Hi, i've tried to use gravitational lensing shader from shadertoy.com (https://www.shadertoy.com/view/Md2XWc# (https://www.shadertoy.com/view/Md2XWc#)), but i have no idea, how to change shader on website so it can be used in my app. :/ It's that code:
// reference: http://www.photon.at/~werner/bh/gvsim.html
vec3 bh=vec3(0.0);
float bh_M=1.;
vec3 eye=vec3(0.,0.,10.);
vec3 up=vec3(0.,1.,0.);
mat3 cam_mat;// camera -> world
float tan_half_vfov=1.0;
vec2 iplane_size=2.*tan_half_vfov*vec2(iResolution.x/iResolution.y,1.);
void setupCamera()
{
vec3 n=normalize(eye-bh);
vec3 s=normalize(cross(up,n));
vec3 t=cross(n,s);
cam_mat[0]=s;
cam_mat[1]=t;
cam_mat[2]=n;
}
vec3 rot_y(vec3 v,float theta)
{
float s=sin(theta),c=cos(theta);
return vec3(c*v.x+s*v.z,v.y,c*v.z-s*v.x);
}
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
setupCamera();
vec2 ixy=(fragCoord.xy/iResolution.xy - 0.5)*iplane_size;
vec3 ray_dir=cam_mat*normalize(vec3(ixy.x,ixy.y,-1.));
vec3 h2e=eye-bh; float l2_h2e=dot(h2e,h2e);
float d=length(cross(ray_dir,h2e));
if(d>3.*bh_M)
{
// closest point
vec3 cp= eye+ray_dir*sqrt(l2_h2e-d*d);
// bend
float alpha=4.*bh_M/d;
ray_dir=normalize(ray_dir+tan(alpha)*normalize(bh-cp));
fragColor=textureCube(iChannel0,rot_y(ray_dir,-0.2*iGlobalTime));
}
else
fragColor=vec4(0.);
}
Thanks!