PrusaSlicer-NonPlainar/resources/shaders/140/dashed_thick_lines.fs
2022-05-26 11:39:53 +02:00

33 lines
1.1 KiB
GLSL

#version 150
// see as reference: https://github.com/mhalber/Lines/blob/master/geometry_shader_lines.h
// https://stackoverflow.com/questions/52928678/dashed-line-in-opengl3
const float aa_radius = 0.5;
uniform float dash_size;
uniform float gap_size;
uniform vec4 uniform_color;
in float line_width;
in vec2 seg_params;
out vec4 out_color;
void main()
{
if (gap_size > 0.0 && fract(seg_params.y / (dash_size + gap_size)) > dash_size / (dash_size + gap_size))
discard;
// We render a quad that is fattened by r, giving total width of the line to be w+r. We want smoothing to happen
// around w, so that the edge is properly smoothed out. As such, in the smoothstep function we have:
// Far edge : 1.0 = (w+r) / (w+r)
// Close edge : 1.0 - (2r / (w+r)) = (w+r)/(w+r) - 2r/(w+r)) = (w-r) / (w+r)
// This way the smoothing is centered around 'w'.
out_color = uniform_color;
float inv_line_width = 1.0 / line_width;
float au = 1.0 - smoothstep(1.0 - (2.0 * aa_radius * inv_line_width), 1.0, abs(seg_params.x * inv_line_width));
out_color.a *= au;
}