diff options
Diffstat (limited to 'shaders/post/ripple.glsl')
| -rw-r--r-- | shaders/post/ripple.glsl | 52 |
1 files changed, 0 insertions, 52 deletions
diff --git a/shaders/post/ripple.glsl b/shaders/post/ripple.glsl deleted file mode 100644 index 3236d339..00000000 --- a/shaders/post/ripple.glsl +++ /dev/null @@ -1,52 +0,0 @@ -// Ripple: the page as a still pool a slow swell crosses. Rings travel out -// from the middle of the window at a fixed speed in pixels, so they look -// the same at any size and frame rate; at the default level the displacement -// is at most a couple of pixels, so text stays readable, and it eases in over its first half -// second instead of snapping on. Each ring catches the light a little on its -// rising side, in linear light, and the result is dithered so the shading -// never bands. It is a Shadertoy file: pardes puts its prefix before it. - -const float TAU = 6.28318530718; -const float EASE_IN = 0.5; // seconds - -// Each at levels 1, 2 and 3 (`Ripple 1`..`Ripple 3`); 2 is the default. -float wavelengthPx() { return pardesByLevel(170.0, 150.0, 120.0); } -float speedPx() { return pardesByLevel(40.0, 55.0, 80.0); } // outward, per second -float amplitudePx() { return pardesByLevel(1.2, 2.2, 5.0); } -float shade() { return pardesByLevel(0.02, 0.035, 0.09); } // light on a slope, linear -float reachEnd() { return pardesByLevel(0.85, 0.95, 1.3); } // how far out it dies away - -vec3 toLinear(vec3 c) { - return mix(pow((c + 0.055) / 1.055, vec3(2.4)), c / 12.92, lessThanEqual(c, vec3(0.04045))); -} - -vec3 toSrgb(vec3 c) { - c = max(c, vec3(0.0)); - return mix(1.055 * pow(c, vec3(1.0 / 2.4)) - 0.055, c * 12.92, lessThanEqual(c, vec3(0.0031308))); -} - -float ign(vec2 p) { - return fract(52.9829189 * fract(dot(p, vec2(0.06711056, 0.00583715)))); -} - -void mainImage(out vec4 fragColor, in vec2 fragCoord) { - vec2 size = iResolution.xy; - vec2 center = 0.5 * size; - vec2 offset = fragCoord - center; - float radius = length(offset); - float reach = 0.5 * length(size); - // Strongest a third of the way out, fading to nothing at the middle - // and at the edges, so the window's frame never wobbles. - float envelope = smoothstep(0.0, 0.18, radius / reach) * (1.0 - smoothstep(0.35, reachEnd(), radius / reach)); - float ease = smoothstep(0.0, EASE_IN, iTime); - float phase = (radius - iTime * speedPx()) * TAU / wavelengthPx(); - float height = sin(phase); - float slope = cos(phase); - vec2 dir = offset / max(radius, 1e-3); - vec2 moved = fragCoord + dir * height * amplitudePx() * envelope * ease; - - vec4 s = texture(iChannel0, moved / size); - vec3 col = toLinear(s.rgb) * (1.0 + shade() * slope * envelope * ease); - vec3 srgb = toSrgb(col) + (ign(fragCoord + float(iFrame % 64) * 5.588238) - 0.5) / 255.0; - fragColor = vec4(clamp(srgb, 0.0, 1.0), s.a); -} |
