107 lines
2.4 KiB
GLSL
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 );
|
|
|
|
}
|