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Diffstat (limited to 'src/mbgl/shaders/line_sdf.hpp')
| -rw-r--r-- | src/mbgl/shaders/line_sdf.hpp | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/src/mbgl/shaders/line_sdf.hpp b/src/mbgl/shaders/line_sdf.hpp new file mode 100644 index 0000000000..473a6ab650 --- /dev/null +++ b/src/mbgl/shaders/line_sdf.hpp @@ -0,0 +1,242 @@ +#pragma once + +// NOTE: DO NOT CHANGE THIS FILE. IT IS AUTOMATICALLY GENERATED. + +#include <mbgl/gl/gl.hpp> + +namespace mbgl { +namespace shaders { + +class line_sdf { +public: + static constexpr const char* name = "line_sdf"; + static constexpr const char* 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; +} +// floor(127 / 2) == 63.0 +// the maximum allowed miter limit is 2.0 at the moment. the extrude normal is +// stored in a byte (-128..127). we scale regular normals up to length 63, but +// there are also "special" normals that have a bigger length (of up to 126 in +// this case). +// #define scale 63.0 +#define scale 0.015873016 + +// We scale the distance before adding it to the buffers so that we can store +// long distances for long segments. Use this value to unscale the distance. +#define LINE_DISTANCE_SCALE 2.0 + +// the distance over which the line edge fades out. +// Retina devices need a smaller distance to avoid aliasing. +#define ANTIALIASING 1.0 / DEVICE_PIXEL_RATIO / 2.0 + +attribute vec2 a_pos; +attribute vec4 a_data; + +uniform mat4 u_matrix; +uniform mediump float u_ratio; +uniform vec2 u_patternscale_a; +uniform float u_tex_y_a; +uniform vec2 u_patternscale_b; +uniform float u_tex_y_b; +uniform vec2 u_gl_units_to_pixels; +uniform mediump float u_width; + +varying vec2 v_normal; +varying vec2 v_width2; +varying vec2 v_tex_a; +varying vec2 v_tex_b; +varying float v_gamma_scale; + +uniform lowp float a_color_t; +attribute lowp vec4 a_color_min; +attribute lowp vec4 a_color_max; +varying lowp vec4 color; +uniform lowp float a_blur_t; +attribute lowp float a_blur_min; +attribute lowp float a_blur_max; +varying lowp float blur; +uniform lowp float a_opacity_t; +attribute lowp float a_opacity_min; +attribute lowp float a_opacity_max; +varying lowp float opacity; +uniform lowp float a_gapwidth_t; +attribute mediump float a_gapwidth_min; +attribute mediump float a_gapwidth_max; +varying mediump float gapwidth; +uniform lowp float a_offset_t; +attribute lowp float a_offset_min; +attribute lowp float a_offset_max; +varying lowp float offset; + +void main() { + color = mix(a_color_min, a_color_max, a_color_t); + blur = mix(a_blur_min, a_blur_max, a_blur_t); + opacity = mix(a_opacity_min, a_opacity_max, a_opacity_t); + gapwidth = mix(a_gapwidth_min, a_gapwidth_max, a_gapwidth_t); + offset = mix(a_offset_min, a_offset_max, a_offset_t); + + vec2 a_extrude = a_data.xy - 128.0; + float a_direction = mod(a_data.z, 4.0) - 1.0; + float a_linesofar = (floor(a_data.z / 4.0) + a_data.w * 64.0) * LINE_DISTANCE_SCALE; + + // We store the texture normals in the most insignificant bit + // transform y so that 0 => -1 and 1 => 1 + // In the texture normal, x is 0 if the normal points straight up/down and 1 if it's a round cap + // y is 1 if the normal points up, and -1 if it points down + mediump vec2 normal = mod(a_pos, 2.0); + normal.y = sign(normal.y - 0.5); + v_normal = normal; + + // these transformations used to be applied in the JS and native code bases. + // moved them into the shader for clarity and simplicity. + gapwidth = gapwidth / 2.0; + float width = u_width / 2.0; + offset = -1.0 * offset; + + float inset = gapwidth + (gapwidth > 0.0 ? ANTIALIASING : 0.0); + float outset = gapwidth + width * (gapwidth > 0.0 ? 2.0 : 1.0) + ANTIALIASING; + + // Scale the extrusion vector down to a normal and then up by the line width + // of this vertex. + mediump vec2 dist =outset * a_extrude * scale; + + // Calculate the offset when drawing a line that is to the side of the actual line. + // We do this by creating a vector that points towards the extrude, but rotate + // it when we're drawing round end points (a_direction = -1 or 1) since their + // extrude vector points in another direction. + mediump float u = 0.5 * a_direction; + mediump float t = 1.0 - abs(u); + mediump vec2 offset2 = offset * a_extrude * scale * normal.y * mat2(t, -u, u, t); + + // Remove the texture normal bit to get the position + vec2 pos = floor(a_pos * 0.5); + + vec4 projected_extrude = u_matrix * vec4(dist / u_ratio, 0.0, 0.0); + gl_Position = u_matrix * vec4(pos + offset2 / u_ratio, 0.0, 1.0) + projected_extrude; + + // calculate how much the perspective view squishes or stretches the extrude + float extrude_length_without_perspective = length(dist); + float extrude_length_with_perspective = length(projected_extrude.xy / gl_Position.w * u_gl_units_to_pixels); + v_gamma_scale = extrude_length_without_perspective / extrude_length_with_perspective; + + v_tex_a = vec2(a_linesofar * u_patternscale_a.x, normal.y * u_patternscale_a.y + u_tex_y_a); + v_tex_b = vec2(a_linesofar * u_patternscale_b.x, normal.y * u_patternscale_b.y + u_tex_y_b); + + v_width2 = vec2(outset, inset); +} +)MBGL_SHADER"; + static constexpr const char* 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_image; +uniform float u_sdfgamma; +uniform float u_mix; + +varying vec2 v_normal; +varying vec2 v_width2; +varying vec2 v_tex_a; +varying vec2 v_tex_b; +varying float v_gamma_scale; + +varying lowp vec4 color; +varying lowp float blur; +varying lowp float opacity; + +void main() { + + + + + // Calculate the distance of the pixel from the line in pixels. + float dist = length(v_normal) * v_width2.s; + + // Calculate the antialiasing fade factor. This is either when fading in + // the line in case of an offset line (v_width2.t) or when fading out + // (v_width2.s) + float blur2 = (blur + 1.0 / DEVICE_PIXEL_RATIO) * v_gamma_scale; + float alpha = clamp(min(dist - (v_width2.t - blur2), v_width2.s - dist) / blur2, 0.0, 1.0); + + float sdfdist_a = texture2D(u_image, v_tex_a).a; + float sdfdist_b = texture2D(u_image, v_tex_b).a; + float sdfdist = mix(sdfdist_a, sdfdist_b, u_mix); + alpha *= smoothstep(0.5 - u_sdfgamma, 0.5 + u_sdfgamma, sdfdist); + + gl_FragColor = color * (alpha * opacity); + +#ifdef OVERDRAW_INSPECTOR + gl_FragColor = vec4(1.0); +#endif +} +)MBGL_SHADER"; +}; + +} // namespace shaders +} // namespace mbgl |