From 75ce14f29fc5c463f33e6a6937d475eb031dfc49 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Magalh=C3=A3es?= <joamag@gmail.com>
Date: Mon, 30 Oct 2023 00:45:12 +0000
Subject: [PATCH] chore: initial implementation of the raw buffer
---
frontends/sdl/src/main.rs | 2 +-
src/gb.rs | 8 ++++
src/ppu.rs | 82 ++++++++++++++++++++++++++++++++++-----
3 files changed, 81 insertions(+), 11 deletions(-)
diff --git a/frontends/sdl/src/main.rs b/frontends/sdl/src/main.rs
index 96835116..5f82603b 100644
--- a/frontends/sdl/src/main.rs
+++ b/frontends/sdl/src/main.rs
@@ -312,7 +312,7 @@ impl Emulator {
fn save_image(&mut self, file_path: &str) {
let width = self.system.display_width() as u32;
let height = self.system.display_height() as u32;
- let pixels = self.system.frame_buffer();
+ let pixels = self.system.frame_buffer_raw();
let mut image_buffer: ImageBuffer<Rgb<u8>, Vec<u8>> = ImageBuffer::new(width, height);
diff --git a/src/gb.rs b/src/gb.rs
index 000ff555..c7f32be2 100644
--- a/src/gb.rs
+++ b/src/gb.rs
@@ -589,6 +589,10 @@ impl GameBoy {
self.frame_buffer().to_vec()
}
+ pub fn frame_buffer_raw_eager(&mut self) -> Vec<u8> {
+ self.frame_buffer_raw().to_vec()
+ }
+
pub fn audio_buffer_eager(&mut self, clear: bool) -> Vec<u8> {
let buffer = Vec::from(self.audio_buffer().clone());
if clear {
@@ -989,6 +993,10 @@ impl GameBoy {
self.ppu().frame_buffer_rgb565_u16()
}
+ pub fn frame_buffer_raw(&mut self) -> [u8; FRAME_BUFFER_SIZE] {
+ self.ppu().frame_buffer_raw()
+ }
+
pub fn audio_buffer(&mut self) -> &VecDeque<u8> {
self.apu().audio_buffer()
}
diff --git a/src/ppu.rs b/src/ppu.rs
index 61516362..0febb408 100644
--- a/src/ppu.rs
+++ b/src/ppu.rs
@@ -61,6 +61,12 @@ pub const DISPLAY_SIZE: usize = DISPLAY_WIDTH * DISPLAY_HEIGHT;
/// range from 0 to 3.
pub const COLOR_BUFFER_SIZE: usize = DISPLAY_SIZE;
+/// The size of the buffer that will hold the palette
+/// index for each of the pixel in the screen, so that
+/// (together with the color buffer) it is possible to
+/// rebuild the pixel buffer from scratch.
+pub const PALETTE_BUFFER_SIZE: usize = DISPLAY_SIZE;
+
/// The size of the RGB frame buffer in bytes.
pub const FRAME_BUFFER_SIZE: usize = DISPLAY_SIZE * RGB_SIZE;
@@ -80,6 +86,8 @@ pub const FRAME_BUFFER_RGB565_SIZE: usize = DISPLAY_SIZE * RGB565_SIZE;
/// custom palettes of the Game Boy.
pub const PALETTE_COLORS: Palette = [[255, 255, 255], [192, 192, 192], [96, 96, 96], [0, 0, 0]];
+/// Default tile data to be used in the DMG compatibility
+/// mode of tile processing (avoids algorithmic forking).
pub const DEFAULT_TILE_ATTR: TileData = TileData {
palette: 0,
vram_bank: 0,
@@ -88,6 +96,15 @@ pub const DEFAULT_TILE_ATTR: TileData = TileData {
priority: false,
};
+/// A basic palette for DMG with the typical high contrast
+/// color characteristic of the Game Boy.
+pub const BASIC_PALETTE: Palette = [
+ [0xff, 0xff, 0xff],
+ [0xc0, 0xc0, 0xc0],
+ [0x60, 0x60, 0x60],
+ [0x00, 0x00, 0x00],
+];
+
/// Defines the Game Boy pixel type as a buffer
/// with the size of RGB (3 bytes).
pub type Pixel = [u8; RGB_SIZE];
@@ -311,6 +328,10 @@ pub struct Ppu {
/// (from 0 to 3) for all the pixels in the screen.
pub color_buffer: Box<[u8; COLOR_BUFFER_SIZE]>,
+ /// The palette buffer that is going to store the palette
+ /// index for all the pixels in the screen.
+ pub palette_buffer: Box<[u8; PALETTE_BUFFER_SIZE]>,
+
/// The 8 bit based RGB frame buffer with the
/// processed set of pixels ready to be displayed on screen.
pub frame_buffer: Box<[u8; FRAME_BUFFER_SIZE]>,
@@ -533,6 +554,7 @@ impl Ppu {
pub fn new(mode: GameBoyMode, gbc: Rc<RefCell<GameBoyConfig>>) -> Self {
Self {
color_buffer: Box::new([0u8; COLOR_BUFFER_SIZE]),
+ palette_buffer: Box::new([0u8; COLOR_BUFFER_SIZE]),
frame_buffer: Box::new([0u8; FRAME_BUFFER_SIZE]),
priority_buffer: Box::new([false; COLOR_BUFFER_SIZE]),
vram: [0u8; VRAM_SIZE],
@@ -590,6 +612,7 @@ impl Ppu {
pub fn reset(&mut self) {
self.color_buffer = Box::new([0u8; COLOR_BUFFER_SIZE]);
+ self.palette_buffer = Box::new([0u8; PALETTE_BUFFER_SIZE]);
self.frame_buffer = Box::new([0u8; FRAME_BUFFER_SIZE]);
self.priority_buffer = Box::new([false; COLOR_BUFFER_SIZE]);
self.vram = [0u8; VRAM_SIZE_CGB];
@@ -1012,6 +1035,38 @@ impl Ppu {
buffer
}
+ /// Obtains the "raw" version of the frame buffer any custom
+ /// color palette operation applied to it. This is can be an
+ /// extremely slow operation (in DMG devices) and because of
+ /// that should be used carefully.
+ pub fn frame_buffer_raw(&self) -> [u8; FRAME_BUFFER_SIZE] {
+ if self.gb_mode == GameBoyMode::Dmg {
+ let mut palettes_color: [Palette; 3] = [
+ [[0u8; RGB_SIZE]; PALETTE_SIZE],
+ [[0u8; RGB_SIZE]; PALETTE_SIZE],
+ [[0u8; RGB_SIZE]; PALETTE_SIZE],
+ ];
+ for (index, palette_color) in palettes_color.iter_mut().enumerate() {
+ Self::compute_palette(palette_color, &BASIC_PALETTE, self.palettes[index]);
+ }
+
+ let mut buffer = [0u8; FRAME_BUFFER_SIZE];
+ for (index, pixel) in self.color_buffer.iter().enumerate() {
+ let palette_index = self.palette_buffer[index];
+ let palette = palettes_color[palette_index as usize];
+ let color = palette[*pixel as usize];
+
+ let frame_offset = (index * 3) as usize;
+ buffer[frame_offset] = color[0];
+ buffer[frame_offset + 1] = color[1];
+ buffer[frame_offset + 2] = color[2];
+ }
+ buffer
+ } else {
+ *self.frame_buffer.clone()
+ }
+ }
+
pub fn vram(&self) -> &[u8; VRAM_SIZE] {
&self.vram
}
@@ -1149,10 +1204,11 @@ impl Ppu {
}
/// Fills the frame buffer with pixels of the provided color,
- /// this method must represent the fastest way of achieving
+ /// this method should represent the fastest way of achieving
/// the fill background with color operation.
pub fn fill_frame_buffer(&mut self, color: Pixel) {
self.color_buffer.fill(0);
+ self.palette_buffer.fill(0);
for index in (0..self.frame_buffer.len()).step_by(RGB_SIZE) {
self.frame_buffer[index] = color[0];
self.frame_buffer[index + 1] = color[1];
@@ -1435,8 +1491,10 @@ impl Ppu {
let color = &palette[pixel as usize];
// updates the pixel in the color buffer, which stores
- // the raw pixel color information (unmapped)
+ // the raw pixel color information (unmapped) and then
+ // updates the palette buffer with the palette index
self.color_buffer[color_offset] = pixel;
+ self.palette_buffer[color_offset] = 0;
// set the color pixel in the frame buffer
self.frame_buffer[frame_offset] = color[0];
@@ -1561,8 +1619,10 @@ impl Ppu {
let color = &self.palette_bg[pixel as usize];
// updates the pixel in the color buffer, which stores
- // the raw pixel color information (unmapped)
+ // the raw pixel color information (unmapped) and then
+ // updates the palette buffer with the palette index
self.color_buffer[color_offset] = pixel;
+ self.palette_buffer[color_offset] = 0;
// set the color pixel in the frame buffer
self.frame_buffer[frame_offset] = color[0];
@@ -1661,22 +1721,22 @@ impl Ppu {
continue;
}
- let palette = if self.gb_mode == GameBoyMode::Cgb {
+ let (palette, palette_index) = if self.gb_mode == GameBoyMode::Cgb {
if self.dmg_compat {
if obj.palette == 0 {
- &self.palette_obj_0
+ (&self.palette_obj_0, 1_u8)
} else if obj.palette == 1 {
- &self.palette_obj_1
+ (&self.palette_obj_1, 2_u8)
} else {
panic!("Invalid object palette: {:02x}", obj.palette);
}
} else {
- &self.palettes_color_obj[obj.palette_cgb as usize]
+ (&self.palettes_color_obj[obj.palette_cgb as usize], 255_u8)
}
} else if obj.palette == 0 {
- &self.palette_obj_0
+ (&self.palette_obj_0, 1_u8)
} else if obj.palette == 1 {
- &self.palette_obj_1
+ (&self.palette_obj_1, 2_u8)
} else {
panic!("Invalid object palette: {:02x}", obj.palette);
};
@@ -1781,8 +1841,10 @@ impl Ppu {
let color = palette[pixel as usize];
// updates the pixel in the color buffer, which stores
- // the raw pixel color information (unmapped)
+ // the raw pixel color information (unmapped) and then
+ // updates the palette buffer with the palette index
self.color_buffer[color_offset as usize] = pixel;
+ self.palette_buffer[color_offset as usize] = palette_index;
// sets the color pixel in the frame buffer
self.frame_buffer[frame_offset as usize] = color[0];
--
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