CCEffect %{
  techniques:
  - name: opaque
    passes:
    - vert: genie-vs:vs      # 程序 genie-vs，入口 vs
      frag: genie-fs:fs      # 程序 genie-fs，入口 fs
      blendState:
        targets:
        - blend: true
          blendSrc: src_alpha
          blendDst: one_minus_src_alpha
      rasterizerState:
        cullMode: none
      properties:
        u_targetPos: { value: [0, -300] }
        u_progress: { value: 0.0, editor: { slide: true, range: [0, 1], step: 0.01 } }
        u_bendStrength: { value: 1.0, editor: { slide: true, range: [0, 3], step: 0.1 } }
        u_shrinkWidth: { value: 0.2, editor: { slide: true, range: [0, 1], step: 0.01 } }
}%

CCProgram genie-vs %{
  precision highp float;
  #include <cc-global>
  #include <cc-local>
  
  in vec3 a_position;
  in vec2 a_uv0;
  in vec4 a_color;
  
  uniform MyConstants {
    vec2 u_targetPos;
    float u_progress;
    float u_bendStrength;
    float u_shrinkWidth;
  };
  
  out vec2 v_uv;
  out vec4 v_color;
  
  vec2 quadBezier(vec2 p0, vec2 p1, vec2 p2, float t) {
    float u = 1.0 - t;
    return u * u * p0 + 2.0 * u * t * p1 + t * t * p2;
  }
  
  vec4 vs() {
    vec2 pos = a_position.xy;
    v_uv = a_uv0;
    v_color = a_color;
    
    float p = clamp(u_progress, 0.0, 1.0);
    float uvY = a_uv0.y;
    float uvX = a_uv0.x;
    
    vec2 topTarget = mix(pos, u_targetPos, p * 0.6);
    vec2 bottomTarget = u_targetPos;
    float bendDown = -80.0 * u_bendStrength * (1.0 - p);
    vec2 bottomControl = mix(pos, u_targetPos, 0.5) + vec2(0.0, bendDown);
    vec2 rowPos = quadBezier(topTarget, bottomControl, bottomTarget, uvY * p);
    
    float widthScale = 1.0 - (1.0 - u_shrinkWidth) * p * uvY;
    vec2 center = mix(topTarget, bottomTarget, uvY);
    rowPos.x = center.x + (rowPos.x - center.x) * widthScale;
    
    float bulge = -sin(uvY * 3.14159) * 30.0 * u_bendStrength * (1.0 - p);
    rowPos.y += bulge * sin((uvX - 0.5) * 3.14159);
    
    // 增强吸进效果
    float depth = 1.0 - p * 0.8 * uvY;
    rowPos = mix(rowPos, u_targetPos, (1.0 - depth) * uvY * 1.0);
    
    // 最终阶段快速收缩到目标点
    if (p > 0.8) {
        float finalT = (p - 0.8) / 0.2;
        rowPos = mix(rowPos, u_targetPos, finalT * 0.8);
    }
    
    return cc_matViewProj * vec4(rowPos, 0.0, 1.0);
  }
}%

CCProgram genie-fs %{
  precision highp float;
  #include <texture>
  
  in vec2 v_uv;
  in vec4 v_color;
  
  uniform sampler2D texture;
  
  vec4 fs() {
    return texture(texture, v_uv) * v_color;
  }
}%