+ int position_attrib = glGetAttribLocation(glsl_program_num, "position");
+ assert(position_attrib != -1);
+ int texcoord_attrib = glGetAttribLocation(glsl_program_num, "texcoord");
+ assert(texcoord_attrib != -1);
+ glEnableVertexAttribArray(position_attrib);
+ check_error();
+ glVertexAttribPointer(position_attrib, 2, GL_FLOAT, GL_FALSE, 0, vertices);
+ check_error();
+ glEnableVertexAttribArray(texcoord_attrib);
+ check_error();
+ glVertexAttribPointer(texcoord_attrib, 2, GL_FLOAT, GL_FALSE, 0, texcoords);
+ check_error();