fixed movement not wrapping around the world.. again

shaders/decay_cs.glsl

@@ -21,14 +21,7 @@ float get_dissipation_from(ivec2 uv) {
 }
 
 ivec2 loop_position(ivec2 pos) {
-    int width = params.texture_size.x;
-    int height = params.texture_size.y;
-    vec2 looped = pos;
-    if (pos.x > width) looped.x = mod(pos.x, width);
-    if (pos.y > height) looped.y = mod(pos.y, height);
-    if (pos.x < 0) looped.x = width - pos.x;
-    if (pos.y < 0) looped.y = height - pos.y;
-    return ivec2(looped);
+    return pos % params.texture_size;
 }
 
 // The code we want to execute in each invocation