v4k-git-backup/demos/art/shadertoys/MtX3Ws.fs

107 lines
2.4 KiB
GLSL

// cube02_0.jpg
// License Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
// Created by S. Guillitte 2015
float zoom=1.;
vec2 cmul( vec2 a, vec2 b ) { return vec2( a.x*b.x - a.y*b.y, a.x*b.y + a.y*b.x ); }
vec2 csqr( vec2 a ) { return vec2( a.x*a.x - a.y*a.y, 2.*a.x*a.y ); }
mat2 rot(float a) {
return mat2(cos(a),sin(a),-sin(a),cos(a));
}
vec2 iSphere( in vec3 ro, in vec3 rd, in vec4 sph )//from iq
{
vec3 oc = ro - sph.xyz;
float b = dot( oc, rd );
float c = dot( oc, oc ) - sph.w*sph.w;
float h = b*b - c;
if( h<0.0 ) return vec2(-1.0);
h = sqrt(h);
return vec2(-b-h, -b+h );
}
float map(in vec3 p) {
float res = 0.;
vec3 c = p;
for (int i = 0; i < 10; ++i) {
p =.7*abs(p)/dot(p,p) -.7;
p.yz= csqr(p.yz);
p=p.zxy;
res += exp(-19. * abs(dot(p,c)));
}
return res/2.;
}
vec3 raymarch( in vec3 ro, vec3 rd, vec2 tminmax )
{
float t = tminmax.x;
float dt = .02;
//float dt = .2 - .195*cos(iGlobalTime*.05);//animated
vec3 col= vec3(0.);
float c = 0.;
for( int i=0; i<64; i++ )
{
t+=dt*exp(-2.*c);
if(t>tminmax.y)break;
vec3 pos = ro+t*rd;
c = map(ro+t*rd);
col = .99*col+ .08*vec3(c*c, c, c*c*c);//green
//col = .99*col+ .08*vec3(c*c*c, c*c, c);//blue
}
return col;
}
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
float time = iGlobalTime;
vec2 q = fragCoord.xy / iResolution.xy;
vec2 p = -1.0 + 2.0 * q;
p.x *= iResolution.x/iResolution.y;
vec2 m = vec2(0.);
if( iMouse.z>0.0 )m = iMouse.xy/iResolution.xy*3.14;
m-=.5;
// camera
vec3 ro = zoom*vec3(4.);
ro.yz*=rot(m.y);
ro.xz*=rot(m.x+ 0.1*time);
vec3 ta = vec3( 0.0 , 0.0, 0.0 );
vec3 ww = normalize( ta - ro );
vec3 uu = normalize( cross(ww,vec3(0.0,1.0,0.0) ) );
vec3 vv = normalize( cross(uu,ww));
vec3 rd = normalize( p.x*uu + p.y*vv + 4.0*ww );
vec2 tmm = iSphere( ro, rd, vec4(0.,0.,0.,2.) );
// raymarch
vec3 col = raymarch(ro,rd,tmm);
if (tmm.x<0.)col = texture(iChannel0, rd.rg).rgb;
else {
vec3 nor=(ro+tmm.x*rd)/2.;
nor = reflect(rd, nor);
float fre = pow(.5+ clamp(dot(nor,rd),0.0,1.0), 3. )*1.3;
col += texture(iChannel0, nor.rg).rgb * fre;
}
// shade
col = .5 *(log(1.+col));
col = clamp(col,0.,1.);
fragColor = vec4( col, 1.0 );
}