shadertoy_glsl_flame.py

from wgpu_shadertoy import Shadertoy

# shader source: https://www.shadertoy.com/view/4sX3zr by XT95

shader_code = """
// Created by anatole duprat - XT95/2013
// License Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.

float noise(vec3 p) //Thx to Las^Mercury
{
   vec3 i = floor(p);
   vec4 a = dot(i, vec3(1., 57., 21.)) + vec4(0., 57., 21., 78.);
   vec3 f = cos((p-i)*acos(-1.))*(-.5)+.5;
   a = mix(sin(cos(a)*a),sin(cos(1.+a)*(1.+a)), f.x);
   a.xy = mix(a.xz, a.yw, f.y);
   return mix(a.x, a.y, f.z);
}

float sphere(vec3 p, vec4 spr)
{
   return length(spr.xyz-p) - spr.w;
}

float flame(vec3 p)
{
   float d = sphere(p*vec3(1.,.5,1.), vec4(.0,-1.,.0,1.));
   return d + (noise(p+vec3(.0,iTime*2.,.0)) + noise(p*3.)*.5)*.25*(p.y) ;
}

float scene(vec3 p)
{
   return min(100.-length(p) , abs(flame(p)) );
}

vec4 raymarch(vec3 org, vec3 dir)
{
   float d = 0.0, glow = 0.0, eps = 0.02;
   vec3  p = org;
   bool glowed = false;

   for(int i=0; i<64; i++)
   {
      d = scene(p) + eps;
      p += d * dir;
      if( d>eps )
      {
         if(flame(p) < .0)
            glowed=true;
         if(glowed)
                glow = float(i)/64.;
      }
   }
   return vec4(p,glow);
}

void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
   vec2 v = -1.0 + 2.0 * fragCoord.xy / iResolution.xy;
   v.x *= iResolution.x/iResolution.y;

   vec3 org = vec3(0., -2., 4.);
   vec3 dir = normalize(vec3(v.x*1.6, -v.y, -1.5));

   vec4 p = raymarch(org, dir);
   float glow = p.w;

   vec4 col = mix(vec4(1.,.5,.1,1.), vec4(0.1,.5,1.,1.), p.y*.02+.4);

   fragColor = mix(vec4(0.), col, pow(glow*2.,4.));
   //fragColor = mix(vec4(1.), mix(vec4(1.,.5,.1,1.),vec4(0.1,.5,1.,1.),p.y*.02+.4), pow(glow*2.,4.));

}



"""
shader = Shadertoy(shader_code)

if __name__ == "__main__":
    shader.show()