export declare const heatmapVertexShaderSource = "\n    precision mediump float;\n    \n    attribute vec2 a_position;\n    attribute vec2 a_center;\n    attribute vec4 a_color;\n    attribute float a_saturation;\n\n    varying vec4 v_color;\n    varying vec2 v_pos;\n\n    uniform vec2 u_dimensions;\n    uniform vec2 u_resolution;\n    // https://tsev.dev/posts/2020-06-19-colour-correction-with-webgl/\n    vec3 adjust_saturation(vec3 color, float value) {\n      // https://www.w3.org/TR/WCAG22/#dfn-relative-luminance\n      const vec3 luminosityFactor = vec3(0.2126, 0.7152, 0.0722);\n      vec3 grayscale = vec3(dot(color, luminosityFactor));\n\n      return mix(grayscale, color, 1.0 + value);\n    }\n\n    void main() {\n      // Convert from pixels to clip space (-1 to 1)\n      vec2 position = a_center + a_position * u_dimensions / 2.0;\n      vec2 clipSpace = (position / u_resolution) * 2.0 - 1.0;\n      gl_Position = vec4(clipSpace * vec2(1, -1), 0, 1);\n\n      v_color = vec4(adjust_saturation(a_color.rgb, a_saturation), 1.0);\n      v_pos = a_position * u_dimensions / 2.0;\n    }\n  ";
export declare const heatmapFragmentShaderSourceNoBorderRadius = "\n    precision mediump float;\n\n    varying vec4 v_color;\n\n    void main() {\n      gl_FragColor = v_color;\n    }\n  ";
export declare const heatmapFragmentShaderSourceWithBorderRadius = "\n    precision mediump float;\n\n    varying vec4 v_color;\n    varying vec2 v_pos;\n\n    uniform vec2 u_dimensions;\n    uniform float u_borderRadius;\n\n    \n    float roundedBoxSDF(vec2 pos, vec2 halfSize, vec4 r) {\n      float radius;\n      if (pos.x < 0.0) {\n        radius = pos.y < 0.0 ? r.x : r.w;\n      } else {\n        radius = pos.y < 0.0 ? r.y : r.z;\n      }\n\n      vec2 q = abs(pos) - halfSize + radius;\n      return min(max(q.x, q.y), 0.0) + length(max(q, 0.0)) - radius;\n    }\n  \n\n    void main() {\n      // Calculate distance from rounded rectangle edge\n      float dist = roundedBoxSDF(v_pos, u_dimensions / 2.0, vec4(u_borderRadius));\n\n      // Create smooth alpha based on distance\n      float alpha = 1.0 - smoothstep(-0.5, 0.5, dist);\n\n      gl_FragColor = vec4(v_color.rgb, v_color.a * alpha);\n    }\n  ";