Add memcpy16_tile8_with_palette_offset function and update affine_background_init to use it

include/graphic_utils.h

@@ -120,4 +120,9 @@ void tte_erase_rect_wrapper(Rect rect);
  */
 void update_text_rect_to_right_align_num(Rect* rect, int num, int overflow_direction);
 
+/*Copies 16 bit data from src to dst, applying a palette offset to the data.
+ * This is intended solely for use with tile8/8bpp data for dst and src.
+ */
+void memcpy16_tile8_with_palette_offset(void* dst, const void* src, uint hwcount, u8 palette_offset);
+
 #endif //GRAPHIC_UTILS_H

source/affine_background.c

@@ -8,14 +8,7 @@ AFF_SRC_EX asx = {32<<8, 64<<8, 120, 80, 0x0100, 0x0100, 0};
 
 void affine_background_init()
 {
-    unsigned int correctedTiles[affine_background_gfxTilesLen / 4];
+    memcpy16_tile8_with_palette_offset(&tile8_mem[AFFINE_BG_CBB], affine_background_gfxTiles, affine_background_gfxTilesLen/2, AFFINE_BG_PB);
-
-    for (int i = 0; i < affine_background_gfxTilesLen / 4; i++)
-    {   
-        correctedTiles[i] = affine_background_gfxTiles[i] | 0xF0F0F0F0;
-    }
-
-    memcpy16(&tile8_mem[AFFINE_BG_CBB], correctedTiles, affine_background_gfxTilesLen/2);
     GRIT_CPY(&se_mem[AFFINE_BG_SBB], affine_background_gfxMap);
     memcpy16(&pal_bg_mem[AFFINE_BG_PB], affine_background_gfxPal, AFFINE_BG_PAL_LEN);
 

source/graphic_utils.c

@@ -168,3 +168,14 @@ void update_text_rect_to_right_align_num(Rect* rect, int num, int overflow_direc
     }
 }
 
+void memcpy16_tile8_with_palette_offset(void* dst, const void* src, uint hwcount, u8 palette_offset)
+{
+    u16* dst16 = (u16*)dst;
+    const u16* src16 = (const u16*)src;
+
+    for (int i = 0; i < hwcount; i++)
+    {
+        // Copying u8 data twice across u16 data
+        dst16[i] = src16[i] + (((palette_offset) << 8) | (palette_offset));
+    }
+}