From 371f6913e7570a5cede360262f1e04bc1ef46435 Mon Sep 17 00:00:00 2001
From: Jeffrey Pfau <jeffrey@endrift.com>
Date: Wed, 17 Feb 2016 19:42:06 -0800
Subject: [PATCH] GB IO: Make palettes readable

---
 src/gb/io.c    | 6 +++++-
 src/gb/video.c | 2 ++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/gb/io.c b/src/gb/io.c
index bafccc14c..d1aab6aa0 100644
--- a/src/gb/io.c
+++ b/src/gb/io.c
@@ -329,6 +329,7 @@ void GBIOWrite(struct GB* gb, unsigned address, uint8_t value) {
 			case REG_BCPS:
 				gb->video.bcpIndex = value & 0x3F;
 				gb->video.bcpIncrement = value & 0x80;
+				gb->memory.io[REG_BCPD] = gb->video.palette[gb->video.bcpIndex >> 1];
 				break;
 			case REG_BCPD:
 				GBVideoProcessDots(&gb->video);
@@ -337,6 +338,7 @@ void GBIOWrite(struct GB* gb, unsigned address, uint8_t value) {
 			case REG_OCPS:
 				gb->video.ocpIndex = value & 0x3F;
 				gb->video.ocpIncrement = value & 0x80;
+				gb->memory.io[REG_OCPD] = gb->video.palette[8 * 4 + (gb->video.ocpIndex >> 1)];
 				break;
 			case REG_OCPD:
 				GBVideoProcessDots(&gb->video);
@@ -453,14 +455,16 @@ uint8_t GBIORead(struct GB* gb, unsigned address) {
 	default:
 		if (gb->model >= GB_MODEL_CGB) {
 			switch (address) {
+			case REG_KEY1:
 			case REG_VBK:
 			case REG_HDMA1:
 			case REG_HDMA2:
 			case REG_HDMA3:
 			case REG_HDMA4:
 			case REG_HDMA5:
+			case REG_BCPD:
+			case REG_OCPD:
 			case REG_SVBK:
-			case REG_KEY1:
 				// Handled transparently by the registers
 				goto success;
 			default:
diff --git a/src/gb/video.c b/src/gb/video.c
index b11ef2c6a..9a97c3407 100644
--- a/src/gb/video.c
+++ b/src/gb/video.c
@@ -314,6 +314,7 @@ void GBVideoWritePalette(struct GBVideo* video, uint16_t address, uint8_t value)
 			if (video->bcpIncrement) {
 				++video->bcpIndex;
 				video->bcpIndex &= 0x3F;
+				video->p->memory.io[REG_BCPD] = video->palette[video->bcpIndex >> 1];
 			}
 			break;
 		case REG_OCPD:
@@ -328,6 +329,7 @@ void GBVideoWritePalette(struct GBVideo* video, uint16_t address, uint8_t value)
 			if (video->ocpIncrement) {
 				++video->ocpIndex;
 				video->ocpIndex &= 0x3F;
+				video->p->memory.io[REG_OCPD] = video->palette[8 * 4 + (video->ocpIndex >> 1)];
 			}
 			break;
 		}