walk around reorienting world torus

src/scenes/shader/tile_frag.glsl

@@ -10,9 +10,9 @@ uniform b_constants {
   uvec4 anim;
   float R1;
   float R2;
+  float R3;
 };
 uniform b_locals {
-  mat4 camera;
   uint millis;
   float treadmill_x;
   float treadmill_y;

src/scenes/shader/torus_vertex.glsl

@@ -15,16 +15,16 @@ uniform b_constants {
   uvec4 anim;
   float R1;
   float R2;
+  float R3;
 };
 uniform b_locals {
-  mat4 camera;
   uint millis;
   float treadmill_x;
   float treadmill_y;
 };
 
 vec3 toroid(vec2 src, float r1, float r2, float r3) {
-  return vec3(r3 * -1.0 * sin(src.x), // use r3 instead of r2 for "deflated" torus
+  return vec3(r3 * sin(src.x), // use r3 instead of r2 for "deflated" torus
               (r1 + r2 * cos(src.x)) * cos(src.y),
               (r1 + r2 * cos(src.x)) * sin(src.y));
 }
@@ -35,8 +35,8 @@ void main() {
 
   vec2 thetaphi = vec2(TWO_PI_CIRC * (a_pos.x + treadmill_x),
                        TWO_PI_CIRC * (a_pos.y + treadmill_y));
-  float height = R1 * TWO_PI_CIRC;
-  vec3 normal = vec3(toroid(thetaphi, 0, height, height));
-  gl_Position = u_matrix * camera *
-      vec4(toroid(thetaphi, R1, R2, R1) + a_pos.z * normal, 1.0);
+  float height = R2 * 4 * TWO_PI_CIRC;
+  vec3 normal = vec3(toroid(thetaphi, 0, height, height)) *
+                vec3(R2 / R3, 1.0, 1.0);
+  gl_Position = u_matrix * vec4(toroid(thetaphi, R1, R2, R3) + a_pos.z * normal, 1.0);
 }