// Ported from my shadertoy work: https://www.shadertoy.com/view/XttSWN // BEGIN: shadertoy porting template // https://gam0022.net/blog/2019/03/04/porting-from-shadertoy-to-glslsandbox/ precision highp float; uniform vec2 resolution; uniform float time; uniform vec2 mouse; #define iResolution resolution #define iTime time #define iMouse mouse void mainImage(out vec4 fragColor, in vec2 fragCoord); void main(void) { vec4 col; mainImage(col, gl_FragCoord.xy); gl_FragColor = col; } // END: shadertoy porting template // consts const float EPS = 1e-4; const float OFFSET = EPS * 10.0; const float PI = 3.14159; const float INF = 1e+10; const vec3 lightDir = vec3( -0.48666426339228763, 0.8111071056538127, -0.3244428422615251 ); const vec3 backgroundColor = vec3( 0.0 ); const vec3 gateColor = vec3( 1.0, 0.1, 0.1 ); const float totalTime = 75.0; // globals vec3 cPos, cDir; float normalizedGlobalTime = 0.0; //vec3 illuminationColor; struct Intersect { bool isHit; vec3 position; float distance; vec3 normal; int material; vec3 color; }; const int BASIC_MATERIAL = 0; const int MIRROR_MATERIAL = 1; // distance functions vec3 opRep( vec3 p, float interval ) { return mod( p, interval ) - 0.5 * interval; } vec2 opRep( vec2 p, float interval ) { return mod( p, interval ) - 0.5 * interval; } float opRep( float x, float interval ) { return mod( x, interval ) - 0.5 * interval; } float sphereDist( vec3 p, vec3 c, float r ) { return length( p - c ) - r; } float sdCappedCylinder( vec3 p, vec2 h ) { vec2 d = abs(vec2(length(p.xz),p.y)) - h; return min(max(d.x,d.y),0.0) + length(max(d,0.0)); } float udBox( vec3 p, vec3 b ) { return length(max(abs(p)-b,0.0)); } float udFloor( vec3 p ){ float t1 = 1.0; float t2 = 3.0; float d = -0.5; for( float i = 0.0; i < 3.0; i++ ) { float f = pow( 2.0, i ); d += 0.1 / f * ( sin( f * t1 * p.x + t2 * iTime ) + sin( f * t1 * p.z + t2 * iTime ) ); } return dot(p,vec3(0.0,1.0,0.0)) - d; } float dGate( vec3 p ) { p.y -= 1.3 * 0.5; float r = 0.05; float left = sdCappedCylinder( p - vec3( -1.0, 0.0, 0.0 ), vec2(r, 1.3)); float right = sdCappedCylinder( p - vec3( 1.0, 0.0, 0.0 ), vec2(r, 1.3)); float ty = 0.02 * p.x * p.x; float tx = 0.5 * ( p.y - 1.3 ); float katsura = udBox( p - vec3( 0.0, 1.3 + ty, 0.0 ), vec3( 1.7 + tx, r * 2.0 + ty, r ) ); float kan = udBox( p - vec3( 0.0, 0.7, 0.0 ), vec3( 1.3, r, r ) ); float gakuduka = udBox( p - vec3( 0.0, 1.0, 0.0), vec3( r, 0.3, r ) ); return min( min( left, right ), min( gakuduka, min( katsura, kan ) ) ); } float dRepGate( vec3 p ) { if ( normalizedGlobalTime <= 0.5 ) { p.z = opRep( p.z, 1.0 + 20.0 * cos( PI * normalizedGlobalTime ) ); } else { p.xz = opRep( p.xz, 10.0 ); } return dGate( p ); } float sceneDistance( vec3 p ) { return udFloor( p ); } // color functions vec3 hsv2rgb( vec3 c ) { vec4 K = vec4( 1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0 ); vec3 p = abs( fract( c.xxx + K.xyz ) * 6.0 - K.www ); return c.z * mix( K.xxx, clamp( p - K.xxx, 0.0, 1.0 ), c.y ); } Intersect minIntersect( Intersect a, Intersect b ) { if ( a.distance < b.distance ) { return a; } else { return b; } } Intersect sceneIntersect( vec3 p ) { Intersect a; a.distance = udFloor( p ); a.material = MIRROR_MATERIAL; // return minIntersect( a, b ); return a; } vec3 getNormal( vec3 p ) { vec2 e = vec2( 1.0, -1.0 ) * 0.001; return normalize( e.xyy * sceneDistance( p + e.xyy ) + e.yyx * sceneDistance( p + e.yyx ) + e.yxy * sceneDistance( p + e.yxy ) + e.xxx * sceneDistance( p + e.xxx ) ); } float getShadow( vec3 ro, vec3 rd ) { float h = 0.0; float c = 0.0; float r = 1.0; float shadowCoef = 0.5; for ( float t = 0.0; t < 50.0; t++ ) { h = sceneDistance( ro + rd * c ); if ( h < EPS ) return shadowCoef; r = min( r, h * 16.0 / c ); c += h; } return 1.0 - shadowCoef + r * shadowCoef; } Intersect getRayColor( vec3 origin, vec3 ray ) { // marching loop float dist, minDist, trueDepth; float depth = 0.0; vec3 p = origin; int count = 0; Intersect nearest; // first pass (water) for ( int i = 0; i < 120; i++ ){ dist = sceneDistance( p ); depth += dist; p = origin + depth * ray; count = i; if ( abs(dist) < EPS ) break; } if ( abs(dist) < EPS ) { nearest = sceneIntersect( p ); nearest.position = p; nearest.normal = getNormal(p); nearest.distance = depth; float diffuse = clamp( dot( lightDir, nearest.normal ), 0.1, 1.0 ); float specular = pow( clamp( dot( reflect( lightDir, nearest.normal ), ray ), 0.0, 1.0 ), 6.0 ); //float shadow = getShadow( p + nearest.normal * OFFSET, lightDir ); if ( nearest.material == BASIC_MATERIAL ) { } else if ( nearest.material == MIRROR_MATERIAL ) { nearest.color = vec3( 0.5, 0.7, 0.8 ) * diffuse + vec3( 1.0 ) * specular; } nearest.isHit = true; } else { nearest.color = backgroundColor; nearest.isHit = false; } nearest.color = clamp( nearest.color - 0.1 * nearest.distance, 0.0, 1.0 ); // second pass (gates) p = origin; depth = 0.0; minDist = INF; for ( int i = 0; i < 20; i++ ){ dist = dRepGate( p ); minDist = min(dist, minDist); /*if ( dist < minDist ) { minDist = dist; trueDepth = depth; }*/ depth += dist; p = origin + depth * ray; if ( i == 9 && normalizedGlobalTime <= 0.5 ) { break; } } if ( abs(dist) < EPS ) { nearest.color += gateColor; } else { nearest.color += gateColor * clamp( 0.05 / minDist, 0.0, 1.0 ); } return nearest; } void mainImage( out vec4 fragColor, in vec2 fragCoord ) { normalizedGlobalTime = mod( iTime / totalTime, 1.0 ); // fragment position vec2 p = ( fragCoord.xy * 2.0 - iResolution.xy ) / min( iResolution.x, iResolution.y ); // camera and ray if ( normalizedGlobalTime < 0.7 ) { cPos = vec3( 0.0, 0.6 + 0.4 * cos( iTime ), 3.0 * iTime ); cDir = normalize( vec3( 0.0, -0.1, 1.0 ) ); } else { cPos = vec3( 0.0, 0.6 + 0.4 * cos( iTime ) + 50.0 * ( normalizedGlobalTime - 0.7 ), 3.0 * iTime ); cDir = normalize( vec3( 0.0, -0.1 - ( normalizedGlobalTime - 0.7 ), 1.0 ) ); } vec3 cSide = normalize( cross( cDir, vec3( 0.0, 1.0 ,0.0 ) ) ); vec3 cUp = normalize( cross( cSide, cDir ) ); float targetDepth = 1.3; vec3 ray = normalize( cSide * p.x + cUp * p.y + cDir * targetDepth ); // Illumination Color // illuminationColor = hsv2rgb( vec3( iTime * 0.02 + 0.6, 1.0, 1.0 ) ); vec3 color = vec3( 0.0 ); float alpha = 1.0; Intersect nearest; for ( int i = 0; i < 3; i++ ) { nearest = getRayColor( cPos, ray ); color += alpha * nearest.color; alpha *= 0.5; ray = normalize( reflect( ray, nearest.normal ) ); cPos = nearest.position + nearest.normal * OFFSET; if ( !nearest.isHit || nearest.material != MIRROR_MATERIAL ) break; } fragColor = vec4(color, 1.0); }