comparing 1b84092191274feb06f6ea20b42dc283cf2ea3e6 and main on baileytownsend.dev/DMG-Playground

+3 -9

src/cartridge_header.rs

···

       5
       5
        
       

     

       6
       6
        
       pub struct CartridgeHeader {

     

       7
       7
        
           //Should be 80 bytes (0x014F(335) - 0x0100(256)) + 1 to include the last address

     

       8
       8
       -
           pub buffer: [u8; 80],

     

       8
       8
       +
           pub _buffer: [u8; 80],

     

       9
       9
        
           pub title: [char; 16],

     

       10
       10
        
           pub manufacturer_code: [char; 4],

     

       11
       11
        
           pub cgb_flag: CGBFlag,

     
···

       49
       49
        
               for (i, true_logo_byte) in NINTENDO_LOGO.iter().enumerate() {

     

       50
       50
        
                   let rom_byte = nintendo_logo_from_rom[i];

     

       51
       51
        
                   if rom_byte != *true_logo_byte {

     

       52
       52
       -
                       return Err(Error::CartridgeReadError);

     

       52
       52
       +
                       return Err(Error::NotAValidRom);

     

       53
       53
        
                   }

     

       54
       54
        
               }

     

       55
       55
        
       

     
···

       97
       97
        
               ]);

     

       98
       98
        
       

     

       99
       99
        
               Ok(Self {

     

       100
       100
       -
                   buffer: header_buffer

     

       100
       100
       +
                   _buffer: header_buffer

     

       101
       101
        
                       .try_into()

     

       102
       102
        
                       .map_err(|_| Error::CartridgeReadError)?,

     

       103
       103
        
                   title: title_chars,

     
···

       115
       115
        
                   global_checksum,

     

       116
       116
        
               })

     

       117
       117
        
           }

     

       118
       118
       -
       

     

       119
       119
       -
           fn print_test(&self) {

     

       120
       120
       -
               for byte in self.buffer.iter() {

     

       121
       121
       -
                   print!("{} ", *byte as char);

     

       122
       122
       -
               }

     

       123
       123
       -
           }

     

       124
       118
        
       }

+1 -1

src/enums.rs

···

       3
       3
        
           CartridgeHeaderStart = 0x0100,

     

       4
       4
        
           CartridgeHeaderEnd = 0x014F,

     

       5
       5
        
           // 0100-0103 — Entry point

     

       6
       6
       -
           EntryPointEnd = 0x0103,

     

       6
       6
       +
           _EntryPointEnd = 0x0103,

     

       7
       7
        
           // 0104-0133 — Nintendo logo

     

       8
       8
        
           NintendoLogoStart = 0x0104,

     

       9
       9
        
           NintendoLogoEnd = 0x00133,

+3 -41

src/main.rs

···

       1
       1
        
       mod cartridge_header;

     

       2
       2
        
       mod enums;

     

       3
       3
       -
       mod tile_map;

     

       3
       3
       +
       

     

       4
       4
        
       use crate::cartridge_header::CartridgeHeader;

     

       5
       5
       -
       use crate::enums::CartridgeHeaderAddress::OldLicenseeCode;

     

       6
       6
       -
       use crate::enums::{

     

       7
       7
       -
           CGBFlag, CartridgeHeaderAddress, CartridgeType, DestinationCode, Error, RamSize, RomSize,

     

       8
       8
       -
       };

     

       9
       9
       -
       use crate::tile_map::{GPU, VRAM_BEGIN, VRAM_END};

     

       10
       10
       -
       use minifb::{Key, Window, WindowOptions};

     

       5
       5
       +
       use crate::enums::DestinationCode;

     

       11
       6
        
       use std::fs::File;

     

       12
       7
        
       use std::io::Read;

     

       13
       8
        
       

     

       14
       14
       -
       const WINDOW_DIMENSIONS: [usize; 2] = [(160 * 1), (144 * 1)];

     

       15
       15
       -
       

     

       16
       9
        
       // https://github.com/ISSOtm/gb-bootroms/blob/2dce25910043ce2ad1d1d3691436f2c7aabbda00/src/dmg.asm#L259-L269

     

       17
       10
        
       // Each tile is encoded using 2 (!) bytes

     

       18
       11
        
       // The tiles are represented below

     
···

       40
       33
        
           rom_file.read_to_end(&mut rom_buffer)?;

     

       41
       34
        
           let cart_header = match CartridgeHeader::parse(&*rom_buffer) {

     

       42
       35
        
               Ok(header) => header,

     

       43
       43
       -
               Err(err) => {

     

       36
       36
       +
               Err(_err) => {

     

       44
       37
        
                   return Err(std::io::Error::new(

     

       45
       38
        
                       std::io::ErrorKind::Other,

     

       46
       39
        
                       "Rom failed to parse",

     
···

       74
       67
        
           println!("Header Checksum: {:#X}", cart_header.header_checksum);

     

       75
       68
        
           println!("Global Checksum: {:#X}", cart_header.global_checksum);

     

       76
       69
        
       

     

       77
       77
       -
           let mut gpu = GPU::new();

     

       78
       78
       -
           let tile_map_buffer = &rom_buffer[VRAM_BEGIN as usize..VRAM_END as usize];

     

       79
       79
       -
           for (i, byte) in tile_map_buffer.iter().enumerate() {

     

       80
       80
       -
               gpu.write_vram(i, *byte);

     

       81
       81
       -
           }

     

       82
       82
       -
           gpu.render_tile_to_rgb(0);

     

       83
       83
       -
           // let range_of_tiles = 0..255;

     

       84
       84
       -
           // for tile_id in range_of_tiles {

     

       85
       85
       -
           //     let idk = gpu.print_tile_ascii(tile_id);

     

       86
       86
       -
           //     println!("{:?}", idk);

     

       87
       87
       -
           // }

     

       88
       88
       -
           let mut window = Window::new(

     

       89
       89
       -
               "DMG-01",

     

       90
       90
       -
               WINDOW_DIMENSIONS[0],

     

       91
       91
       -
               WINDOW_DIMENSIONS[1],

     

       92
       92
       -
               WindowOptions {

     

       93
       93
       -
                   scale: minifb::Scale::X2,

     

       94
       94
       -
                   ..WindowOptions::default()

     

       95
       95
       -
               },

     

       96
       96
       -
           )

     

       97
       97
       -
           .unwrap();

     

       98
       98
       -
           let mut tile_ids: Vec<u8> = (0..100).collect();

     

       99
       99
       -
           let tile_map_buffer = gpu.render_background_to_rgb(true, true, 25, 25); // let idk = gpu.render_tile_to_rgb(1).unwrap();

     

       100
       100
       -
           let buffer_u32: Vec<u32> = tile_map_buffer

     

       101
       101
       -
               .iter()

     

       102
       102
       -
               .map(|(r, g, b)| ((*r as u32) << 16) | ((*g as u32) << 8) | (*b as u32))

     

       103
       103
       -
               .collect();

     

       104
       104
       -
           while window.is_open() && !window.is_key_down(Key::Escape) {

     

       105
       105
       -
               window.update_with_buffer(&buffer_u32).unwrap();

     

       106
       106
       -
           }

     

       107
       107
       -
       

     

       108
       70
        
           Ok(())

     

       109
       71
        
       }

-274

src/tile_map.rs

···

       1
       1
       -
       pub const VRAM_BEGIN: usize = 0x8000;

     

       2
       2
       -
       pub const VRAM_END: usize = 0x9FFF;

     

       3
       3
       -
       pub const VRAM_SIZE: usize = VRAM_END - VRAM_BEGIN + 1;

     

       4
       4
       -
       

     

       5
       5
       -
       // Tilemap locations in VRAM

     

       6
       6
       -
       pub const TILEMAP_0_START: usize = 0x1800; // $9800 - $8000 = 0x1800

     

       7
       7
       -
       pub const TILEMAP_1_START: usize = 0x1C00; // $9C00 - $8000 = 0x1C00

     

       8
       8
       -
       pub const TILEMAP_SIZE: usize = 32 * 32; // 1024 bytes

     

       9
       9
       -
       

     

       10
       10
       -
       #[derive(Copy, Clone, Debug, PartialEq)]

     

       11
       11
       -
       pub enum TilePixelValue {

     

       12
       12
       -
           Zero,

     

       13
       13
       -
           One,

     

       14
       14
       -
           Two,

     

       15
       15
       -
           Three,

     

       16
       16
       -
       }

     

       17
       17
       -
       

     

       18
       18
       -
       impl TilePixelValue {

     

       19
       19
       -
           /// Convert pixel value to grayscale color (0-255)

     

       20
       20
       -
           pub fn to_grayscale(&self) -> u8 {

     

       21
       21
       -
               match self {

     

       22
       22
       -
                   TilePixelValue::Zero => 255, // White

     

       23
       23
       -
                   TilePixelValue::One => 170,  // Light gray (66% brightness)

     

       24
       24
       -
                   TilePixelValue::Two => 85,   // Dark gray (33% brightness)

     

       25
       25
       -
                   TilePixelValue::Three => 0,  // Black

     

       26
       26
       -
               }

     

       27
       27
       -
           }

     

       28
       28
       -
       

     

       29
       29
       -
           /// Convert pixel value to RGB color tuple

     

       30
       30
       -
           pub fn to_rgb(&self) -> (u8, u8, u8) {

     

       31
       31
       -
               let gray = self.to_grayscale();

     

       32
       32
       -
               (gray, gray, gray)

     

       33
       33
       -
           }

     

       34
       34
       -
       

     

       35
       35
       -
           /// Convert pixel value to classic Game Boy green colors

     

       36
       36
       -
           pub fn to_gameboy_green(&self) -> (u8, u8, u8) {

     

       37
       37
       -
               match self {

     

       38
       38
       -
                   TilePixelValue::Zero => (224, 248, 208), // Lightest green

     

       39
       39
       -
                   TilePixelValue::One => (136, 192, 112),  // Light green

     

       40
       40
       -
                   TilePixelValue::Two => (52, 104, 86),    // Dark green

     

       41
       41
       -
                   TilePixelValue::Three => (8, 24, 32),    // Darkest green/black

     

       42
       42
       -
               }

     

       43
       43
       -
           }

     

       44
       44
       -
       }

     

       45
       45
       -
       

     

       46
       46
       -
       type Tile = [[TilePixelValue; 8]; 8];

     

       47
       47
       -
       

     

       48
       48
       -
       fn empty_tile() -> Tile {

     

       49
       49
       -
           [[TilePixelValue::Zero; 8]; 8]

     

       50
       50
       -
       }

     

       51
       51
       -
       

     

       52
       52
       -
       pub struct GPU {

     

       53
       53
       -
           vram: [u8; VRAM_SIZE],

     

       54
       54
       -
           tile_set: [Tile; 384], // 384 tiles total (256 from first set + 128 from second set)

     

       55
       55
       -
       }

     

       56
       56
       -
       

     

       57
       57
       -
       impl GPU {

     

       58
       58
       -
           pub fn new() -> Self {

     

       59
       59
       -
               Self {

     

       60
       60
       -
                   vram: [0; VRAM_SIZE],

     

       61
       61
       -
                   tile_set: [empty_tile(); 384],

     

       62
       62
       -
               }

     

       63
       63
       -
           }

     

       64
       64
       -
       

     

       65
       65
       -
           pub fn read_vram(&self, address: usize) -> u8 {

     

       66
       66
       -
               self.vram[address]

     

       67
       67
       -
           }

     

       68
       68
       -
       

     

       69
       69
       -
           pub fn write_vram(&mut self, index: usize, value: u8) {

     

       70
       70
       -
               self.vram[index] = value;

     

       71
       71
       -
       

     

       72
       72
       -
               // If our index is greater than 0x1800, we're not writing to the tile set storage

     

       73
       73
       -
               // so we can just return.

     

       74
       74
       -
               if index >= 0x1800 {

     

       75
       75
       -
                   return;

     

       76
       76
       -
               }

     

       77
       77
       -
       

     

       78
       78
       -
               // Tiles rows are encoded in two bytes with the first byte always

     

       79
       79
       -
               // on an even address. Bitwise ANDing the address with 0xffe

     

       80
       80
       -
               // gives us the address of the first byte.

     

       81
       81
       -
               let normalized_index = index & 0xFFFE;

     

       82
       82
       -
       

     

       83
       83
       -
               // First we need to get the two bytes that encode the tile row.

     

       84
       84
       -
               let byte1 = self.vram[normalized_index];

     

       85
       85
       -
               let byte2 = self.vram[normalized_index + 1];

     

       86
       86
       -
       

     

       87
       87
       -
               // A tile is 8 rows tall. Since each row is encoded with two bytes a tile

     

       88
       88
       -
               // is therefore 16 bytes in total.

     

       89
       89
       -
               let tile_index = index / 16;

     

       90
       90
       -
               // Every two bytes is a new row

     

       91
       91
       -
               let row_index = (index % 16) / 2;

     

       92
       92
       -
       

     

       93
       93
       -
               // Now we're going to loop 8 times to get the 8 pixels that make up a given row.

     

       94
       94
       -
               for pixel_index in 0..8 {

     

       95
       95
       -
                   let mask = 1 << (7 - pixel_index);

     

       96
       96
       -
                   let lsb = byte1 & mask;

     

       97
       97
       -
                   let msb = byte2 & mask;

     

       98
       98
       -
       

     

       99
       99
       -
                   let value = match (lsb != 0, msb != 0) {

     

       100
       100
       -
                       (true, true) => TilePixelValue::Three,

     

       101
       101
       -
                       (false, true) => TilePixelValue::Two,

     

       102
       102
       -
                       (true, false) => TilePixelValue::One,

     

       103
       103
       -
                       (false, false) => TilePixelValue::Zero,

     

       104
       104
       -
                   };

     

       105
       105
       -
       

     

       106
       106
       -
                   self.tile_set[tile_index][row_index][pixel_index] = value;

     

       107
       107
       -
               }

     

       108
       108
       -
           }

     

       109
       109
       -
       

     

       110
       110
       -
           /// Get a tile by its index, handling Game Boy's two addressing modes

     

       111
       111
       -
           pub fn get_tile(&self, tile_index: u8, use_signed_addressing: bool) -> Option<&Tile> {

     

       112
       112
       -
               let actual_index = if use_signed_addressing {

     

       113
       113
       -
                   // Signed addressing mode: $8800-$97FF

     

       114
       114
       -
                   // Index 0-127 maps to tiles 256-383, index 128-255 maps to tiles 0-127

     

       115
       115
       -
                   if tile_index < 128 {

     

       116
       116
       -
                       256 + tile_index as usize

     

       117
       117
       -
                   } else {

     

       118
       118
       -
                       (tile_index as i8 as i16 + 256) as usize

     

       119
       119
       -
                   }

     

       120
       120
       -
               } else {

     

       121
       121
       -
                   // Unsigned addressing mode: $8000-$8FFF

     

       122
       122
       -
                   tile_index as usize

     

       123
       123
       -
               };

     

       124
       124
       -
       

     

       125
       125
       -
               if actual_index < self.tile_set.len() {

     

       126
       126
       -
                   Some(&self.tile_set[actual_index])

     

       127
       127
       -
               } else {

     

       128
       128
       -
                   None

     

       129
       129
       -
               }

     

       130
       130
       -
           }

     

       131
       131
       -
       

     

       132
       132
       -
           /// Read tilemap data from VRAM

     

       133
       133
       -
           pub fn get_tilemap_data(&self, tilemap_select: bool) -> [u8; TILEMAP_SIZE] {

     

       134
       134
       -
               let start_addr = if tilemap_select {

     

       135
       135
       -
                   TILEMAP_1_START

     

       136
       136
       -
               } else {

     

       137
       137
       -
                   TILEMAP_0_START

     

       138
       138
       -
               };

     

       139
       139
       -
       

     

       140
       140
       -
               let mut tilemap = [0u8; TILEMAP_SIZE];

     

       141
       141
       -
               for i in 0..TILEMAP_SIZE {

     

       142
       142
       -
                   tilemap[i] = self.vram[start_addr + i];

     

       143
       143
       -
               }

     

       144
       144
       -
               tilemap

     

       145
       145
       -
           }

     

       146
       146
       -
       

     

       147
       147
       -
           /// Render the entire tilemap to RGB (256x256 pixels)

     

       148
       148
       -
           pub fn render_full_tilemap_to_rgb(

     

       149
       149
       -
               &self,

     

       150
       150
       -
               tilemap_select: bool,

     

       151
       151
       -
               use_signed_addressing: bool,

     

       152
       152
       -
           ) -> Vec<(u8, u8, u8)> {

     

       153
       153
       -
               let tilemap_data = self.get_tilemap_data(tilemap_select);

     

       154
       154
       -
               let total_pixels = 256 * 256; // 32x32 tiles, each 8x8 pixels

     

       155
       155
       -
               let mut color_buffer = vec![(0, 0, 0); total_pixels];

     

       156
       156
       -
       

     

       157
       157
       -
               for tilemap_y in 0..32 {

     

       158
       158
       -
                   for tilemap_x in 0..32 {

     

       159
       159
       -
                       let tilemap_index = tilemap_y * 32 + tilemap_x;

     

       160
       160
       -
                       let tile_id = tilemap_data[tilemap_index];

     

       161
       161
       -
       

     

       162
       162
       -
                       if let Some(tile) = self.get_tile(tile_id, use_signed_addressing) {

     

       163
       163
       -
                           // Render this tile into the color buffer

     

       164
       164
       -
                           for tile_row in 0..8 {

     

       165
       165
       -
                               for tile_col in 0..8 {

     

       166
       166
       -
                                   let pixel_x = tilemap_x * 8 + tile_col;

     

       167
       167
       -
                                   let pixel_y = tilemap_y * 8 + tile_row;

     

       168
       168
       -
                                   let buffer_index = pixel_y * 256 + pixel_x;

     

       169
       169
       -
       

     

       170
       170
       -
                                   if buffer_index < color_buffer.len() {

     

       171
       171
       -
                                       color_buffer[buffer_index] =

     

       172
       172
       -
                                           tile[tile_row][tile_col].to_gameboy_green();

     

       173
       173
       -
                                   }

     

       174
       174
       -
                               }

     

       175
       175
       -
                           }

     

       176
       176
       -
                       }

     

       177
       177
       -
                   }

     

       178
       178
       -
               }

     

       179
       179
       -
       

     

       180
       180
       -
               color_buffer

     

       181
       181
       -
           }

     

       182
       182
       -
       

     

       183
       183
       -
           /// Render a visible portion of the tilemap (160x144 pixels) with scrolling

     

       184
       184
       -
           pub fn render_background_to_rgb(

     

       185
       185
       -
               &self,

     

       186
       186
       -
               tilemap_select: bool,

     

       187
       187
       -
               use_signed_addressing: bool,

     

       188
       188
       -
               scroll_x: u8,

     

       189
       189
       -
               scroll_y: u8,

     

       190
       190
       -
           ) -> Vec<(u8, u8, u8)> {

     

       191
       191
       -
               let tilemap_data = self.get_tilemap_data(tilemap_select);

     

       192
       192
       -
               let mut color_buffer = vec![(0, 0, 0); 160 * 144];

     

       193
       193
       -
       

     

       194
       194
       -
               for screen_y in 0..144 {

     

       195
       195
       -
                   for screen_x in 0..160 {

     

       196
       196
       -
                       // Calculate the position in the 256x256 tilemap with wrapping

     

       197
       197
       -
                       let bg_x = ((screen_x as u16 + scroll_x as u16) % 256) as u8;

     

       198
       198
       -
                       let bg_y = ((screen_y as u16 + scroll_y as u16) % 256) as u8;

     

       199
       199
       -
       

     

       200
       200
       -
                       // Which tile are we in?

     

       201
       201
       -
                       let tile_x = (bg_x / 8) as usize;

     

       202
       202
       -
                       let tile_y = (bg_y / 8) as usize;

     

       203
       203
       -
                       let tilemap_index = tile_y * 32 + tile_x;

     

       204
       204
       -
       

     

       205
       205
       -
                       // Which pixel within that tile?

     

       206
       206
       -
                       let pixel_x = (bg_x % 8) as usize;

     

       207
       207
       -
                       let pixel_y = (bg_y % 8) as usize;

     

       208
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       -
       

     

       209
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       -
                       let tile_id = tilemap_data[tilemap_index];

     

       210
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       -
       

     

       211
       211
       -
                       if let Some(tile) = self.get_tile(tile_id, use_signed_addressing) {

     

       212
       212
       -
                           let buffer_index = screen_y * 160 + screen_x;

     

       213
       213
       -
                           color_buffer[buffer_index] = tile[pixel_y][pixel_x].to_gameboy_green();

     

       214
       214
       -
                       }

     

       215
       215
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                   }

     

       216
       216
       -
               }

     

       217
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       -
       

     

       218
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       -
               color_buffer

     

       219
       219
       -
           }

     

       220
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       -
       

     

       221
       221
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           /// Render a tile to a color buffer (64 pixels as RGB values)

     

       222
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       -
           pub fn render_tile_to_rgb(&self, tile_index: usize) -> Option<[(u8, u8, u8); 64]> {

     

       223
       223
       -
               if tile_index >= self.tile_set.len() {

     

       224
       224
       -
                   return None;

     

       225
       225
       -
               }

     

       226
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       -
       

     

       227
       227
       -
               let tile = &self.tile_set[tile_index];

     

       228
       228
       -
               let mut color_buffer = [(0, 0, 0); 64];

     

       229
       229
       -
       

     

       230
       230
       -
               for (row_idx, row) in tile.iter().enumerate() {

     

       231
       231
       -
                   for (col_idx, &pixel) in row.iter().enumerate() {

     

       232
       232
       -
                       let buffer_index = row_idx * 8 + col_idx;

     

       233
       233
       -
                       color_buffer[buffer_index] = pixel.to_gameboy_green();

     

       234
       234
       -
                   }

     

       235
       235
       -
               }

     

       236
       236
       -
       

     

       237
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       -
               Some(color_buffer)

     

       238
       238
       -
           }

     

       239
       239
       -
       

     

       240
       240
       -
           /// Debug function to print tilemap as hex values

     

       241
       241
       -
           pub fn print_tilemap_hex(&self, tilemap_select: bool) {

     

       242
       242
       -
               let tilemap_data = self.get_tilemap_data(tilemap_select);

     

       243
       243
       -
               println!("Tilemap {} contents:", if tilemap_select { 1 } else { 0 });

     

       244
       244
       -
       

     

       245
       245
       -
               for row in 0..32 {

     

       246
       246
       -
                   for col in 0..32 {

     

       247
       247
       -
                       let index = row * 32 + col;

     

       248
       248
       -
                       print!("{:02X} ", tilemap_data[index]);

     

       249
       249
       -
                   }

     

       250
       250
       -
                   println!();

     

       251
       251
       -
               }

     

       252
       252
       -
           }

     

       253
       253
       -
       

     

       254
       254
       -
           /// Debug function to print a tile as ASCII art

     

       255
       255
       -
           pub fn print_tile_ascii(&self, tile_index: usize) {

     

       256
       256
       -
               if let Some(tile) = self.tile_set.get(tile_index) {

     

       257
       257
       -
                   println!("Tile {}:", tile_index);

     

       258
       258
       -
                   for row in tile {

     

       259
       259
       -
                       for &pixel in row {

     

       260
       260
       -
                           let char = match pixel {

     

       261
       261
       -
                               TilePixelValue::Zero => '░',  // Light

     

       262
       262
       -
                               TilePixelValue::One => '▒',   // Light gray

     

       263
       263
       -
                               TilePixelValue::Two => '▓',   // Dark gray

     

       264
       264
       -
                               TilePixelValue::Three => '█', // Dark

     

       265
       265
       -
                           };

     

       266
       266
       -
                           print!("{}", char);

     

       267
       267
       -
                       }

     

       268
       268
       -
                       println!();

     

       269
       269
       -
                   }

     

       270
       270
       -
               } else {

     

       271
       271
       -
                   println!("Tile {} not found", tile_index);

     

       272
       272
       -
               }

     

       273
       273
       -
           }

     

       274
       274
       -
       }

+8 -1

README.md

···

       1
       1
       -
       # GameBoyPlayground

     

       1
       1
       +
       # DMG Playground

     

       2
       2
       +
       

     

       3
       3
       +
       Just some experiments with Gameboy emulation. Right now it just reads

     

       4
       4
       +
       the [Cartridge Header](https://gbdev.io/pandocs/The_Cartridge_Header.html) of a GB rom and parses it

     

       5
       5
       +
       out

     

       6
       6
       +
       

     

       7
       7
       +
       1. Obtain a `LegallyObtainedRom.gb` and name it as such in the root of the project

     

       8
       8
       +
       2. `cargo run` You should see it list out things like the name of the game, etc

Compare changes