{$PROPERTY TestProperty '0'}

{$FUNC 'vec4' 'CalcColor' 'vec4' 'seed'}
    {$UNIFORM 'sampler2D' 'uTexture0'}
    {$UNIFORM 'sampler2D' 'uTexture1'}
    return texture2D(uTexture0, texCoord) * 
           texture2D(uTexture1, texCoord) *
           seed;
{$END}

{$MAIN}
    {$UNIFORM 'vec4' 'uColor'}
    gl_FragColor = {$IF TestProperty}uColor{$ELSE}{$CALL CalcColor 'uColor'}{$END};
{$END}