attribute vec4 in_position;
attribute vec3 in_normal;
attribute vec2 in_uv;

varying vec3 npos;
varying vec3 normal, binormal, tangent;
varying vec2 uv;

uniform float flipState;

void main()
{
	normal = normalize(gl_NormalMatrix * in_normal);
	binormal = normalize(cross(normal, gl_NormalMatrix * vec3(0.0,0.999,0.04471017781)));
	tangent = normalize(cross(normal, binormal));
	
	vec4 pos = gl_ModelViewMatrix * in_position;
	npos = -pos.xyz;
	
	vec2 baseUV = in_uv;
	if(flipState < 0.5) {
		if(flipState < 0.25) {
			baseUV.x = 1.0 - baseUV.x;
			binormal = -binormal;
		}
	}
	else {
		if(flipState < 0.75) {
			baseUV.y = 1.0 - baseUV.y;
			tangent = -tangent;
		}
		else {
			baseUV = vec2(1.0) - baseUV;
			binormal = -binormal;
			tangent = -tangent;
		}
	}
	uv = baseUV;
	gl_Position = gl_ProjectionMatrix * pos;
}