From 527fbf0fc5bbe2c8f82d06e38cfabd4b0b8fd6cb Mon Sep 17 00:00:00 2001
From: Jeffrey Pfau <jeffrey@endrift.com>
Date: Sun, 28 Jun 2015 23:50:17 -0700
Subject: [PATCH] GBA Hardware: Add a function for detecting a GB
 Player-compatible game

---
 src/gba/hardware.c | 24 ++++++++++++++++++++++++
 src/gba/hardware.h |  3 +++
 2 files changed, 27 insertions(+)

diff --git a/src/gba/hardware.c b/src/gba/hardware.c
index f2a6fef44..b11204e66 100644
--- a/src/gba/hardware.c
+++ b/src/gba/hardware.c
@@ -6,6 +6,7 @@
 #include "hardware.h"
 
 #include "gba/serialize.h"
+#include "util/hash.h"
 
 static void _readPins(struct GBACartridgeHardware* hw);
 static void _outputPins(struct GBACartridgeHardware* hw, unsigned pins);
@@ -420,6 +421,29 @@ uint8_t GBAHardwareTiltRead(struct GBACartridgeHardware* hw, uint32_t address) {
 	return 0xFF;
 }
 
+// == Game Boy Player
+
+static const uint16_t _logoPalette[] = {
+	0xFFDF, 0x640C, 0xE40C, 0xE42D, 0x644E, 0xE44E, 0xE46E, 0x68AF,
+	0xE8B0, 0x68D0, 0x68F0, 0x6911, 0xE911, 0x6D32, 0xED32, 0xED73,
+	0x6D93, 0xED94, 0x6DB4, 0xF1D5, 0x71F5, 0xF1F6, 0x7216, 0x7257,
+	0xF657, 0x7678, 0xF678, 0xF699, 0xF6B9, 0x76D9, 0xF6DA, 0x7B1B,
+	0xFB1B, 0xFB3C, 0x7B5C, 0x7B7D, 0xFF7D, 0x7F9D, 0x7FBE, 0x7FFF,
+	0x642D, 0x648E, 0xE88F, 0xE8F1, 0x6D52, 0x6D73, 0xF1B4, 0xF216,
+	0x7237, 0x7698, 0x7AFA, 0xFAFA, 0xFB5C, 0xFFBE, 0x7FDE, 0xFFFF,
+	0xFFFF, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000
+};
+
+static const uint32_t _logoHash = 0xEEDA6963;
+
+bool GBAHardwarePlayerCheckScreen(const struct GBAVideo* video) {
+	if (memcmp(video->palette, _logoPalette, sizeof(_logoPalette)) != 0) {
+		return false;
+	}
+	uint32_t hash = hash32(&video->renderer->vram[0x4000], 0x4000, 0);
+	return hash == _logoHash;
+}
+
 // == Serialization
 
 void GBAHardwareSerialize(const struct GBACartridgeHardware* hw, struct GBASerializedState* state) {
diff --git a/src/gba/hardware.h b/src/gba/hardware.h
index d7c9a6dfc..6c6da3932 100644
--- a/src/gba/hardware.h
+++ b/src/gba/hardware.h
@@ -129,6 +129,9 @@ void GBAHardwareGPIOWrite(struct GBACartridgeHardware* gpio, uint32_t address, u
 void GBAHardwareTiltWrite(struct GBACartridgeHardware* gpio, uint32_t address, uint8_t value);
 uint8_t GBAHardwareTiltRead(struct GBACartridgeHardware* gpio, uint32_t address);
 
+struct GBAVideo;
+bool GBAHardwarePlayerCheckScreen(cosnt struct GBAVideo* video);
+
 struct GBASerializedState;
 void GBAHardwareSerialize(const struct GBACartridgeHardware* gpio, struct GBASerializedState* state);
 void GBAHardwareDeserialize(struct GBACartridgeHardware* gpio, const struct GBASerializedState* state);