Balls.fs

/*{
    "CATEGORIES": [
        "XXX"
    ],
    "CREDIT": "",
    "INPUTS": [
        {
            "DEFAULT": 0,
            "NAME": "width",
            "TYPE": "float"
        },
        {
            "DEFAULT": [
                0,
                0
            ],
            "MAX": [
                1,
                1
            ],
            "MIN": [
                0,
                0
            ],
            "NAME": "offset",
            "TYPE": "point2D"
        },
        {
            "DEFAULT": [
                1,
                1,
                1,
                1
            ],
            "NAME": "color1",
            "TYPE": "color"
        },
        {
            "DEFAULT": [
                0,
                0,
                0,
                1
            ],
            "NAME": "color2",
            "TYPE": "color"
        },
        {
            "DEFAULT": [
                0.5,
                0.5
            ],
            "MAX": [
                1,
                1
            ],
            "MIN": [
                0,
                0
            ],
            "NAME": "splitPos",
            "TYPE": "point2D"
        },
        {
            "MAX": 1,
            "NAME": "lol",
            "TYPE": "float"
        },
        {
            "NAME": "color3",
            "TYPE": "color"
        }
    ],
    "ISFVSN": "2"
}
*/


struct Camera {
    vec3 Obs;
    vec3 View;
    vec3 Up;
    vec3 Horiz;
    float H;
    float W;
    float z;
};


struct Ray {
    vec3 Origin;
    vec3 Dir;
};

Camera camera(in vec3 Obs, in vec3 LookAt, in float aperture) {
   Camera C;
   C.Obs = Obs;
   C.View = normalize(LookAt - Obs);
   C.Horiz = normalize(cross(vec3(0.0, 0.0, 1.0), C.View));
   C.Up = cross(C.View, C.Horiz);
   C.W = float(RENDERSIZE.x);
   C.H = float(RENDERSIZE.y);
   C.z = (C.H/2.0) / tan((aperture * 3.1415 / 180.0) / 2.0);
   return C;
}


struct Sphere {
   vec3 Center;
   float R;
};

bool intersect_sphere(in Ray R, in Sphere S, out float t) {
   vec3 CO = R.Origin - S.Center;
   float a = dot(R.Dir, R.Dir);
   float b = 2.0*dot(R.Dir, CO);
   float c = dot(CO, CO) - S.R*S.R;
   float delta = b*b - 4.0*a*c;
   if(delta < 0.0) {
      return false;
   }
   t = (-b-sqrt(delta)) / (2.0*a);
   return true;
}


Ray launch(in Camera C, in vec2 XY) {
   return Ray(
      C.Obs,
      C.z*C.View+(XY.x-C.W/2.0)*C.Horiz+(XY.y-C.H/2.0)*C.Up 
   );
}



void main() {
	//	determine if we are on an even or odd line
	//	math goes like..
	//	mod(((coord+offset) / width),2)
	
	
	vec4		out_color = color2;
	float		size = width * RENDERSIZE.x;
	
    Camera C = camera(
       vec3(2.0, 2.0, 1.5),
       vec3(0.5, 0.5, 0.5),
       50.0       
   );
   
   
   float pos = lol * 10.0 - 8.0;
   
   float outw = 0.5 + ((sin(lol*10.0) ));

   Ray R = launch(C, vec2(gl_FragCoord.x, gl_FragCoord.y));
   Sphere S = Sphere(vec3(0.0, pos, 0.0), 0.5);
   Sphere S2 = Sphere(vec3(outw, pos, 0.0), 0.25);
   Sphere S3 = Sphere(vec3(-outw, pos, 0), 0.25);
      Sphere S4 = Sphere(vec3(0, pos, outw), 0.25);
   Sphere S5 = Sphere(vec3(0, pos, -outw), 0.25);
   
   float t;
   if( intersect_sphere(R,S,t)  ) {

		out_color = color1;

	}
	
	   if(intersect_sphere(R,S2,t)  || intersect_sphere(R,S3,t)  || intersect_sphere(R,S4,t)  || intersect_sphere(R,S5,t)  ) {

		out_color *= color3;


	}
	
	
	gl_FragColor = out_color;
}