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From Michael Platings, "On nvidia cards mipmap generation for non-power-of-two textures with

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GL_GENERATE_MIPMAP_SGIS is very slow (over half a second for a 720*576
texture). However, glGenerateMipmapEXT() performs well (16ms for the
same texture), so I have modified the attached files to use
Texture::generateMipmap() if glGenerateMipmapEXT is supported, instead
of enabling & disabling GL_GENERATE_MIPMAP_SGIS."

Notes, from Robert Osfield, I've tested the out of the previous path using
GL_GENERATE_MIPMAP_SGIS and non power of two textures on NVidia 7800GT and
Nvidia linux drivers with the image size 720x576 and only get compile times
of 56ms, so the above half second speed looks to be a driver bug.  With
Muchael's changes the cost goes done to less than 5ms, so it's certainly 
an effective change, even given that Michael's poor expereiences with
GL_GENERATE_MIP_SGIS do look to be a driver bug.
This commit is contained in:
Robert Osfield
2008-05-28 11:19:41 +00:00
parent 20f3e74643
commit 8677c4d6d6
4 changed files with 111 additions and 46 deletions
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97
src/osg/Texture.cpp
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@@ -881,7 +881,7 @@ void Texture::computeRequiredTextureDimensions(State& state, const osg::Image& i
inwidth = width;
inheight = height;
bool useHardwareMipMapGeneration = !image.isMipmap() && _useHardwareMipMapGeneration && extensions->isGenerateMipMapSupported();
bool useHardwareMipMapGeneration = !image.isMipmap() && isHardwareMipmapGenerationEnabled(state);
if( _min_filter == LINEAR || _min_filter == NEAREST || useHardwareMipMapGeneration )
{
@@ -933,8 +933,6 @@ void Texture::applyTexImage2D_load(State& state, GLenum target, const Image* ima
// current OpenGL context.
const unsigned int contextID = state.getContextID();
const Extensions* extensions = getExtensions(contextID,true);
bool generateMipMapSupported = extensions->isGenerateMipMapSupported();
// select the internalFormat required for the texture.
bool compressed_image = isCompressedInternalFormat((GLenum)image->getPixelFormat());
@@ -1035,17 +1033,18 @@ void Texture::applyTexImage2D_load(State& state, GLenum target, const Image* ima
pbo = 0;
}
bool useHardwareMipMapGeneration = !image->isMipmap() && _useHardwareMipMapGeneration && generateMipMapSupported;
bool useHardwareMipMapGeneration = !image->isMipmap() && isHardwareMipmapGenerationEnabled(state);
if( _min_filter == LINEAR || _min_filter == NEAREST || useHardwareMipMapGeneration)
{
bool hardwareMipMapOn = false;
if (_min_filter != LINEAR && _min_filter != NEAREST)
if (_min_filter == LINEAR || _min_filter == NEAREST)
{
if (useHardwareMipMapGeneration) glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS,GL_TRUE);
hardwareMipMapOn = true;
useHardwareMipMapGeneration = false;
}
GenerateMipmapMode mipmapResult = mipmapBeforeTexImage(state, useHardwareMipMapGeneration);
if ( !compressed_image)
{
numMipmapLevels = 1;
@@ -1070,7 +1069,7 @@ void Texture::applyTexImage2D_load(State& state, GLenum target, const Image* ima
data-dataMinusOffset+dataPlusOffset);
}
if (hardwareMipMapOn) glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS,GL_FALSE);
mipmapAfterTexImage(state, mipmapResult);
}
else
{
@@ -1219,8 +1218,6 @@ void Texture::applyTexImage2D_subload(State& state, GLenum target, const Image*
// current OpenGL context.
const unsigned int contextID = state.getContextID();
const Extensions* extensions = getExtensions(contextID,true);
bool generateMipMapSupported = extensions->isGenerateMipMapSupported();
// select the internalFormat required for the texture.
bool compressed_image = isCompressedInternalFormat((GLenum)image->getPixelFormat());
@@ -1267,7 +1264,7 @@ void Texture::applyTexImage2D_subload(State& state, GLenum target, const Image*
}
bool useHardwareMipMapGeneration = !image->isMipmap() && _useHardwareMipMapGeneration && generateMipMapSupported;
bool useHardwareMipMapGeneration = !image->isMipmap() && isHardwareMipmapGenerationEnabled(state);
unsigned char* dataMinusOffset=0;
unsigned char* dataPlusOffset=0;
@@ -1290,13 +1287,9 @@ void Texture::applyTexImage2D_subload(State& state, GLenum target, const Image*
if( _min_filter == LINEAR || _min_filter == NEAREST || useHardwareMipMapGeneration)
{
bool hardwareMipMapOn = false;
if (_min_filter != LINEAR && _min_filter != NEAREST)
{
if (useHardwareMipMapGeneration) glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS,GL_TRUE);
hardwareMipMapOn = true;
}
bool hardwareMipMapOn = _min_filter != LINEAR && _min_filter != NEAREST;
GenerateMipmapMode mipmapResult = mipmapBeforeTexImage(state, hardwareMipMapOn);
if (!compressed_image)
{
@@ -1321,7 +1314,7 @@ void Texture::applyTexImage2D_subload(State& state, GLenum target, const Image*
data - dataMinusOffset + dataPlusOffset );
}
if (hardwareMipMapOn) glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS,GL_FALSE);
mipmapAfterTexImage(state, mipmapResult);
}
else
{
@@ -1405,6 +1398,62 @@ void Texture::applyTexImage2D_subload(State& state, GLenum target, const Image*
}
}
bool Texture::isHardwareMipmapGenerationEnabled(const State& state) const
{
if (_useHardwareMipMapGeneration)
{
unsigned int contextID = state.getContextID();
const Extensions* extensions = getExtensions(contextID,true);
if (extensions->isGenerateMipMapSupported())
{
return true;
}
const FBOExtensions* fbo_ext = FBOExtensions::instance(contextID,true);
if (fbo_ext->glGenerateMipmapEXT)
{
return true;
}
}
return false;
}
Texture::GenerateMipmapMode Texture::mipmapBeforeTexImage(const State& state, bool hardwareMipmapOn) const
{
if (hardwareMipmapOn)
{
//GL_GENERATE_MIPMAP_SGIS with non-power-of-two textures on NVIDIA hardware
//is extremely slow. Use glGenerateMipmapEXT() instead if supported.
if (_internalFormatType != SIGNED_INTEGER &&
_internalFormatType != UNSIGNED_INTEGER &&
FBOExtensions::instance(state.getContextID(), true)->glGenerateMipmapEXT)
{
return GENERATE_MIPMAP;
}
else
{
glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS, GL_TRUE);
return GENERATE_MIPMAP_TEX_PARAMETER;
}
}
return GENERATE_MIPMAP_NONE;
}
void Texture::mipmapAfterTexImage(State& state, GenerateMipmapMode beforeResult) const
{
switch (beforeResult)
{
case GENERATE_MIPMAP:
generateMipmap(state);
break;
case GENERATE_MIPMAP_TEX_PARAMETER:
glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS, GL_FALSE);
break;
}
}
void Texture::generateMipmap(State& state) const
{
@@ -1432,6 +1481,9 @@ void Texture::generateMipmap(State& state) const
if (fbo_ext->glGenerateMipmapEXT)
{
textureObject->bind();
// osg::notify(osg::NOTICE)<<"Using generate glGenerateMipmap"<<std::endl;
fbo_ext->glGenerateMipmapEXT(textureObject->_target);
// inform state that this texture is the current one bound.
@@ -1455,7 +1507,12 @@ void Texture::generateMipmap(State& state) const
void Texture::compileGLObjects(State& state) const
{
// osg::Timer_t startTick = osg::Timer::instance()->tick();
apply(state);
// osg::Timer_t endTick = osg::Timer::instance()->tick();
// osg::notify(osg::NOTICE)<<"compile time = "<<osg::Timer::instance()->delta_m(startTick, endTick)<<std::endl;;
}
void Texture::resizeGLObjectBuffers(unsigned int maxSize)