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

#include <mbgl/shaders/raster.hpp>

namespace mbgl {
namespace shaders {

const char* raster::name = "raster";
const char* raster::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;
}
uniform mat4 u_matrix;
uniform vec2 u_tl_parent;
uniform float u_scale_parent;
uniform float u_buffer_scale;

attribute vec2 a_pos;
attribute vec2 a_texture_pos;

varying vec2 v_pos0;
varying vec2 v_pos1;

void main() {
    gl_Position = u_matrix * vec4(a_pos, 0, 1);
    v_pos0 = (((a_texture_pos / 32767.0) - 0.5) / u_buffer_scale ) + 0.5;
    v_pos1 = (v_pos0 * u_scale_parent) + u_tl_parent;
}

)MBGL_SHADER";
const char* raster::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 float u_fade_t;
uniform float u_opacity;
uniform sampler2D u_image0;
uniform sampler2D u_image1;
varying vec2 v_pos0;
varying vec2 v_pos1;

uniform float u_brightness_low;
uniform float u_brightness_high;

uniform float u_saturation_factor;
uniform float u_contrast_factor;
uniform vec3 u_spin_weights;

void main() {

    // read and cross-fade colors from the main and parent tiles
    vec4 color0 = texture2D(u_image0, v_pos0);
    vec4 color1 = texture2D(u_image1, v_pos1);
    vec4 color = mix(color0, color1, u_fade_t);
    color.a *= u_opacity;
    vec3 rgb = color.rgb;

    // spin
    rgb = vec3(
        dot(rgb, u_spin_weights.xyz),
        dot(rgb, u_spin_weights.zxy),
        dot(rgb, u_spin_weights.yzx));

    // saturation
    float average = (color.r + color.g + color.b) / 3.0;
    rgb += (average - rgb) * u_saturation_factor;

    // contrast
    rgb = (rgb - 0.5) * u_contrast_factor + 0.5;

    // brightness
    vec3 u_high_vec = vec3(u_brightness_low, u_brightness_low, u_brightness_low);
    vec3 u_low_vec = vec3(u_brightness_high, u_brightness_high, u_brightness_high);

    gl_FragColor = vec4(mix(u_high_vec, u_low_vec, rgb) * color.a, color.a);

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

)MBGL_SHADER";

} // namespace shaders
} // namespace mbgl