaluatorCache,
                                                &g_clDeviceContext);
#endif
#ifdef OPENSUBDIV_HAS_CUDA
    } else if (kernel == kCUDA) {
        g_mesh = new OpenSubdiv::Osd::Mesh<OpenSubdiv::Osd::CudaGLVertexBuffer,
                                           OpenSubdiv::Osd::CudaStencilTables,
                                           OpenSubdiv::Osd::CudaEvaluator,
                                           OpenSubdiv::Osd::GLDrawContext>(
                                                refiner,
                                                numVertexElements,
                                                numVaryingElements,
                                                level, bits);
#endif
#ifdef OPENSUBDIV_HAS_GLSL_TRANSFORM_FEEDBACK
    } else if (kernel == kGLSL) {
        static OpenSubdiv::Osd::EvaluatorCacheT<OpenSubdiv::Osd::GLXFBEvaluator> glXFBEvaluatorCache;
        g_mesh = new OpenSubdiv::Osd::Mesh<OpenSubdiv::Osd::GLVertexBuffer,
                                           OpenSubdiv::Osd::GLStencilTablesTBO,
                                           OpenSubdiv::Osd::GLXFBEvaluator,
                                           OpenSubdiv::Osd::GLDrawContext>(
                                               refiner,
                                               numVertexElements,
                                               numVaryingElements,
                                               level, bits,
                                               &glXFBEvaluatorCache);
#endif
#ifdef OPENSUBDIV_HAS_GLSL_COMPUTE
    } else if (kernel == kGLSLCompute) {
        static OpenSubdiv::Osd::EvaluatorCacheT<OpenSubdiv::Osd::GLComputeEvaluator> glComputeEvaluatorCache;
        g_mesh = new OpenSubdiv::Osd::Mesh<OpenSubdiv::Osd::GLVertexBuffer,
                                           OpenSubdiv::Osd::GLStencilTablesSSBO,
                                           OpenSubdiv::Osd::GLComputeEvaluator,
                                           OpenSubdiv::Osd::GLDrawContext>(
                                                refiner,
                                                numVertexElements,
                                                numVaryingElements,
                                                level, bits,
                                               &glComputeEvaluatorCache);
#endif
    } else {
        printf("Unsupported kernel %s\n", getKernelName(kernel));
    }

    if (glGetError() != GL_NO_ERROR) {
        printf("GLERROR\n");
    }

    updateGeom();

    // ------ VAO
    glBindVertexArray(g_vao);

    glBindBuffer(GL_ARRAY_BUFFER, g_mesh->BindVertexBuffer());

    if (g_adaptive) {
        glEnableVertexAttribArray(0);
        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
    } else {
        glEnableVertexAttribArray(0);
        glEnableVertexAttribArray(1);
        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 6, 0);
        glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 6, (float*)12);
    }
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_mesh->GetDrawContext()->GetPatchIndexBuffer());

    // ------ Cage VAO
    glBindVertexArray(g_cageEdgeVAO);

    glBindBuffer(GL_ARRAY_BUFFER, g_mesh->BindVertexBuffer());

    if (g_adaptive) {
        glEnableVertexAttribArray(0);
        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
    } else {
        glEnableVertexAttribArray(0);
        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 6, 0);
    }
    if (not g_edgeIndexBuffer) glGenBuffers(1, &g_edgeIndexBuffer);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_edgeIndexBuffer);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(int)*edgeIndices.size(),
                 &edgeIndices[0], GL_STATIC_DRAW);
    g_numCageEdges = (int)edgeIndices.size();

    glBindVertexArray(0);
}

//------------------------------------------------------------------------------

void
createSky() {

    const int U_DIV = 20;
    const int V_DIV = 20;

    std::vector<float> vbo;
    std::vector<int> indices;
    for (int u = 0; u <= U_DIV; ++u) {
        for (int v = 0; v < V_DIV; ++v) {
            float s = float(2*M_PI*float(u)/U_DIV);
            float t = float(M_PI*float(v)/(V_DIV-1));
            vbo.push_back(-sin(t)*sin(s));
            vbo.push_back(cos(t));
            vbo.push_back(-sin(t)*cos(s));
            vbo.push_back(u/float(U_DIV));
            vbo.push_back(v/float(V_DIV));

            if (v > 0 && u > 0) {
                indices.push_back((u-1)*V_DIV+v-1);
                indices.push_back(u*V_DIV+v-1);
                indices.push_back((u-1)*V_DIV+v);
                indices.push_back((u-1)*V_DIV+v);
                indices.push_back(u*V_DIV+v-1);
                indices.push_back(u*V_DIV+v);
            }
        }
    }

    glGenBuffers(1, &g_sky.vertexBuffer);
    glBindBuffer(GL_ARRAY_BUFFER, g_sky.vertexBuffer);
    glBufferData(GL_ARRAY_BUFFER, sizeof(float)*vbo.size(), &vbo[0], GL_STATIC_DRAW);
    glBindBuffer(GL_ARRAY_BUFFER, 0);

    glGenBuffers(1, &g_sky.elementBuffer);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_sky.elementBuffer);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(int)*indices.size(), &indices[0], GL_STATIC_DRAW);

    g_sky.numIndices = (int)indices.size();

    g_sky.program = glCreateProgram();

    OpenSubdiv::Osd::DrawShaderSource common, vertexShader, fragmentShader;
    vertexShader.source = g_skyShaderSource;
    vertexShader.version = "#version 410\n";
    vertexShader.AddDefine("SKY_VERTEX_SHADER");
    fragmentShader.source = g_skyShaderSource;
    fragmentShader.version = "#version 410\n";
    fragmentShader.AddDefine("SKY_FRAGMENT_SHADER");
    GLuint vs = compileShader(GL_VERTEX_SHADER,
                              common, vertexShader);
    GLuint fs = compileShader(GL_FRAGMENT_SHADER,
                              common, fragmentShader);

    glAttachShader(g_sky.program, vs);
    glAttachShader(g_sky.program, fs);
    glLinkProgram(g_sky.program);

    glDeleteShader(vs);
    glDeleteShader(fs);

    GLint environmentMap = glGetUniformLocation(g_sky.program, "environmentMap");
#if defined(GL_ARB_separate_shader_objects) || defined(GL_VERSION_4_1)
    if (g_specularEnvironmentMap)
        glProgramUniform1i(g_sky.program, environmentMap, 6);
    else
        glProgramUniform1i(g_sky.program, environmentMap, 5);
#else
    glUseProgram(g_sky.program);
    if (g_specularEnvironmentMap)
      glUniform1i(environmentMap, 6);
    else
      glUniform1i(environmentMap, 5);
#endif

    g_sky.mvpMatrix = glGetUniformLocation(g_sky.program, "ModelViewProjectionMatrix");
}

GLuint
compileImageShader(const char *define) {

    GLuint program = glCreateProgram();

    OpenSubdiv::Osd::DrawShaderSource common, vertexShader, fragmentShader;
    vertexShader.source = g_imageShaderSource;
    vertexShader.version = "#version 410\n";
    vertexShader.AddDefine("IMAGE_VERTEX_SHADER");
    fragmentShader.source = g_imageShaderSource;
    fragmentShader.version = "#version 410\n";
    fragmentShader.AddDefine("IMAGE_FRAGMENT_SHADER");
    fragmentShader.AddDefine(define);

    GLuint vs = compileShader(GL_VERTEX_SHADER,
                              common, vertexShader);
    GLuint fs = compileShader(GL_FRAGMENT_SHADER,
                              common, fragmentShader);

    glAttachShader(program, vs);
    glAttachShader(program, fs);
    glLinkProgram(program);

    glDeleteShader(vs);
    glDeleteShader(fs);

#if defined(GL_ARB_separate_shader_objects) || defined(GL_VERSION_4_1)
    GLint colorMap = glGetUniformLocation(program, "colorMap");
    if (colorMap != -1)
        glProgramUniform1i(program, colorMap, 0);  // GL_TEXTURE0
    GLint depthMap = glGetUniformLocation(program, "depthMap");
    if (depthMap != -1)
        glProgramUniform1i(program, depthMap, 1);  // GL_TEXTURE1
#else
    glUseProgram(program);
    GLint colorMap = glGetUniformLocation(program, "colorMap");
    if (colorMap != -1)
        glUniform1i(colorMap, 0);  // GL_TEXTURE0
    GLint depthMap = glGetUniformLocation(program, "depthMap");
    if (depthMap != -1)
        glUniform1i(depthMap, 1);  // GL_TEXTURE1
#endif

    return program;
}

//------------------------------------------------------------------------------

void
createImageShader() {

    g_imageShader.blurProgram = compileImageShader("BLUR");
    g_imageShader.hipassProgram = compileImageShader("HIPASS");
    g_imageShader.compositeProgram = compileImageShader("COMPOSITE");

    glGenVertexArrays(1, &g_imageShader.vao);
    glBindVertexArray(g_imageShader.vao);
    glGenBuffers(1, &g_imageShader.vbo);
    float pos[] = { -1, -1, 1, -1, -1,  1, 1,  1 };
    glGenBuffers(1, &g_imageShader.vbo);
    glBindBuffer(GL_ARRAY_BUFFER, g_imageShader.vbo);
    glBufferData(GL_ARRAY_BUFFER,
                 sizeof(pos), pos, GL_STATIC_DRAW);
    glBindBuffer(GL_ARRAY_BUFFER, g_imageShader.vbo);

    glEnableVertexAttribArray(0);
    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, 0);

    glBindVertexArray(0);
    glBindBuffer(GL_ARRAY_BUFFER, 0);
}

//------------------------------------------------------------------------------

void
applyImageShader() {

    int w = g_imageShader.smallWidth, h = g_imageShader.smallHeight;
    const float hoffsets[10] = {
        -2.0f / w, 0,
        -1.0f / w, 0,
        0, 0,
        +1.0f / w, 0,
        +2.0f / w, 0,
    };
    const float voffsets[10] = {
        0, -2.0f / h,
        0, -1.0f / h,
        0, 0,
        0, +1.0f / h,
        0, +2.0f / h,
    };
    const float weights[5] = {
        1.0f / 16.0f,
        4.0f / 16.0f,
        6.0f / 16.0f,
        4.0f / 16.0f,
        1.0f / 16.0f,
    };

    checkGLErrors("image shader begin");
    glBindVertexArray(g_imageShader.vao);

    GLint uniformAlpha = glGetUniformLocation(g_imageShader.compositeProgram, "alpha");

    if (g_bloom) {
        // XXX: fix me
        GLint uniformOffsets = glGetUniformLocation(g_imageShader.blurProgram, "Offsets");
        GLint uniformWeights = glGetUniformLocation(g_imageShader.blurProgram, "Weights");

        // down sample
        glUseProgram(g_imageShader.hipassProgram);
        glViewport(0, 0, g_imageShader.smallWidth, g_imageShader.smallHeight);
        glBindFramebuffer(GL_FRAMEBUFFER, g_imageShader.smallFrameBuffer[0]);
        glActiveTexture(GL_TEXTURE0);
        glBindTexture(GL_TEXTURE_2D, g_imageShader.frameBufferTexture);
        glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

        // horizontal blur pass
        glUseProgram(g_imageShader.blurProgram);
        glBindFramebuffer(GL_FRAMEBUFFER, g_imageShader.smallFrameBuffer[1]);
        glBindTexture(GL_TEXTURE_2D, g_imageShader.smallFrameBufferTexture[0]);
        glUniform2fv(uniformOffsets, 5, hoffsets);
        glUniform1fv(uniformWeights, 5, weights);
        glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

        // vertical blur pass
        glBindFramebuffer(GL_FRAMEBUFFER, g_imageShader.smallFrameBuffer[0]);
        glBindTexture(GL_TEXTURE_2D, g_imageShader.smallFrameBufferTexture[1]);
        glUniform2fv(uniformOffsets, 5, voffsets);
        glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
    }


    glBindFramebuffer(GL_FRAMEBUFFER, 0);
    glClear(GL_COLOR_BUFFER_BIT);
    glViewport(0, 0, g_width, g_height);

    // blit full-res
    glUseProgram(g_imageShader.compositeProgram);
    glUniform1f(uniformAlpha, 1);
    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, g_imageShader.frameBufferTexture);
    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

    if (g_bloom) {
        glUseProgram(g_imageShader.compositeProgram);
        glUniform1f(uniformAlpha, 0.5);
        glBlendFunc(GL_ONE, GL_ONE);
        glEnable(GL_BLEND);
        glActiveTexture(GL_TEXTURE0);
        glBindTexture(GL_TEXTURE_2D, g_imageShader.smallFrameBufferTexture[0]);
        glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
        glDisable(GL_BLEND);
    }

    glBindVertexArray(0);
    glUseProgram(0);

    checkGLErrors("image shader");
}

//------------------------------------------------------------------------------

static void
updateUniformBlocks() {

    if (g_transformUB == 0) {
        glGenBuffers(1, &g_transformUB);
        glBindBuffer(GL_UNIFORM_BUFFER, g_transformUB);
        glBufferData(GL_UNIFORM_BUFFER,
                sizeof(transformData), NULL, GL_STATIC_DRAW);
    };
    glBindBuffer(GL_UNIFORM_BUFFER, g_transformUB);
    glBufferSubData(GL_UNIFORM_BUFFER,
                0, sizeof(transformData), &transformData);
    glBindBuffer(GL_UNIFORM_BUFFER, 0);

    glBindBufferBase(GL_UNIFORM_BUFFER, g_transformBinding, g_transformUB);

    // Update and bind tessellation state
    struct Tessellation {
        float TessLevel;
    } tessellationData;

    tessellationData.TessLevel = static_cast<float>(1 << g_tessLevel);

    if (g_tessellationUB == 0) {
        glGenBuffers(1, &g_tessellationUB);
        glBindBuffer(GL_UNIFORM_BUFFER, g_tessellationUB);
        glBufferData(GL_UNIFORM_BUFFER,
                sizeof(tessellationData), NULL, GL_STATIC_DRAW);
    };
    glBindBuffer(GL_UNIFORM_BUFFER, g_tessellationUB);
    glBufferSubData(GL_UNIFORM_BUFFER,
                0, sizeof(tessellationData), &tessellationData);
    glBindBuffer(GL_UNIFORM_BUFFER, 0);

    glBindBufferBase(GL_UNIFORM_BUFFER, g_tessellationBinding, g_tessellationUB);

    // Update and bind lighting state
    struct Lighting {
        struct Light {
            float position[4];
            float ambient[4];
            float diffuse[4];
            float specular[4];
        } lightSource[2];
    } lightingData = {
       {{  { 0.6f, 1.0f, 0.6f, 0.0f },
           { 0.1f, 0.1f, 0.1f, 1.0f },
           { 1.7f, 1.3f, 1.1f, 1.0f },
           { 1.0f, 1.0f, 1.0f, 1.0f } },

         { { -0.8f, 0.6f, -0.7f, 0.0f },
           {  0.0f, 0.0f,  0.0f, 1.0f },
           {  0.8f, 0.8f,  1.5f, 1.0f },
           {  0.4f, 0.4f,  0.4f, 1.0f } }}
    };
    if (g_lightingUB == 0) {
        glGenBuffers(1, &g_lightingUB);
        glBindBuffer(GL_UNIFORM_BUFFER, g_lightingUB);
        glBufferData(GL_UNIFORM_BUFFER,
                sizeof(lightingData), NULL, GL_STATIC_DRAW);
    };
    glBindBuffer(GL_UNIFORM_BUFFER, g_lightingUB);
    glBufferSubData(GL_UNIFORM_BUFFER,
                0, sizeof(lightingData), &lightingData);
    glBindBuffer(GL_UNIFORM_BUFFER, 0);

    glBindBufferBase(GL_UNIFORM_BUFFER, g_lightingBinding, g_lightingUB);
}

//------------------------------------------------------------------------------
static GLuint
bindProgram(Effect effect, OpenSubdiv::Osd::DrawContext::PatchDescriptor const &desc) {

    EffectDrawRegistry::ConfigType *
        config = getInstance(effect, desc);

    GLuint program = config->program;

    glUseProgram(program);

    //-----------------
    int sampler = 7;

    // color ptex
    GLint texData = glGetUniformLocation(program, "textureImage_Data");
    GLint texPacking = glGetUniformLocation(program, "textureImage_Packing");
    sampler = bindPTexture(program, g_osdPTexImage, texData, texPacking, sampler);

    // displacement ptex
    if (g_displacement != DISPLACEMENT_NONE || g_normal) {
        texData = glGetUniformLocation(program, "textureDisplace_Data");
        texPacking = glGetUniformLocation(program, "textureDisplace_Packing");
        sampler = bindPTexture(program, g_osdPTexDisplacement, texData, texPacking, sampler);
    }

    // occlusion ptex
    if (g_occlusion) {
        texData = glGetUniformLocation(program, "textureOcclusion_Data");
        texPacking = glGetUniformLocation(program, "textureOcclusion_Packing");
        sampler = bindPTexture(program, g_osdPTexOcclusion, texData, texPacking, sampler);
    }

    // specular ptex
    if (g_specular) {
        texData = glGetUniformLocation(program, "textureSpecular_Data");
        texPacking = glGetUniformLocation(program, "textureSpecular_Packing");
        sampler = bindPTexture(program, g_osdPTexSpecular, texData, texPacking, sampler);
    }

    // other textures
    if (g_ibl) {
        if (g_diffuseEnvironmentMap) {
#if defined(GL_ARB_separate_shader_objects) || defined(GL_VERSION_4_1)
            glProgramUniform1i(program, glGetUniformLocation(program, "diffuseEnvironmentMap"), 5);
#else
            glUniform1i(glGetUniformLocation(program, "diffuseEnvironmentMap"), 5);
#endif
            glActiveTexture(GL_TEXTURE5);
            glBindTexture(GL_TEXTURE_2D, g_diffuseEnvironmentMap);
        }
        if (g_specularEnvironmentMap) {
#if defined(GL_ARB_separate_shader_objects) || defined(GL_VERSION_4_1)
            glProgramUniform1i(program, glGetUniformLocation(program, "specularEnvironmentMap"), 6);
#else
            glUniform1i(glGetUniformLocation(program, "specularEnvironmentMap"), 6);
#endif
            glActiveTexture(GL_TEXTURE6);
            glBindTexture(GL_TEXTURE_2D, g_specularEnvironmentMap);
        }
        glActiveTexture(GL_TEXTURE0);
    }

    return program;
}

//------------------------------------------------------------------------------
void
drawModel() {

#if defined(GL_ARB_tessellation_shader) || defined(GL_VERSION_4_0)
    GLuint bVertex = g_mesh->BindVertexBuffer();
#else
    g_mesh->BindVertexBuffer();
#endif

    OpenSubdiv::Osd::DrawContext::PatchArrayVector const & patches =
        g_mesh->GetDrawContext()->GetPatchArrays();
    glBindVertexArray(g_vao);

    // patch drawing
    for (int i = 0; i < (int)patches.size(); ++i) {
        OpenSubdiv::Osd::DrawContext::PatchArray const & patch = patches[i];

        OpenSubdiv::Osd::DrawContext::PatchDescriptor desc = patch.GetDescriptor();
        OpenSubdiv::Far::PatchDescriptor::Type patchType = desc.GetType();

        GLenum primType;
        switch (patchType) {
        case OpenSubdiv::Far::PatchDescriptor::QUADS:
            primType = GL_LINES_ADJACENCY;
            break;
        case OpenSubdiv::Far::PatchDescriptor::TRIANGLES:
            primType = GL_TRIANGLES;
            break;
        default:
#if defined(GL_ARB_tessellation_shader) || defined(GL_VERSION_4_0)
            primType = GL_PATCHES;
            glPatchParameteri(GL_PATCH_VERTICES, desc.GetNumControlVertices());
#else
            primType = GL_POINTS;
#endif
        }

#if defined(GL_ARB_tessellation_shader) || defined(GL_VERSION_4_0)
        if (g_mesh->GetDrawContext()->GetVertexTextureBuffer()) {
            glActiveTexture(GL_TEXTURE0);
            glBindTexture(GL_TEXTURE_BUFFER,
                g_mesh->GetDrawContext()->GetVertexTextureBuffer());
            glTexBuffer(GL_TEXTURE_BUFFER, GL_R32F, bVertex);
        }
        if (g_mesh->GetDrawContext()->GetVertexValenceTextureBuffer()) {
            glActiveTexture(GL_TEXTURE1);
            glBindTexture(GL_TEXTURE_BUFFER,
                g_mesh->GetDrawContext()->GetVertexValenceTextureBuffer());
        }
        if (g_mesh->GetDrawContext()->GetQuadOffsetsTextureBuffer()) {
            glActiveTexture(GL_TEXTURE2);
            glBindTexture(GL_TEXTURE_BUFFER,
                g_mesh->GetDrawContext()->GetQuadOffsetsTextureBuffer());
        }
#endif
        if (g_mesh->GetDrawContext()->GetPatchParamTextureBuffer()) {
            glActiveTexture(GL_TEXTURE3);
            glBindTexture(GL_TEXTURE_BUFFER,
                g_mesh->GetDrawContext()->GetPatchParamTextureBuffer());
        }
        glActiveTexture(GL_TEXTURE0);

        Effect effect;
        effect.value = 0;

        effect.color = g_color;
        effect.displacement = g_displacement;

        effect.occlusion = g_occlusion;
        effect.normal = g_normal;
        effect.specular = g_specular;
        effect.patchCull = g_patchCull;
        effect.screenSpaceTess = g_screenSpaceTess;
        effect.fractionalSpacing = g_fractionalSpacing;
        effect.ibl = g_ibl;
        effect.wire = g_wire;
        effect.seamless = g_seamless;

        GLuint program = bindProgram(effect, patch.GetDescriptor());

        GLint nonAdaptiveLevel = glGetUniformLocation(program, "nonAdaptiveLevel");
        if (nonAdaptiveLevel != -1) {
#if defined(GL_ARB_separate_shader_objects) || defined(GL_VERSION_4_1)
            glProgramUniform1i(program, nonAdaptiveLevel, g_level);
#else
            glUniform1i(nonAdaptiveLevel, g_level);
#endif
        }

        GLint displacementScale = glGetUniformLocation(program, "displacementScale");
        if (displacementScale != -1)
            glUniform1f(displacementScale, g_displacementScale);

        GLint mipmapBias = glGetUniformLocation(program, "mipmapBias");
        if (mipmapBias != -1)
            glUniform1f(mipmapBias, g_mipmapBias);

#if defined(GL_ARB_tessellation_shader) || defined(GL_VERSION_4_0)
        GLuint overrideColor = glGetUniformLocation(program, "overrideColor");

        float const * color = getAdaptivePatchColor(desc);
        glProgramUniform4f(program, overrideColor, color[0], color[1], color[2], color[3]);
#endif

        if (g_wire == DISPLAY_WIRE) {
            glDisable(GL_CULL_FACE);
        }

        GLuint uniformGregoryQuadOffsetBase =
            glGetUniformLocation(program, "GregoryQuadOffsetBase");
        GLuint uniformPrimitiveIdBase =
            glGetUniformLocation(program, "PrimitiveIdBase");

#if defined(GL_ARB_tessellation_shader) || defined(GL_VERSION_4_0)
        glProgramUniform1i(program, uniformGregoryQuadOffsetBase,
                           patch.GetQuadOffsetIndex());
        glProgramUniform1i(program, uniformPrimitiveIdBase,
                           patch.GetPatchIndex());
#else
        glUniform1i(uniformGregoryQuadOffsetBase,
                    patch.GetQuadOffsetIndex());
        glUniform1i(uniformPrimitiveIdBase,
                    patch.GetPatchIndex());
#endif

        glDrawElements(primType,
                       patch.GetNumIndices(), GL_UNSIGNED_INT,
                       (void *)(patch.GetVertIndex() * sizeof(unsigned int)));
        if (g_wire == DISPLAY_WIRE) {
            glEnable(GL_CULL_FACE);
        }
    }
    glBindVertexArray(0);
}

//------------------------------------------------------------------------------

void
drawSky() {
    glUseProgram(g_sky.program);

    glDisable(GL_DEPTH_TEST);
    glDepthMask(GL_FALSE);

    float modelView[16], projection[16], mvp[16];
    double aspect = g_width/(double)g_height;

    identity(modelView);
    rotate(modelView, g_rotate[1], 1, 0, 0);
    rotate(modelView, g_rotate[0], 0, 1, 0);
    perspective(projection, 45.0f, (float)aspect, g_size*0.001f, g_size+g_dolly);
    multMatrix(mvp, modelView, projection);
    glUniformMatrix4fv(g_sky.mvpMatrix, 1, GL_FALSE, mvp);

    glBindVertexArray(g_skyVAO);

    glEnableVertexAttribArray(0);
    glEnableVertexAttribArray(1);

    glBindBuffer(GL_ARRAY_BUFFER, g_sky.vertexBuffer);
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 5, 0);
    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 5,
                          (void*)(sizeof(GLfloat)*3));

    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_sky.elementBuffer);
    glDrawElements(GL_TRIANGLES, g_sky.numIndices, GL_UNSIGNED_INT, 0);

    glDisableVertexAttribArray(0);
    glDisableVertexAttribArray(1);

    glBindVertexArray(0);

    glEnable(GL_DEPTH_TEST);
    glDepthMask(GL_TRUE);

    checkGLErrors("draw model");
}

//------------------------------------------------------------------------------

void
drawCageEdges() {

    g_mesh->BindVertexBuffer();

    glBindVertexArray(g_cageEdgeVAO);

    Effect effect;
    effect.value = 0;

    typedef OpenSubdiv::Far::PatchDescriptor FDesc;

    OpenSubdiv::Osd::DrawContext::PatchDescriptor desc(
        FDesc(FDesc::LINES), 0, 0);
    EffectDrawRegistry::ConfigType *config = getInstance(effect, desc);
    glUseProgram(config->program);

    glDrawElements(GL_LINES, g_numCageEdges, GL_UNSIGNED_INT, 0);

    glBindVertexArray(0);
    glUseProgram(0);

    checkGLErrors("draw cage edges");
}

//------------------------------------------------------------------------------

void
display() {

    glBindFramebuffer(GL_FRAMEBUFFER, g_imageShader.frameBuffer);

    Stopwatch s;
    s.Start();

    glViewport(0, 0, g_width, g_height);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    if (g_ibl) {
        glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
        drawSky();
    }

    // primitive counting
    glBeginQuery(GL_PRIMITIVES_GENERATED, g_queries[0]);
#if defined(GL_VERSION_3_3)
    glBeginQuery(GL_TIME_ELAPSED, g_queries[1]);
#endif

    double aspect = g_width/(double)g_height;
    identity(transformData.ModelViewMatrix);
    translate(transformData.ModelViewMatrix, -g_pan[0], -g_pan[1], -g_dolly);
    rotate(transformData.ModelViewMatrix, g_rotate[1], 1, 0, 0);
    rotate(transformData.ModelViewMatrix, g_rotate[0], 0, 1, 0);
    if (g_yup)
        rotate(transformData.ModelViewMatrix, -90, 1, 0, 0);
    translate(transformData.ModelViewMatrix, -g_center[0], -g_center[1], -g_center[2]);
    perspective(transformData.ProjectionMatrix, 45.0f, (float)aspect, g_size*0.001f,
                g_size+g_dolly);

    multMatrix(transformData.ModelViewProjectionMatrix,
               transformData.ModelViewMatrix,
               transformData.ProjectionMatrix);
    inverseMatrix(transformData.ModelViewInverseMatrix,
                  transformData.ModelViewMatrix);

    updateUniformBlocks();

    glEnable(GL_DEPTH_TEST);

    drawModel();

    glEndQuery(GL_PRIMITIVES_GENERATED);
#if defined(GL_VERSION_3_3)
    glEndQuery(GL_TIME_ELAPSED);
#endif

    if (g_drawCageEdges)
        drawCageEdges();

    glDisable(GL_DEPTH_TEST);

    glUseProgram(0);

    applyImageShader();

    s.Stop();
    float drawCpuTime = float(s.GetElapsed() * 1000.0f);

    GLuint numPrimsGenerated = 0;
    GLuint timeElapsed = 0;
    glGetQueryObjectuiv(g_queries[0], GL_QUERY_RESULT, &numPrimsGenerated);
#if defined(GL_VERSION_3_3)
    glGetQueryObjectuiv(g_queries[1], GL_QUERY_RESULT, &timeElapsed);
#endif
    float drawGpuTime = timeElapsed / 1000.0f / 1000.0f;

    g_fpsTimer.Stop();
    float elapsed = (float)g_fpsTimer.GetElapsed();
    if (not g_freeze)
        g_animTime += elapsed;
    g_fpsTimer.Start();

    if (g_hud.IsVisible()) {
        double fps = 1.0/elapsed;

        // Avereage fps over a defined number of time samples for
        // easier reading in the HUD
        g_fpsTimeSamples[g_currentFpsTimeSample++] = float(fps);
        if (g_currentFpsTimeSample >= NUM_FPS_TIME_SAMPLES)
            g_currentFpsTimeSample = 0;
        double averageFps = 0;
        for (int i = 0; i < NUM_FPS_TIME_SAMPLES; ++i) {
            averageFps += g_fpsTimeSamples[i]/(float)NUM_FPS_TIME_SAMPLES;
        }

        g_hud.DrawString(10, -220, "Ptex memory use : %.1f mb", g_ptexMemoryUsage/1024.0/1024.0);
        g_hud.DrawString(10, -180, "Tess level (+/-): %d", g_tessLevel);
        if (numPrimsGenerated > 1000000) {
            g_hud.DrawString(10, -160, "Primitives      : %3.1f million",
                             (float)numPrimsGenerated/1000000.0);
        } else if (numPrimsGenerated > 1000) {
            g_hud.DrawString(10, -160, "Primitives      : %3.1f thousand",
                             (float)numPrimsGenerated/1000.0);
        } else {
            g_hud.DrawString(10, -160, "Primitives      : %d", numPrimsGenerated);
        }
        g_hud.DrawString(10, -140, "Vertices        : %d", g_mesh->GetNumVertices());
        g_hud.DrawString(10, -120, "Scheme          : %s", g_scheme == 0 ? "CATMARK" : "LOOP");
        g_hud.DrawString(10, -100, "GPU Kernel      : %.3f ms", g_gpuTime);
        g_hud.DrawString(10, -80,  "CPU Kernel      : %.3f ms", g_cpuTime);
        g_hud.DrawString(10, -60,  "GPU Draw        : %.3f ms", drawGpuTime);
        g_hud.DrawString(10, -40,  "CPU Draw        : %.3f ms", drawCpuTime);
        g_hud.DrawString(10, -20,  "FPS             : %3.1f", averageFps);

        g_hud.Flush();
    }

    glFinish();

    checkGLErrors("draw end");
}

//------------------------------------------------------------------------------
void
screenshot(int multiplier=4) {

    int oldwidth = g_width,
        oldheight = g_height,
        width = multiplier * g_width,
        height = multiplier * g_height;

    reshape(g_window, width, height);
    display();

    std::vector<unsigned char> data(width*height*4 /*RGBA*/);

    glPixelStorei(GL_PACK_ROW_LENGTH, 0);
    glPixelStorei(GL_PACK_ALIGNMENT, 1);
    glPixelStorei(GL_PACK_SKIP_PIXELS, 0);
    glPixelStorei(GL_PACK_SKIP_ROWS, 0);

    GLint restoreBinding, restoreActiveTexture;
    glGetIntegerv( GL_TEXTURE_BINDING_2D, &restoreBinding );
    glGetIntegerv( GL_ACTIVE_TEXTURE, & restoreActiveTexture);

    glActiveTexture( GL_TEXTURE0 );

    glBindTexture( GL_TEXTURE_2D, g_imageShader.frameBufferTexture );
    glGetTexImage(GL_TEXTURE_2D, 0, GL_RGBA, GL_UNSIGNED_BYTE, &data[0]);

    glActiveTexture( restoreActiveTexture );
    glBindTexture( GL_TEXTURE_2D, restoreBinding );

    reshape(g_window, oldwidth, oldheight);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    static int counter=0;
    char fname[64];
    snprintf(fname, 64, "screenshot.%d.png", counter++);

    // flip vertical
    stbi_write_png(fname, width, height, 4, &data[width*4*(height-1)], -width*4);

    fprintf(stdout, "Saved %s\n", fname);
}

//------------------------------------------------------------------------------
static void
mouse(GLFWwindow *, int button, int state, int /* mods */) {

    if (state == GLFW_RELEASE)
        g_hud.MouseRelease();

    if (button == 0 && state == GLFW_PRESS && g_hud.MouseClick(g_prev_x, g_prev_y))
        return;
    g_mbutton[button] = (state == GLFW_PRESS);
}

//------------------------------------------------------------------------------
static void
motion(GLFWwindow *, double dx, double dy) {
    int x = (int)dx, y = (int)dy;

    if (g_hud.MouseCapture()) {
        // check gui
        g_hud.MouseMotion(x, y);
    } else if (g_mbutton[0] && !g_mbutton[1] && !g_mbutton[2]) {
        // orbit
        g_rotate[0] += x - g_prev_x;
        g_rotate[1] += y - g_prev_y;
    } else if (!g_mbutton[0] && !g_mbutton[1] && g_mbutton[2]) {
        // pan
        g_pan[0] -= g_dolly*(x - g_prev_x)/g_width;
        g_pan[1] += g_dolly*(y - g_prev_y)/g_height;
    } else if ((g_mbutton[0] && !g_mbutton[1] && g_mbutton[2]) or
               (!g_mbutton[0] && g_mbutton[1] && !g_mbutton[2])) {
        // dolly
        g_dolly -= g_dolly*0.01f*(x - g_prev_x);
        if (g_dolly <= 0.01) g_dolly = 0.01f;
    }

    g_prev_x = x;
    g_prev_y = y;
}

//------------------------------------------------------------------------------
void uninitGL() {
    if (g_osdPTexImage) delete g_osdPTexImage;
    if (g_osdPTexDisplacement) delete g_osdPTexDisplacement;
    if (g_osdPTexOcclusion) delete g_osdPTexOcclusion;
    if (g_osdPTexSpecular) delete g_osdPTexSpecular;

    glDeleteQueries(2, g_queries);
    glDeleteVertexArrays(1, &g_vao);
    glDeleteVertexArrays(1, &g_cageEdgeVAO);
    glDeleteVertexArrays(1, &g_skyVAO);

    if (g_mesh)
        delete g_mesh;

    if (g_diffuseEnvironmentMap)
        glDeleteTextures(1, &g_diffuseEnvironmentMap);
    if (g_specularEnvironmentMap)
        glDeleteTextures(1, &g_specularEnvironmentMap);

    if (g_sky.program) glDeleteProgram(g_sky.program);
    if (g_sky.vertexBuffer) glDeleteBuffers(1, &g_sky.vertexBuffer);
    if (g_sky.elementBuffer) glDeleteBuffers(1, &g_sky.elementBuffer);

    glDeleteFramebuffers(1, &g_imageShader.frameBuffer);
    glDeleteTextures(1, &g_imageShader.frameBufferTexture);
    glDeleteTextures(1, &g_imageShader.frameBufferDepthTexture);

    glDeleteFramebuffers(2, g_imageShader.smallFrameBuffer);
    glDeleteTextures(2, g_imageShader.smallFrameBufferTexture);

    glDeleteProgram(g_imageShader.blurProgram);
    glDeleteProgram(g_imageShader.hipassProgram);
    glDeleteProgram(g_imageShader.compositeProgram);

    glDeleteVertexArrays(1, &g_imageShader.vao);
    glDeleteBuffers(1, &g_imageShader.vbo);
}

//------------------------------------------------------------------------------
static void
callbackWireframe(int b) {
    g_wire = b;
}
static void
callbackKernel(int k) {
    g_kernel = k;

#ifdef OPENSUBDIV_HAS_OPENCL
    if (g_kernel == kCL and (not g_clDeviceContext.IsInitialized())) {
        // Initialize OpenCL
        if (g_clDeviceContext.Initialize() == false) {
            printf("Error in initializing OpenCL\n");
            exit(1);
        }
    }
#endif
#ifdef OPENSUBDIV_HAS_CUDA
    if (g_kernel == kCUDA and (not g_cudaDeviceContext.IsInitialized())) {
        if (g_cudaDeviceContext.Initialize() == false) {
            printf("Error in initializing Cuda\n");
            exit(1);
        }
    }
#endif
    createOsdMesh(g_level, g_kernel);
}

static void
callbackScheme(int s) {
    g_scheme = s;
    createOsdMesh(g_level, g_kernel);
}
static void
callbackLevel(int l) {
    g_level = l;
    createOsdMesh(g_level, g_kernel);
}
static void
callbackColor(int c) {
    g_color = c;
}
static void
callbackDisplacement(int d) {
    g_displacement = d;
}
static void
callbackNormal(int n) {
    g_normal = n;
}
static void
callbackCheckBox(bool checked, int button) {
    bool rebuild = false;

    switch (button) {
    case HUD_CB_ADAPTIVE:
        if (OpenSubdiv::Osd::GLDrawContext::SupportsAdaptiveTessellation()) {
            g_adaptive = checked;
            rebuild = true;
        }
        break;
    case HUD_CB_DISPLAY_OCCLUSION:
        g_occlusion = checked;
        break;
    case HUD_CB_DISPLAY_SPECULAR:
        g_specular = checked;
        break;
    case HUD_CB_CAGE_EDGES:
        g_drawCageEdges = checked;
        break;
    case HUD_CB_ANIMATE_VERTICES:
        g_moveScale = checked ? 1.0f : 0.0f;
        g_animTime = 0;
        break;
    case HUD_CB_VIEW_LOD:
        g_screenSpaceTess = checked;
        break;
    case HUD_CB_FRACTIONAL_SPACING:
        g_fractionalSpacing = checked;
        break;
    case HUD_CB_PATCH_CULL:
        g_patchCull = checked;
        break;
    case HUD_CB_IBL:
        g_ibl = checked;
        break;
    case HUD_CB_BLOOM:
        g_bloom = checked;
        break;
    case HUD_CB_SEAMLESS_MIPMAP:
        g_seamless = checked;
        break;
    case HUD_CB_FREEZE:
        g_freeze = checked;
        break;
    }

    if (rebuild)
        createOsdMesh(g_level, g_kernel);
}

static void
callbackSlider(float value, int data) {
    switch (data) {
    case 0:
        g_mipmapBias = value;
        break;
    case 1:
        g_displacementScale = value;
        break;
    }
}
//-------------------------------------------------------------------------------
void
reloadShaderFile() {
    if (not g_shaderFilename) return;

    std::ifstream ifs(g_shaderFilename);
    if (not ifs) return;
    printf("Load shader %s\n", g_shaderFilename);

    std::stringstream ss;
    ss << ifs.rdbuf();
    ifs.close();

    g_shaderSource = ss.str();

    effectRegistry.Reset();
}

//------------------------------------------------------------------------------
static void
toggleFullScreen() {
    // XXXX manuelk : to re-implement from glut
}

//------------------------------------------------------------------------------
void
keyboard(GLFWwindow *, int key, int /* scancode */, int event, int /* mods */) {

    if (event == GLFW_RELEASE) return;
    if (g_hud.KeyDown(tolower(key))) return;

    switch (key) {
        case 'Q': g_running = 0; break;
        case 'E': g_drawNormals = (g_drawNormals+1)%2; break;
        case 'F': fitFrame(); break;
        case GLFW_KEY_TAB: toggleFullScreen(); break;
        case 'R': reloadShaderFile(); createOsdMesh(g_level, g_kernel); break;
        case '+':
        case '=': g_tessLevel++; break;
        case '-': g_tessLevel = std::max(1, g_tessLevel-1); break;
        case GLFW_KEY_ESCAPE: g_hud.SetVisible(!g_hud.IsVisible()); break;
        case 'X': screenshot(); break;
    }
}

//------------------------------------------------------------------------------
void
idle() {
    if (not g_freeze)
        g_frame++;

    updateGeom();

    if (g_repeatCount != 0 && g_frame >= g_repeatCount)
        g_running = 0;
}

//------------------------------------------------------------------------------
void
initGL() {
    glClearColor(0.1f, 0.1f, 0.1f, 0.0f);
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LEQUAL);
    glEnable(GL_CULL_FACE);

    glGenQueries(2, g_queries);
    glGenVertexArrays(1, &g_vao);
    glGenVertexArrays(1, &g_cageEdgeVAO);
    glGenVertexArrays(1, &g_skyVAO);

    glGenFramebuffers(1, &g_imageShader.frameBuffer);
    glGenTextures(1, &g_imageShader.frameBufferTexture);
    glGenTextures(1, &g_imageShader.frameBufferDepthTexture);

    glGenFramebuffers(2, g_imageShader.smallFrameBuffer);
    glGenTextures(2, g_imageShader.smallFrameBufferTexture);

    glBindTexture(GL_TEXTURE_2D, g_imageShader.frameBufferTexture);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

    glBindTexture(GL_TEXTURE_2D, g_imageShader.frameBufferDepthTexture);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

    for (int i = 0; i < 2; ++i) {
        glBindTexture(GL_TEXTURE_2D, g_imageShader.smallFrameBufferTexture[i]);
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    }

    glBindTexture(GL_TEXTURE_2D, 0);
}

//------------------------------------------------------------------------------
void usage(const char *program) {
    printf("Usage: %s [options] <color.ptx> [<displacement.ptx>] [occlusion.ptx>] "
           "[specular.ptx] [pose.obj]...\n", program);
    printf("Options:  -l level                : subdivision level\n");
    printf("          -c count                : frame count until exit (for profiler)\n");
    printf("          -d <diffseEnvMap.hdr>   : diffuse environment map for IBL\n");
    printf("          -e <specularEnvMap.hdr> : specular environment map for IBL\n");
    printf("          -s <shaderfile.glsl>    : custom shader file\n");
    printf("          -y                      : Y-up model\n");
    printf("          -m level                : max mimmap level (default=10)\n");
    printf("          -x <ptex limit MB>      : ptex target memory size\n");
    printf("          --disp <scale>          : Displacment scale\n");
}

//------------------------------------------------------------------------------
static void
callbackError(OpenSubdiv::Far::ErrorType err, const char *message) {
    printf("Error: %d\n", err);
    printf("%s", message);
}

//------------------------------------------------------------------------------
static void
callbackErrorGLFW(int error, const char* description) {
    fprintf(stderr, "GLFW Error (%d) : %s\n", error, description);
}
//------------------------------------------------------------------------------
static void
setGLCoreProfile() {

    #define glfwOpenWindowHint glfwWindowHint
    #define GLFW_OPENGL_VERSION_MAJOR GLFW_CONTEXT_VERSION_MAJOR
    #define GLFW_OPENGL_VERSION_MINOR GLFW_CONTEXT_VERSION_MINOR

    glfwOpenWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
#if not defined(__APPLE__)
    glfwOpenWindowHint(GLFW_OPENGL_VERSION_MAJOR, 4);
#ifdef OPENSUBDIV_HAS_GLSL_COMPUTE
    glfwOpenWindowHint(GLFW_OPENGL_VERSION_MINOR, 3);
#else
    glfwOpenWindowHint(GLFW_OPENGL_VERSION_MINOR, 2);
#endif

#else
    glfwOpenWindowHint(GLFW_OPENGL_VERSION_MAJOR, 3);
    glfwOpenWindowHint(GLFW_OPENGL_VERSION_MINOR, 2);
#endif
    glfwOpenWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
}

//------------------------------------------------------------------------------
int main(int argc, char ** argv) {

    std::vector<std::string> animobjs;
    const char *diffuseEnvironmentMap = NULL, *specularEnvironmentMap = NULL;
    const char *colorFilename = NULL, *displacementFilename = NULL,
        *occlusionFilename = NULL, *specularFilename = NULL;
    int memLimit = 0, colorMem = 0, displacementMem = 0,
        occlusionMem = 0, specularMem = 0;
    bool fullscreen = false;

    for (int i = 1; i < argc; ++i) {
        if (strstr(argv[i], ".obj"))
            animobjs.push_back(argv[i]);
        else if (!strcmp(argv[i], "-l"))
            g_level = atoi(argv[++i]);
        else if (!strcmp(argv[i], "-c"))
            g_repeatCount = atoi(argv[++i]);
        else if (!strcmp(argv[i], "-d"))
            diffuseEnvironmentMap = argv[++i];
        else if (!strcmp(argv[i], "-e"))
            specularEnvironmentMap = argv[++i];
        else if (!strcmp(argv[i], "-s"))
            g_shaderFilename = argv[++i];
        else if (!strcmp(argv[i], "-f"))
            fullscreen = true;
        else if (!strcmp(argv[i], "-y"))
            g_yup = true;
        else if (!strcmp(argv[i], "-m"))
            g_maxMipmapLevels = atoi(argv[++i]);
        else if (!strcmp(argv[i], "-x"))
            memLimit = atoi(argv[++i]);
        else if (!strcmp(argv[i], "--disp"))
            g_displacementScale = (float)atof(argv[++i]);
        else if (colorFilename == NULL) {
            colorFilename = argv[i];
            colorMem = memLimit;
        } else if (displacementFilename == NULL) {
            displacementFilename = argv[i];
            displacementMem = memLimit;
            g_displacement = DISPLACEMENT_BILINEAR;
            g_normal = NORMAL_BIQUADRATIC;
        } else if (occlusionFilename == NULL) {
            occlusionFilename = argv[i];
            occlusionMem = memLimit;
            g_occlusion = 1;
        } else if (specularFilename == NULL) {
            specularFilename = argv[i];
            specularMem = memLimit;
            g_specular = 1;
        }
    }

    OpenSubdiv::Far::SetErrorCallback(callbackError);

    g_shaderSource = g_defaultShaderSource;
    reloadShaderFile();

    g_ptexColorFilename = colorFilename;
    if (g_ptexColorFilename == NULL) {
        usage(argv[0]);
        return 1;
    }

    glfwSetErrorCallback(callbackErrorGLFW);
    if (not glfwInit()) {
        printf("Failed to initialize GLFW\n");
        return 1;
    }

    static const char windowTitle[] = "OpenSubdiv glPtexViewer" OPENSUBDIV_VERSION_STRING;

#define CORE_PROFILE
#ifdef CORE_PROFILE
    setGLCoreProfile();
#endif

    if (fullscreen) {
        g_primary = glfwGetPrimaryMonitor();

        // apparently glfwGetPrimaryMonitor fails under linux : if no primary,
        // settle for the first one in the list
        if (not g_primary) {
            int count = 0;
            GLFWmonitor ** monitors = glfwGetMonitors(&count);

            if (count)
                g_primary = monitors[0];
        }

        if (g_primary) {
            GLFWvidmode const * vidmode = glfwGetVideoMode(g_primary);
            g_width = vidmode->width;
            g_height = vidmode->height;
        }
    }

    if (not (g_window=glfwCreateWindow(g_width, g_height, windowTitle,
                                       fullscreen and g_primary ? g_primary : NULL, NULL))) {
        printf("Failed to open window.\n");
        glfwTerminate();
        return 1;
    }
    glfwMakeContextCurrent(g_window);
    glfwSetKeyCallback(g_window, keyboard);
    glfwSetCursorPosCallback(g_window, motion);
    glfwSetMouseButtonCallback(g_window, mouse);

#if defined(OSD_USES_GLEW)
#ifdef CORE_PROFILE
    // this is the only way to initialize glew correctly under core profile context.
    glewExperimental = true;
#endif
    if (GLenum r = glewInit() != GLEW_OK) {
        printf("Failed to initialize glew. error = %d\n", r);
        exit(1);
    }
#ifdef CORE_PROFILE
    // clear GL errors which was generated during glewInit()
    glGetError();
#endif
#endif

    initGL();

    // accommodate high DPI displays (e.g. mac retina displays)
    glfwGetFramebufferSize(g_window, &g_width, &g_height);
    glfwSetFramebufferSizeCallback(g_window, reshape);

    glfwSetWindowCloseCallback(g_window, windowClose);
    // as of GLFW 3.0.1 this callback is not implicit
    reshape();

    // activate feature adaptive tessellation if OSD supports it
    g_adaptive = OpenSubdiv::Osd::GLDrawContext::SupportsAdaptiveTessellation();

    int windowWidth = g_width, windowHeight = g_height;

    // window size might not match framebuffer size on a high DPI display
    glfwGetWindowSize(g_window, &windowWidth, &windowHeight);

    g_hud.Init(windowWidth, windowHeight, g_width, g_height);

    if (occlusionFilename != NULL) {
        g_hud.AddCheckBox("Ambient Occlusion (A)", g_occlusion,
                          -200, 570, callbackCheckBox, HUD_CB_DISPLAY_OCCLUSION, 'a');
    }
    if (specularFilename != NULL)
        g_hud.AddCheckBox("Specular (S)", g_specular,
                          -200, 590, callbackCheckBox, HUD_CB_DISPLAY_SPECULAR, 's');

    if (diffuseEnvironmentMap or specularEnvironmentMap) {
        g_hud.AddCheckBox("IBL (I)", g_ibl,
                          -200, 610, callbackCheckBox, HUD_CB_IBL, 'i');
    }

    g_hud.AddCheckBox("Cage Edges (H)", g_drawCageEdges != 0,
                      10, 10, callbackCheckBox, HUD_CB_CAGE_EDGES, 'h');
    g_hud.AddCheckBox("Animate vertices (M)", g_moveScale != 0.0,
                      10, 30, callbackCheckBox, HUD_CB_ANIMATE_VERTICES, 'm');
    g_hud.AddCheckBox("Screen space LOD (V)",  g_screenSpaceTess,
                      10, 50, callbackCheckBox, HUD_CB_VIEW_LOD, 'v');
    g_hud.AddCheckBox("Fractional spacing (T)",  g_fractionalSpacing,
                      10, 70, callbackCheckBox, HUD_CB_FRACTIONAL_SPACING, 't');
    g_hud.AddCheckBox("Frustum Patch Culling (B)",  g_patchCull,
                      10, 90, callbackCheckBox, HUD_CB_PATCH_CULL, 'b');
    g_hud.AddCheckBox("Bloom (Y)", g_bloom,
                      10, 110, callbackCheckBox, HUD_CB_BLOOM, 'y');
    g_hud.AddCheckBox("Freeze (spc)", g_freeze,
                      10, 130, callbackCheckBox, HUD_CB_FREEZE, ' ');

    g_hud.AddRadioButton(HUD_RB_SCHEME, "CATMARK", true, 10, 190, callbackScheme, 0);
    g_hud.AddRadioButton(HUD_RB_SCHEME, "BILINEAR", false, 10, 210, callbackScheme, 1);

    if (OpenSubdiv::Osd::GLDrawContext::SupportsAdaptiveTessellation())
        g_hud.AddCheckBox("Adaptive (`)", g_adaptive,
                          10, 300, callbackCheckBox, HUD_CB_ADAPTIVE, '`');

    for (int i = 1; i < 8; ++i) {
        char level[16];
        sprintf(level, "Lv. %d", i);
        g_hud.AddRadioButton(HUD_RB_LEVEL, level, i == g_level,
                             10, 320+i*20, callbackLevel, i, '0'+i);
    }

    int compute_pulldown = g_hud.AddPullDown("Compute (K)", 475, 10, 300, callbackKernel, 'k');
    g_hud.AddPullDownButton(compute_pulldown, "CPU", kCPU);
#ifdef OPENSUBDIV_HAS_OPENMP
    g_hud.AddPullDownButton(compute_pulldown, "OpenMP", kOPENMP);
#endif
#ifdef OPENSUBDIV_HAS_TBB
    g_hud.AddPullDownButton(compute_pulldown, "TBB", kTBB);
#endif
#ifdef OPENSUBDIV_HAS_CUDA
    g_hud.AddPullDownButton(compute_pulldown, "CUDA", kCUDA);
#endif
#ifdef OPENSUBDIV_HAS_OPENCL
    if (CLDeviceContext::HAS_CL_VERSION_1_1()) {
        g_hud.AddPullDownButton(compute_pulldown, "OpenCL", kCL);
    }
#endif
#ifdef OPENSUBDIV_HAS_GLSL_TRANSFORM_FEEDBACK
    g_hud.AddPullDownButton(compute_pulldown, "GLSL TransformFeedback", kGLSL);
#endif
#ifdef OPENSUBDIV_HAS_GLSL_COMPUTE
    // Must also check at run time for OpenGL 4.3
    if (GLEW_VERSION_4_3) {
        g_hud.AddPullDownButton(compute_pulldown, "GLSL Compute", kGLSLCompute);
    }
#endif

    int shading_pulldown = g_hud.AddPullDown("Shading (W)", 250, 10, 250, callbackWireframe, 'w');
    g_hud.AddPullDownButton(shading_pulldown, "Wire", DISPLAY_WIRE, g_wire==DISPLAY_WIRE);
    g_hud.AddPullDownButton(shading_pulldown, "Shaded", DISPLAY_SHADED, g_wire==DISPLAY_SHADED);
    g_hud.AddPullDownButton(shading_pulldown, "Wire+Shaded", DISPLAY_WIRE_ON_SHADED, g_wire==DISPLAY_WIRE_ON_SHADED);

    g_hud.AddLabel("Color (C)", -200, 10);
    g_hud.AddRadioButton(HUD_RB_COLOR, "None", (g_color == COLOR_NONE),
                         -200, 30, callbackColor, COLOR_NONE, 'c');
    g_hud.AddRadioButton(HUD_RB_COLOR, "Ptex Nearest", (g_color == COLOR_PTEX_NEAREST),
                         -200, 50, callbackColor, COLOR_PTEX_NEAREST, 'c');
    g_hud.AddRadioButton(HUD_RB_COLOR, "Ptex HW bilinear", (g_color == COLOR_PTEX_HW_BILINEAR),
                         -200, 70, callbackColor, COLOR_PTEX_HW_BILINEAR, 'c');
    g_hud.AddRadioButton(HUD_RB_COLOR, "Ptex bilinear", (g_color == COLOR_PTEX_BILINEAR),
                         -200, 90, callbackColor, COLOR_PTEX_BILINEAR, 'c');
    g_hud.AddRadioButton(HUD_RB_COLOR, "Ptex biquadratic", (g_color == COLOR_PTEX_BIQUADRATIC),
                         -200, 110, callbackColor, COLOR_PTEX_BIQUADRATIC, 'c');
    g_hud.AddRadioButton(HUD_RB_COLOR, "Patch type", (g_color == COLOR_PATCHTYPE),
                         -200, 130, callbackColor, COLOR_PATCHTYPE, 'c');
    g_hud.AddRadioButton(HUD_RB_COLOR, "Patch coord", (g_color == COLOR_PATCHCOORD),
                         -200, 150, callbackColor, COLOR_PATCHCOORD, 'c');
    g_hud.AddRadioButton(HUD_RB_COLOR, "Normal", (g_color == COLOR_NORMAL),
                         -200, 170, callbackColor, COLOR_NORMAL, 'c');

    if (displacementFilename != NULL) {
        g_hud.AddLabel("Displacement (D)", -200, 200);
        g_hud.AddRadioButton(HUD_RB_DISPLACEMENT, "None",
                             (g_displacement == DISPLACEMENT_NONE),
                             -200, 220, callbackDisplacement, DISPLACEMENT_NONE, 'd');
        g_hud.AddRadioButton(HUD_RB_DISPLACEMENT, "HW bilinear",
                             (g_displacement == DISPLACEMENT_HW_BILINEAR),
                             -200, 240, callbackDisplacement, DISPLACEMENT_HW_BILINEAR, 'd');
        g_hud.AddRadioButton(HUD_RB_DISPLACEMENT, "Bilinear",
                             (g_displacement == DISPLACEMENT_BILINEAR),
                             -200, 260, callbackDisplacement, DISPLACEMENT_BILINEAR, 'd');
        g_hud.AddRadioButton(HUD_RB_DISPLACEMENT, "Biquadratic",
                             (g_displacement == DISPLACEMENT_BIQUADRATIC),
                             -200, 280, callbackDisplacement, DISPLACEMENT_BIQUADRATIC, 'd');

        g_hud.AddLabel("Normal (N)", -200, 310);
        g_hud.AddRadioButton(HUD_RB_NORMAL, "Surface",
                             (g_normal == NORMAL_SURFACE),
                             -200, 330, callbackNormal, NORMAL_SURFACE, 'n');
        g_hud.AddRadioButton(HUD_RB_NORMAL, "Facet",
                             (g_normal == NORMAL_FACET),
                             -200, 350, callbackNormal, NORMAL_FACET, 'n');
        g_hud.AddRadioButton(HUD_RB_NORMAL, "HW Screen space",
                             (g_normal == NORMAL_HW_SCREENSPACE),
                             -200, 370, callbackNormal, NORMAL_HW_SCREENSPACE, 'n');
        g_hud.AddRadioButton(HUD_RB_NORMAL, "Screen space",
                             (g_normal == NORMAL_SCREENSPACE),
                             -200, 390, callbackNormal, NORMAL_SCREENSPACE, 'n');
        g_hud.AddRadioButton(HUD_RB_NORMAL, "Biquadratic",
                             (g_normal == NORMAL_BIQUADRATIC),
                             -200, 410, callbackNormal, NORMAL_BIQUADRATIC, 'n');
        g_hud.AddRadioButton(HUD_RB_NORMAL, "Biquadratic WG",
                             (g_normal == NORMAL_BIQUADRATIC_WG),
                             -200, 430, callbackNormal, NORMAL_BIQUADRATIC_WG, 'n');
    }

    g_hud.AddSlider("Mipmap Bias", 0, 5, 0,
                    -200, 450, 20, false, callbackSlider, 0);
    g_hud.AddSlider("Displacement", 0, 5, 1,
                    -200, 490, 20, false, callbackSlider, 1);
    g_hud.AddCheckBox("Seamless Mipmap", g_seamless,
                      -200, 530, callbackCheckBox, HUD_CB_SEAMLESS_MIPMAP, 'j');

    // create mesh from ptex metadata
    createOsdMesh(g_level, g_kernel);

    // load ptex files
    if (colorFilename)
        g_osdPTexImage = createPtex(colorFilename, colorMem);
    if (displacementFilename)
        g_osdPTexDisplacement = createPtex(displacementFilename, displacementMem);
    if (occlusionFilename)
        g_osdPTexOcclusion = createPtex(occlusionFilename, occlusionMem);
    if (specularFilename)
        g_osdPTexSpecular = createPtex(specularFilename, specularMem);

    g_ptexMemoryUsage =
        (g_osdPTexImage ? g_osdPTexImage->GetMemoryUsage() : 0)
        + (g_osdPTexDisplacement ? g_osdPTexDisplacement->GetMemoryUsage() : 0)
        + (g_osdPTexOcclusion ? g_osdPTexOcclusion->GetMemoryUsage() : 0)
        + (g_osdPTexSpecular ? g_osdPTexSpecular->GetMemoryUsage() : 0);

    // load animation obj sequences (optional)
    if (not animobjs.empty()) {
        for (int i = 0; i < (int)animobjs.size(); ++i) {
            std::ifstream ifs(animobjs[i].c_str());
            if (ifs) {
                std::stringstream ss;
                ss << ifs.rdbuf();
                ifs.close();

                printf("Reading %s\r", animobjs[i].c_str());
                std::string str = ss.str();
                Shape *shape = Shape::parseObj(str.c_str(), kCatmark);

                if (shape->verts.size() != g_positions.size()) {
                    printf("Error: vertex count doesn't match.\n");
                    goto error;
                }

                g_animPositions.push_back(shape->verts);
                delete shape;
            } else {
                printf("Error in reading %s\n", animobjs[i].c_str());
                goto error;
            }
        }
        printf("\n");
        glBindBuffer(GL_ARRAY_BUFFER, 0);
    }

    if (diffuseEnvironmentMap) {
        HdrInfo info;
        unsigned char * image = loadHdr(diffuseEnvironmentMap, &info, /*convertToFloat=*/true);
        if (image) {
            glGenTextures(1, &g_diffuseEnvironmentMap);
            glBindTexture(GL_TEXTURE_2D, g_diffuseEnvironmentMap);
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, info.width, info.height,
                         0, GL_RGBA, GL_FLOAT, image);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
            glBindTexture(GL_TEXTURE_2D, 0);
            free(image);
        }
    }
    if (specularEnvironmentMap) {
        HdrInfo info;
        unsigned char * image = loadHdr(specularEnvironmentMap, &info, /*convertToFloat=*/true);
        if (image) {
            glGenTextures(1, &g_specularEnvironmentMap);
            glBindTexture(GL_TEXTURE_2D, g_specularEnvironmentMap);
            // glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE);  // deprecated
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, info.width, info.height,
                         0, GL_RGBA, GL_FLOAT, image);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
            // glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
            glBindTexture(GL_TEXTURE_2D, 0);
            free(image);
        }
    }
    if (diffuseEnvironmentMap || specularEnvironmentMap) {
        createSky();
    }
    createImageShader();

    fitFrame();

    while (g_running) {
        idle();
        display();

        glfwPollEvents();
        glfwSwapBuffers(g_window);

        glFinish();
    }
  error:
    uninitGL();
    glfwTerminate();
}