void
ShaderPreProcessor::applySupportForNoFFP(osg::Shader* shader)
{
if (!shader)
return;
#if !defined(OSG_GL_FIXED_FUNCTION_AVAILABLE)
GLSLChunker chunker;
GLSLChunker::Chunks chunks;
chunker.read(shader->getShaderSource(), chunks);
applySupportForNoFFPImpl(chunks);
std::string output;
chunker.write(chunks, output);
shader->setShaderSource(output);
#endif // !defined(OSG_GL_FIXED_FUNCTION_AVAILABLE)
}
void
ShaderPreProcessor::run(osg::Shader* shader)
{
if ( shader )
{
bool dirty = false;
// only runs for non-FFP (GLES, GL3+, etc.)
std::string source = shader->getShaderSource();
// First replace any quotes with spaces. Quotes are illegal.
if ( source.find('\"') != std::string::npos )
{
osgEarth::replaceIn(source, "\"", " ");
dirty = true;
}
// find the first legal insertion point for replacement declarations. GLSL requires that nothing
// precede a "#version" compiler directive, so we must insert new declarations after it.
std::string::size_type declPos = source.rfind( "#version " );
if ( declPos != std::string::npos )
{
// found the string, now find the next linefeed and set the insertion point after it.
declPos = source.find( '\n', declPos );
declPos = declPos != std::string::npos ? declPos+1 : source.length();
}
else
{
declPos = 0;
}
// Perform the no-FFP replacements:
if ( s_NO_FFP )
{
int maxLights = Registry::capabilities().getMaxLights();
for( int i=0; i<maxLights; ++i )
{
if ( replaceAndInsertDeclaration(
source, declPos,
Stringify() << "gl_LightSource[" << i << "]",
Stringify() << "osg_LightSource" << i,
Stringify()
<< osg_LightSourceParameters::glslDefinition() << "\n"
<< "uniform osg_LightSourceParameters " ) )
{
dirty = true;
}
if ( replaceAndInsertDeclaration(
source, declPos,
Stringify() << "gl_FrontLightProduct[" << i << "]",
Stringify() << "osg_FrontLightProduct" << i,
Stringify()
<< osg_LightProducts::glslDefinition() << "\n"
<< "uniform osg_LightProducts " ) )
{
dirty = true;
}
}
}
// Chunk the shader.
GLSLChunker chunker;
GLSLChunker::Chunks chunks;
chunker.read( source, chunks );
dirty = replaceVaryings( shader->getType(), chunks );
if ( dirty )
{
chunker.write( chunks, source );
shader->setShaderSource( source );
}
}
}
