CocosCreator-Shader-Effect-Demo/assets/effects/sprite-outline.effect

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

CCEffect %{
  techniques:
  - passes:
    - vert: vs
      frag: fs
      blendState:
        targets:
        - blend: true
      rasterizerState:
        cullMode: none
      properties:
        texture: { value: grey }
        alphaThreshold: { value: 0.5 }
        outlineColor: { value: [1, 1, 1, 1], editor: { type: color } }
        outlineSize: { value: 5.0 }
}%


CCProgram vs %{
  precision highp float;

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

  in vec3 a_position;
  in vec4 a_color;
  out vec4 v_color;

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

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

    #if CC_USE_MODEL
    pos = cc_matViewProj * cc_matWorld * pos;
    #else
    pos = cc_matViewProj * pos;
    #endif

    #if USE_TEXTURE
    v_uv0 = a_uv0;
    #endif

    v_color = a_color;

    gl_Position = pos;
  }
}%


CCProgram fs %{
  precision highp float;
  
  #include <alpha-test>

  in vec4 v_color;

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



  #if SHOW_OUT_LINE
  uniform Outline {
    // 描边颜色 
    vec4 outlineColor;
    // 描边偏移大小
    float outlineSize;
    // 特别地，必须是 vec4 先于 float 声明
  };
  #endif

  // // 获取背面颜色
  // float getBackArea() {
  //   vec4 color_up;
  //   vec4 color_down;
  //   vec4 color_left; 
  //   vec4 color_right; 
  //   vec4 color_up_left; 
  //   vec4 color_up_right; 
  //   vec4 color_down_left; 
  //   vec4 color_down_right; 
  //   float total = 0 ; 

  //   color_up = texture(texture, v_uv0 + vec2(0, outlineSize)); 
  //   color_down = texture(texture, v_uv0 - vec2(0, outlineSize)); 
  //   color_left = texture(texture, v_uv0 - vec2(outlineSize, 0)); 
  //   color_right = texture(texture, v_uv0 + vec2(outlineSize, 0)); 
  //   color_up_left = texture(texture, v_uv0 + vec2(outlineSize, -outlineSize)); 
  //   color_up_right = texture(texture, v_uv0 + vec2(outlineSize, outlineSize)); 
  //   color_down_left = texture(texture, v_uv0 + vec2(-outlineSize, -outlineSize)); 
  //   color_down_right = texture(texture, v_uv0 + vec2(-outlineSize, outlineSize)); 
  //   total = color_right.a + color_left.a + color_down.a + color_up.a + color_up_left.a + color_up_right.a + color_down_left.a + color_down_right.a; 
  //   return clamp(total, 0.0, 1.0);
  // }

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

    #if USE_TEXTURE
    o *= texture(texture, v_uv0);
      #if CC_USE_ALPHA_ATLAS_TEXTURE
      o.a *= texture2D(texture, v_uv0 + vec2(0, 0.5)).r;
      #endif
    #endif

    o *= v_color;

    ALPHA_TEST(o);

    gl_FragColor = o;
    // gl_FragColor = vec4(0.0, 0.0, 1.0, 1.0);
  }
}%