[require]
GLSL >= 1.10

# GL_ARB_color_buffer_float provides a way to disable vertex color clamping,
# but without it, the vertex colors must be clamped.

[vertex shader]
void main()
{
	gl_Position = ftransform();
	gl_FrontColor = vec4(-2, -1, 0.5, 3);		  /* (0, 0,   0.5, 1) */
	gl_FrontSecondaryColor = vec4(2, 0.5, 1.5, -0.5); /* (1, 0.5, 1,   0) */
}

[fragment shader]
uniform vec4 arg0;
void main()
{
	gl_FragColor = (gl_Color + gl_SecondaryColor) * 0.5;
}

[test]
draw rect -1 -1 2 2
probe rgba 1 1 0.5 0.25 0.75 0.5