+namespace
+{
+/**
+ * This struct is used to record the position of a uniform declaration
+ * within the fragment shader source code.
+ */
+struct LocationPosition
+{
+ GLint uniformLocation; ///< The location of the uniform (used as an identifier)
+ int position; ///< the position of the uniform declaration
+ LocationPosition( GLint uniformLocation, int position )
+ : uniformLocation(uniformLocation), position(position)
+ {
+ }
+};
+
+bool sortByPosition( LocationPosition a, LocationPosition b )
+{
+ return a.position < b.position;
+}
+}
+
+void Program::GetActiveSamplerUniforms()
+{
+ GLint numberOfActiveUniforms = -1;
+ GLint uniformMaxNameLength=-1;
+
+ mGlAbstraction.GetProgramiv( mProgramId, GL_ACTIVE_UNIFORMS, &numberOfActiveUniforms );
+ mGlAbstraction.GetProgramiv( mProgramId, GL_ACTIVE_UNIFORM_MAX_LENGTH, &uniformMaxNameLength );
+
+ std::vector<std::string> samplerNames;
+ std::vector<char> name(uniformMaxNameLength + 1); // Allow for null terminator
+ std::vector< LocationPosition > samplerUniformLocations;
+
+ {
+ int nameLength = -1;
+ int number = -1;
+ GLenum type = GL_ZERO;
+
+ for( int i=0; i<numberOfActiveUniforms; ++i )
+ {
+ mGlAbstraction.GetActiveUniform( mProgramId, static_cast< GLuint >( i ), uniformMaxNameLength,
+ &nameLength, &number, &type, name.data() );
+
+ if( type == GL_SAMPLER_2D || type == GL_SAMPLER_CUBE || type == GL_SAMPLER_EXTERNAL_OES )
+ {
+ GLuint location = mGlAbstraction.GetUniformLocation( mProgramId, name.data() );
+ samplerNames.push_back( name.data() );
+ samplerUniformLocations.push_back(LocationPosition(location, -1));
+ }
+ }
+ }
+
+ //Determine declaration order of each sampler
+ char* fragShader = strdup( mProgramData->GetFragmentShader() );
+ char* nextPtr = NULL;
+ const char* token = strtok_r( fragShader, " ;\n", &nextPtr );
+ int samplerPosition = 0;
+ while( token )
+ {
+ if( ( strncmp( token, "sampler2D", 9u ) == 0 ) ||
+ ( strncmp( token, "samplerCube", 11u ) == 0 ) ||
+ ( strncmp( token, "samplerExternalOES", 18u ) == 0 ) )
+ {
+ bool found( false );
+ token = strtok_r( NULL, " ;\n", &nextPtr );
+ for( size_t i=0; i<samplerUniformLocations.size(); ++i )
+ {
+ if( samplerUniformLocations[i].position == -1 &&
+ strncmp( token, samplerNames[i].c_str(), samplerNames[i].size() ) == 0 )
+ {
+ samplerUniformLocations[i].position = samplerPosition++;
+ found = true;
+ break;
+ }
+ }
+ if( !found )
+ {
+ DALI_LOG_ERROR("Sampler uniform %s declared but not used in the shader\n", token );
+ }
+ }
+ else
+ {
+ token = strtok_r( NULL, " ;\n", &nextPtr );
+ }
+ }
+
+ free( fragShader );
+
+ // Re-order according to declaration order in the fragment source.
+ size_t samplerUniformCount = samplerUniformLocations.size();
+ if( samplerUniformCount > 1 )
+ {
+ std::sort( samplerUniformLocations.begin(), samplerUniformLocations.end(), sortByPosition);
+ }
+
+ mSamplerUniformLocations.resize( samplerUniformCount );
+ for( size_t i=0; i<samplerUniformCount; ++i )
+ {
+ mSamplerUniformLocations[i] = samplerUniformLocations[i].uniformLocation;
+ }
+}
+
+bool Program::GetSamplerUniformLocation( unsigned int index, GLint& location )
+{
+ bool result = false;
+ if( index < mSamplerUniformLocations.size() )
+ {
+ location = mSamplerUniformLocations[index];
+ result = true;
+ }
+ return result;
+}
+
+size_t Program::GetActiveSamplerCount() const
+{
+ return mSamplerUniformLocations.size();
+}
+