OpenSubdiv/opensubdiv/osd/glPtexMipmapTexture.cpp
2013-10-04 18:23:20 -07:00

139 lines
4.4 KiB
C++

//
// 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.
//
#include "../osd/glPtexMipmapTexture.h"
#include "../osd/ptexMipmapTextureLoader.h"
#include "../osd/opengl.h"
#include <Ptexture.h>
namespace OpenSubdiv {
namespace OPENSUBDIV_VERSION {
OsdGLPtexMipmapTexture::OsdGLPtexMipmapTexture()
: _width(0), _height(0), _depth(0), _layout(0), _texels(0)
{
}
OsdGLPtexMipmapTexture::~OsdGLPtexMipmapTexture()
{
if (glIsTexture(_layout))
glDeleteTextures(1, &_layout);
if (glIsTexture(_texels))
glDeleteTextures(1, &_texels);
}
static GLuint
genTextureBuffer(GLenum format, GLsizeiptr size, GLvoid const * data)
{
GLuint buffer, result;
glGenBuffers(1, &buffer);
glBindBuffer(GL_TEXTURE_BUFFER, buffer);
glBufferData(GL_TEXTURE_BUFFER, size, data, GL_STATIC_DRAW);
glGenTextures(1, & result);
glBindTexture(GL_TEXTURE_BUFFER, result);
glTexBuffer(GL_TEXTURE_BUFFER, format, buffer);
// need to reset texture binding before deleting the source buffer.
glBindTexture(GL_TEXTURE_BUFFER, 0);
glDeleteBuffers(1, &buffer);
return result;
}
OsdGLPtexMipmapTexture *
OsdGLPtexMipmapTexture::Create(PtexTexture * reader, int maxLevels)
{
OsdGLPtexMipmapTexture * result = NULL;
GLint maxNumPages = 0;
glGetIntegerv(GL_MAX_ARRAY_TEXTURE_LAYERS, &maxNumPages);
// Read the ptexture data and pack the texels
OsdPtexMipmapTextureLoader loader(reader, maxNumPages, maxLevels);
// Setup GPU memory
int numFaces = loader.GetNumFaces();
GLuint layout = genTextureBuffer(GL_R16I,
numFaces * 5 * sizeof(GLshort),
loader.GetLayoutBuffer());
GLenum format, type;
switch (reader->dataType()) {
case Ptex::dt_uint16 : type = GL_UNSIGNED_SHORT; break;
case Ptex::dt_float : type = GL_FLOAT; break;
case Ptex::dt_half : type = GL_HALF_FLOAT; break;
default : type = GL_UNSIGNED_BYTE; break;
}
switch (reader->numChannels()) {
case 1 : format = GL_RED; break;
case 2 : format = GL_RG; break;
case 3 : format = GL_RGB; break;
case 4 : format = GL_RGBA; break;
default: format = GL_RED; break;
}
// actual texels texture array
GLuint texels;
glGenTextures(1, &texels);
glBindTexture(GL_TEXTURE_2D_ARRAY, texels);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexImage3D(GL_TEXTURE_2D_ARRAY, 0,
(type == GL_FLOAT) ? GL_RGBA32F : GL_RGBA,
loader.GetPageWidth(),
loader.GetPageHeight(),
loader.GetNumPages(),
0, format, type,
loader.GetTexelBuffer());
// loader.ClearBuffers();
// Return the Osd Ptexture object
result = new OsdGLPtexMipmapTexture;
result->_width = loader.GetPageWidth();
result->_height = loader.GetPageHeight();
result->_depth = loader.GetNumPages();
result->_format = format;
result->_layout = layout;
result->_texels = texels;
return result;
}
} // end namespace OPENSUBDIV_VERSION
} // end namespace OpenSubdiv