Files
MapLibreParticleLab/shaders/drawable.line_gradient.fragment.glsl
Alex Cristici 9fbcb031f0 Line layer UBO improvements (#1946)
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
2023-12-12 19:32:20 +02:00

62 lines
1.6 KiB
GLSL

layout (std140) uniform LineGradientUBO {
highp mat4 u_matrix;
mediump float u_ratio;
lowp float pad2, pad3, pad4;
};
layout (std140) uniform LineGradientPropertiesUBO {
lowp float u_blur;
lowp float u_opacity;
mediump float u_gapwidth;
lowp float u_offset;
mediump float u_width;
highp float pad5;
highp vec2 pad6;
};
layout (std140) uniform LineGradientInterpolationUBO {
lowp float u_blur_t;
lowp float u_opacity_t;
lowp float u_gapwidth_t;
lowp float u_offset_t;
lowp float u_width_t;
highp float pad7;
highp vec2 pad8;
};
uniform sampler2D u_image;
in vec2 v_width2;
in vec2 v_normal;
in float v_gamma_scale;
in highp float v_lineprogress;
#pragma mapbox: define lowp float blur
#pragma mapbox: define lowp float opacity
void main() {
#pragma mapbox: initialize lowp float blur
#pragma mapbox: initialize lowp float opacity
// 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);
// For gradient lines, v_lineprogress is the ratio along the entire line,
// scaled to [0, 2^15), and the gradient ramp is stored in a texture.
vec4 color = texture(u_image, vec2(v_lineprogress, 0.5));
fragColor = color * (alpha * opacity);
#ifdef OVERDRAW_INSPECTOR
fragColor = vec4(1.0);
#endif
}