OpenSubdiv/examples/glPtexViewer/shader_gl3.glsl
David G. Yu c245407854 Re-organized patch tessellation shader code
This change refactors the GLSL and HLSL patch shader code so that
most of the work is implemented within a library of common functions
and the remaining shader snippets just manage plumbing.

There is more to do here:
  - varying and face-varying data can be managed entirely by the client
  - similarly, displacement can be implemented in client code
  - there's still quite a bit of residual boiler-plate code needed
    in each shader stage that we should be able to wrap up in a more
    convenient form.
2015-05-29 23:00:19 -07:00

546 lines
17 KiB
GLSL

//
// 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.
//
#define NUM_LIGHTS 2
struct LightSource {
vec4 position;
vec4 ambient;
vec4 diffuse;
vec4 specular;
};
layout(std140) uniform Constant {
mat4 ModelViewMatrix;
mat4 ProjectionMatrix;
mat4 ModelViewProjectionMatrix;
mat4 ModelViewInverseMatrix;
LightSource lightSource[NUM_LIGHTS];
float TessLevel;
float displacementScale;
float mipmapBias;
};
uniform int PrimitiveIdBase;
int OsdPrimitiveIdBase()
{
return PrimitiveIdBase;
}
//--------------------------------------------------------------
// Common
//--------------------------------------------------------------
#if defined(DISPLACEMENT_HW_BILINEAR) \
|| defined(DISPLACEMENT_BILINEAR) \
|| defined(DISPLACEMENT_BIQUADRATIC) \
|| defined(NORMAL_HW_SCREENSPACE) \
|| defined(NORMAL_SCREENSPACE) \
|| defined(NORMAL_BIQUADRATIC) \
|| defined(NORMAL_BIQUADRATIC_WG)
uniform sampler2DArray textureDisplace_Data;
uniform isamplerBuffer textureDisplace_Packing;
#endif
vec4 displacement(vec4 position, vec3 normal, vec4 patchCoord)
{
#if defined(DISPLACEMENT_HW_BILINEAR)
float disp = PtexLookupFast(patchCoord,
textureDisplace_Data,
textureDisplace_Packing).x;
#elif defined(DISPLACEMENT_BILINEAR)
float disp = PtexMipmapLookup(patchCoord,
mipmapBias,
textureDisplace_Data,
textureDisplace_Packing).x;
#elif defined(DISPLACEMENT_BIQUADRATIC)
float disp = PtexMipmapLookupQuadratic(patchCoord,
mipmapBias,
textureDisplace_Data,
textureDisplace_Packing).x;
#else
float disp = 0.0;
#endif
return position + vec4(disp * normal, 0) * displacementScale;
}
//--------------------------------------------------------------
// Vertex Shader
//--------------------------------------------------------------
#ifdef VERTEX_SHADER
layout (location=0) in vec4 position;
layout (location=1) in vec3 normal;
out vec4 vPosition;
out vec3 vNormal;
void main()
{
vPosition = ModelViewMatrix * position;
vNormal = (ModelViewMatrix * vec4(normal, 0)).xyz;
}
#endif
//--------------------------------------------------------------
// Geometry Shader
//--------------------------------------------------------------
#ifdef GEOMETRY_SHADER
#ifdef PRIM_QUAD
layout(lines_adjacency) in;
layout(triangle_strip, max_vertices = 4) out;
#define EDGE_VERTS 4
in vec4 vPosition[4];
in vec3 vNormal[4];
#endif // PRIM_QUAD
#ifdef PRIM_TRI
layout(triangles) in;
layout(triangle_strip, max_vertices = 3) out;
#define EDGE_VERTS 3
in vec4 vPosition[3];
in vec3 vNormal[3];
#endif // PRIM_TRI
out vec4 gPosition;
out vec4 gPatchCoord;
out vec3 gNormal;
noperspective out vec4 gEdgeDistance;
// --------------------------------------
void emit(int index, vec4 position, vec3 normal, vec4 patchCoord)
{
gPosition = position;
gPatchCoord = patchCoord;
gNormal = normal;
gl_Position = ProjectionMatrix * gPosition;
EmitVertex();
}
const float VIEWPORT_SCALE = 1024.0; // XXXdyu
float edgeDistance(vec4 p, vec4 p0, vec4 p1)
{
return VIEWPORT_SCALE *
abs((p.x - p0.x) * (p1.y - p0.y) -
(p.y - p0.y) * (p1.x - p0.x)) / length(p1.xy - p0.xy);
}
#if defined(GEOMETRY_OUT_WIRE) || defined(GEOMETRY_OUT_LINE)
void emit(int index, vec4 position, vec3 normal, vec4 patchCoord, vec4 edgeVerts[EDGE_VERTS])
{
gEdgeDistance[0] =
edgeDistance(edgeVerts[index], edgeVerts[0], edgeVerts[1]);
gEdgeDistance[1] =
edgeDistance(edgeVerts[index], edgeVerts[1], edgeVerts[2]);
#ifdef PRIM_TRI
gEdgeDistance[2] =
edgeDistance(edgeVerts[index], edgeVerts[2], edgeVerts[0]);
#endif
#ifdef PRIM_QUAD
gEdgeDistance[2] =
edgeDistance(edgeVerts[index], edgeVerts[2], edgeVerts[3]);
gEdgeDistance[3] =
edgeDistance(edgeVerts[index], edgeVerts[3], edgeVerts[0]);
#endif
emit(index, position, normal, patchCoord);
}
#endif
// --------------------------------------
vec4 GeneratePatchCoord(vec2 uv, int primitiveID) // for non-adaptive
{
ivec3 patchParam = OsdGetPatchParam(OsdGetPatchIndex(primitiveID));
return OsdInterpolatePatchCoord(uv, patchParam);
}
void main()
{
gl_PrimitiveID = gl_PrimitiveIDIn;
#ifdef PRIM_QUAD
vec4 patchCoord[4];
vec4 position[4];
vec3 normal[4];
// need to generate patch coord for non-patch quads
patchCoord[0] = GeneratePatchCoord(vec2(0, 0), gl_PrimitiveID);
patchCoord[1] = GeneratePatchCoord(vec2(1, 0), gl_PrimitiveID);
patchCoord[2] = GeneratePatchCoord(vec2(1, 1), gl_PrimitiveID);
patchCoord[3] = GeneratePatchCoord(vec2(0, 1), gl_PrimitiveID);
#if defined(DISPLACEMENT_HW_BILINEAR) || defined(DISPLACEMENT_BILINEAR) || defined(DISPLACEMENT_BIQUADRATIC)
position[0] = displacement(vPosition[0], vNormal[0], patchCoord[0]);
position[1] = displacement(vPosition[1], vNormal[1], patchCoord[1]);
position[2] = displacement(vPosition[2], vNormal[2], patchCoord[2]);
position[3] = displacement(vPosition[3], vNormal[3], patchCoord[3]);
#else
position[0] = vPosition[0];
position[1] = vPosition[1];
position[2] = vPosition[2];
position[3] = vPosition[3];
#endif
#ifdef NORMAL_FACET
// emit flat normals for displaced surface
vec3 A = (position[0] - position[1]).xyz;
vec3 B = (position[2] - position[1]).xyz;
normal[0] = normalize(cross(B, A));
normal[1] = normal[0];
normal[2] = normal[0];
normal[3] = normal[0];
#else
normal[0] = vNormal[0];
normal[1] = vNormal[1];
normal[2] = vNormal[2];
normal[3] = vNormal[3];
#endif
#if defined(GEOMETRY_OUT_WIRE) || defined(GEOMETRY_OUT_LINE)
vec4 edgeVerts[EDGE_VERTS];
edgeVerts[0] = ProjectionMatrix * vPosition[0];
edgeVerts[1] = ProjectionMatrix * vPosition[1];
edgeVerts[2] = ProjectionMatrix * vPosition[2];
edgeVerts[3] = ProjectionMatrix * vPosition[3];
edgeVerts[0].xy /= edgeVerts[0].w;
edgeVerts[1].xy /= edgeVerts[1].w;
edgeVerts[2].xy /= edgeVerts[2].w;
edgeVerts[3].xy /= edgeVerts[3].w;
emit(0, position[0], normal[0], patchCoord[0], edgeVerts);
emit(1, position[1], normal[1], patchCoord[1], edgeVerts);
emit(3, position[3], normal[3], patchCoord[3], edgeVerts);
emit(2, position[2], normal[2], patchCoord[2], edgeVerts);
#else
gEdgeDistance = vec4(0);
emit(0, position[0], normal[0], patchCoord[0]);
emit(1, position[1], normal[1], patchCoord[1]);
emit(3, position[3], normal[3], patchCoord[3]);
emit(2, position[2], normal[2], patchCoord[2]);
#endif
#endif // PRIM_QUAD
#ifdef PRIM_TRI
vec4 position[3];
vec4 patchCoord[3];
vec3 normal[3];
// patch coords are computed in tessellation shader
patchCoord[0] = vPatchCoord[0];
patchCoord[1] = vPatchCoord[1];
patchCoord[2] = vPatchCoord[2];
#if defined(DISPLACEMENT_HW_BILINEAR) || defined(DISPLACEMENT_BILINEAR) || defined(DISPLACEMENT_BIQUADRATIC)
position[0] = displacement(vPosition[0], vNormal[0], patchCoord[0]);
position[1] = displacement(vPosition[1], vNormal[1], patchCoord[1]);
position[2] = displacement(vPosition[2], vNormal[2], patchCoord[2]);
#else
position[0] = vPosition[0];
position[1] = vPosition[1];
position[2] = vPosition[2];
#endif
#ifdef NORMAL_FACET
// emit flat normals for displaced surface
vec3 A = (position[0] - position[1]).xyz;
vec3 B = (position[2] - position[1]).xyz;
normal[0] = normalize(cross(B, A));
normal[1] = normal[0];
normal[2] = normal[0];
#else
normal[0] = vNormal[0];
normal[1] = vNormal[1];
normal[2] = vNormal[2];
#endif
#if defined(GEOMETRY_OUT_WIRE) || defined(GEOMETRY_OUT_LINE)
vec4 edgeVerts[EDGE_VERTS];
edgeVerts[0] = ProjectionMatrix * vPosition[0];
edgeVerts[1] = ProjectionMatrix * vPosition[1];
edgeVerts[2] = ProjectionMatrix * vPosition[2];
edgeVerts[0].xy /= edgeVerts[0].w;
edgeVerts[1].xy /= edgeVerts[1].w;
edgeVerts[2].xy /= edgeVerts[2].w;
emit(0, position[0], normal[0], patchCoord[0], edgeVerts);
emit(1, position[1], normal[1], patchCoord[1], edgeVerts);
emit(2, position[2], normal[2], patchCoord[2], edgeVerts);
#else
gEdgeDistance = vec4(0);
emit(0, position[0], normal[0], patchCoord[0]);
emit(1, position[1], normal[1], patchCoord[1]);
emit(2, position[2], normal[2], patchCoord[2]);
#endif
#endif // PRIM_TRI
EndPrimitive();
}
#endif
//--------------------------------------------------------------
// Fragment Shader
//--------------------------------------------------------------
#ifdef FRAGMENT_SHADER
in vec4 gPosition;
in vec3 gNormal;
in vec4 gPatchCoord;
noperspective in vec4 gEdgeDistance;
out vec4 outColor;
#if defined(COLOR_PTEX_NEAREST) || defined(COLOR_PTEX_HW_BILINEAR) || \
defined(COLOR_PTEX_BILINEAR) || defined(COLOR_PTEX_BIQUADRATIC)
uniform sampler2DArray textureImage_Data;
uniform isamplerBuffer textureImage_Packing;
#endif
#ifdef USE_PTEX_OCCLUSION
uniform sampler2DArray textureOcclusion_Data;
uniform samplerBuffer textureOcclusion_Packing;
#endif
#ifdef USE_PTEX_SPECULAR
uniform sampler2DArray textureSpecular_Data;
uniform samplerBuffer textureSpecular_Packing;
#endif
uniform bool overrideColorEnable = false;
uniform vec4 overrideColor;
#if defined(NORMAL_HW_SCREENSPACE) || defined(NORMAL_SCREENSPACE)
vec3
perturbNormalFromDisplacement(vec3 position, vec3 normal, vec4 patchCoord)
{
// by Morten S. Mikkelsen
// http://jbit.net/~sparky/sfgrad_bump/mm_sfgrad_bump.pdf
// slightly modified for ptex guttering
vec3 vSigmaS = dFdx(position);
vec3 vSigmaT = dFdy(position);
vec3 vN = normal;
vec3 vR1 = cross(vSigmaT, vN);
vec3 vR2 = cross(vN, vSigmaS);
float fDet = dot(vSigmaS, vR1);
#if 0
// not work well with ptex
float dBs = dFdx(disp);
float dBt = dFdy(disp);
#else
vec2 texDx = dFdx(patchCoord.xy);
vec2 texDy = dFdy(patchCoord.xy);
// limit forward differencing to the width of ptex gutter
const float resolution = 128.0;
float d = min(1, (0.5/resolution)/max(length(texDx), length(texDy)));
vec4 STll = patchCoord;
vec4 STlr = patchCoord + d * vec4(texDx.x, texDx.y, 0, 0);
vec4 STul = patchCoord + d * vec4(texDy.x, texDy.y, 0, 0);
#if defined NORMAL_HW_SCREENSPACE
float Hll = PtexLookupFast(STll, textureDisplace_Data, textureDisplace_Packing).x * displacementScale;
float Hlr = PtexLookupFast(STlr, textureDisplace_Data, textureDisplace_Packing).x * displacementScale;
float Hul = PtexLookupFast(STul, textureDisplace_Data, textureDisplace_Packing).x * displacementScale;
#elif defined NORMAL_SCREENSPACE
float Hll = PtexMipmapLookup(STll, mipmapBias, textureDisplace_Data, textureDisplace_Packing).x * displacementScale;
float Hlr = PtexMipmapLookup(STlr, mipmapBias, textureDisplace_Data, textureDisplace_Packing).x * displacementScale;
float Hul = PtexMipmapLookup(STul, mipmapBias, textureDisplace_Data, textureDisplace_Packing).x * displacementScale;
#endif
float dBs = (Hlr - Hll)/d;
float dBt = (Hul - Hll)/d;
#endif
vec3 vSurfGrad = sign(fDet) * (dBs * vR1 + dBt * vR2);
return normalize(abs(fDet) * vN - vSurfGrad);
}
#endif // USE_PTEX_NORMAL
uniform sampler2D diffuseEnvironmentMap;
uniform sampler2D specularEnvironmentMap;
vec4 getEnvironmentHDR(sampler2D sampler, vec3 dir)
{
dir = (ModelViewInverseMatrix * vec4(dir, 0)).xyz;
vec2 uv = vec2((atan(dir.x,dir.z)/3.1415926535897+1)*0.5, (1-dir.y)*0.5);
vec4 tex = texture(sampler, uv);
tex = vec4(pow(tex.xyz, vec3(0.4545)), 1);
return tex;
}
vec4
lighting(vec4 texColor, vec3 Peye, vec3 Neye, float spec, float occ)
{
vec4 color = vec4(0);
vec3 n = Neye;
for (int i = 0; i < NUM_LIGHTS; ++i) {
vec4 Plight = lightSource[i].position;
vec3 l = (Plight.w == 0.0)
? normalize(Plight.xyz) : normalize(Plight.xyz - Peye);
vec3 h = normalize(l + vec3(0,0,1)); // directional viewer
float d = max(0.0, dot(n, l));
float s = pow(max(0.0, dot(n, h)), 64.0f);
color += (1.0-occ) * ((lightSource[i].ambient +
d * lightSource[i].diffuse) * texColor +
spec * s * lightSource[i].specular);
}
color.a = 1;
return color;
}
vec4
edgeColor(vec4 Cfill)
{
#if defined(GEOMETRY_OUT_WIRE) || defined(GEOMETRY_OUT_LINE)
#ifdef PRIM_TRI
float d =
min(gEdgeDistance[0], min(gEdgeDistance[1], gEdgeDistance[2]));
#endif
#ifdef PRIM_QUAD
float d =
min(min(gEdgeDistance[0], gEdgeDistance[1]),
min(gEdgeDistance[2], gEdgeDistance[3]));
#endif
#ifdef PRIM_LINE
float d = 0;
#endif
vec4 Cedge = vec4(1.0, 1.0, 0.0, 1.0);
float p = exp2(-2 * d * d);
#if defined(GEOMETRY_OUT_WIRE)
if (p < 0.25) discard;
#endif
Cfill.rgb = mix(Cfill.rgb, Cedge.rgb, p);
#endif
return Cfill;
}
void
main()
{
// ------------ normal ---------------
#if defined(NORMAL_HW_SCREENSPACE) || defined(NORMAL_SCREENSPACE)
vec3 normal = perturbNormalFromDisplacement(gPosition.xyz,
gNormal,
gPatchCoord);
#else
vec3 normal = gNormal;
#endif
// ------------ color ---------------
#if defined COLOR_PTEX_NEAREST
vec4 texColor = PtexLookupNearest(gPatchCoord,
textureImage_Data,
textureImage_Packing);
#elif defined COLOR_PTEX_HW_BILINEAR
vec4 texColor = PtexLookupFast(gPatchCoord,
textureImage_Data,
textureImage_Packing);
#elif defined COLOR_PTEX_BILINEAR
vec4 texColor = PtexMipmapLookup(gPatchCoord,
mipmapBias,
textureImage_Data,
textureImage_Packing);
#elif defined COLOR_PTEX_BIQUADRATIC
vec4 texColor = PtexMipmapLookupQuadratic(gPatchCoord,
mipmapBias,
textureImage_Data,
textureImage_Packing);
#elif defined COLOR_PATCHTYPE
vec4 texColor = edgeColor(lighting(GetOverrideColor(OsdGetPatchParam(OsdGetPatchIndex(gl_PrimitiveID))),
gPosition.xyz, normal, 1, 0));
outColor = texColor;
return;
#elif defined COLOR_PATCHCOORD
vec4 texColor = edgeColor(lighting(gPatchCoord, gPosition.xyz, normal, 1, 0));
outColor = texColor;
return;
#elif defined COLOR_NORMAL
vec4 texColor = edgeColor(vec4(normal, 1));
outColor = texColor;
return;
#else // COLOR_NONE
vec4 texColor = vec4(0.5);
#endif
// ------------ occlusion ---------------
#ifdef USE_PTEX_OCCLUSION
float occ = PtexMipmapLookup(gPatchCoord,
mipmapBias,
textureOcclusion_Data,
textureOcclusion_Packing).x;
#else
float occ = 0.0;
#endif
// ------------ specular ---------------
#ifdef USE_PTEX_SPECULAR
float specular = PtexMipmapLookup(gPatchCoord,
mipmapBias,
textureSpecular_Data,
textureSpecular_Packing).x;
#else
float specular = 1.0;
#endif
vec4 Cf = lighting(texColor, gPosition.xyz, normal, specular, occ);
// ------------ wireframe ---------------
outColor = edgeColor(Cf);
}
#endif