// Rounded Corner Sprite Effect
// 用于实现圆角矩形裁剪效果，性能优于 Mask 方案
CCEffect %{
techniques:
  - passes:
      - vert: sprite-vs:vert
        frag: sprite-fs:frag
        depthStencilState:
          depthTest: false
          depthWrite: false
        blendState:
          targets:
            - blend: true
              blendSrc: src_alpha
              blendDst: one_minus_src_alpha
              blendSrcAlpha: src_alpha
              blendDstAlpha: one_minus_src_alpha
        rasterizerState:
          cullMode: none
        properties:
          alphaThreshold: { value: 0.5 }
          # 圆角参数: x=圆角半径比例(0-0.5), y=预留, z=节点宽度, w=节点高度
          roundedParams: { value: [0.08, 0.0, 347.0, 200.0] }
          # UV 区域: x=minU, y=minV, z=rangeU, w=rangeV (用于裁剪后的 SpriteFrame 归一化)
          uvRect: { value: [0.0, 0.0, 1.0, 1.0] }
}%

CCProgram sprite-vs %{
precision highp float;
#include <builtin/uniforms/cc-global>
#if USE_LOCAL
  #include <builtin/uniforms/cc-local>
#endif
#if SAMPLE_FROM_RT
  #include <common/common-define>
#endif
in vec3 a_position;
in vec2 a_texCoord;
in vec4 a_color;

out vec4 color;
out vec2 uv0;

vec4 vert() {
  vec4 pos = vec4(a_position, 1);

  #if USE_LOCAL
    pos = cc_matWorld * pos;
  #endif

  #if USE_PIXEL_ALIGNMENT
    pos = cc_matView * pos;
    pos.xyz = floor(pos.xyz);
    pos = cc_matProj * pos;
  #else
    pos = cc_matViewProj * pos;
  #endif

  uv0 = a_texCoord;
  #if SAMPLE_FROM_RT
    CC_HANDLE_RT_SAMPLE_FLIP(uv0);
  #endif
  color = a_color;

  return pos;
}
}%

CCProgram sprite-fs %{
precision highp float;
#include <builtin/internal/embedded-alpha>
#include <builtin/internal/alpha-test>

in vec4 color;
in vec2 uv0;

// roundedParams: x=圆角半径比例, y=预留, z=节点宽度, w=节点高度
// uvRect: x=minU, y=minV, z=rangeU, w=rangeV (裁剪后的 SpriteFrame UV 归一化)
uniform Custom {
  vec4 roundedParams;
  vec4 uvRect;
};

#if USE_TEXTURE
  #pragma builtin(local)
  layout(set = 2, binding = 12) uniform sampler2D cc_spriteTexture;
#endif

// 计算点到圆角矩形边界的有符号距离
float roundedBoxSDF(vec2 centerPos, vec2 halfSize, float radius) {
  vec2 q = abs(centerPos) - halfSize + radius;
  return length(max(q, 0.0)) + min(max(q.x, q.y), 0.0) - radius;
}

vec4 frag() {
  vec4 o = vec4(1, 1, 1, 1);

  #if USE_TEXTURE
    o *= CCSampleWithAlphaSeparated(cc_spriteTexture, uv0);
  #endif

  o *= color;

  // 解析参数
  float cornerRadius = roundedParams.x;
  vec2 nodeSize = vec2(roundedParams.z, roundedParams.w);

  // 将实际 UV 归一化到 0→1 范围（兼容裁剪后的 SpriteFrame）
  // uvRect: (minU, minV, rangeU, rangeV)
  vec2 normalizedUV = (uv0 - uvRect.xy) / uvRect.zw;

  // 将归一化 UV 转换为以中心为原点的坐标系
  vec2 centerUV = normalizedUV - 0.5;

  // 计算实际的圆角半径（基于短边）
  float minSize = min(nodeSize.x, nodeSize.y);
  float radius = cornerRadius * minSize;

  // 将 UV 坐标转换为像素坐标
  vec2 pixelPos = centerUV * nodeSize;
  vec2 halfSize = nodeSize * 0.5;

  // 计算 SDF 距离
  float dist = roundedBoxSDF(pixelPos, halfSize, radius);

  // 使用平滑的抗锯齿边缘
  float smoothEdge = 1.0 - smoothstep(-1.0, 1.0, dist);

  o.a *= smoothEdge;

  // 灰度转换（与 Cocos 内置 sprite shader 一致的 luminance 权重）
  #if USE_GRAY_SCALE
    float gray = dot(o.rgb, vec3(0.2126, 0.7152, 0.0722));
    o.rgb = vec3(gray);
  #endif

  ALPHA_TEST(o);
  return o;
}
}%