Update colour_t to use a union

include/window/window.h

@@ -7,10 +7,17 @@
 #include <stdbool.h>
 
 typedef struct {
-  u8 r;
-  u8 g;
-  u8 b;
   u8 a;
+  u8 b;
+  u8 g;
+  u8 r;
+} rgba_t;
+
+typedef struct {
+  union {
+    rgba_t rgba;
+    u32 colour;
+  };
 } colour_t;
 
 typedef struct {

src/raytracer/main.c

@@ -31,7 +31,8 @@ colour_t trace_ray(vec3f_t origin, vec3f_t direction, f32 t_min, f32 t_max,
                    const scene_t *scene, colour_t default_colour);
 
 i32 main(i32 argc, char *argv[]) {
-  colour_t bg = (colour_t){.r = 27, .g = 38, .b = 79, .a = 255};
+  colour_t bg =
+      (colour_t){.rgba.r = 27, .rgba.g = 38, .rgba.b = 79, .rgba.a = 255};
   vec3f_t camera = {.x = 0.0f, .y = 0.0f, .z = 0.0f};
   vec3f_t viewport = {.x = 1.0f, .y = 1.0f, .z = 1.0f};
 
@@ -48,17 +49,23 @@ i32 main(i32 argc, char *argv[]) {
       (sphere_t){
           .radius = 1.0f,
           .centre = (vec3f_t){.x = 0.0f, .y = -1.0f, .z = 3.0f},
-          .colour = (colour_t){.r = 245, .g = 238, .b = 158, .a = 255},
+          .colour =
+              (colour_t){
+                  .rgba.r = 245, .rgba.g = 238, .rgba.b = 158, .rgba.a = 255},
       },
       (sphere_t){
           .radius = 1.0f,
           .centre = (vec3f_t){.x = -2.0f, .y = 0.0f, .z = 4.0f},
-          .colour = (colour_t){.r = 59, .g = 142, .b = 165, .a = 255},
+          .colour =
+              (colour_t){
+                  .rgba.r = 59, .rgba.g = 142, .rgba.b = 165, .rgba.a = 255},
       },
       (sphere_t){
           .radius = 1.0f,
           .centre = (vec3f_t){.x = 2.0f, .y = 0.0f, .z = 4.0f},
-          .colour = (colour_t){.r = 171, .g = 52, .b = 40, .a = 255},
+          .colour =
+              (colour_t){
+                  .rgba.r = 171, .rgba.g = 52, .rgba.b = 40, .rgba.a = 255},
       },
   };
 

src/window/window.c

@@ -8,7 +8,6 @@
 #include <stdbool.h>
 #include <stdio.h>
 
-u32 colour_to_u32(colour_t colour);
 u32 index_from_coordinates(window_t *wnd, u32 x, u32 y);
 i32 denormalise(i32 value, u32 max, u32 abs_half);
 vec2i_t denormalised_coords(const window_t *wnd, i32 x, i32 y);
@@ -92,13 +91,11 @@ void close_window(window_t *wnd) {
 void clear_window(window_t *wnd, colour_t colour) {
   SDL_LockSurface(wnd->back_buffer);
 
-  u32 c = colour_to_u32(colour);
-
   u32 *pixels = (u32 *)(wnd->back_buffer->pixels);
   u32 count = wnd->back_buffer->w * wnd->back_buffer->h;
 
   for (u32 i = 0; i < count; ++i) {
-    pixels[i] = c;
+    pixels[i] = colour.colour;
   }
 
   SDL_UnlockSurface(wnd->back_buffer);
@@ -124,11 +121,6 @@ void swap_buffers(window_t *wnd) {
   SDL_UpdateWindowSurface(wnd->window);
 }
 
-u32 colour_to_u32(colour_t colour) {
-  return ((u32)(colour.r) << 24) | ((u32)(colour.g) << 16) |
-         ((u32)(colour.b) << 8) | (u32)(colour.a);
-}
-
 u32 index_from_coordinates(window_t *wnd, u32 x, u32 y) {
   return y * wnd->width + x;
 }
@@ -160,11 +152,9 @@ vec2i_t denormalised_coords(const window_t *wnd, i32 x, i32 y) {
 
 void set_screen_pixel(window_t *wnd, u32 x, u32 y, colour_t colour) {
   u32 index = index_from_coordinates(wnd, x, y);
-  u32 c = colour_to_u32(colour);
-
   u32 *pixels = (u32 *)(wnd->back_buffer->pixels);
 
-  pixels[index] = c;
+  pixels[index] = colour.colour;
 }
 
 vec3f_t window_to_viewport(window_t *wnd, i32 x, i32 y, vec3f_t viewport) {