Add affine background color functionality and integrate into game loop

source/affine_background.c

@@ -0,0 +1,63 @@
+#include "affine_background.h"
+#include "affine_background_gfx.h"
+
+#include "graphic_utils.h"
+
+BG_AFFINE bgaff;
+AFF_SRC_EX asx = {32<<8, 64<<8, 120, 80, 0x0100, 0x0100, 0};
+
+void affine_background_init()
+{
+    unsigned int correctedTiles[affine_background_gfxTilesLen / 4];
+
+    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);
+
+	bgaff = bg_aff_default;
+
+    affine_background_set_color(AFFINE_BG_DEFAULT_COLOR);
+}
+
+void affine_background_update()
+{
+    static uint timer = 0;
+    timer++;
+
+    // These values are not permament, just the current configuration for the affine background
+    asx.tex_x += 5;
+    asx.tex_y += 12;
+    asx.sx = (lu_sin(timer * 100)) >> 8; // Scale the sine value to fit in a s16
+    asx.sx += 256; // Add 256 to the sine value to make it positive
+    asx.sy = (lu_sin(timer * 100 + 0x4000)) >> 8; // Scale the sine value to fit in a s16
+    asx.sy += 256; // Add 256 to the sine value to make it positive
+    bg_rotscale_ex(&bgaff, &asx);
+	REG_BG_AFFINE[2] = bgaff;
+}
+
+void affine_background_set_color(COLOR color)
+{
+    memcpy16(&pal_bg_mem[AFFINE_BG_PB], affine_background_gfxPal, AFFINE_BG_PAL_LEN);
+    for (int i = 0; i < AFFINE_BG_PAL_LEN; i++)
+    {
+        COLOR old_color;
+        memcpy16(&old_color, &pal_bg_mem[AFFINE_BG_PB] + i, 1); // Copy the color from the background palette
+
+        int r, g, b;
+        r = (old_color >> 10) & 0b11111; // Extract red component
+        g = (old_color >> 5) & 0b11111; // Extract green component
+        b = old_color & 0b11111; // Extract blue component
+
+        int brightness = (r + g + b) / 3; // Calculate brightness
+
+        const float brightness_divergence = 0.03f; // The difference in brightness between each color in the palette
+        const float brightness_modifier = -0.4f; // The overall brightness modifier for the palette
+
+        clr_adj_brightness(&pal_bg_mem[AFFINE_BG_PB] + i, &color, 1, float2fx(brightness_modifier + (brightness * brightness_divergence))); // Adjust brightness for the palette colors
+    }
+}