// Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.  

CCEffect %{
  techniques:
  - passes:
    - vert: vs
      frag: fs
      depthStencilState:
        depthTest: true
        depthWrite: false
      blendState:
        targets:
        - blend: true
          blendSrc: src_alpha
          blendDst: one_minus_src_alpha
          blendDstAlpha: one_minus_src_alpha
      rasterizerState:
        cullMode: none
      properties:
        texture: { value: white }
        startColor: { value: [1, 1, 1, 1], editor : { type: color } }
        endColor: { value: [1, 1, 1, 1], editor : { type: color } }
}%


CCProgram vs %{
  precision highp float;

  #include <cc-global>
  #include <cc-local>

  in vec3 a_position;

  in vec2 a_uv0;
  out vec2 v_uv0;
  #if USE_TEXTURE
  #endif

  void main () {
    vec4 pos = vec4(a_position, 1);

    pos = cc_matViewProj * cc_matWorld * pos;

    v_uv0 = a_uv0;

    gl_Position = pos;
  }
}%


CCProgram fs %{
  precision highp float;

  in vec2 v_uv0;
  #if USE_TEXTURE
  uniform sampler2D texture;
  #endif

  uniform color {
    vec4 startColor;
    vec4 endColor;
  };

  void main () {
    vec4 o = vec4(1, 1, 1, 1);

    #if USE_TEXTURE
    o *= texture(texture, v_uv0);
    #endif

    vec4 fade = endColor - startColor;
    fade *= v_uv0.x;
    fade += startColor;
    o *= fade;

    gl_FragColor = o;
  }
}%