Movement.

src/duskgl/display/shader/data/entities.c

@@ -27,8 +27,10 @@ void entitiesUpdate() {
     entitiesdataent_t *dst = &ENTITIES_DATA.entities[i];
 
     // Copy position data.
-    assertTrue(
-      (&src->subY - &src->x) + sizeof(uint8_t) == sizeof(uint_t),
+    assertMemoryRangeMatches(
+      &src->x,
+      &src->direction,
+      sizeof(uint_t),
       "Entity data is not packed correctly any more."
     );
     memcpy(&dst->position, &src->x, sizeof(uint_t));

src/duskgl/display/shader/data/entities.glsl

@@ -26,8 +26,8 @@ vec2 entityGetVertice(uint instanceIndex, uint indiceIndex) {
 
   uint x = packedGetU8(0u, entities[instanceIndex].position);
   uint y = packedGetU8(1u, entities[instanceIndex].position);
-  uint subX = packedGetU8(2u, entities[instanceIndex].position);
-  uint subY = packedGetU8(3u, entities[instanceIndex].position);
+  int subX = packedGetI8(2u, entities[instanceIndex].position);
+  int subY = packedGetI8(3u, entities[instanceIndex].position);
 
   vert.x += float(x);
   vert.y += float(y);

src/duskgl/display/shader/fragments/packed.glsl

@@ -5,4 +5,9 @@
 
 uint packedGetU8(uint position, uint data) {
   return (data >> (position * 8u)) & 0xFFu;
+}
+
+int packedGetI8(uint position, uint data) {
+  int shift = int(position * 8u);
+  return int(data << (24 - shift)) >> 24;
 }