// 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: white }
        alphaThreshold: { value: 0.5 }
        glyphRect: { value: [0, 0, 1, 1] }
        glyphSize: { value: [50, 62] }
}%


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>
  #include <texture>

  in vec4 v_color;

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

  uniform Glyph {
    vec4 glyphRect;
    vec2 glyphSize;
  };

  #if USE_TEXTURE
  float maskAt(vec2 point) {
    vec2 uv = point / glyphSize;
    if (uv.x < 0.0 || uv.y < 0.0 || uv.x > 1.0 || uv.y > 1.0) return 0.0;
    vec4 sampleColor = vec4(1.0);
    CCTexture(texture, glyphRect.xy + uv * glyphRect.zw, sampleColor);
    return sampleColor.a * sampleColor.r;
  }
  #endif

  void main () {
    vec4 o = v_color;
    #if USE_TEXTURE
    // Reserve 8 pixels around the original glyph inside this single sprite's quad.
    vec2 point = (v_uv0 - glyphRect.xy) / glyphRect.zw * (glyphSize + vec2(16.0)) - vec2(8.0);
    float fill = maskAt(point);
    float outer = 0.0;
    float inner = 0.0;
    for (int i = 0; i < 16; i++) {
      float angle = float(i) * 0.3926990817;
      vec2 direction = vec2(cos(angle), sin(angle));
      outer = 1.0 - (1.0 - outer) * (1.0 - maskAt(point + direction * 8.0));
      inner = 1.0 - (1.0 - inner) * (1.0 - maskAt(point + direction * 4.0));
    }
    float alpha = fill + (1.0 - fill) * (inner + (1.0 - inner) * outer);
    vec3 color = vec3(1.0, 242.0 / 255.0, 0.0) * fill
      + (1.0 - fill) * (vec3(164.0, 61.0, 19.0) / 255.0 * inner
      + (1.0 - inner) * vec3(outer));
    o = vec4(color / max(alpha, 0.0001), alpha * v_color.a);
    #endif

    ALPHA_TEST(o);

    #if USE_BGRA
      gl_FragColor = o.bgra;
    #else
      gl_FragColor = o.rgba;
    #endif
  }
}%