uniform mat4 u_MVPMatrix;
attribute vec4 a_position;
attribute vec2 a_texCoord;
varying vec2 TextureCoordOut;
void main(void)
{
gl_Position = u_MVPMatrix * a_position;
TextureCoordOut = a_texCoord;
TextureCoordOut.y = 1.0 - TextureCoordOut.y;
}