spg-project/resources/background.tes

#version 430

layout (quads, equal_spacing, ccw) in;

uniform mat4 proj;
uniform mat4 view;
uniform mat4 model;
uniform mat4 shadow;

out vec4 varShadowPosition;

void main (void) {
    vec4 pos = vec4(gl_TessCoord.x, gl_TessCoord.y, sin(gl_TessCoord.x * 6.283185 * 2.0) * 50, 1.0);
	gl_Position = proj * view * model * pos;
    varShadowPosition = shadow * model * pos;
}