6b67cfe63f
This is primarily done to lower the GTK version dependency below GTK 3.22, since GTK 3.22 is unlikely to be widely availale any time soon.
42 lines
1.2 KiB
GLSL
42 lines
1.2 KiB
GLSL
//-----------------------------------------------------------------------------
|
|
// Edge rendering shader
|
|
//
|
|
// Copyright 2016 Aleksey Egorov
|
|
//-----------------------------------------------------------------------------
|
|
const float feather = 0.5;
|
|
|
|
attribute vec3 pos;
|
|
attribute vec3 loc;
|
|
attribute vec3 tan;
|
|
|
|
uniform mat4 modelview;
|
|
uniform mat4 projection;
|
|
uniform float width;
|
|
uniform float pixel;
|
|
|
|
varying vec3 fragLoc;
|
|
|
|
void main() {
|
|
// get camera direction from modelview matrix
|
|
vec3 dir = vec3(modelview[0].z, modelview[1].z, modelview[2].z);
|
|
|
|
// calculate line contour extension basis for constant width and caps
|
|
vec3 norm = normalize(cross(tan, dir));
|
|
norm = normalize(norm - dir * dot(dir, norm));
|
|
vec3 perp = normalize(cross(dir, norm));
|
|
|
|
// calculate line extension width considering antialiasing
|
|
float ext = width + feather * pixel;
|
|
|
|
// extend line contour
|
|
vec3 vertex = pos;
|
|
vertex += ext * loc.x * normalize(perp);
|
|
vertex += ext * loc.y * normalize(norm);
|
|
|
|
// write fragment location for calculating caps and antialiasing
|
|
fragLoc = loc;
|
|
|
|
// transform resulting vertex with modelview and projection matrices
|
|
gl_Position = projection * modelview * vec4(vertex, 1.0);
|
|
}
|