So I've been trying to follow this blog and I'm having trouble drawing the shader.
OBJ_Player
Create Event:
//Shader Init
maskshader_col = shader_get_uniform( SDR_MaskShader, 'u_MaskCol' );
Draw event:
shader_set(SDR_MaskShader);
shader_set_uniform_f( maskshader_col, 255, 255, 255, 1.0 )...