/**
 * @see https://github.com/ShenCiao/Ciallo/blob/main/docs/shaders/articulatedLine.vert
 */
export declare enum Location {
    BARYCENTRIC = 0,
    POINTA = 1,
    POINTB = 2,
    VERTEX_NUM = 3
}
export declare const vert = "\n  layout(std140) uniform SceneUniforms {\n    mat3 u_ProjectionMatrix;\n    mat3 u_ViewMatrix;\n    mat3 u_ViewProjectionInvMatrix;\n    vec4 u_BackgroundColor;\n    vec4 u_GridColor;\n    float u_ZoomScale;\n    float u_CheckboardStyle;\n  };\n  \n  \n#ifdef USE_WIREFRAME\n  layout(location = 0) in vec3 a_Barycentric;\n  out vec3 v_Barycentric;\n#endif\n\n  layout(location = 1) in vec4 a_PointA;\n  layout(location = 2) in vec4 a_PointB;\n  layout(location = 3) in float a_VertexNum;\n  \n  layout(std140) uniform ShapeUniforms {\n    mat3 u_ModelMatrix;\n    vec4 u_StrokeColor;\n    vec4 u_ZIndexStrokeWidth;\n    vec4 u_Opacity;\n    vec4 u_Stamp;\n  };\n\n  out vec2 p0;\n  out float r0;\n  out float l0;\n  out vec2 p1;\n  out float r1;\n  out float l1;\n  out vec2 p;\n  \n  void main() {\n    \n#ifdef USE_WIREFRAME\n  v_Barycentric = a_Barycentric;\n#endif\n\n  \n    mat3 model;\n    vec4 fillColor;\n    vec4 strokeColor;\n    float zIndex;\n    float strokeWidth;\n\n    model = u_ModelMatrix;\n    strokeColor = u_StrokeColor;\n    zIndex = u_ZIndexStrokeWidth.x;\n    strokeWidth = u_ZIndexStrokeWidth.y;\n\n    p0 = a_PointA.xy;\n    r0 = a_PointA.z;\n    l0 = a_PointA.w;\n    p1 = a_PointB.xy;\n    r1 = a_PointB.z;\n    l1 = a_PointB.w;\n\n    vec2 tangentDirection = normalize(p1 - p0);\n    vec2 normalDirection = vec2(-tangentDirection.y, tangentDirection.x);\n    float cosTheta = (r0 - r1)/distance(p0, p1);\n    if(abs(cosTheta) >= 1.0) return; \n\n    vec2 tangent = normalize(p1 - p0);\n    vec2 normal = vec2(-tangent.y, tangent.x);\n\n    float vertexNum = a_VertexNum;\n\n    vec2 position;\n    vec2 offsetSign;\n    float r;\n    if (vertexNum < 0.5) {\n      position = p0;\n      r = r0;\n      offsetSign = vec2(-1.0, -1.0);\n    } else if (vertexNum < 1.5) {\n      position = p0;\n      r = r0;\n      offsetSign = vec2(-1.0, 1.0);\n    } else if (vertexNum < 2.5) {\n      position = p1;\n      r = r1;\n      offsetSign = vec2(1.0, 1.0);\n    } else if (vertexNum < 3.5) {\n      position = p1;\n      r = r1;\n      offsetSign = vec2(1.0, -1.0);\n    }\n\n    // Apply the half angle formula from cos(theta) to tan(theta/2)\n    float tanHalfTheta = sqrt((1.0+cosTheta) / (1.0-cosTheta));\n    float cotHalfTheta = 1.0 / tanHalfTheta;\n    float normalTanValue = vec4(tanHalfTheta, tanHalfTheta, cotHalfTheta, cotHalfTheta)[gl_VertexID];\n    // Corner case: The small circle is very close to the big one, casuing large offset in the normal direction, discard the edge\n    if(normalTanValue > 10.0 || normalTanValue < 0.1) return;\n    \n    vec2 trapzoidVertexPosition = position + \n        offsetSign.x * r * tangentDirection + \n        offsetSign.y * r * normalDirection * normalTanValue;\n    p = trapzoidVertexPosition;\n  \n    gl_Position = vec4((u_ProjectionMatrix \n      * u_ViewMatrix\n      * model \n      * vec3(trapzoidVertexPosition, 1)).xy, zIndex, 1);\n  }\n  ";
export declare const frag = "\n  layout(std140) uniform SceneUniforms {\n    mat3 u_ProjectionMatrix;\n    mat3 u_ViewMatrix;\n    mat3 u_ViewProjectionInvMatrix;\n    vec4 u_BackgroundColor;\n    vec4 u_GridColor;\n    float u_ZoomScale;\n    float u_CheckboardStyle;\n  };\n  \n  layout(std140) uniform ShapeUniforms {\n    mat3 u_ModelMatrix;\n    vec4 u_StrokeColor;\n    vec4 u_ZIndexStrokeWidth;\n    vec4 u_Opacity;\n    vec4 u_Stamp;\n  };\n  \n  \n#ifdef USE_WIREFRAME\n  in vec3 v_Barycentric;\n\n  float edgeFactor() {\n    float u_WireframeLineWidth = 1.0;\n    vec3 d = fwidth(v_Barycentric);\n    vec3 a3 = smoothstep(vec3(0.0), d * u_WireframeLineWidth, v_Barycentric);\n    return min(min(a3.x, a3.y), a3.z);\n  }\n#endif\n\n  \n  in vec2 p0;\n  in float r0;\n  in float l0;\n  in vec2 p1;\n  in float r1;\n  in float l1;\n  in vec2 p;\n\n  #ifdef USE_FILLIMAGE\n    uniform sampler2D u_Texture;\n  #endif\n\n  out vec4 outputColor;\n  \n  float epsilon = 0.000001;\n\n  const int EquiDistance = 0, RatioDistance = 1;\n\n  float x2n(float x){\n    float stampInterval = u_Stamp.x;\n    int stampMode = int(u_Stamp.w);\n    if(stampMode == EquiDistance) return x / stampInterval;\n    if(stampMode == RatioDistance){\n      float L = distance(p0, p1);\n      if(r0 == r1) return x/(stampInterval*r0);\n      else return -L / stampInterval / (r0 - r1) * log(1.0 - (1.0 - r1/r0)/L * x);\n    }\n  }\n\n  float n2x(float n){\n    float stampInterval = u_Stamp.x;\n    int stampMode = int(u_Stamp.w);\n    if(stampMode == EquiDistance) return n * stampInterval;\n    if(stampMode == RatioDistance){\n      float L = distance(p0, p1);\n      if(r0 == r1) return n * stampInterval * r0;\n      else return L * (1.0-exp(-(r0-r1)*n*stampInterval/L)) / (1.0-r1/r0);\n    }\n  }\n\n  mat2 rotate(float angle){\n    return mat2(cos(angle), -sin(angle), sin(angle), cos(angle));\n  }\n\n  \n  \n  float random (in vec2 st) {\n    return fract(sin(dot(st.xy,\n                        vec2(12.9898,78.233)))*\n        43758.5453123);\n  }\n\n\n  // Based on Morgan McGuire @morgan3d\n  // https://www.shadertoy.com/view/4dS3Wd\n  float noise (in vec2 st) {\n    vec2 i = floor(st);\n    vec2 f = fract(st);\n\n    // Four corners in 2D of a tile\n    float a = random(i);\n    float b = random(i + vec2(1.0, 0.0));\n    float c = random(i + vec2(0.0, 1.0));\n    float d = random(i + vec2(1.0, 1.0));\n\n    vec2 u = f * f * (3.0 - 2.0 * f);\n\n    return mix(a, b, u.x) +\n            (c - a)* u.y * (1.0 - u.x) +\n            (d - b) * u.x * u.y;\n  }\n\n  #define OCTAVES 6\n  float fbm (in vec2 st) {\n    // Initial values\n    float value = 0.0;\n    float amplitude = .5;\n    float frequency = 0.;\n    //\n    // Loop of octaves\n    for (int i = 0; i < OCTAVES; i++) {\n        value += amplitude * noise(st);\n        st *= 2.;\n        amplitude *= .5;\n    }\n    return value;\n  }\n\n  \n  void main() {\n    float strokeWidth;\n    vec4 strokeColor;\n    float opacity;\n    float strokeOpacity;\n    float brushType;\n    \n    strokeColor = u_StrokeColor;\n    strokeWidth = u_ZIndexStrokeWidth.y;\n    brushType = u_ZIndexStrokeWidth.z;\n    opacity = u_Opacity.x;\n    strokeOpacity = u_Opacity.z;\n\n    vec2 tangent = normalize(p1 - p0);\n    vec2 normal = vec2(-tangent.y, tangent.x);\n\n    // The local coordinate orgin at p0, x axis along the tangent direct.\n    float len = distance(p1, p0);\n    vec2 pLocal = vec2(dot(p-p0, tangent), dot(p-p0, normal));\n    vec2 p0Local = vec2(0, 0);\n    vec2 p1Local = vec2(len, 0);\n\n    float cosTheta = (r0 - r1)/len;\n    float d0 = distance(p, p0);\n    float d0cos = pLocal.x / d0;\n    float d1 = distance(p, p1);\n    float d1cos = (pLocal.x - len) / d1;\n\n    // Remove corners\n    if(d0cos < cosTheta && d0 > r0) discard;\n    if(d1cos > cosTheta && d1 > r1) discard;\n    \n    vec4 color = strokeColor;\n\n    if (brushType < 0.5) {\n      // Vanilla brush\n      if(d0 < r0 && d1 < r1) discard;\n      float A = (d0 < r0 || d1 < r1) ? 1.0 - sqrt(1.0 - color.a) : color.a;\n      outputColor = vec4(color.rgb, A);\n      return;\n    } else if (brushType < 1.5) {\n      // Stamp brush\n      // The method here is not published yet, it should be explained in a 10min video.\n      // The footprint is a disk instead of a square.\n      // We set a quadratic polynomial to calculate the effect range, the range on polyline edge footprint can touch the current pixel.\n      // Two roots of the quadratic polynomial are the effectRangeFront and effectRangeBack.\n      // Formulas from SIGGRAPH 2022 Talk - A Fast & Robust Solution for Cubic & Higher-Order Polynomials\n      // The quadratic equation\n      float a, b, c, delta;\n      a = 1.0 - pow(cosTheta, 2.0);\n      b = 2.0 * (r0 * cosTheta - pLocal.x);\n      c = pow(pLocal.x, 2.0) + pow(pLocal.y, 2.0) - pow(r0, 2.0);\n      delta = pow(b, 2.0) - 4.0*a*c;\n      if(delta <= 0.0) discard; // This should never happen.\n      \n      // Solve the quadratic equation\n      // Need to learn how to solve a quadratic equation? Check this talk by Cem Yuksel:\n      // https://www.youtube.com/watch?v=ok0EZ0fBCMA\n      float tempMathBlock = b + sign(b) * sqrt(delta);\n      float x1 = -2.0 * c / tempMathBlock;\n      float x2 = -tempMathBlock / (2.0*a);\n      float effectRangeFront = x1 <= x2 ? x1 : x2;\n      float effectRangeBack = x1 > x2 ? x1 : x2;\n\n      float stampInterval = u_Stamp.x;\n      float noiseFactor = u_Stamp.y;\n      float rotationFactor = u_Stamp.z;\n\n      // With the distance to the polyline's first vertex, we can compute a \"stamp index\" value.\n      // which indicate the number of stamps from the first vertex to current point.\n      // We stamp on polyline every time the stamp index comes to an integer.\n      float index0 = l0/stampInterval; // The stamp index of vertex0.\n      float startIndex, endIndex;\n      if (effectRangeFront <= 0.0){\n          startIndex = ceil(index0);\n      }\n      else{\n          startIndex = ceil(index0 + x2n(effectRangeFront));\n      }\n      float index1 = l1/stampInterval;\n      float backIndex = x2n(effectRangeBack) + index0;\n      endIndex = index1 < backIndex ? index1 : backIndex;\n      if(startIndex > endIndex) discard;\n\n      // The main loop to sample and blend color from the footprint, from startIndex to endIndex\n      int MAX_i = 128; float currIndex = startIndex;\n      float A = 0.0;\n      for(int i = 0; i < MAX_i; i++){\n          float currStampLocalX = n2x(currIndex - index0);\n          // Apply roation and sample the footprint.\n          vec2 pToCurrStamp = pLocal - vec2(currStampLocalX, 0.0);\n          float currStampRadius = r0 - cosTheta * currStampLocalX;\n          float angle = rotationFactor*radians(360.0*fract(sin(currIndex)*1.0));\n          pToCurrStamp *= rotate(angle);\n          vec2 textureCoordinate = (pToCurrStamp/currStampRadius + 1.0)/2.0;\n\n          float opacity = 1.0;\n          #ifdef USE_FILLIMAGE\n            opacity = texture(SAMPLER_2D(u_Texture), textureCoordinate).a;\n          #endif\n          // Blend opacity.\n          float opacityNoise = noiseFactor*fbm(textureCoordinate*50.0);\n          opacity = clamp(opacity - opacityNoise, 0.0, 1.0) * color.a;\n          A = A * (1.0-opacity) + opacity;\n\n          currIndex += 1.0;\n          if(currIndex > endIndex) break;\n      }\n      if(A < 1e-4) discard;\n      outputColor = vec4(color.rgb, A);\n    }\n  \n    \n#ifdef USE_WIREFRAME\n  vec3 u_WireframeLineColor = vec3(0.0, 0.0, 0.0);\n\n  outputColor.xyz = mix(outputColor.xyz, u_WireframeLineColor, (1.0 - edgeFactor()));\n  if (any(lessThan(v_Barycentric, vec3(0.01)))) {\n    outputColor.a = 0.95;\n  }\n#endif\n\n  }\n  ";