MapLibreParticleLab/src/mbgl/shaders/symbol_sdf.cpp

// NOTE: DO NOT CHANGE THIS FILE. IT IS AUTOMATICALLY GENERATED.

#include <mbgl/shaders/symbol_sdf.hpp>

namespace mbgl {
namespace shaders {

const char* symbol_sdf::name = "symbol_sdf";
const char* symbol_sdf::vertexSource = R"MBGL_SHADER(
#ifdef GL_ES
precision highp float;
#else

#if !defined(lowp)
#define lowp
#endif

#if !defined(mediump)
#define mediump
#endif

#if !defined(highp)
#define highp
#endif

#endif

float evaluate_zoom_function_1(const vec4 values, const float t) {
    if (t < 1.0) {
        return mix(values[0], values[1], t);
    } else if (t < 2.0) {
        return mix(values[1], values[2], t - 1.0);
    } else {
        return mix(values[2], values[3], t - 2.0);
    }
}
vec4 evaluate_zoom_function_4(const vec4 value0, const vec4 value1, const vec4 value2, const vec4 value3, const float t) {
    if (t < 1.0) {
        return mix(value0, value1, t);
    } else if (t < 2.0) {
        return mix(value1, value2, t - 1.0);
    } else {
        return mix(value2, value3, t - 2.0);
    }
}

// The offset depends on how many pixels are between the world origin and the edge of the tile:
// vec2 offset = mod(pixel_coord, size)
//
// At high zoom levels there are a ton of pixels between the world origin and the edge of the tile.
// The glsl spec only guarantees 16 bits of precision for highp floats. We need more than that.
//
// The pixel_coord is passed in as two 16 bit values:
// pixel_coord_upper = floor(pixel_coord / 2^16)
// pixel_coord_lower = mod(pixel_coord, 2^16)
//
// The offset is calculated in a series of steps that should preserve this precision:
vec2 get_pattern_pos(const vec2 pixel_coord_upper, const vec2 pixel_coord_lower,
    const vec2 pattern_size, const float tile_units_to_pixels, const vec2 pos) {

    vec2 offset = mod(mod(mod(pixel_coord_upper, pattern_size) * 256.0, pattern_size) * 256.0 + pixel_coord_lower, pattern_size);
    return (tile_units_to_pixels * pos + offset) / pattern_size;
}
const float PI = 3.141592653589793;

attribute vec2 a_pos;
attribute vec2 a_offset;
attribute vec2 a_texture_pos;
attribute vec4 a_data;


// matrix is for the vertex position.
uniform mat4 u_matrix;

uniform mediump float u_zoom;
uniform bool u_rotate_with_map;
uniform bool u_pitch_with_map;
uniform mediump float u_pitch;
uniform mediump float u_bearing;
uniform mediump float u_aspect_ratio;
uniform vec2 u_extrude_scale;

uniform vec2 u_texsize;

varying vec2 v_tex;
varying vec2 v_fade_tex;
varying float v_gamma_scale;

void main() {
    vec2 a_tex = a_texture_pos.xy;
    mediump float a_labelminzoom = a_data[0];
    mediump vec2 a_zoom = a_data.pq;
    mediump float a_minzoom = a_zoom[0];
    mediump float a_maxzoom = a_zoom[1];

    // u_zoom is the current zoom level adjusted for the change in font size
    mediump float z = 2.0 - step(a_minzoom, u_zoom) - (1.0 - step(a_maxzoom, u_zoom));

    // pitch-alignment: map
    // rotation-alignment: map | viewport
    if (u_pitch_with_map) {
        lowp float angle = u_rotate_with_map ? (a_data[1] / 256.0 * 2.0 * PI) : u_bearing;
        lowp float asin = sin(angle);
        lowp float acos = cos(angle);
        mat2 RotationMatrix = mat2(acos, asin, -1.0 * asin, acos);
        vec2 offset = RotationMatrix * a_offset;
        vec2 extrude = u_extrude_scale * (offset / 64.0);
        gl_Position = u_matrix * vec4(a_pos + extrude, 0, 1);
        gl_Position.z += z * gl_Position.w;
    // pitch-alignment: viewport
    // rotation-alignment: map
    } else if (u_rotate_with_map) {
        // foreshortening factor to apply on pitched maps
        // as a label goes from horizontal <=> vertical in angle
        // it goes from 0% foreshortening to up to around 70% foreshortening
        lowp float pitchfactor = 1.0 - cos(u_pitch * sin(u_pitch * 0.75));

        lowp float lineangle = a_data[1] / 256.0 * 2.0 * PI;

        // use the lineangle to position points a,b along the line
        // project the points and calculate the label angle in projected space
        // this calculation allows labels to be rendered unskewed on pitched maps
        vec4 a = u_matrix * vec4(a_pos, 0, 1);
        vec4 b = u_matrix * vec4(a_pos + vec2(cos(lineangle),sin(lineangle)), 0, 1);
        lowp float angle = atan((b[1]/b[3] - a[1]/a[3])/u_aspect_ratio, b[0]/b[3] - a[0]/a[3]);
        lowp float asin = sin(angle);
        lowp float acos = cos(angle);
        mat2 RotationMatrix = mat2(acos, -1.0 * asin, asin, acos);

        vec2 offset = RotationMatrix * (vec2((1.0-pitchfactor)+(pitchfactor*cos(angle*2.0)), 1.0) * a_offset);
        vec2 extrude = u_extrude_scale * (offset / 64.0);
        gl_Position = u_matrix * vec4(a_pos, 0, 1) + vec4(extrude, 0, 0);
        gl_Position.z += z * gl_Position.w;
    // pitch-alignment: viewport
    // rotation-alignment: viewport
    } else {
        vec2 extrude = u_extrude_scale * (a_offset / 64.0);
        gl_Position = u_matrix * vec4(a_pos, 0, 1) + vec4(extrude, 0, 0);
    }

    v_gamma_scale = gl_Position.w;

    v_tex = a_tex / u_texsize;
    v_fade_tex = vec2(a_labelminzoom / 255.0, 0.0);
}

)MBGL_SHADER";
const char* symbol_sdf::fragmentSource = R"MBGL_SHADER(
#ifdef GL_ES
precision mediump float;
#else

#if !defined(lowp)
#define lowp
#endif

#if !defined(mediump)
#define mediump
#endif

#if !defined(highp)
#define highp
#endif

#endif
uniform sampler2D u_texture;
uniform sampler2D u_fadetexture;
uniform lowp vec4 u_color;
uniform lowp float u_opacity;
uniform lowp float u_buffer;
uniform highp float u_gamma;

varying vec2 v_tex;
varying vec2 v_fade_tex;
varying float v_gamma_scale;

void main() {
    lowp float dist = texture2D(u_texture, v_tex).a;
    lowp float fade_alpha = texture2D(u_fadetexture, v_fade_tex).a;
    highp float gamma = u_gamma * v_gamma_scale;
    highp float alpha = smoothstep(u_buffer - gamma, u_buffer + gamma, dist) * fade_alpha;

    gl_FragColor = u_color * (alpha * u_opacity);

#ifdef OVERDRAW_INSPECTOR
    gl_FragColor = vec4(1.0);
#endif
}

)MBGL_SHADER";

} // namespace shaders
} // namespace mbgl