simple tile heights

src/scenes/shader/tile_frag.glsl

@@ -0,0 +1,28 @@
+#version 150
+
+in vec2 v_uv;
+flat in uint v_tileidx;
+out vec4 pixcolor;
+uniform sampler2D t_atlas;
+uniform b_constants {
+  //uvec4 animdata;
+  uint animdata;
+  float R1;
+  float R2;
+};
+uniform b_locals {
+  mat4 camera;
+  uint millis;
+  float treadmill_x;
+  float treadmill_y;
+};
+
+void main() {
+  vec2 anim_uv = v_uv;
+  //if (v_tileidx < 128u && bool(animdata[0 /*v_tileidx / 32u*/] & 1u << v_tileidx % 32u)) {
+  if (v_tileidx < 32u && bool(animdata & 1u << v_tileidx)) {
+    anim_uv = vec2(v_uv.x, float((uint(v_uv.y * 1000.0) + millis / 4u) % 1000u) / 1000.0);
+  }
+  vec2 uv = vec2(anim_uv.x, float(v_tileidx) / 256.0 + (1.0 - anim_uv.y) / 256.0);
+  pixcolor = texture(t_atlas, uv);
+}

src/scenes/shader/torus_vertex.glsl

@@ -0,0 +1,50 @@
+#version 150
+#define PI 3.1415926538
+#define PI_CIRC (PI / 256.0)
+#define TWO_PI_CIRC (2.0 * PI / 256.0)
+
+in vec3 a_pos;
+in vec2 a_uv;
+in uint a_tileidx;
+out vec2 v_uv;
+flat out uint v_tileidx;
+uniform b_trans {
+  mat4 u_matrix;
+};
+uniform b_constants {
+  //uvec4 animdata;
+  uint animdata;
+  float R1;
+  float R2;
+};
+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
+              (r1 + r2 * cos(src.x)) * cos(src.y),
+              (r1 + r2 * cos(src.x)) * sin(src.y));
+}
+
+void main() {
+  v_uv = a_uv;
+  v_tileidx = a_tileidx;
+
+  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);
+  /*
+    gl_Position = u_matrix * camera *
+    vec4(R2 * -1.0 * sin(TWO_PI_CIRC * (a_pos.x + treadmill_x)),
+    (R1 + R2 * cos(TWO_PI_CIRC * (a_pos.x + treadmill_x))) * cos(TWO_PI_CIRC * (a_pos.z + treadmill_y)),
+    (R1 + R2 * cos(TWO_PI_CIRC * (a_pos.x + treadmill_x))) * sin(TWO_PI_CIRC * (a_pos.z + treadmill_y)),
+    1.0);
+  */
+}