From eb1016cd25db5ed2fe9f4200876ddd89f5c5f9b4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Magalh=C3=A3es?= <joamag@gmail.com>
Date: Sat, 2 Jul 2022 14:05:54 +0100
Subject: [PATCH] feat: more PPU support added
---
src/cpu.rs | 10 +++++++
src/inst.rs | 13 +++++++--
src/mmu.rs | 4 +--
src/ppu.rs | 83 ++++++++++++++++++++++++++++++++++++++++++-----------
4 files changed, 89 insertions(+), 21 deletions(-)
diff --git a/src/cpu.rs b/src/cpu.rs
index ff2f4c52..04cd30ec 100644
--- a/src/cpu.rs
+++ b/src/cpu.rs
@@ -244,4 +244,14 @@ impl Cpu {
pub fn set_carry(&mut self, value: bool) {
self.carry = value;
}
+
+ #[inline(always)]
+ pub fn enable_int(&mut self) {
+ // @todo implement this one
+ }
+
+ #[inline(always)]
+ pub fn disable_int(&mut self) {
+ // @todo implement this one
+ }
}
diff --git a/src/inst.rs b/src/inst.rs
index 8ff0b303..314afe79 100644
--- a/src/inst.rs
+++ b/src/inst.rs
@@ -59,7 +59,7 @@ pub const INSTRUCTIONS: [(fn(&mut Cpu), u8, &'static str); 256] = [
(noimpl, 4, "! UNIMP !"),
(noimpl, 4, "! UNIMP !"),
(noimpl, 4, "! UNIMP !"),
- (noimpl, 4, "! UNIMP !"),
+ (ld_mhl_u8, 12, "LD [HL], u8 "),
(noimpl, 4, "! UNIMP !"),
(noimpl, 4, "! UNIMP !"),
(noimpl, 4, "! UNIMP !"),
@@ -260,7 +260,7 @@ pub const INSTRUCTIONS: [(fn(&mut Cpu), u8, &'static str); 256] = [
(ld_a_mff00u8, 12, "LD A, [FF00+u8]"),
(noimpl, 4, "! UNIMP !"),
(noimpl, 4, "! UNIMP !"),
- (noimpl, 4, "! UNIMP !"),
+ (di, 4, "DI"),
(noimpl, 4, "! UNIMP !"),
(noimpl, 4, "! UNIMP !"),
(noimpl, 4, "! UNIMP !"),
@@ -681,6 +681,11 @@ fn ld_mhld_a(cpu: &mut Cpu) {
cpu.set_hl(cpu.hl().wrapping_sub(1));
}
+fn ld_mhl_u8(cpu: &mut Cpu) {
+ let byte = cpu.read_u8();
+ cpu.mmu.write(cpu.hl(), byte);
+}
+
fn dec_a(cpu: &mut Cpu) {
let a = cpu.a;
let value = a.wrapping_sub(1);
@@ -808,6 +813,10 @@ fn ld_a_mff00u8(cpu: &mut Cpu) {
cpu.a = cpu.mmu.read(0xff00 + byte as u16);
}
+fn di(cpu: &mut Cpu) {
+ cpu.disable_int();
+}
+
fn cp_a_u8(cpu: &mut Cpu) {
let byte = cpu.read_u8();
sub_set_flags(cpu, cpu.a, byte);
diff --git a/src/mmu.rs b/src/mmu.rs
index 06a10491..a840ad23 100644
--- a/src/mmu.rs
+++ b/src/mmu.rs
@@ -64,7 +64,7 @@ impl Mmu {
0x000 | 0x100 | 0x200 | 0x300 | 0x400 | 0x500 | 0x600 | 0x700 | 0x800 | 0x900
| 0xa00 | 0xb00 | 0xc00 | 0xd00 => self.ram[(addr & 0x1fff) as usize],
0xe00 => {
- println!("READING FROM GPU OAM - NOT IMPLEMENTED");
+ println!("READING FROM PPU OAM - NOT IMPLEMENTED");
0x00
}
0xf00 => {
@@ -126,7 +126,7 @@ impl Mmu {
self.ram[(addr & 0x1fff) as usize] = value;
}
0xe00 => {
- println!("WRITING TO GPU OAM");
+ println!("WRITING TO PPU OAM");
}
0xf00 => {
if addr >= 0xff80 {
diff --git a/src/ppu.rs b/src/ppu.rs
index 0b321b17..f83abba0 100644
--- a/src/ppu.rs
+++ b/src/ppu.rs
@@ -32,7 +32,7 @@ pub struct Ppu {
/// processed set of pixels ready to be displayed on screen.
pub frame_buffer: Box<[u8; FRAME_BUFFER_SIZE]>,
/// Video dedicated memory (VRAM) where both the tiles and
- /// the sprites are going to be stored.
+ /// the sprites/objects are going to be stored.
pub vram: [u8; VRAM_SIZE],
/// High RAM memory that should provide extra speed for regular
/// operations.
@@ -40,8 +40,13 @@ pub struct Ppu {
/// The current set of processed tiles that are store in the
/// PPU related structures.
tiles: [[[u8; 8]; 8]; TILE_COUNT],
- /// The palette of colors that is currently loaded in Game Boy.
+ /// The palette of colors that is currently loaded in Game Boy
+ /// and used for background (tiles).
palette: [[u8; RGB_SIZE]; PALETTE_SIZE],
+ // The palette that is going to be used for sprites/objects #0.
+ palette_obj_0: [[u8; RGB_SIZE]; PALETTE_SIZE],
+ // The palette that is going to be used for sprites/objects #1.
+ palette_obj_1: [[u8; RGB_SIZE]; PALETTE_SIZE],
/// The scroll Y register that controls the Y offset
/// of the background.
scy: u8,
@@ -52,10 +57,16 @@ pub struct Ppu {
/// range between 0 (0x00) and 153 (0x99), representing
/// the 154 lines plus 10 extra v-blank lines.
line: u8,
+ /// The current execution mode of the PPU, should change
+ /// between states over the drawing of a frame.
+ mode: PpuMode,
+ /// Internal clock counter used to control the time in ticks
+ /// spent in each of the PPU modes.
+ mode_clock: u16,
/// Controls if the background is going to be drawn to screen.
switch_bg: bool,
- /// Controls if the sprites are going to be drawn to screen.
- switch_sprites: bool,
+ /// Controls if the sprites/objects are going to be drawn to screen.
+ switch_obj: bool,
/// Controls the map that is going to be drawn to screen, the
/// offset in VRAM will be adjusted according to this.
bg_map: bool,
@@ -65,12 +76,10 @@ pub struct Ppu {
/// Flag that controls if the LCD screen is ON and displaying
/// content.
switch_lcd: bool,
- /// The current execution mode of the PPU, should change
- /// between states over the drawing of a frame.
- mode: PpuMode,
- /// Internal clock counter used to control the time in ticks
- /// spent in each of the PPU modes.
- mode_clock: u16,
+ stat_hblank: bool,
+ stat_vblank: bool,
+ stat_oam: bool,
+ stat_lyc: bool,
}
pub enum PpuMode {
@@ -88,16 +97,22 @@ impl Ppu {
hram: [0u8; HRAM_SIZE],
tiles: [[[0u8; 8]; 8]; TILE_COUNT],
palette: [[0u8; RGB_SIZE]; PALETTE_SIZE],
+ palette_obj_0: [[0u8; RGB_SIZE]; PALETTE_SIZE],
+ palette_obj_1: [[0u8; RGB_SIZE]; PALETTE_SIZE],
scy: 0x0,
scx: 0x0,
line: 0x0,
+ mode: PpuMode::OamRead,
+ mode_clock: 0,
switch_bg: false,
- switch_sprites: false,
+ switch_obj: false,
bg_map: false,
bg_tile: false,
switch_lcd: false,
- mode: PpuMode::OamRead,
- mode_clock: 0,
+ stat_hblank: false,
+ stat_vblank: false,
+ stat_oam: false,
+ stat_lyc: false,
}
}
@@ -105,7 +120,7 @@ impl Ppu {
self.mode_clock += cycles as u16;
match self.mode {
PpuMode::OamRead => {
- if self.mode_clock >= 204 {
+ if self.mode_clock >= 80 {
self.mode_clock = 0;
self.mode = PpuMode::VramRead;
}
@@ -157,12 +172,19 @@ impl Ppu {
match addr & 0x00ff {
0x0040 => {
let value = if self.switch_bg { 0x01 } else { 0x00 }
- | if self.switch_sprites { 0x02 } else { 0x00 }
+ | if self.switch_obj { 0x02 } else { 0x00 }
| if self.bg_map { 0x08 } else { 0x00 }
| if self.bg_tile { 0x10 } else { 0x00 }
| if self.switch_lcd { 0x80 } else { 0x00 };
value
}
+ 0x0041 => {
+ let value = if self.stat_hblank { 0x04 } else { 0x00 }
+ | if self.stat_vblank { 0x08 } else { 0x00 }
+ | if self.stat_oam { 0x10 } else { 0x00 }
+ | if self.stat_lyc { 0x20 } else { 0x00 };
+ value
+ }
0x0042 => self.scy,
0x0043 => self.scx,
0x0044 => self.line,
@@ -174,11 +196,17 @@ impl Ppu {
match addr & 0x00ff {
0x0040 => {
self.switch_bg = value & 0x01 == 0x01;
- self.switch_sprites = value & 0x02 == 0x02;
+ self.switch_obj = value & 0x02 == 0x02;
self.bg_map = value & 0x08 == 0x08;
self.bg_tile = value & 0x10 == 0x10;
self.switch_lcd = value & 0x80 == 0x80;
}
+ 0x0041 => {
+ self.stat_hblank = value & 0x04 == 0x04;
+ self.stat_vblank = value & 0x08 == 0x08;
+ self.stat_oam = value & 0x10 == 0x10;
+ self.stat_lyc = value & 0x20 == 0x20;
+ }
0x0042 => self.scy = value,
0x0043 => self.scx = value,
0x0047 => {
@@ -192,6 +220,28 @@ impl Ppu {
}
}
}
+ 0x0048 => {
+ for index in 0..PALETTE_SIZE {
+ match (value >> (index * 2)) & 3 {
+ 0 => self.palette_obj_0[index] = [255, 255, 255],
+ 1 => self.palette_obj_0[index] = [192, 192, 192],
+ 2 => self.palette_obj_0[index] = [96, 96, 96],
+ 3 => self.palette_obj_0[index] = [0, 0, 0],
+ color_index => panic!("Invalid palette color index {:04x}", color_index),
+ }
+ }
+ }
+ 0x0049 => {
+ for index in 0..PALETTE_SIZE {
+ match (value >> (index * 2)) & 3 {
+ 0 => self.palette_obj_1[index] = [255, 255, 255],
+ 1 => self.palette_obj_1[index] = [192, 192, 192],
+ 2 => self.palette_obj_1[index] = [96, 96, 96],
+ 3 => self.palette_obj_1[index] = [0, 0, 0],
+ color_index => panic!("Invalid palette color index {:04x}", color_index),
+ }
+ }
+ }
addr => panic!("Writing in unknown PPU location 0x{:04x}", addr),
}
}
@@ -246,7 +296,6 @@ impl Ppu {
// Game Boy screen width and RGB pixel (3 bytes) size
let mut frame_offset = self.line as usize * DISPLAY_WIDTH * RGB_SIZE;
-
for _index in 0..DISPLAY_WIDTH {
// obtains the current pixel data from the tile and
// re-maps it according to the current palette
--
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