[require]
GLSL >= 1.10

[vertex shader]
uniform int n;
varying vec4 gl_TexCoord[5];
void main()
{
	for (int i = 0; i < n; i++) {
		gl_TexCoord[i] = vec4(0.5, 0.5, 0.5, 0.5) * float(i);
	}
	gl_Position = gl_Vertex;
}

[fragment shader]
uniform int index;
varying vec4 gl_TexCoord[5];
void main()
{
	gl_FragColor = gl_TexCoord[index];
}

[test]
uniform int index 1
uniform int n 4
draw rect -1 -1 2 2
probe rgba 1 1 0.5 0.5 0.5 0.5