text: // NOTE: DO NOT CHANGE THIS FILE. IT IS AUTOMATICALLY GENERATED.
  
  #include <mbgl/shaders/collision_circle.hpp>
  
  namespace mbgl {
  namespace shaders {
  
  const char* collision_circle::name = "collision_circle";
  const char* collision_circle::vertexSource = R"MBGL_SHADER(
  attribute vec2 a_pos;
  attribute vec2 a_anchor_pos;
  attribute vec2 a_extrude;
  attribute vec2 a_placed;
  
  uniform mat4 u_matrix;
  uniform vec2 u_extrude_scale;
  uniform float u_camera_to_center_distance;
  
  varying float v_placed;
  varying float v_notUsed;
  varying float v_radius;
  
  varying vec2 v_extrude;
  varying vec2 v_extrude_scale;
  
  void main() {
      vec4 projectedPoint = u_matrix * vec4(a_anchor_pos, 0, 1);
      highp float camera_to_anchor_distance = projectedPoint.w;
      highp float collision_perspective_ratio = clamp(
          0.5 + 0.5 * (u_camera_to_center_distance / camera_to_anchor_distance),
          0.0, // Prevents oversized near-field circles in pitched/overzoomed tiles
          4.0);
  
      gl_Position = u_matrix * vec4(a_pos, 0.0, 1.0);
  
      highp float padding_factor = 1.2; // Pad the vertices slightly to make room for anti-alias blur
      gl_Position.xy += a_extrude * u_extrude_scale * padding_factor * gl_Position.w * collision_perspective_ratio;
  
      v_placed = a_placed.x;
      v_notUsed = a_placed.y;
      v_radius = abs(a_extrude.y); // We don't pitch the circles, so both units of the extrusion vector are equal in magnitude to the radius
  
      v_extrude = a_extrude * padding_factor;
      v_extrude_scale = u_extrude_scale * u_camera_to_center_distance * collision_perspective_ratio;
  }
  
  )MBGL_SHADER";
  const char* collision_circle::fragmentSource = R"MBGL_SHADER(
  uniform float u_overscale_factor;
  
  varying float v_placed;
  varying float v_notUsed;
  varying float v_radius;
  varying vec2 v_extrude;
  varying vec2 v_extrude_scale;
  
  void main() {
      float alpha = 0.5;
  
      // Red = collision, hide label
      vec4 color = vec4(1.0, 0.0, 0.0, 1.0) * alpha;
  
      // Blue = no collision, label is showing
      if (v_placed > 0.5) {
          color = vec4(0.0, 0.0, 1.0, 0.5) * alpha;
      }
  
      if (v_notUsed > 0.5) {
          // This box not used, fade it out
          color *= .2;
      }
  
      float extrude_scale_length = length(v_extrude_scale);
      float extrude_length = length(v_extrude) * extrude_scale_length;
      float stroke_width = 15.0 * extrude_scale_length / u_overscale_factor;
      float radius = v_radius * extrude_scale_length;
  
      float distance_to_edge = abs(extrude_length - radius);
      float opacity_t = smoothstep(-stroke_width, 0.0, -distance_to_edge);
  
      gl_FragColor = opacity_t * color;
  }
  
  )MBGL_SHADER";
  
  } // namespace shaders
  } // namespace mbgl
  