Method bindIDShader

src/IECoreGL/Selector.cpp:405–451

		}

		void bindIDShader( const IECoreGL::Shader *shader )
		{
			if( shader == m_currentIDShader )
			{
				// early out to avoid the relatively expensive operations
				// below if we've already loaded the shader.
				return;
			}

			const IECoreGL::Shader::Parameter *nameParameter = shader->uniformParameter( "ieCoreGLNameIn" );
			if( !nameParameter )
			{
				throw IECore::Exception( "ID shader does not have an ieCoreGLNameIn parameter" );
			}

			GLint fragDataLocation = glGetFragDataLocation( shader->program(), "ieCoreGLNameOut" );
			if( fragDataLocation < 0 )
			{
				throw IECore::Exception( "ID shader does not have an ieCoreGLNameOut output" );
			}

			GLint depthDataLocation = 0;
			if( m_useCameraDepth )
			{
				depthDataLocation = glGetFragDataLocation( shader->program(), "ieCoreGLCameraDepth" );
				if( depthDataLocation < 0 )
				{
					throw IECore::Exception( "ID shader does not have ieCoreGLCameraDepth output" );
				}
			}

			m_nameUniformLocation = nameParameter->location;

			m_currentIDShader = shader;
			glUseProgram( m_currentIDShader->program() );

			std::vector<GLenum> buffers;
			buffers.resize( std::max( fragDataLocation, depthDataLocation ) + 1, GL_NONE );
			buffers[fragDataLocation] = GL_COLOR_ATTACHMENT0;
			if( m_useCameraDepth )
			{
				buffers[depthDataLocation] = GL_COLOR_ATTACHMENT1;
			}
			glDrawBuffers( buffers.size(), &buffers[0] );

			loadNameIDRender( m_currentName );
		}

		//////////////////////////////////////////////////////////////////////////
		// OcclusionQuery