From 44c2d15ca9f3b1b758fc70acdf6d0cf1cf74cf5f Mon Sep 17 00:00:00 2001
From: Kurausukun <lord.uber1@gmail.com>
Date: Fri, 23 Oct 2020 22:07:30 -0400
Subject: [PATCH] re-match sub_81C79BC (from #1177)

also re-define RBG macros
---
 include/constants/rgb.h |   4 +
 include/pokenav.h       |   2 +-
 src/pokenav_main_menu.c | 166 ++++++++--------------------------------
 3 files changed, 39 insertions(+), 133 deletions(-)

diff --git a/include/constants/rgb.h b/include/constants/rgb.h
index 80d951f4b..1896250d2 100644
--- a/include/constants/rgb.h
+++ b/include/constants/rgb.h
@@ -1,6 +1,10 @@
 #ifndef GUARD_RGB_H
 #define GUARD_RGB_H
 
+#define GET_R(color) ((color) & 0x1F)
+#define GET_G(color) (((color) >> 5) & 0x1F)
+#define GET_B(color) (((color) >> 10) & 0x1F)
+
 #define RGB(r, g, b) ((r) | ((g) << 5) | ((b) << 10))
 #define RGB2(r, g, b) (((b) << 10) | ((g) << 5) | (r))
 #define _RGB(r, g, b) ((((b) & 0x1F) << 10) + (((g) & 0x1F) << 5) + ((r) & 0x1F))
diff --git a/include/pokenav.h b/include/pokenav.h
index ac916f3ba..ed4e5a906 100644
--- a/include/pokenav.h
+++ b/include/pokenav.h
@@ -313,7 +313,7 @@ bool32 WaitForHelpBar(void);
 void sub_81C78A0(void);
 bool32 MainMenuLoopedTaskIsBusy(void);
 void sub_81C7FDC(void);
-void sub_81C79BC(const u16 *a0, const u16 *a1, u32 a2, u32 a3, u32 a4, u16 *a5);
+void sub_81C79BC(const u16 *a0, const u16 *a1, int a2, int a3, int a4, u16 *palette);
 void sub_81C7B40(void);
 struct Sprite *PauseSpinningPokenavSprite(void);
 void ResumeSpinningPokenavSprite(void);
diff --git a/src/pokenav_main_menu.c b/src/pokenav_main_menu.c
index 0e2425d4e..a100e2c23 100644
--- a/src/pokenav_main_menu.c
+++ b/src/pokenav_main_menu.c
@@ -471,139 +471,41 @@ void sub_81C7990(u32 a0, u16 a1)
     CpuFill16(a1, gPlttBufferFaded + 0x100 + (a0 * 16), 16 * sizeof(u16));
 }
 
-NAKED
-void sub_81C79BC(const u16 *a0, const u16 *a1, u32 a2, u32 a3, u32 a4, u16 *a5)
+void sub_81C79BC(const u16 *a0, const u16 *a1, int a2, int a3, int a4, u16 *palette)
 {
-    asm_unified(
-    "push {r4-r7,lr}\n\
-    mov r7, r10\n\
-    mov r6, r9\n\
-    mov r5, r8\n\
-    push {r5-r7}\n\
-    sub sp, 0xC\n\
-    str r0, [sp]\n\
-    str r1, [sp, 0x4]\n\
-    mov r10, r2\n\
-    str r3, [sp, 0x8]\n\
-    ldr r0, [sp, 0x2C]\n\
-    cmp r0, 0\n\
-    bne _081C79E4\n\
-    ldr r2, =0x001fffff\n\
-    mov r1, r10\n\
-    ands r2, r1\n\
-    ldr r0, [sp]\n\
-    b _081C79F4\n\
-    .pool\n\
-_081C79E4:\n\
-    ldr r2, [sp, 0x2C]\n\
-    ldr r0, [sp, 0x8]\n\
-    cmp r2, r0\n\
-    blt _081C7A00\n\
-    ldr r2, =0x001fffff\n\
-    mov r1, r10\n\
-    ands r2, r1\n\
-    ldr r0, [sp, 0x4]\n\
-_081C79F4:\n\
-    ldr r1, [sp, 0x30]\n\
-    bl CpuSet\n\
-    b _081C7AAE\n\
-    .pool\n\
-_081C7A00:\n\
-    movs r2, 0x1\n\
-    negs r2, r2\n\
-    add r10, r2\n\
-    b _081C7AA6\n\
-_081C7A08:\n\
-    ldr r1, [sp]\n\
-    ldrh r0, [r1]\n\
-    movs r2, 0x1F\n\
-    mov r9, r2\n\
-    mov r1, r9\n\
-    ands r1, r0\n\
-    mov r9, r1\n\
-    lsls r0, 16\n\
-    lsrs r2, r0, 21\n\
-    movs r1, 0x1F\n\
-    ands r1, r2\n\
-    mov r8, r1\n\
-    lsrs r7, r0, 26\n\
-    movs r2, 0x1F\n\
-    ands r7, r2\n\
-    ldr r0, [sp, 0x4]\n\
-    ldrh r4, [r0]\n\
-    movs r0, 0x1F\n\
-    ands r0, r4\n\
-    mov r1, r9\n\
-    subs r0, r1\n\
-    lsls r0, 8\n\
-    ldr r1, [sp, 0x8]\n\
-    bl __divsi3\n\
-    ldr r2, [sp, 0x2C]\n\
-    adds r6, r0, 0\n\
-    muls r6, r2\n\
-    asrs r6, 8\n\
-    lsls r4, 16\n\
-    lsrs r0, r4, 21\n\
-    movs r1, 0x1F\n\
-    ands r0, r1\n\
-    mov r2, r8\n\
-    subs r0, r2\n\
-    lsls r0, 8\n\
-    ldr r1, [sp, 0x8]\n\
-    bl __divsi3\n\
-    ldr r1, [sp, 0x2C]\n\
-    adds r5, r0, 0\n\
-    muls r5, r1\n\
-    asrs r5, 8\n\
-    lsrs r4, 26\n\
-    movs r2, 0x1F\n\
-    ands r4, r2\n\
-    subs r4, r7\n\
-    lsls r4, 8\n\
-    adds r0, r4, 0\n\
-    ldr r1, [sp, 0x8]\n\
-    bl __divsi3\n\
-    ldr r1, [sp, 0x2C]\n\
-    muls r0, r1\n\
-    asrs r0, 8\n\
-    add r6, r9\n\
-    movs r2, 0x1F\n\
-    ands r6, r2\n\
-    add r5, r8\n\
-    ands r5, r2\n\
-    adds r0, r7, r0\n\
-    ands r0, r2\n\
-    lsls r0, 10\n\
-    lsls r5, 5\n\
-    orrs r0, r5\n\
-    orrs r0, r6\n\
-    ldr r1, [sp, 0x30]\n\
-    strh r0, [r1]\n\
-    ldr r2, [sp]\n\
-    adds r2, 0x2\n\
-    str r2, [sp]\n\
-    ldr r0, [sp, 0x4]\n\
-    adds r0, 0x2\n\
-    str r0, [sp, 0x4]\n\
-    adds r1, 0x2\n\
-    str r1, [sp, 0x30]\n\
-    movs r1, 0x1\n\
-    negs r1, r1\n\
-    add r10, r1\n\
-_081C7AA6:\n\
-    movs r0, 0x1\n\
-    negs r0, r0\n\
-    cmp r10, r0\n\
-    bne _081C7A08\n\
-_081C7AAE:\n\
-    add sp, 0xC\n\
-    pop {r3-r5}\n\
-    mov r8, r3\n\
-    mov r9, r4\n\
-    mov r10, r5\n\
-    pop {r4-r7}\n\
-    pop {r0}\n\
-    bx r0");
+
+    if (a4 == 0)
+    {
+        CpuCopy16(a0, palette, a2 * 2);
+    }
+    else if (a4 >= a3)
+    {
+        CpuCopy16(a1, palette, a2 * 2);
+    }
+    else
+    {
+        int r, g, b;
+        int r1, g1, b1;
+        while (a2--)
+        {
+            r = GET_R(*a0);
+            g = GET_G(*a0);
+            b = GET_B(*a0);
+
+            r1 = ((((GET_R(*a1) << 8) - (r << 8)) / a3) * a4) >> 8;
+            g1 = ((((GET_G(*a1) << 8) - (g << 8)) / a3) * a4) >> 8;
+            b1 = ((((GET_B(*a1) << 8) - (b << 8)) / a3) * a4) >> 8;
+
+            r = (r + r1) & 0x1F; //_RGB(r + r1, g + g1, b + b1); doesn't match; I have to assign the value of ((r + r1) & 0x1F) to r1
+            g = (g + g1) & 0x1F; //See above
+            b = (b + b1) & 0x1F; //See above
+
+            *palette = RGB2(r, g, b); //See above comment
+
+            a0++, a1++;
+            palette++;
+        }
+    }
 }
 
 void PokenavFadeScreen(s32 fadeType)