Match ApplyFadeOnColor from color_effects.c (lucky guess)

README.md

@@ -2,7 +2,7 @@
 
 This is a work in progress decompilation of Metroid - Zero Mission.
 
-2697/2721 functions decompiled (99.11%, 24 left)
+2698/2721 functions decompiled (99.15%, 23 left)
 
 0x76b014/0x76b014 bytes of data not in blobs (100%, 0 left)
 

src/color_effects.c

@@ -612,16 +612,23 @@ void ApplySpecialBackgroundFadingColor(u8 type, u8 color, u16** ppSrc, u16** ppD
     }
 }
 
-#ifdef NON_MATCHING
+/**
+ * @brief 5bbe4 | cc | Applies a fade effect on a color, unused
+ * 
+ * @param type Fading type
+ * @param color Color
+ * @param currentColor Current color
+ */
 u16 ApplyFadeOnColor(u8 type, u16 color, u8 currentColor)
 {
-    // https://decomp.me/scratch/RdwBt
+    u8 red;
+    u8 green;
+    u8 blue;
 
-    s32 red;
-    s32 green;
-    s32 blue;
+    u32 tmp_red;
 
-    red = RED(color);
+    tmp_red = RED(color);
+    red = tmp_red; // Needed to produce matching ASM.
     green = GREEN(color);
     blue = BLUE(color);
 
@@ -654,120 +661,3 @@ u16 ApplyFadeOnColor(u8 type, u16 color, u8 currentColor)
 
     return COLOR_GRAD(red, green, blue);
 }
-#else
-NAKED_FUNCTION
-u16 ApplyFadeOnColor(u8 type, u16 color, u8 currentColor)
-{
-    asm(" \n\
-    push {r4, r5, r6, r7, lr} \n\
-    lsl r0, r0, #0x18 \n\
-    lsr r6, r0, #0x18 \n\
-    mov ip, r6 \n\
-    lsl r1, r1, #0x10 \n\
-    lsr r1, r1, #0x10 \n\
-    lsl r2, r2, #0x18 \n\
-    lsr r5, r2, #0x18 \n\
-    movs r7, #0x1f \n\
-    add r3, r1, #0 \n\
-    and r3, r7 \n\
-    movs r0, #0xf8 \n\
-    lsl r0, r0, #2 \n\
-    and r0, r1 \n\
-    lsr r4, r0, #5 \n\
-    movs r0, #0xf8 \n\
-    lsl r0, r0, #7 \n\
-    and r0, r1 \n\
-    lsr r2, r0, #0xa \n\
-    cmp r6, #1 \n\
-    beq lbl_0805bc3e \n\
-    cmp r6, #1 \n\
-    bgt lbl_0805bc18 \n\
-    cmp r6, #0 \n\
-    beq lbl_0805bc24 \n\
-    b lbl_0805bc9e \n\
-lbl_0805bc18: \n\
-    mov r0, ip \n\
-    cmp r0, #2 \n\
-    beq lbl_0805bc5e \n\
-    cmp r0, #3 \n\
-    beq lbl_0805bc7e \n\
-    b lbl_0805bc9e \n\
-lbl_0805bc24: \n\
-    add r0, r3, #0 \n\
-    mul r0, r5, r0 \n\
-    asr r3, r0, #5 \n\
-    movs r1, #0x1f \n\
-    and r3, r1 \n\
-    add r0, r4, #0 \n\
-    mul r0, r5, r0 \n\
-    asr r4, r0, #5 \n\
-    and r4, r1 \n\
-    add r0, r2, #0 \n\
-    mul r0, r5, r0 \n\
-    asr r2, r0, #5 \n\
-    b lbl_0805bc9c \n\
-lbl_0805bc3e: \n\
-    sub r0, r7, r3 \n\
-    mul r0, r5, r0 \n\
-    asr r0, r0, #5 \n\
-    movs r1, #0x1f \n\
-    sub r3, r1, r0 \n\
-    and r3, r1 \n\
-    sub r0, r7, r4 \n\
-    mul r0, r5, r0 \n\
-    asr r0, r0, #5 \n\
-    sub r4, r1, r0 \n\
-    and r4, r1 \n\
-    sub r0, r7, r2 \n\
-    mul r0, r5, r0 \n\
-    asr r0, r0, #5 \n\
-    sub r2, r1, r0 \n\
-    b lbl_0805bc9c \n\
-lbl_0805bc5e: \n\
-    add r0, r3, #0 \n\
-    mul r0, r5, r0 \n\
-    asr r0, r0, #5 \n\
-    sub r3, r3, r0 \n\
-    movs r1, #0x1f \n\
-    and r3, r1 \n\
-    add r0, r4, #0 \n\
-    mul r0, r5, r0 \n\
-    asr r0, r0, #5 \n\
-    sub r4, r4, r0 \n\
-    and r4, r1 \n\
-    add r0, r2, #0 \n\
-    mul r0, r5, r0 \n\
-    asr r0, r0, #5 \n\
-    sub r2, r2, r0 \n\
-    b lbl_0805bc9c \n\
-lbl_0805bc7e: \n\
-    sub r0, r7, r3 \n\
-    mul r0, r5, r0 \n\
-    asr r0, r0, #5 \n\
-    add r3, r3, r0 \n\
-    movs r1, #0x1f \n\
-    and r3, r1 \n\
-    sub r0, r7, r4 \n\
-    mul r0, r5, r0 \n\
-    asr r0, r0, #5 \n\
-    add r4, r4, r0 \n\
-    and r4, r1 \n\
-    sub r0, r7, r2 \n\
-    mul r0, r5, r0 \n\
-    asr r0, r0, #5 \n\
-    add r2, r2, r0 \n\
-lbl_0805bc9c: \n\
-    and r2, r1 \n\
-lbl_0805bc9e: \n\
-    lsl r0, r4, #5 \n\
-    orr r3, r0 \n\
-    lsl r0, r2, #0xa \n\
-    orr r3, r0 \n\
-    lsl r0, r3, #0x10 \n\
-    lsr r0, r0, #0x10 \n\
-    pop {r4, r5, r6, r7} \n\
-    pop {r1} \n\
-    bx r1 \n\
-    ");
-}
-#endif