[require] GLSL >= 1.20 [vertex shader] void main() { gl_Position = gl_Vertex; } [fragment shader] #version 120 void main() { float f1 = 1f; float f2 = 0.5F; gl_FragColor = vec4(f2, f1, 0.0, 0.0); } [test] draw rect -1 -1 2 2 probe rgba 1 1 0.5 1.0 0.0 0.0