46 lines
1.1 KiB
GLSL
46 lines
1.1 KiB
GLSL
#version 300 es
|
|
|
|
precision mediump float;
|
|
|
|
|
|
#define INFINITY 10000.0
|
|
#define LINE_COUNT 50
|
|
|
|
|
|
uniform vec2[LINE_COUNT * 2] lines;
|
|
uniform float[LINE_COUNT * 2] radii;
|
|
|
|
float lineDistance(
|
|
in vec2 target,
|
|
in vec2 start,
|
|
in vec2 end,
|
|
in float radiusFrom,
|
|
in float radiusTo
|
|
) {
|
|
vec2 pa = target - start, ba = end - start;
|
|
float h = clamp(dot(pa, ba) / dot(ba, ba), 0.0, 1.0);
|
|
return distance(pa, ba * h) - mix(radiusFrom, radiusTo, smoothstep(0.0, 1.0, h));
|
|
}
|
|
|
|
float getDistance(in vec2 target) {
|
|
float minDistance = INFINITY;
|
|
|
|
for (int i = 0; i < LINE_COUNT; i++) {
|
|
vec2 start = lines[2 * i];
|
|
vec2 end = lines[2 * i + 1];
|
|
float rFrom = radii[2 * i];
|
|
float rTo = radii[2 * i + 1];
|
|
minDistance = min(minDistance, lineDistance(target, start, end, rFrom, rTo));
|
|
}
|
|
|
|
return -minDistance;
|
|
}
|
|
|
|
uniform mat3 distanceScreenToWorld;
|
|
out vec4 fragmentColor;
|
|
|
|
void main() {
|
|
vec2 position = (vec3(gl_FragCoord.xy, 1.0) * distanceScreenToWorld).xy;
|
|
float distance = getDistance(position);
|
|
fragmentColor = vec4(vec3(0.0), distance / 256.0 + 0.5);
|
|
}
|