From ad9858a56407764ba96241d978856496f517f285 Mon Sep 17 00:00:00 2001
From: Sergio Martin <eienburuu@gmail.com>
Date: Sun, 14 Jan 2024 19:28:40 +0100
Subject: [PATCH] Adding no frills memcpy-based ines loader

---
 meson_options.txt        |  1 -
 source/core/Nes_Cart.cpp | 21 +++++++++++++++++++++
 source/core/Nes_Cart.h   |  1 +
 source/core/Nes_Emu.cpp  |  7 +++++++
 source/core/Nes_Emu.h    |  1 +
 source/emuInstance.hpp   | 14 ++++++++++----
 6 files changed, 40 insertions(+), 5 deletions(-)

diff --git a/meson_options.txt b/meson_options.txt
index 88c694e..935082b 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -11,6 +11,5 @@ option('CPUFunctionAlignment',
   value : 1024,
   description : '''Indicates the alignment for the main emulator CPU function.
                  This is a large function that may cross page boundaries, which impacts performance. 
-                 We recommend setting this value for the architecture own page size. 
                  This requires the GNU compiler to work.'''
 )
\ No newline at end of file
diff --git a/source/core/Nes_Cart.cpp b/source/core/Nes_Cart.cpp
index 5a1ccde..a205150 100644
--- a/source/core/Nes_Cart.cpp
+++ b/source/core/Nes_Cart.cpp
@@ -118,3 +118,24 @@ const char * Nes_Cart::load_ines( Auto_File_Reader in )
 	
 	return 0;
 }
+
+const char * Nes_Cart::load_ines( const uint8_t* buffer )
+{
+	ines_header_t h;
+
+	size_t bufferPos = 0;
+	{ size_t copySize = sizeof(ines_header_t); memcpy(&h, &buffer[bufferPos], copySize); bufferPos += copySize; }
+	if ( h.zero [7] )	h.flags2 = 0;
+	set_mapper( h.flags, h.flags2 );
+	
+	// skip trainer
+	if ( h.flags & 0x04 ) bufferPos += 512;
+	
+	resize_prg( h.prg_count * 16 * 1024L );
+	resize_chr( h.chr_count * 8 * 1024L );
+	
+	{ size_t copySize = prg_size(); memcpy(prg(), &buffer[bufferPos], copySize); bufferPos += copySize; }
+	{ size_t copySize = chr_size(); memcpy(chr(), &buffer[bufferPos], copySize); bufferPos += copySize; }
+
+	return 0;
+}
diff --git a/source/core/Nes_Cart.h b/source/core/Nes_Cart.h
index 18417ca..7548ab2 100644
--- a/source/core/Nes_Cart.h
+++ b/source/core/Nes_Cart.h
@@ -16,6 +16,7 @@ public:
 	~Nes_Cart();
 	
 	// Load iNES file
+	const char * load_ines( const uint8_t* buffer );
 	const char * load_ines( Auto_File_Reader );
 	static const char not_ines_file [];
 	
diff --git a/source/core/Nes_Emu.cpp b/source/core/Nes_Emu.cpp
index 9057fea..e806f02 100644
--- a/source/core/Nes_Emu.cpp
+++ b/source/core/Nes_Emu.cpp
@@ -189,6 +189,13 @@ const char * Nes_Emu::emulate_frame( int joypad1, int joypad2 )
 
 // Extras
 
+const char * Nes_Emu::load_ines( const uint8_t* buffer )
+{
+	close();
+	private_cart.load_ines( buffer );
+	return set_cart( &private_cart );
+}
+
 const char * Nes_Emu::load_ines( Auto_File_Reader in )
 {
 	close();
diff --git a/source/core/Nes_Emu.h b/source/core/Nes_Emu.h
index 7a2ab46..bf78e6f 100644
--- a/source/core/Nes_Emu.h
+++ b/source/core/Nes_Emu.h
@@ -21,6 +21,7 @@ public:
 
 	// Load iNES file into emulator and clear recording
 	const char * load_ines( Auto_File_Reader );
+	const char * load_ines( const uint8_t* buffer );
 
 	// Set sample rate for sound generation
 	const char * set_sample_rate( long );
diff --git a/source/emuInstance.hpp b/source/emuInstance.hpp
index 522c205..ab848e3 100644
--- a/source/emuInstance.hpp
+++ b/source/emuInstance.hpp
@@ -46,10 +46,16 @@ class EmuInstance
   _romSHA1String = SHA1::GetHash((uint8_t*)romData.data(), romData.size());
 
   // Loading the rom into the emulator
-  Mem_File_Reader romReader(romData.data(), (int)romData.size());
-  Auto_File_Reader romFile(romReader);
-  auto result = _nes->load_ines(romFile);
-  if (result != 0) EXIT_WITH_ERROR("Could not initialize emulator with rom file: %s\n", romFilePath.c_str());
+  #ifdef USE_ORIGINAL_QUICKNES
+    Mem_File_Reader romReader(romData.data(), (int)romData.size());
+    Auto_File_Reader romFile(romReader);
+    auto result = _nes->load_ines(romFile);
+    if (result != 0) EXIT_WITH_ERROR("Could not initialize emulator with rom file: %s\n", romFilePath.c_str());
+  #else
+    auto result = _nes->load_ines((const uint8_t*) romData.data());
+    if (result != 0) EXIT_WITH_ERROR("Could not initialize emulator with rom file: %s\n", romFilePath.c_str());
+  #endif
+   
 
   // Getting state size to use
   _stateSize = getStateSizeImpl();