precision lowp float;
attribute vec2 aVertexPosition;
attribute vec2 aTextureCoord;
attribute vec4 aColor;
attribute float aTextureId;

uniform mat3 projectionMatrix;

varying vec2 vTextureCoord;
varying vec4 vColor;
varying float vTextureId;

void main(void){
   gl_Position = vec4((projectionMatrix * vec3(aVertexPosition, 1.0)).xy, 0.0, 1.0);
   vTextureCoord = aTextureCoord;
   vTextureId = aTextureId;
   vColor = vec4(aColor.rgb * aColor.a, aColor.a);
}