layout(constant_id=0) const bool use_texture = false;
layout(constant_id=1) const bool use_vertex_color = false;
uniform sampler2D tex;
uniform mat4 mvp;

#pragma MSP stage(vertex)
layout(location=0) in vec4 position;
layout(location=1) in vec4 color;
layout(location=2) in vec2 texcoord;
void main()
{
	passthrough;
	gl_Position = mvp*position;
}

#pragma MSP stage(fragment)
layout(location=0) out vec4 frag_color;
void main()
{
	frag_color = vec4(1.0);
	if(use_texture)
		frag_color *= texture(tex, texcoord);
	if(use_vertex_color)
		frag_color *= color;
}

// Specialize: use_texture true

/* Expected output: vertex
uniform mat4 mvp;
layout(location=0) in vec4 position;
layout(location=2) in vec2 texcoord;
out vec2 _vs_out_texcoord;
void main()
{
	_vs_out_texcoord = texcoord;
	gl_Position = mvp*position;
}
*/

/* Expected output: fragment
uniform sampler2D tex;
layout(location=0) out vec4 frag_color;
in vec2 _vs_out_texcoord;
void main()
{
	frag_color = vec4(1.0);
	frag_color *= texture(tex, _vs_out_texcoord);
}
*/