collision_circle.hpp

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// Generated code, do not modify this file!
// Generated on 2023-04-05T16:25:15.886Z by mwilsnd using shaders/generate_shader_code.js
 
#pragma once
#include <mbgl/shaders/shader_source.hpp>
 
namespace mbgl {
namespace shaders {
 
template <> struct ShaderSource<BuiltIn::CollisionCircleProgram, gfx::Backend::Type::OpenGL> {
    static constexpr const char* vertex = R"(layout (location = 0) in vec2 a_pos;
layout (location = 1) in vec2 a_anchor_pos;
layout (location = 2) in vec2 a_extrude;
layout (location = 3) in vec2 a_placed;
 
uniform mat4 u_matrix;
uniform vec2 u_extrude_scale;
uniform float u_camera_to_center_distance;
 
out float v_placed;
out float v_notUsed;
out float v_radius;
out vec2 v_extrude;
out 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;
}
)";
    static constexpr const char* fragment = R"(uniform float u_overscale_factor;
 
in float v_placed;
in float v_notUsed;
in float v_radius;
in vec2 v_extrude;
in 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);
 
    fragColor = opacity_t * color;
}
)";
};
 
} // namespace shaders
} // namespace mbgl