precision mediump float;

attribute vec2 aVertexPosition;

uniform mat4 uModelMatrix;
uniform mat4 uViewMatrix;
uniform mat4 uProjectionMatrix;

varying vec2 uv1;
varying vec2 uv2;
varying float blend;

uniform vec2 uAtlasOffset1;
uniform vec2 uAtlasOffset2;
uniform vec2 uAtlasInfo;

void main() {

  vec2 uv = aVertexPosition + vec2(0.5, 0.5);
  uv.y = 1.0 - uv.y;
  uv /= uAtlasInfo.x;
  uv1 = uv + uAtlasOffset1;
  uv2 = uv + uAtlasOffset2;
  blend = uAtlasInfo.y;

  vec4 worldPosition = uModelMatrix * vec4(aVertexPosition, 0.0, 1.0);
  gl_Position = uProjectionMatrix * uViewMatrix * worldPosition;
}