feat!: raymarcher init with movement

raymarcher.glsl

@@ -6,20 +6,66 @@ in vec2 texture_coordinates;
 uniform float time;
 uniform sampler2D uSampler1;
 uniform sampler2D uSampler2;
+uniform vec3 camera_pos;
 
 // Output
 out vec4 color;
 
 const float PI = 3.1415;
 
+// Raymarching variables
+#define MAX_ITERATIONS 20
+#define MIN_TOLERANCE .01
+
+//const vec3 camera_pos = vec3(0.);
+const vec3 color1 = vec3(0.494, 0.361, 0.678);
+const vec3 color2 = vec3(0.827, 0.945, 0.875);
+
+// Scene Object (sphere)
+
+// returns the distance from the ray to this sphere in the scene
+float sphere_render(vec3 ray_pos, float radius, vec3 sphere_pos) {
+
+  return distance(ray_pos, sphere_pos) - radius;
+}
+
+float remap11(float val ) {
+  return ((val - .5) * 2.);
+
+}
+
+
 void main() {
 
+  // Set up camera and sphere object
+  vec3 ray_dir = normalize(vec3( remap11(texture_coordinates.x) , remap11(texture_coordinates.y), 1.));
+  vec3 ray_pos = camera_pos;
+  const vec3 sphere_pos = vec3(0.,0.,3.);
+  const float rad = 1.;
+
+  for(int i = 0; i < MAX_ITERATIONS; i++) {
+
+    float distance = sphere_render(ray_pos, rad, sphere_pos);
+
+    // Check If within tolerances
+    if( distance < MIN_TOLERANCE) {
+      break;
+    }
+
+    ray_pos += (distance * ray_dir);
+    color = vec4(mix(color1, color2, float(i) / float(MAX_ITERATIONS)),1.);
+  }
+
+
+  // Image stuff for later
+  /*
   if ((texture_coordinates.x + texture_coordinates.y) > 1.) {
     color = texture(uSampler1, texture_coordinates);
   }
   else {
     color = texture(uSampler2, texture_coordinates);
-  }
+  }*/
 
+  // Basic color time shift
   // color = vec4( texture_coordinates, (sin( time * PI) + 1.)/2. , 1.);
 }