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/shaders/fragment/dissolve.fs

https://github.com/ajanthanm/cssfilterlab
F# | 171 lines | 118 code | 40 blank | 13 comment | 1 complexity | 803fc07122e38468ce528e90208c9ef6 MD5 | raw file
  1/*
  2 * Copyright (c) 2012 Adobe Systems Incorporated. All rights reserved.
  3 * Copyright (c) 2012 Branislav Ulicny
  4 * 
  5 * Licensed under the Apache License, Version 2.0 (the "License");
  6 * you may not use this file except in compliance with the License.
  7 * You may obtain a copy of the License at
  8 * 
  9 *     http://www.apache.org/licenses/LICENSE-2.0
 10 * 
 11 * Unless required by applicable law or agreed to in writing, software
 12 * distributed under the License is distributed on an "AS IS" BASIS,
 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 14 * See the License for the specific language governing permissions and
 15 * limitations under the License.
 16 */
 17
 18precision mediump float;
 19
 20/*
 21 * WebGL Noise (Start)
 22 * From: https://github.com/ashima/webgl-noise
 23 */
 24
 25/* 
 26 * Copyright (C) 2011 by Ashima Arts (Simplex noise)
 27 * Copyright (C) 2011 by Stefan Gustavson (Classic noise)
 28 *
 29 * Permission is hereby granted, free of charge, to any person obtaining a copy
 30 * of this software and associated documentation files (the "Software"), to deal
 31 * in the Software without restriction, including without limitation the rights
 32 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 33 * copies of the Software, and to permit persons to whom the Software is
 34 * furnished to do so, subject to the following conditions:
 35 *
 36 * The above copyright notice and this permission notice shall be included in
 37 * all copies or substantial portions of the Software.
 38 *
 39 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 40 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 41 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 42 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 43 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 44 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 45 * THE SOFTWARE.
 46 */
 47
 48vec4 permute(vec4 x)
 49{
 50	return mod(((x * 34.0) + 1.0) * x, 289.0);
 51}
 52
 53vec4 taylorInvSqrt(vec4 r)
 54{
 55	return 1.79284291400159 - 0.85373472095314 * r;
 56}
 57
 58float snoise(vec3 v)
 59{
 60	const vec2 C = vec2(1.0 / 6.0, 1.0 / 3.0);
 61	const vec4 D = vec4(0.0, 0.5, 1.0, 2.0);
 62
 63	// First corner
 64
 65	vec3 i  = floor(v + dot(v, C.yyy));
 66	vec3 x0 = v - i + dot(i, C.xxx);
 67
 68	// Other corners
 69
 70	vec3 g = step(x0.yzx, x0.xyz);
 71	vec3 l = 1.0 - g;
 72	vec3 i1 = min(g.xyz, l.zxy);
 73	vec3 i2 = max(g.xyz, l.zxy);
 74
 75	vec3 x1 = x0 - i1 + 1.0 * C.xxx;
 76	vec3 x2 = x0 - i2 + 2.0 * C.xxx;
 77	vec3 x3 = x0 - 1. + 3.0 * C.xxx;
 78
 79	// Permutations
 80
 81	i = mod(i, 289.0);
 82	vec4 p = permute(permute(permute(
 83			 i.z + vec4(0.0, i1.z, i2.z, 1.0))
 84		   + i.y + vec4(0.0, i1.y, i2.y, 1.0))
 85		   + i.x + vec4(0.0, i1.x, i2.x, 1.0));
 86
 87	// Gradients
 88	// (N*N points uniformly over a square, mapped onto an octahedron.)
 89
 90	float n_ = 1.0 / 7.0; // N=7
 91
 92	vec3 ns = n_ * D.wyz - D.xzx;
 93
 94	vec4 j = p - 49.0 * floor(p * ns.z *ns.z);  //  mod(p,N*N)
 95
 96	vec4 x_ = floor(j * ns.z);
 97	vec4 y_ = floor(j - 7.0 * x_);    // mod(j,N)
 98
 99	vec4 x = x_ *ns.x + ns.yyyy;
100	vec4 y = y_ *ns.x + ns.yyyy;
101	vec4 h = 1.0 - abs(x) - abs(y);
102
103	vec4 b0 = vec4(x.xy, y.xy);
104	vec4 b1 = vec4(x.zw, y.zw);
105
106
107	vec4 s0 = floor(b0) * 2.0 + 1.0;
108	vec4 s1 = floor(b1) * 2.0 + 1.0;
109	vec4 sh = -step(h, vec4(0.0));
110
111	vec4 a0 = b0.xzyw + s0.xzyw * sh.xxyy;
112	vec4 a1 = b1.xzyw + s1.xzyw * sh.zzww;
113
114	vec3 p0 = vec3(a0.xy, h.x);
115	vec3 p1 = vec3(a0.zw, h.y);
116	vec3 p2 = vec3(a1.xy, h.z);
117	vec3 p3 = vec3(a1.zw, h.w);
118
119	// Normalise gradients
120
121	vec4 norm = taylorInvSqrt(vec4(dot(p0, p0), dot(p1, p1), dot(p2, p2), dot(p3, p3)));
122	p0 *= norm.x;
123	p1 *= norm.y;
124	p2 *= norm.z;
125	p3 *= norm.w;
126
127	// Mix final noise value
128
129	vec4 m = max(0.6 - vec4(dot(x0, x0), dot(x1, x1), dot(x2, x2), dot(x3, x3)), 0.0);
130	m = m * m;
131	return 42.0 * dot(m*m, vec4(dot(p0, x0), dot(p1, x1), dot(p2, x2), dot(p3, x3)));
132}
133
134/*
135 * WebGL Noise (End)
136 */
137
138// Uniforms passed in from CSS
139
140uniform float amount;
141
142// Varyings
143
144varying vec2 v_uv;
145
146// Construct height map out of base noise function
147
148float surface(vec2 p, float time)
149{
150	vec3 coord = vec3(p, -time * 0.001125);
151
152	float n = 0.5;
153
154	//n += 0.5 * abs(snoise(coord * 128.0));
155	n += 0.25 * abs(snoise(coord * 256.0));
156	n += 0.5 * abs(snoise(coord * 512.0));
157	n += 0.25 * abs(snoise(coord * 1024.0));
158	//n += 0.125 * abs(snoise(coord * 2048.0));
159
160	return n;
161}
162
163// Main
164
165void main()
166{
167	float time = 0.075 + amount * 0.75;
168	float n = surface(0.035 * v_uv, time) * v_uv.y;
169	bool isVisible = (n >= 1.25 * amount);
170	css_ColorMatrix = isVisible ? mat4(1.0) : mat4(0.0);
171}