#define PI 3.1415926535897932384626433832795
#define PI_2 1.5707963267948966192313216916398

attribute vec2 aTextureCoord;

uniform mat4 prMvMatrix;
uniform mat3 normMatrix;
uniform vec3 directLightDir;

varying vec2 vTextureCoord;
varying float vLightWeight;

void main(void)
{
	float ha = mix(-PI, PI, aTextureCoord.x);
	float va = mix(-PI_2, PI_2, aTextureCoord.y);
	float vCos =  cos(va);
	vec3 position = vec3(sin(ha) * vCos, sin(va), cos(ha) * vCos);
	gl_Position = prMvMatrix * vec4(position * 0.1, 1.0);
	vLightWeight = max(dot(normMatrix * position, directLightDir), 0.0);
	vTextureCoord = aTextureCoord;
}