CPP-PPRasteriser/shaders/fragment.glsl
2025-09-25 19:48:40 +01:00

100 lines
2.5 KiB
GLSL

#version 410 core
#ifdef GL_ES
precision mediump float;
#endif
out vec4 FragColor; // Output to screen
uniform vec2 u_resolution; // <-- screen resolution from CPU
uniform float u_time; // <-- time from CPU
uniform float u_oscilator; // <-- oscislator from CPU
uniform float u_direction; // <-- direction from CPU
vec3 hsv2rgb(vec3 c) {
vec3 rgb = clamp(
abs(mod(c.x*6.0 + vec3(0.0,4.0,2.0),
6.0) - 3.0) - 1.0,
0.0,
1.0
);
return c.z * mix(vec3(1.0), rgb, c.y);
}
vec3 getPaletteColor(float idx, float seed) {
float baseHue = fract(seed); // 0..1 base hue
float sat = 0.9;
float val = 0.9;
// Shift hue across palette (idx ensures difference)
float hue = fract(baseHue + (idx * 0.33));
return hsv2rgb(vec3(hue, sat, val));
}
vec2 random(vec2 p) {
return normalize(vec2(
fract(sin(dot(p, vec2(127.1, 311.7))) * 43758.5453),
fract(sin(dot(p, vec2(269.5, 183.3))) * 43758.5453)
) * 2.0 - 1.0);
}
int randomInt(int x, int y) {
return int(fract(sin(float(x * 12 + y * 78)) * 43758.5453) * 256.0);
}
float perlinNoise(vec2 st) {
vec2 i = floor(st);
vec2 f = fract(st);
// Corners
vec2 g00 = random(i + vec2(0.0,0.0));
vec2 g10 = random(i + vec2(1.0,0.0));
vec2 g01 = random(i + vec2(0.0,1.0));
vec2 g11 = random(i + vec2(1.0,1.0));
// Offsets
float n00 = dot(g00, f - vec2(0.0,0.0));
float n10 = dot(g10, f - vec2(1.0,0.0));
float n01 = dot(g01, f - vec2(0.0,1.0));
float n11 = dot(g11, f - vec2(1.0,1.0));
// Interpolation
vec2 u = f*f*(3.0-2.0*f);
return mix(mix(n00, n10, u.x), mix(n01, n11, u.x), u.y);
}
mat2 rotate2d(float angle){
return mat2(cos(angle),-sin(angle),
sin(angle),cos(angle));
}
void main() {
vec2 st = gl_FragCoord.xy / u_resolution; // Normalize coordinates
st += 13.0 + (u_oscilator * 0.001); // Center the coordinates
vec2 pos = st * (3.0);
pos = rotate2d(perlinNoise(pos)) * pos;
pos -= (u_time * (float(u_oscilator) * 0.5) * 0.2);
float n = perlinNoise(pos);
vec3 color;
if (n > 0.4) {
color = vec3((n + 0.4), (n + 0.4), (n + 0.4));
// color = getPaletteColor(u_oscilator, (n + 0.5));
} else if (n > 0.1) {
color = vec3(n + 0.5, n + 0.1 , 0.0);
// color = getPaletteColor(u_oscilator + 1, (n + 0.5));
} else {
color = vec3(n + 0.05, n + 0.05, n + 0.05);
// color = getPaletteColor(u_oscilator + 2, (n + 0.5));
// color = vec3(0.0);
}
FragColor = vec4(color, 1.0);
}