URL: http://glslsandbox.com/e#25418.10
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 |
// Stormy Night // By: Brandon Fogerty // bfogerty at gmail dot com // xdpixel.com #ifdef GL_ES precision mediump float; #endif uniform float time; uniform vec2 resolution; float Hash( vec2 p) { vec3 p2 = vec3(p.xy,1.0); return fract(sin(dot(p2,vec3(37.1,61.7, 12.4)))*3758.5453123); } float noise(in vec2 p) { vec2 i = floor(p); vec2 f = fract(p); f *= f * (3.0-2.0*f); return mix(mix(Hash(i + vec2(0.,0.)), Hash(i + vec2(1.,0.)),f.x), mix(Hash(i + vec2(0.,1.)), Hash(i + vec2(1.,1.)),f.x), f.y); } float fbm(vec2 p) { float v = 0.0; v += noise(p*1.0)*.5; v += noise(p*2.)*.25; v += noise(p*4.)*.125; return v; } vec3 clouds( vec2 uv, vec2 dir ) { dir *= time; vec3 finalColor = fbm( (uv * 1.5) + dir ) * vec3( 1.0 ); return finalColor; } vec3 lightning( vec2 uv ) { float timeVal = time; vec3 finalColor = vec3( 0.0 ); for( int i=0; i < 3; ++i ) { float indexAsFloat = float(i); float amp = 40.0 + (indexAsFloat*1.0); float period = 2.0 + (indexAsFloat+2.0); float thickness = mix( 0.1, 0.7, uv.y * 0.5 + 0.5 ); float intensity = mix( 0.5, 1.5, noise(uv*10.0) ); float t = abs( thickness / (sin(uv.x + fbm( uv + timeVal * period )) * amp) * intensity ); float show = fract(abs(sin(timeVal))) >= 0.95 ? 1.0 : 0.0; show *= step( abs(fbm( vec2( sin(time * 50.0), 0.0 ) )), 0.4); finalColor += t * vec3( 0.3, 0.5, 2.0 ) * show; } return finalColor; } void main( void ) { vec2 uv = ( gl_FragCoord.xy / resolution.xy ) * 2.0 - 1.0; uv.x *= resolution.x/resolution.y; vec3 finalColor = vec3( 0.0 ); finalColor += sin( clouds( uv, vec2( 1.0, 0.1 ) )); float xOffset = mix( 1.5, -1.5, fbm(vec2( fract(time), 0.00 ) ) ); vec2 uvOffset = vec2( xOffset, 0.0 ); vec2 lightningUV = uv + uvOffset; float theta = 3.14159 * 2.1; lightningUV.x = uv.x * cos(theta) - uv.y*sin(theta); lightningUV.y = uv.x * sin(theta) + uv.y*cos(theta); finalColor += lightning( lightningUV + uvOffset ); finalColor -= sin( clouds( uv, vec2( 2.0 ) )) * 0.30; gl_FragColor = vec4( finalColor, 1.0 ); } |