Use RGBA for the uint32_t color pixels. Closes #49.

raycaster.cpp

@@ -22,7 +22,7 @@ union ColorConv {
     uint8_t b;
     uint8_t a;
   } as_color;
-  uint32_t as_int;
+  RGBA as_int;
 };
 
 // from: https://permadi.com/1996/05/ray-casting-tutorial-19/
@@ -40,7 +40,7 @@ union ColorConv {
  * and I guess the compiler can handle it better than shifting
  * bits around.
  */
-inline uint32_t lighting_calc(uint32_t pixel, float dist, int level) {
+inline RGBA lighting_calc(RGBA pixel, float dist, int level) {
   ColorConv conv{.as_int=pixel};
 
   if(conv.as_color.b < GLOW_LIMIT
@@ -327,8 +327,8 @@ void Raycaster::draw_ceiling_floor() {
   constexpr static const int texture_height = TEXTURE_HEIGHT;
   auto &lights = $level.lights->lighting();
   size_t surface_i = 0;
-  const uint32_t *floor_texture = textures::get_surface(surface_i);
+  const RGBA *floor_texture = textures::get_surface(surface_i);
-  const uint32_t *ceiling_texture = textures::get_ceiling(surface_i);
+  const RGBA *ceiling_texture = textures::get_ceiling(surface_i);
 
   for(int y = $height / 2 + 1; y < $height; ++y) {
     // rayDir for leftmost ray (x=0) and rightmost (x = w)
@@ -375,7 +375,7 @@ void Raycaster::draw_ceiling_floor() {
       floor_y += floor_step_y;
 
       // now get the pixel from the texture
-      uint32_t color;
+      RGBA color;
       // this uses the previous ty/tx fractional parts of
       // floor_x cell_x to find the texture x/y. How?
       int map_x = int(floor_x);