KlassischeKeplerKriege/data/shader/particle.frag
2016-10-05 23:26:55 +02:00

49 lines
1.2 KiB
GLSL

#version 120
varying vec2 vertex;
varying vec3 velocity;
varying float decay;
varying float explCenterDist;
float pi = 3.14159;
vec3 hsv2rgb(vec3 c)
{
vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
}
float hash(float n)
{
return fract(sin(n)*43758.5453);
}
void main()
{
// normalize radius from 0..1
vec2 vn = 2.0*vertex;
float rn = length(vn);
float angle = atan(vn.y, vn.x);
float hs = 20.0;
float removeCorners = 0.5 * (hash(fract(hs*vertex.x)) + hash(fract(hs*vertex.y)));
if (rn+removeCorners > 1.0) {
discard;
}
//float rf = 0.5-0.5*rn;
float rf = 1.0;
float d = decay/(1.0+max(0.0, 1.0-2.0*explCenterDist));
float h = max(0.0, (1.0-d)/6.0) * rf;
float v = max(0.0, (1.0-log(d)));
float s = max(0.0, min(30.0 * sqrt(decay) * explCenterDist, 1.0));
//v /= 1.0 + max(0.0, min(35.0*(decay-0.2), 1.0)) + 10.0 * explCenterDist;
v /= 1.0 + 10.0 * explCenterDist;
gl_FragColor = vec4(hsv2rgb(vec3(h, s, v)), v*0.2);
//gl_FragColor = vec4(1.0, 1.0, 0.0, 1.0);
//gl_FragColor.rgb = vec3(0.5+0.5*(a/pi));
}