[require] GL >= 2.0 GLSL >= 1.20 [vertex shader] void main() { gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex; } [fragment shader] #version 120 uniform float a[] = float[](0,1,2,3,4); void main() { if (a.length() == 5) gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0); else gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0); } [test] clear color 0.0 0.0 0.0 0.0 clear ortho draw rect 10 10 10 10 probe rgb 15 15 0.0 1.0 0.0