From b7426f93c0b1082be51e920a2db6a81fd139752d Mon Sep 17 00:00:00 2001
From: Lior Halphon <LIJI32@gmail.com>
Date: Fri, 20 Jul 2018 23:23:47 +0300
Subject: [PATCH] Randomize object palettes. Slightly more accurate emulation
 of FF4C.

---
 Core/gb.c     | 17 +++++++++++++++++
 Core/memory.c |  3 ++-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/Core/gb.c b/Core/gb.c
index 8ce8326..ff5851e 100644
--- a/Core/gb.c
+++ b/Core/gb.c
@@ -344,7 +344,13 @@ void GB_set_rgb_encode_callback(GB_gameboy_t *gb, GB_rgb_encode_callback_t callb
         gb->sprite_palettes_rgb[7] = gb->sprite_palettes_rgb[3] = gb->background_palettes_rgb[3] =
         callback(gb, 0, 0, 0);
     }
+
     gb->rgb_encode_callback = callback;
+    
+    for (unsigned i = 0; i < 32; i++) {
+        GB_palette_changed(gb, true, i * 2);
+        GB_palette_changed(gb, false, i * 2);
+    }
 }
 
 void GB_set_infrared_callback(GB_gameboy_t *gb, GB_infrared_callback_t callback)
@@ -489,6 +495,17 @@ static void reset_ram(GB_gameboy_t *gb)
     for (unsigned i = 0; i < sizeof(gb->extra_oam); i++) {
         gb->extra_oam[i] = (random() & 0xFF);
     }
+    
+    if (GB_is_cgb(gb)) {
+        for (unsigned i = 0; i < 64; i++) {
+            gb->background_palettes_data[i] = random() & 0xFF; /* Doesn't really matter as the boot ROM overrides it anyway*/
+            gb->sprite_palettes_data[i] = random() & 0xFF;
+        }
+        for (unsigned i = 0; i < 32; i++) {
+            GB_palette_changed(gb, true, i * 2);
+            GB_palette_changed(gb, false, i * 2);
+        }
+    }
 }
 
 void GB_reset(GB_gameboy_t *gb)
diff --git a/Core/memory.c b/Core/memory.c
index b658fd5..412af34 100644
--- a/Core/memory.c
+++ b/Core/memory.c
@@ -734,8 +734,9 @@ static void write_high_memory(GB_gameboy_t *gb, uint16_t addr, uint8_t value)
                 return;
 
             case GB_IO_DMG_EMULATION:
+                GB_log(gb, "4c = %x\n", value);
                 if (GB_is_cgb(gb) && !gb->boot_rom_finished) {
-                    gb->cgb_mode = value != 4; /* The real "contents" of this register aren't quite known yet. */
+                    gb->cgb_mode = !(value & 0xC); /* The real "contents" of this register aren't quite known yet. */
                 }
                 return;