paoda/gb
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

chore: change how bus components are clocked

Browse Source
This commit is contained in:
Rekai Nyangadzayi Musuka
2021-06-09 19:41:10 -05:00
parent aa4a898a6b
commit 50efe12aec
5 changed files with 125 additions and 134 deletions
Download Patch File Download Diff File Expand all files Collapse all files

191
src/ppu.rs
View File

@@ -66,124 +66,119 @@ impl BusIo for Ppu {
}
impl Ppu {
pub(crate) fn step(&mut self, cycles: Cycle) {
let start: u32 = self.cycle.into();
let end: u32 = cycles.into();
pub(crate) fn clock(&mut self) {
self.cycle += 1;
for _ in start..(start + end) {
self.cycle += 1;
match self.stat.mode() {
PpuMode::OamScan => {
if self.cycle >= 80.into() {
self.stat.set_mode(PpuMode::Drawing);
}
match self.stat.mode() {
PpuMode::OamScan => {
if self.cycle >= 80.into() {
self.stat.set_mode(PpuMode::Drawing);
self.scan_oam();
}
PpuMode::Drawing => {
if self.x_pos >= 160 {
if self.stat.hblank_int() {
// Enable HBlank LCDStat Interrupt
self.int.set_lcd_stat(true);
}
self.scan_oam();
// Done with rendering this frame,
// we can reset the ppu x_pos and fetcher state now
// Increment Window line counter if scanline had any window pixels on it
// only increment once per scanline though
if self.window_stat.should_draw() {
self.fetch.back.window_line.increment();
}
self.x_pos = 0;
self.fetch.hblank_reset();
self.window_stat.hblank_reset();
self.obj_buffer.clear();
self.fifo.back.clear();
self.fifo.obj.clear();
self.stat.set_mode(PpuMode::HBlank);
} else if self.ctrl.lcd_enabled() {
// Only Draw when the LCD Is Enabled
self.draw(self.cycle.into());
} else {
self.reset();
}
PpuMode::Drawing => {
if self.x_pos >= 160 {
if self.stat.hblank_int() {
// Enable HBlank LCDStat Interrupt
}
PpuMode::HBlank => {
// This mode will always end at 456 cycles
if self.cycle >= 456.into() {
self.cycle %= 456;
self.pos.line_y += 1;
// Update LY==LYC bit
let are_equal = self.pos.line_y == self.pos.ly_compare;
self.stat.set_coincidence(are_equal);
// Request LCD STAT interrupt if conditions met
if self.stat.coincidence_int() && are_equal {
self.int.set_lcd_stat(true);
}
let next_mode = if self.pos.line_y >= 144 {
// Request VBlank Interrupt
self.int.set_vblank(true);
// Reset Window Line Counter in Fetcher
self.fetch.vblank_reset();
// Reset WY=LY coincidence flag
self.window_stat.vblank_reset();
if self.stat.vblank_int() {
// Enable Vblank LCDStat Interrupt
self.int.set_lcd_stat(true);
}
// Done with rendering this frame,
// we can reset the ppu x_pos and fetcher state now
// Increment Window line counter if scanline had any window pixels on it
// only increment once per scanline though
if self.window_stat.should_draw() {
self.fetch.back.window_line.increment();
}
self.x_pos = 0;
self.fetch.hblank_reset();
self.window_stat.hblank_reset();
self.obj_buffer.clear();
self.fifo.back.clear();
self.fifo.obj.clear();
self.stat.set_mode(PpuMode::HBlank);
} else if self.ctrl.lcd_enabled() {
// Only Draw when the LCD Is Enabled
self.draw(self.cycle.into());
PpuMode::VBlank
} else {
self.reset();
}
}
PpuMode::HBlank => {
// This mode will always end at 456 cycles
if self.cycle >= 456.into() {
self.cycle %= 456;
self.pos.line_y += 1;
// Update LY==LYC bit
let are_equal = self.pos.line_y == self.pos.ly_compare;
self.stat.set_coincidence(are_equal);
// Request LCD STAT interrupt if conditions met
if self.stat.coincidence_int() && are_equal {
if self.stat.oam_int() {
// Enable OAM LCDStat Interrupt
self.int.set_lcd_stat(true);
}
let next_mode = if self.pos.line_y >= 144 {
// Request VBlank Interrupt
self.int.set_vblank(true);
self.scan_state.reset();
PpuMode::OamScan
};
// Reset Window Line Counter in Fetcher
self.fetch.vblank_reset();
// Reset WY=LY coincidence flag
self.window_stat.vblank_reset();
if self.stat.vblank_int() {
// Enable Vblank LCDStat Interrupt
self.int.set_lcd_stat(true);
}
PpuMode::VBlank
} else {
if self.stat.oam_int() {
// Enable OAM LCDStat Interrupt
self.int.set_lcd_stat(true);
}
self.scan_state.reset();
PpuMode::OamScan
};
self.stat.set_mode(next_mode);
}
self.stat.set_mode(next_mode);
}
PpuMode::VBlank => {
if self.cycle > 456.into() {
self.cycle %= 456;
self.pos.line_y += 1;
}
PpuMode::VBlank => {
if self.cycle > 456.into() {
self.cycle %= 456;
self.pos.line_y += 1;
// Update LY==LYC bit
let are_equal = self.pos.line_y == self.pos.ly_compare;
self.stat.set_coincidence(are_equal);
// Update LY==LYC bit
let are_equal = self.pos.line_y == self.pos.ly_compare;
self.stat.set_coincidence(are_equal);
// Request LCD STAT interrupt if conditions met
if self.stat.coincidence_int() && are_equal {
// Request LCD STAT interrupt if conditions met
if self.stat.coincidence_int() && are_equal {
self.int.set_lcd_stat(true);
}
if self.pos.line_y == 154 {
self.pos.line_y = 0;
if self.stat.oam_int() {
// Enable OAM LCDStat Interrupt
self.int.set_lcd_stat(true);
}
if self.pos.line_y == 154 {
self.pos.line_y = 0;
self.scan_state.reset();
if self.stat.oam_int() {
// Enable OAM LCDStat Interrupt
self.int.set_lcd_stat(true);
}
self.scan_state.reset();
self.stat.set_mode(PpuMode::OamScan);
}
self.stat.set_mode(PpuMode::OamScan);
}
}
}