attribute vec4 a_position;
attribute vec4 a_texcoord;

uniform vec2 u_InvTextureSize;
uniform vec2 u_HalfActualWindowSize;

varying vec2 v_texCoord;

void main()
{
    vec2 k1 = vec2(a_position.z,-a_position.w);
	vec2 k2 = vec2(a_position.z,1.0-a_position.w);
	gl_Position = CC_MVPMatrix * vec4(a_position.xy,0.0 ,1.0);
	vec2 a = floor(gl_Position.xy * u_HalfActualWindowSize + k1 * a_texcoord.zw) / u_HalfActualWindowSize - vec2(0.001,0.001);
	vec2 b = ceil(gl_Position.xy * u_HalfActualWindowSize + k1 * a_texcoord.zw) / u_HalfActualWindowSize + vec2(0.001,0.001);