uniform mat4 mvp;
uniform int mask_index;

#pragma MSP stage(vertex)
layout(location=0) in vec4 position;
layout(location=1) in vec4 color;
out VertexOut
{
	vec4 color;
	vec4 mask_color;
} vs_out;
void main()
{
	int index = mask_index%4;
	vs_out.color = color;
	vs_out.color[index] = 0.0;
	vs_out.mask_color = vec4(1.0);
	vs_out.mask_color[index] = 1.0;
	gl_Position = mvp*position;
}

#pragma MSP stage(fragment)
layout(location=0) out vec4 frag_color;
void main()
{
	frag_color = vs_out.color+vs_out.mask_color;
}

// Target API: OpenGL

/* Expected output: vertex
layout(location=0) uniform mat4 mvp;
layout(location=4) uniform int mask_index;
layout(location=0) in vec4 position;
layout(location=1) in vec4 color;
out VertexOut
{
	vec4 color;
	vec4 mask_color;
} vs_out;
void main()
{
	int index = mask_index%4;
	vs_out.color = color;
	vs_out.color[index] = 0.0;
	vs_out.mask_color = vec4(1.0);
	vs_out.mask_color[index] = 1.0;
	gl_Position = mvp*position;
	gl_Position.z = gl_Position.z*2.0-gl_Position.w;
}
/*

/* Expected output: fragment
layout(location=0) out vec4 frag_color;
in VertexOut
{
	vec4 color;
	vec4 mask_color;
} vs_out;
void main()
{
	frag_color = vs_out.color+vs_out.mask_color;
}
*/