GLSL snippets - Revision history

Vegard: /* Colours */ blue ice gradient

2024-04-09T09:03:45Z

Colours: blue ice gradient

← Older revision		Revision as of 09:03, 9 April 2024
Line 156:		Line 156:
	// gamma correction (RGB to sRGB)		// gamma correction (RGB to sRGB)
	col = pow(col, vec3(1. / gamma));		col = pow(col, vec3(1. / gamma));
			</source>

			=== Ice gradient ===

			[[File:ice_gradient.png\|420px\|thumb\|Blue ice gradient]]

			<source lang="GLSL">
			vec3 col = smoothstep(vec3(.2, .1, .0), vec3(1.2, 1.1, 1.0), vec3(x));
	</source>		</source>

2022-12-08T13:18:48Z

Smooth variant: fix again

2022-12-08T13:14:09Z

Smooth variant: fix saturation/value

← Older revision		Revision as of 13:14, 8 December 2022
Line 133:		Line 133:
	// https://www.shadertoy.com/view/wlsSRB		// https://www.shadertoy.com/view/wlsSRB
	vec3 hsv2rgb2(vec3 c, float k) {		vec3 hsv2rgb2(vec3 c, float k) {
	~~return~~ ~~smoothstep~~(0. + k, 1. - k,		vec4 K = vec4(3. / 3., 2. / 3., 1. / 3., 3.);
			vec3 p = smoothstep(0. + k, 1. - k,
	.5 + .5 * cos(~~(vec3~~(c.x) + ~~vec3(3., 2., 1.) / 3~~.) * radians(360.)));		.5 + .5 * cos((c.xxx + K.xyz) * radians(360.)));
			return c.z * mix(K.www, p, c.y);
	}		}
	</source>		</source>

2022-10-24T22:56:27Z

Smooth variant

← Older revision		Revision as of 22:56, 24 October 2022
Line 137:		Line 137:
	}		}
	</source>		</source>

			A good value for <code>k</code> is e.g. 0.07.

	=== Gamma ===		=== Gamma ===

2021-12-30T11:02:01Z

Ray marching: fix rayDirection()

← Older revision		Revision as of 11:02, 30 December 2021
Line 24:		Line 24:
	// http://jamie-wong.com/2016/07/15/ray-marching-signed-distance-functions/		// http://jamie-wong.com/2016/07/15/ray-marching-signed-distance-functions/
	vec3 rayDirection(float fieldOfView, vec2 size, vec2 fragCoord) {		vec3 rayDirection(float fieldOfView, vec2 size, vec2 fragCoord) {
	vec2 xy = fragCoord - size / 2.0;		vec2 xy = fragCoord - size / 2.;
	float z = size.y / tan(radians(fieldOfView) / 2.0);		float z = size.y / tan(radians(fieldOfView) / 2.) / 2.;
	return normalize(vec3(xy, -z));		return normalize(vec3(xy, -z));
	}		}
	</source>		</source>

			Note: The original <tt>rayDirection()</tt> is missing the divide by 2 when calculating z. This causes the field of view parameter to be incorrect.

	<source lang="GLSL">		<source lang="GLSL">

2020-03-24T16:09:47Z

Gamma: fix bug

2020-03-24T13:24:33Z

Volumetric light scattering (God rays): attribution

← Older revision		Revision as of 13:24, 24 March 2020
Line 217:		Line 217:
	}		}
	</source>		</source>

			Dithering suggested by Jessica Mak.

	[[Category:Graphics programming]]		[[Category:Graphics programming]]

2020-03-24T12:18:55Z

HSV: illustrations

← Older revision		Revision as of 12:18, 24 March 2020
Line 110:		Line 110:

	=== HSV ===		=== HSV ===

			==== Plain HSV ====

			[[File:hsv2rgb.png\|420px\|thumb\|<tt>hsv2rgb()</tt>]]

	<source lang="GLSL">		<source lang="GLSL">
Line 119:		Line 123:
	}		}
	</source>		</source>

			==== Smooth variant ====

			[[File:hsv2rgb2.png\|420px\|thumb\|<tt>hsv2rgb2()</tt>]]

	<source lang="GLSL">		<source lang="GLSL">

2020-03-24T11:34:15Z

Volumetric light scattering (God rays)

← Older revision		Revision as of 11:34, 24 March 2020
Line 176:		Line 176:

	=== Volumetric light scattering (God rays) ===		=== Volumetric light scattering (God rays) ===

			[[File:godrays.png\|420px\|thumb\|Example of volumetric light scattering post-processing effect (with dithering).]]

	<source lang="GLSL">		<source lang="GLSL">
Line 197:		Line 199:
	texCoord -= deltaTexCoord;		texCoord -= deltaTexCoord;

	~~vec3~~ ~~sample_~~ = texture(iChannel0, texCoord + deltaTexCoord * rand(fragCoord + 0.vec2(200.float(i), 23.*float(i)))~~).rgb~~;		float dither = rand(fragCoord + vec2(200. * float(i), 23. * float(i)));
			vec3 sample_ = texture(iChannel0, texCoord + deltaTexCoord * dither).rgb;
	sample_ = illuminationDecay Weight;		sample_ = illuminationDecay Weight;
	color += sample_;		color += sample_;

2020-03-24T10:03:03Z

add godrays

@@ Line 170: / Line 170: @@
     return (major + minor) / levels;
 #endif
+}
 </source>