59 lines
1.9 KiB
GLSL
59 lines
1.9 KiB
GLSL
#define SDF_PX 8.0
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uniform bool u_is_halo;
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uniform sampler2D u_texture;
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uniform highp float u_gamma_scale;
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uniform lowp float u_device_pixel_ratio;
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uniform bool u_is_text;
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in vec2 v_data0;
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in vec3 v_data1;
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#pragma mapbox: define highp vec4 fill_color
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#pragma mapbox: define highp vec4 halo_color
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#pragma mapbox: define lowp float opacity
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#pragma mapbox: define lowp float halo_width
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#pragma mapbox: define lowp float halo_blur
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void main() {
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#pragma mapbox: initialize highp vec4 fill_color
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#pragma mapbox: initialize highp vec4 halo_color
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#pragma mapbox: initialize lowp float opacity
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#pragma mapbox: initialize lowp float halo_width
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#pragma mapbox: initialize lowp float halo_blur
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float EDGE_GAMMA = 0.105 / u_device_pixel_ratio;
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vec2 tex = v_data0.xy;
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float gamma_scale = v_data1.x;
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float size = v_data1.y;
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float fade_opacity = v_data1[2];
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float fontScale = u_is_text ? size / 24.0 : size;
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lowp vec4 color = fill_color;
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highp float gamma = EDGE_GAMMA / (fontScale * u_gamma_scale);
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lowp float inner_edge = (256.0 - 64.0) / 256.0;
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if (u_is_halo) {
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color = halo_color;
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gamma = (halo_blur * 1.19 / SDF_PX + EDGE_GAMMA) / (fontScale * u_gamma_scale);
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inner_edge = inner_edge + gamma * gamma_scale;
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}
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lowp float dist = texture(u_texture, tex).a;
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highp float gamma_scaled = gamma * gamma_scale;
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highp float alpha = smoothstep(inner_edge - gamma_scaled, inner_edge + gamma_scaled, dist);
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if (u_is_halo) {
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// When drawing halos, we want the inside of the halo to be transparent as well
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// in case the text fill is transparent.
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lowp float halo_edge = (6.0 - halo_width / fontScale) / SDF_PX;
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alpha = min(smoothstep(halo_edge - gamma_scaled, halo_edge + gamma_scaled, dist), 1.0 - alpha);
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}
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fragColor = color * (alpha * opacity * fade_opacity);
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#ifdef OVERDRAW_INSPECTOR
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fragColor = vec4(1.0);
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#endif
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}
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