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Diffstat (limited to 'resources/seascape.glsl')
| -rw-r--r-- | resources/seascape.glsl | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/resources/seascape.glsl b/resources/seascape.glsl new file mode 100644 index 0000000..7a69f40 --- /dev/null +++ b/resources/seascape.glsl @@ -0,0 +1,196 @@ +/* + * "Seascape" by Alexander Alekseev aka TDM - 2014 + * License Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. + * Contact: [email protected] + */ + +#version 330 core + +uniform vec2 uResolution; +uniform float uTime; +uniform vec4 uMouse; + +// This is how much you are drifting around. Zero means it only moves when the mouse moves +uniform float uDrift; + +out vec4 fragColor; + +const int NUM_STEPS = 8; +const float PI = 3.141592; +const float EPSILON = 1e-3; +#define EPSILON_NRM (0.1 / uResolution.x) + +// sea +const int ITER_GEOMETRY = 3; +const int ITER_FRAGMENT = 5; +const float SEA_HEIGHT = 0.6; +const float SEA_CHOPPY = 4.0; +const float SEA_SPEED = 0.8; +const float SEA_FREQ = 0.16; +const vec3 SEA_BASE = vec3(0.1,0.19,0.22); +const vec3 SEA_WATER_COLOR = vec3(0.8,0.9,0.6); +#define SEA_TIME (1.0 + uTime * SEA_SPEED) +const mat2 octave_m = mat2(1.6,1.2,-1.2,1.6); + +// math +mat3 fromEuler(vec3 ang) { + vec2 a1 = vec2(sin(ang.x),cos(ang.x)); + vec2 a2 = vec2(sin(ang.y),cos(ang.y)); + vec2 a3 = vec2(sin(ang.z),cos(ang.z)); + mat3 m; + m[0] = vec3(a1.y*a3.y+a1.x*a2.x*a3.x,a1.y*a2.x*a3.x+a3.y*a1.x,-a2.y*a3.x); + m[1] = vec3(-a2.y*a1.x,a1.y*a2.y,a2.x); + m[2] = vec3(a3.y*a1.x*a2.x+a1.y*a3.x,a1.x*a3.x-a1.y*a3.y*a2.x,a2.y*a3.y); + return m; +} +float hash( vec2 p ) { + float h = dot(p,vec2(127.1,311.7)); + return fract(sin(h)*43758.5453123); +} +float noise( in vec2 p ) { + vec2 i = floor( p ); + vec2 f = fract( p ); + vec2 u = f*f*(3.0-2.0*f); + return -1.0+2.0*mix( mix( hash( i + vec2(0.0,0.0) ), + hash( i + vec2(1.0,0.0) ), u.x), + mix( hash( i + vec2(0.0,1.0) ), + hash( i + vec2(1.0,1.0) ), u.x), u.y); +} + +// lighting +float diffuse(vec3 n,vec3 l,float p) { + return pow(dot(n,l) * 0.4 + 0.6,p); +} +float specular(vec3 n,vec3 l,vec3 e,float s) { + float nrm = (s + 8.0) / (PI * 8.0); + return pow(max(dot(reflect(e,n),l),0.0),s) * nrm; +} + +// sky +vec3 getSkyColor(vec3 e) { + e.y = max(e.y,0.0); + return vec3(pow(1.0-e.y,2.0), 1.0-e.y, 0.6+(1.0-e.y)*0.4); +} + +// sea +float sea_octave(vec2 uv, float choppy) { + uv += noise(uv); + vec2 wv = 1.0-abs(sin(uv)); + vec2 swv = abs(cos(uv)); + wv = mix(wv,swv,wv); + return pow(1.0-pow(wv.x * wv.y,0.65),choppy); +} + +float map(vec3 p) { + float freq = SEA_FREQ; + float amp = SEA_HEIGHT; + float choppy = SEA_CHOPPY; + vec2 uv = p.xz; uv.x *= 0.75; + + float d, h = 0.0; + for(int i = 0; i < ITER_GEOMETRY; i++) { + d = sea_octave((uv+SEA_TIME)*freq,choppy); + d += sea_octave((uv-SEA_TIME)*freq,choppy); + h += d * amp; + uv *= octave_m; freq *= 1.9; amp *= 0.22; + choppy = mix(choppy,1.0,0.2); + } + return p.y - h; +} + +float map_detailed(vec3 p) { + float freq = SEA_FREQ; + float amp = SEA_HEIGHT; + float choppy = SEA_CHOPPY; + vec2 uv = p.xz; uv.x *= 0.75; + + float d, h = 0.0; + for(int i = 0; i < ITER_FRAGMENT; i++) { + d = sea_octave((uv+SEA_TIME)*freq,choppy); + d += sea_octave((uv-SEA_TIME)*freq,choppy); + h += d * amp; + uv *= octave_m; freq *= 1.9; amp *= 0.22; + choppy = mix(choppy,1.0,0.2); + } + return p.y - h; +} + +vec3 getSeaColor(vec3 p, vec3 n, vec3 l, vec3 eye, vec3 dist) { + float fresnel = clamp(1.0 - dot(n,-eye), 0.0, 1.0); + fresnel = pow(fresnel,3.0) * 0.65; + + vec3 reflected = getSkyColor(reflect(eye,n)); + vec3 refracted = SEA_BASE + diffuse(n,l,80.0) * SEA_WATER_COLOR * 0.12; + + vec3 color = mix(refracted,reflected,fresnel); + + float atten = max(1.0 - dot(dist,dist) * 0.001, 0.0); + color += SEA_WATER_COLOR * (p.y - SEA_HEIGHT) * 0.18 * atten; + + color += vec3(specular(n,l,eye,60.0)); + + return color; +} + +// tracing +vec3 getNormal(vec3 p, float eps) { + vec3 n; + n.y = map_detailed(p); + n.x = map_detailed(vec3(p.x+eps,p.y,p.z)) - n.y; + n.z = map_detailed(vec3(p.x,p.y,p.z+eps)) - n.y; + n.y = eps; + return normalize(n); +} + +float heightMapTracing(vec3 ori, vec3 dir, out vec3 p) { + float tm = 0.0; + float tx = 1000.0; + float hx = map(ori + dir * tx); + if(hx > 0.0) return tx; + float hm = map(ori + dir * tm); + float tmid = 0.0; + for(int i = 0; i < NUM_STEPS; i++) { + tmid = mix(tm,tx, hm/(hm-hx)); + p = ori + dir * tmid; + float hmid = map(p); + if(hmid < 0.0) { + tx = tmid; + hx = hmid; + } else { + tm = tmid; + hm = hmid; + } + } + return tmid; +} + +// main +void main() +{ + vec2 uv = gl_FragCoord.xy / uResolution.xy; + uv = uv * 2.0 - 1.0; + uv.x *= uResolution.x / uResolution.y; + float time = uTime * uDrift * 5 + uMouse.x*0.01; + + // ray + vec3 ang = vec3(sin(time*3.0)*0.1,sin(time)*0.2+0.3,time); + vec3 ori = vec3(0.0,3.5,time*5.0); + vec3 dir = normalize(vec3(uv.xy,-2.0)); dir.z += length(uv) * 0.15; + dir = normalize(dir) * fromEuler(ang); + + // tracing + vec3 p; + heightMapTracing(ori,dir,p); + vec3 dist = p - ori; + vec3 n = getNormal(p, dot(dist,dist) * EPSILON_NRM); + vec3 light = normalize(vec3(0.0,1.0,0.8)); + + // color + vec3 color = mix( + getSkyColor(dir), + getSeaColor(p,n,light,dir,dist), + pow(smoothstep(0.0,-0.05,dir.y),0.3)); + + // post + fragColor = vec4(pow(color,vec3(0.75)), 1.0); +} |