New APIs, Document.m no longer requires GB_INTERNAL, fixed a bug where the sprite viewer showed incorrect sprites for some CGB exclusive games.

Cocoa/Document.m

@@ -1,4 +1,3 @@
-#define GB_INTERNAL // Todo: several debugging functions access the GB struct directly
 #include <AVFoundation/AVFoundation.h>
 #include <CoreAudio/CoreAudio.h>
 #include "GBAudioClient.h"
@@ -47,8 +46,8 @@
 @property GBAudioClient *audioClient;
 - (void) vblank;
 - (void) log: (const char *) log withAttributes: (GB_log_attributes) attributes;
-- (const char *) getDebuggerInput;
-- (const char *) getAsyncDebuggerInput;
+- (char *) getDebuggerInput;
+- (char *) getAsyncDebuggerInput;
 - (void) cameraRequestUpdate;
 - (uint8_t) cameraGetPixelAtX:(uint8_t)x andY:(uint8_t)y;
 - (void) printImage:(uint32_t *)image height:(unsigned) height
@@ -71,14 +70,14 @@ static void consoleLog(GB_gameboy_t *gb, const char *string, GB_log_attributes a
 static char *consoleInput(GB_gameboy_t *gb)
 {
     Document *self = (__bridge Document *)GB_get_user_data(gb);
-    return strdup([self getDebuggerInput]);
+    return [self getDebuggerInput];
 }
 
 static char *asyncConsoleInput(GB_gameboy_t *gb)
 {
     Document *self = (__bridge Document *)GB_get_user_data(gb);
-    const char *ret = [self getAsyncDebuggerInput];
-    return ret? strdup(ret) : NULL;
+    char *ret = [self getAsyncDebuggerInput];
+    return ret;
 }
 
 static uint32_t rgbEncode(GB_gameboy_t *gb, uint8_t r, uint8_t g, uint8_t b)
@@ -195,8 +194,7 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
     if (!running) return;
     GB_debugger_set_disabled(&gb, true);
     if (GB_debugger_is_stopped(&gb)) {
-        gb.debug_stopped = false;
-        [self consoleInput:nil];
+        [self interruptDebugInputRead];
     }
     stopping = true;
     running = false;
@@ -413,7 +411,7 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
         return !GB_debugger_is_stopped(&gb);
     }
     else if ([anItem action] == @selector(reset:) && anItem.tag != 0) {
-        [(NSMenuItem*)anItem setState:(anItem.tag == 1 && !gb.is_cgb) || (anItem.tag == 2 && gb.is_cgb)];
+        [(NSMenuItem*)anItem setState:(anItem.tag == 1 && !GB_is_cgb(&gb)) || (anItem.tag == 2 && GB_is_cgb(&gb))];
     }
     else if ([anItem action] == @selector(toggleBlend:)) {
         [(NSMenuItem*)anItem setState:self.view.shouldBlendFrameWithPrevious];
@@ -557,7 +555,14 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
     [sender setStringValue:@""];
 }
 
-- (const char *) getDebuggerInput
+- (void) interruptDebugInputRead
+{
+    [has_debugger_input lock];
+    [debugger_input_queue addObject:[NSNull null]];
+    [has_debugger_input unlockWithCondition:1];
+}
+
+- (char *) getDebuggerInput
 {
     [self log:">"];
     in_sync_input = true;
@@ -566,10 +571,13 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
     [debugger_input_queue removeObjectAtIndex:0];
     [has_debugger_input unlockWithCondition:[debugger_input_queue count] != 0];
     in_sync_input = false;
-    return [input UTF8String];
+    if ((id) input == [NSNull null]) {
+        return NULL;
+    }
+    return strdup([input UTF8String]);
 }
 
-- (const char *) getAsyncDebuggerInput
+- (char *) getAsyncDebuggerInput
 {
     [has_debugger_input lock];
     NSString *input = [debugger_input_queue firstObject];
@@ -577,7 +585,7 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
         [debugger_input_queue removeObjectAtIndex:0];
     }
     [has_debugger_input unlockWithCondition:[debugger_input_queue count] != 0];
-    return [input UTF8String];
+    return input? strdup([input UTF8String]): NULL;
 }
 
 - (IBAction)saveState:(id)sender
@@ -731,8 +739,7 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
             case 2:
             /* OAM */
             {
-                oamCount = GB_get_oam_info(&gb, oamInfo);
-                oamHeight = (gb.io_registers[GB_IO_LCDC] & 4) ? 16:8;
+                oamCount = GB_get_oam_info(&gb, oamInfo, &oamHeight);
                 dispatch_async(dispatch_get_main_queue(), ^{
                     if (!oamUpdating) {
                         oamUpdating = true;
@@ -799,17 +806,23 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
 
         uint16_t n_banks = 1;
         switch ([(GBMemoryByteArray *)(hex_controller.byteArray) mode]) {
-            case GBMemoryROM:
-                n_banks = gb.rom_size / 0x4000;
+            case GBMemoryROM: {
+                size_t rom_size;
+                GB_get_direct_access(&gb, GB_DIRECT_ACCESS_ROM, &rom_size, NULL);
+                n_banks = rom_size / 0x4000;
                 break;
+            }
             case GBMemoryVRAM:
-                n_banks = gb.is_cgb ? 2 : 1;
+                n_banks = GB_is_cgb(&gb) ? 2 : 1;
                 break;
-            case GBMemoryExternalRAM:
-                n_banks = (gb.mbc_ram_size + 0x1FFF) / 0x2000;
+            case GBMemoryExternalRAM: {
+                size_t ram_size;
+                GB_get_direct_access(&gb, GB_DIRECT_ACCESS_CART_RAM, &ram_size, NULL);
+                n_banks = (ram_size + 0x1FFF) / 0x2000;
                 break;
+            }
             case GBMemoryRAM:
-                n_banks = gb.is_cgb ? 8 : 1;
+                n_banks = GB_is_cgb(&gb) ? 8 : 1;
                 break;
             case GBMemoryEntireSpace:
                 break;
@@ -833,23 +846,28 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
     self.memoryBankItem.enabled = [sender indexOfSelectedItem] != GBMemoryEntireSpace;
     GBMemoryByteArray *byteArray = (GBMemoryByteArray *)(hex_controller.byteArray);
     [byteArray setMode:(GB_memory_mode_t)[sender indexOfSelectedItem]];
+    uint16_t bank;
     switch ((GB_memory_mode_t)[sender indexOfSelectedItem]) {
         case GBMemoryEntireSpace:
         case GBMemoryROM:
             lineRep.valueOffset = 0;
-            byteArray.selectedBank = gb.mbc_rom_bank;
+            GB_get_direct_access(&gb, GB_DIRECT_ACCESS_ROM, NULL, &bank);
+            byteArray.selectedBank = bank;
             break;
         case GBMemoryVRAM:
             lineRep.valueOffset = 0x8000;
-            byteArray.selectedBank = gb.cgb_vram_bank;
+            GB_get_direct_access(&gb, GB_DIRECT_ACCESS_VRAM, NULL, &bank);
+            byteArray.selectedBank = bank;
             break;
         case GBMemoryExternalRAM:
             lineRep.valueOffset = 0xA000;
-            byteArray.selectedBank = gb.mbc_ram_bank;
+            GB_get_direct_access(&gb, GB_DIRECT_ACCESS_CART_RAM, NULL, &bank);
+            byteArray.selectedBank = bank;
             break;
         case GBMemoryRAM:
             lineRep.valueOffset = 0xC000;
-            byteArray.selectedBank = gb.cgb_ram_bank;
+            GB_get_direct_access(&gb, GB_DIRECT_ACCESS_RAM, NULL, &bank);
+            byteArray.selectedBank = bank;
             break;
     }
     [self.memoryBankInput setStringValue:[NSString stringWithFormat:@"$%x", byteArray.selectedBank]];
@@ -1011,16 +1029,18 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
         uint16_t map_base = 0x1800;
         GB_map_type_t map_type = (GB_map_type_t) self.tilemapMapButton.indexOfSelectedItem;
         GB_tileset_type_t tileset_type = (GB_tileset_type_t) self.TilemapSetButton.indexOfSelectedItem;
+        uint8_t lcdc = ((uint8_t *)GB_get_direct_access(&gb, GB_DIRECT_ACCESS_IO, NULL, NULL))[GB_IO_LCDC];
+        uint8_t *vram = GB_get_direct_access(&gb, GB_DIRECT_ACCESS_VRAM, NULL, NULL);
         
-        if (map_type == GB_MAP_9C00 || (map_type == GB_MAP_AUTO && gb.io_registers[GB_IO_LCDC] & 0x08)) {
+        if (map_type == GB_MAP_9C00 || (map_type == GB_MAP_AUTO && lcdc & 0x08)) {
             map_base = 0x1c00;
         }
         
         if (tileset_type == GB_TILESET_AUTO) {
-            tileset_type = (gb.io_registers[GB_IO_LCDC] & 0x10)? GB_TILESET_8800 : GB_TILESET_8000;
+            tileset_type = (lcdc & 0x10)? GB_TILESET_8800 : GB_TILESET_8000;
         }
         
-        uint8_t tile = gb.vram[map_base + map_offset];
+        uint8_t tile = vram[map_base + map_offset];
         uint16_t tile_address = 0;
         if (tileset_type == GB_TILESET_8000) {
             tile_address = 0x8000 + tile * 0x10;
@@ -1029,8 +1049,8 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
             tile_address = 0x9000 + (int8_t)tile * 0x10;
         }
         
-        if (gb.is_cgb) {
-            uint8_t attributes = gb.vram[map_base + map_offset + 0x2000];
+        if (GB_is_cgb(&gb)) {
+            uint8_t attributes = vram[map_base + map_offset + 0x2000];
             self.vramStatusLabel.stringValue = [NSString stringWithFormat:@"Tile number $%02x (%d:$%04x) at map address $%04x (Attributes: %c%c%c%d%d)",
                                                 tile,
                                                 attributes & 0x8? 1 : 0,
@@ -1070,12 +1090,13 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
     NSUInteger columnIndex = [[tableView tableColumns] indexOfObject:tableColumn];
     if (tableView == self.paletteTableView) {
         if (columnIndex == 0) {
-            return [NSString stringWithFormat:@"%s %d", row >=8? "Object" : "Background", (int)(row & 7)];
+            return [NSString stringWithFormat:@"%s %d", row >=8 ? "Object" : "Background", (int)(row & 7)];
         }
         
+        uint8_t *palette_data = GB_get_direct_access(&gb, row >= 8? GB_DIRECT_ACCESS_OBP : GB_DIRECT_ACCESS_BGP, NULL, NULL);
+
         uint16_t index = columnIndex - 1 + (row & 7) * 4;
-        return @(((row >= 8? gb.sprite_palletes_data : gb.background_palletes_data)[(index << 1) + 1] << 8) |
-                  (row >= 8? gb.sprite_palletes_data : gb.background_palletes_data)[(index << 1)]);
+        return @((palette_data[(index << 1) + 1] << 8) | palette_data[(index << 1)]);
     }
     else if (tableView == self.spritesTableView) {
         switch (columnIndex) {
@@ -1092,7 +1113,7 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
             case 5:
                 return [NSString stringWithFormat:@"$%04x", oamInfo[row].oam_addr];
             case 6:
-                if (gb.cgb_mode) {
+                if (GB_is_cgb(&gb)) {
                     return [NSString stringWithFormat:@"%c%c%c%d%d",
                             oamInfo[row].flags & 0x80? 'P' : '-',
                             oamInfo[row].flags & 0x40? 'Y' : '-',

Core/debugger.c

@@ -1368,7 +1368,7 @@ static bool palettes(GB_gameboy_t *gb, char *arguments, char *modifiers, const d
 
     GB_log(gb, "Background palettes: \n");
     for (unsigned i = 0; i < 32; i++) {
-        GB_log(gb, "%04x ", ((uint16_t *)&gb->background_palletes_data)[i]);
+        GB_log(gb, "%04x ", ((uint16_t *)&gb->background_palettes_data)[i]);
         if (i % 4 == 3) {
             GB_log(gb, "\n");
         }
@@ -1376,7 +1376,7 @@ static bool palettes(GB_gameboy_t *gb, char *arguments, char *modifiers, const d
 
     GB_log(gb, "Sprites palettes: \n");
     for (unsigned i = 0; i < 32; i++) {
-        GB_log(gb, "%04x ", ((uint16_t *)&gb->sprite_palletes_data)[i]);
+        GB_log(gb, "%04x ", ((uint16_t *)&gb->sprite_palettes_data)[i]);
         if (i % 4 == 3) {
             GB_log(gb, "\n");
         }
@@ -1704,6 +1704,12 @@ next_command:
         gb->stack_leak_detection = false;
         input = gb->input_callback(gb);
 
+        if (input == NULL) {
+            /* Debugging is no currently available, continue running */
+            gb->debug_stopped = false;
+            return;
+        }
+
         if (GB_debugger_do_command(gb, input)) {
             goto next_command;
         }

Core/display.c

@@ -157,7 +157,7 @@ static uint32_t get_pixel(GB_gameboy_t *gb, uint8_t x, uint8_t y)
             sprite_pixel = (gb->io_registers[use_obp1? GB_IO_OBP1:GB_IO_OBP0] >> (sprite_pixel << 1)) & 3;
             sprite_palette = use_obp1;
         }
-        return gb->sprite_palletes_rgb[sprite_palette * 4 + sprite_pixel];
+        return gb->sprite_palettes_rgb[sprite_palette * 4 + sprite_pixel];
     }
 
     if (bg_enabled) {
@@ -188,14 +188,14 @@ static uint32_t get_pixel(GB_gameboy_t *gb, uint8_t x, uint8_t y)
             sprite_pixel = (gb->io_registers[use_obp1? GB_IO_OBP1:GB_IO_OBP0] >> (sprite_pixel << 1)) & 3;
             sprite_palette = use_obp1;
         }
-        return gb->sprite_palletes_rgb[sprite_palette * 4 + sprite_pixel];
+        return gb->sprite_palettes_rgb[sprite_palette * 4 + sprite_pixel];
     }
 
     if (!gb->cgb_mode) {
         background_pixel = ((gb->io_registers[GB_IO_BGP] >> (background_pixel << 1)) & 3);
     }
 
-    return gb->background_palletes_rgb[(attributes & 7) * 4 + background_pixel];
+    return gb->background_palettes_rgb[(attributes & 7) * 4 + background_pixel];
 }
 
 static int64_t get_nanoseconds(void)
@@ -269,7 +269,7 @@ static inline uint8_t scale_channel(uint8_t x)
 
 void GB_palette_changed(GB_gameboy_t *gb, bool background_palette, uint8_t index)
 {
-    uint8_t *palette_data = background_palette? gb->background_palletes_data : gb->sprite_palletes_data;
+    uint8_t *palette_data = background_palette? gb->background_palettes_data : gb->sprite_palettes_data;
     uint16_t color = palette_data[index & ~1] | (palette_data[index | 1] << 8);
 
     // No need to &, scale channel does that.
@@ -277,7 +277,7 @@ void GB_palette_changed(GB_gameboy_t *gb, bool background_palette, uint8_t index
     uint8_t g = scale_channel(color >> 5);
     uint8_t b = scale_channel(color >> 10);
     assert (gb->rgb_encode_callback);
-    (background_palette? gb->background_palletes_rgb : gb->sprite_palletes_rgb)[index / 2] = gb->rgb_encode_callback(gb, r, g, b);
+    (background_palette? gb->background_palettes_rgb : gb->sprite_palettes_rgb)[index / 2] = gb->rgb_encode_callback(gb, r, g, b);
 }
 
 /*
@@ -584,17 +584,17 @@ void GB_draw_tileset(GB_gameboy_t *gb, uint32_t *dest, GB_palette_type_t palette
             palette = none_palette;
             break;
         case GB_PALETTE_BACKGROUND:
-            palette = gb->background_palletes_rgb + (4 * (palette_index & 7));
+            palette = gb->background_palettes_rgb + (4 * (palette_index & 7));
             break;
         case GB_PALETTE_OAM:
-            palette = gb->sprite_palletes_rgb + (4 * (palette_index & 7));
+            palette = gb->sprite_palettes_rgb + (4 * (palette_index & 7));
             break;
     }
     
     for (unsigned y = 0; y < 192; y++) {
         for (unsigned x = 0; x < 256; x++) {
             if (x >= 128 && !gb->is_cgb) {
-                *(dest++) = gb->background_palletes_rgb[0];
+                *(dest++) = gb->background_palettes_rgb[0];
                 continue;
             }
             uint16_t tile = (x % 128) / 8 + y / 8 * 16;
@@ -634,10 +634,10 @@ void GB_draw_tilemap(GB_gameboy_t *gb, uint32_t *dest, GB_palette_type_t palette
             palette = none_palette;
             break;
         case GB_PALETTE_BACKGROUND:
-            palette = gb->background_palletes_rgb + (4 * (palette_index & 7));
+            palette = gb->background_palettes_rgb + (4 * (palette_index & 7));
             break;
         case GB_PALETTE_OAM:
-            palette = gb->sprite_palletes_rgb + (4 * (palette_index & 7));
+            palette = gb->sprite_palettes_rgb + (4 * (palette_index & 7));
             break;
         case GB_PALETTE_AUTO:
             break;
@@ -683,16 +683,16 @@ void GB_draw_tilemap(GB_gameboy_t *gb, uint32_t *dest, GB_palette_type_t palette
                 *(dest++) = palette[pixel];
             }
             else {
-                *(dest++) = gb->background_palletes_rgb[(attributes & 7) * 4 + pixel];
+                *(dest++) = gb->background_palettes_rgb[(attributes & 7) * 4 + pixel];
             }
         }
     }
 }
 
-uint8_t GB_get_oam_info(GB_gameboy_t *gb, GB_oam_info_t *dest)
+uint8_t GB_get_oam_info(GB_gameboy_t *gb, GB_oam_info_t *dest, uint8_t *sprite_height)
 {
     uint8_t count = 0;
-    unsigned sprite_height = (gb->io_registers[GB_IO_LCDC] & 4) ? 16:8;
+    *sprite_height = (gb->io_registers[GB_IO_LCDC] & 4) ? 16:8;
     uint8_t oam_to_dest_index[40] = {0,};
     for (unsigned y = 0; y < LINES; y++) {
         GB_sprite_t *sprite = (GB_sprite_t *) &gb->oam;
@@ -701,7 +701,7 @@ uint8_t GB_get_oam_info(GB_gameboy_t *gb, GB_oam_info_t *dest)
             int sprite_y = sprite->y - 16;
             bool obscured = false;
             // Is sprite not in this line?
-            if (sprite_y > y || sprite_y + sprite_height <= y) continue;
+            if (sprite_y > y || sprite_y + *sprite_height <= y) continue;
             if (++sprites_in_line == 11) obscured = true;
             
             GB_oam_info_t *info = NULL;
@@ -710,7 +710,7 @@ uint8_t GB_get_oam_info(GB_gameboy_t *gb, GB_oam_info_t *dest)
                 oam_to_dest_index[i] = ++count;
                 info->x = sprite->x;
                 info->y = sprite->y;
-                info->tile = sprite_height == 16? sprite->tile & 0xFE : sprite->tile;
+                info->tile = *sprite_height == 16? sprite->tile & 0xFE : sprite->tile;
                 info->flags = sprite->flags;
                 info->obscured_by_line_limit = false;
                 info->oam_addr = 0xFE00 + i * sizeof(*sprite);
@@ -727,8 +727,11 @@ uint8_t GB_get_oam_info(GB_gameboy_t *gb, GB_oam_info_t *dest)
         uint16_t vram_address = dest[i].tile * 0x10;
         uint8_t flags = dest[i].flags;
         uint8_t palette = gb->cgb_mode? (flags & 7) : ((flags & 0x10)? 1 : 0);
+        if (gb->is_cgb && (flags & 0x8)) {
+            vram_address += 0x2000;
+        }
 
-        for (unsigned y = 0; y < sprite_height; y++) {
+        for (unsigned y = 0; y < *sprite_height; y++) {
             for (unsigned x = 0; x < 8; x++) {
                 uint8_t color = (((gb->vram[vram_address    ] >> ((~x)&7)) & 1 ) |
                                  ((gb->vram[vram_address + 1] >> ((~x)&7)) & 1) << 1 );
@@ -736,7 +739,7 @@ uint8_t GB_get_oam_info(GB_gameboy_t *gb, GB_oam_info_t *dest)
                 if (!gb->cgb_mode) {
                     color = (gb->io_registers[palette? GB_IO_OBP1:GB_IO_OBP0] >> (color << 1)) & 3;
                 }
-                dest[i].image[((flags & 0x20)?7-x:x) + ((flags & 0x40)?sprite_height - 1 -y:y) * 8] = gb->sprite_palletes_rgb[palette * 4 + color];
+                dest[i].image[((flags & 0x20)?7-x:x) + ((flags & 0x40)?*sprite_height - 1 -y:y) * 8] = gb->sprite_palettes_rgb[palette * 4 + color];
             }
             vram_address += 2;
         }

Core/display.h

@@ -35,6 +35,6 @@ typedef struct {
 
 void GB_draw_tileset(GB_gameboy_t *gb, uint32_t *dest, GB_palette_type_t palette_type, uint8_t palette_index);
 void GB_draw_tilemap(GB_gameboy_t *gb, uint32_t *dest, GB_palette_type_t palette_type, uint8_t palette_index, GB_map_type_t map_type, GB_tileset_type_t tileset_type);
-uint8_t GB_get_oam_info(GB_gameboy_t *gb, GB_oam_info_t *dest);
+uint8_t GB_get_oam_info(GB_gameboy_t *gb, GB_oam_info_t *dest, uint8_t *sprite_height);
 
 #endif /* display_h */

Core/gb.c

@@ -447,13 +447,13 @@ void GB_set_async_input_callback(GB_gameboy_t *gb, GB_input_callback_t callback)
 void GB_set_rgb_encode_callback(GB_gameboy_t *gb, GB_rgb_encode_callback_t callback)
 {
     if (!gb->rgb_encode_callback && !gb->is_cgb) {
-        gb->sprite_palletes_rgb[4] = gb->sprite_palletes_rgb[0] = gb->background_palletes_rgb[0] =
+        gb->sprite_palettes_rgb[4] = gb->sprite_palettes_rgb[0] = gb->background_palettes_rgb[0] =
         callback(gb, 0xFF, 0xFF, 0xFF);
-        gb->sprite_palletes_rgb[5] = gb->sprite_palletes_rgb[1] = gb->background_palletes_rgb[1] =
+        gb->sprite_palettes_rgb[5] = gb->sprite_palettes_rgb[1] = gb->background_palettes_rgb[1] =
         callback(gb, 0xAA, 0xAA, 0xAA);
-        gb->sprite_palletes_rgb[6] = gb->sprite_palletes_rgb[2] = gb->background_palletes_rgb[2] =
+        gb->sprite_palettes_rgb[6] = gb->sprite_palettes_rgb[2] = gb->background_palettes_rgb[2] =
         callback(gb, 0x55, 0x55, 0x55);
-        gb->sprite_palletes_rgb[7] = gb->sprite_palletes_rgb[3] = gb->background_palletes_rgb[3] =
+        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;
@@ -540,6 +540,11 @@ bool GB_is_inited(GB_gameboy_t *gb)
     return gb->magic == 'SAME';
 }
 
+bool GB_is_cgb(GB_gameboy_t *gb)
+{
+    return gb->is_cgb;
+}
+
 void GB_set_turbo_mode(GB_gameboy_t *gb, bool on, bool no_frame_skip)
 {
     gb->turbo = on;
@@ -592,13 +597,13 @@ void GB_reset(GB_gameboy_t *gb)
         memset(gb->vram, 0, gb->vram_size);
         
         if (gb->rgb_encode_callback) {
-            gb->sprite_palletes_rgb[4] = gb->sprite_palletes_rgb[0] = gb->background_palletes_rgb[0] =
+            gb->sprite_palettes_rgb[4] = gb->sprite_palettes_rgb[0] = gb->background_palettes_rgb[0] =
                 gb->rgb_encode_callback(gb, 0xFF, 0xFF, 0xFF);
-            gb->sprite_palletes_rgb[5] = gb->sprite_palletes_rgb[1] = gb->background_palletes_rgb[1] =
+            gb->sprite_palettes_rgb[5] = gb->sprite_palettes_rgb[1] = gb->background_palettes_rgb[1] =
                 gb->rgb_encode_callback(gb, 0xAA, 0xAA, 0xAA);
-            gb->sprite_palletes_rgb[6] = gb->sprite_palletes_rgb[2] = gb->background_palletes_rgb[2] =
+            gb->sprite_palettes_rgb[6] = gb->sprite_palettes_rgb[2] = gb->background_palettes_rgb[2] =
                 gb->rgb_encode_callback(gb, 0x55, 0x55, 0x55);
-            gb->sprite_palletes_rgb[7] = gb->sprite_palletes_rgb[3] = gb->background_palletes_rgb[3] =
+            gb->sprite_palettes_rgb[7] = gb->sprite_palettes_rgb[3] = gb->background_palettes_rgb[3] =
                 gb->rgb_encode_callback(gb, 0, 0, 0);
         }
         
@@ -621,3 +626,63 @@ void GB_switch_model_and_reset(GB_gameboy_t *gb, bool is_cgb)
     GB_reset(gb);
 
 }
+
+void *GB_get_direct_access(GB_gameboy_t *gb, GB_direct_access_t access, size_t *size, uint16_t *bank)
+{
+    /* Set size and bank to dummy pointers if not set */
+    if (!size) {
+        size = alloca(sizeof(size));
+    }
+    
+    if (!bank) {
+        bank = alloca(sizeof(bank));
+    }
+    
+    
+    switch (access) {
+        case GB_DIRECT_ACCESS_ROM:
+            *size = gb->rom_size;
+            *bank = gb->mbc_rom_bank;
+            return gb->rom;
+        case GB_DIRECT_ACCESS_RAM:
+            *size = gb->ram_size;
+            *bank = gb->cgb_ram_bank;
+            return gb->ram;
+        case GB_DIRECT_ACCESS_CART_RAM:
+            *size = gb->mbc_ram_size;
+            *bank = gb->mbc_ram_bank;
+            return gb->mbc_ram;
+        case GB_DIRECT_ACCESS_VRAM:
+            *size = gb->vram_size;
+            *bank = gb->cgb_vram_bank;
+            return gb->vram;
+        case GB_DIRECT_ACCESS_HRAM:
+            *size = sizeof(gb->hram);
+            *bank = 0;
+            return &gb->hram;
+        case GB_DIRECT_ACCESS_IO:
+            *size = sizeof(gb->io_registers);
+            *bank = 0;
+            return &gb->io_registers;
+        case GB_DIRECT_ACCESS_BOOTROM:
+            *size = gb->is_cgb? sizeof(gb->boot_rom) : 0x100;
+            *bank = 0;
+            return &gb->boot_rom;
+        case GB_DIRECT_ACCESS_OAM:
+            *size = sizeof(gb->oam);
+            *bank = 0;
+            return &gb->oam;
+        case GB_DIRECT_ACCESS_BGP:
+            *size = sizeof(gb->background_palettes_data);
+            *bank = 0;
+            return &gb->background_palettes_data;
+        case GB_DIRECT_ACCESS_OBP:
+            *size = sizeof(gb->sprite_palettes_data);
+            *bank = 0;
+            return &gb->sprite_palettes_data;
+        default:
+            *size = 0;
+            *bank = 0;
+            return NULL;
+    }
+}

Core/gb.h

@@ -361,10 +361,10 @@ struct GB_gameboy_internal_s {
         uint32_t vram_size; // Different between CGB and DMG
         uint8_t cgb_vram_bank;
         uint8_t oam[0xA0];
-        uint8_t background_palletes_data[0x40];
-        uint8_t sprite_palletes_data[0x40];
-        uint32_t background_palletes_rgb[0x20];
-        uint32_t sprite_palletes_rgb[0x20];
+        uint8_t background_palettes_data[0x40];
+        uint8_t sprite_palettes_data[0x40];
+        uint32_t background_palettes_rgb[0x20];
+        uint32_t sprite_palettes_rgb[0x20];
         int16_t previous_lcdc_x;
         uint8_t padding;
         bool effective_window_enabled;
@@ -481,11 +481,29 @@ __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
 void GB_init(GB_gameboy_t *gb);
 void GB_init_cgb(GB_gameboy_t *gb);
 bool GB_is_inited(GB_gameboy_t *gb);
+bool GB_is_cgb(GB_gameboy_t *gb);
 void GB_free(GB_gameboy_t *gb);
 void GB_reset(GB_gameboy_t *gb);
 void GB_switch_model_and_reset(GB_gameboy_t *gb, bool is_cgb);
 void GB_run(GB_gameboy_t *gb);
 
+typedef enum {
+    GB_DIRECT_ACCESS_ROM,
+    GB_DIRECT_ACCESS_RAM,
+    GB_DIRECT_ACCESS_CART_RAM,
+    GB_DIRECT_ACCESS_VRAM,
+    GB_DIRECT_ACCESS_HRAM,
+    GB_DIRECT_ACCESS_IO, /* Warning: Some registers can only be read/written correctly via GB_memory_read/write. */
+    GB_DIRECT_ACCESS_BOOTROM,
+    GB_DIRECT_ACCESS_OAM,
+    GB_DIRECT_ACCESS_BGP,
+    GB_DIRECT_ACCESS_OBP,
+} GB_direct_access_t;
+
+/* Returns a mutable pointer to various hardware memories. If that memory is banked, the current bank
+   is returned at *bank, even if only a portion of the memory is banked. */
+void *GB_get_direct_access(GB_gameboy_t *gb, GB_direct_access_t access, size_t *size, uint16_t *bank);
+
 void *GB_get_user_data(GB_gameboy_t *gb);
 void GB_set_user_data(GB_gameboy_t *gb, void *data);
 

Core/memory.c

@@ -206,8 +206,8 @@ static uint8_t read_high_memory(GB_gameboy_t *gb, uint16_t addr)
                 }
                 uint8_t index_reg = (addr & 0xFF) - 1;
                 return ((addr & 0xFF) == GB_IO_BGPD?
-                       gb->background_palletes_data :
-                       gb->sprite_palletes_data)[gb->io_registers[index_reg] & 0x3F];
+                       gb->background_palettes_data :
+                       gb->sprite_palettes_data)[gb->io_registers[index_reg] & 0x3F];
             }
 
             case GB_IO_KEY1:
@@ -526,8 +526,8 @@ static void write_high_memory(GB_gameboy_t *gb, uint16_t addr, uint8_t value)
                 }
                 uint8_t index_reg = (addr & 0xFF) - 1;
                 ((addr & 0xFF) == GB_IO_BGPD?
-                 gb->background_palletes_data :
-                 gb->sprite_palletes_data)[gb->io_registers[index_reg] & 0x3F] = value;
+                 gb->background_palettes_data :
+                 gb->sprite_palettes_data)[gb->io_registers[index_reg] & 0x3F] = value;
                 GB_palette_changed(gb, (addr & 0xFF) == GB_IO_BGPD, gb->io_registers[index_reg] & 0x3F);
                 if (gb->io_registers[index_reg] & 0x80) {
                     gb->io_registers[index_reg]++;