#version 130
#extension GL_ARB_explicit_attrib_location: require

uniform mat4 mvp;
uniform mat3 mv_normal;

layout(location = 0) in vec2 uv;

out vec4 color;
out vec2 frag_uv;

// Direction of the normal in camera-space.
out vec3 normal_cs;

void main(void)
{
	/* Center the region at the origin.  Assume that it's 7 units by 7
	 * units.
	 */
	vec2 bias_uv = uv - 0.5;
	vec4 position = vec4(bias_uv.x * 7.,
			     0.0,
			     bias_uv.y * 7.,
			     1.0);
	gl_Position = mvp * position;

	/* Transform the normal by the inverse-transpose of the model-view
	 * matrix.
	 */
	normal_cs = mv_normal * vec3(0., 1., 0.);

	frag_uv = uv;
}