fix(ppu): engines don't have unique vcount + dispstat (cpus do)

This commit is contained in:
2023-11-04 02:34:34 -05:00
parent 83f94f6d9d
commit bf08e93508
3 changed files with 53 additions and 49 deletions

View File

@@ -23,10 +23,20 @@ pub const Ppu = struct {
io: Io = .{},
const Io = struct {
const types = @import("nds9/io.zig");
pub const Io = struct {
const ty = @import("nds9/io.zig");
powcnt: types.PowCnt = .{ .raw = 0x0000_0000 },
nds9: struct {
dispstat: ty.Dispstat = .{ .raw = 0x0000_0000 },
vcount: ty.Vcount = .{ .raw = 0x0000_0000 },
} = .{},
nds7: struct {
dispstat: ty.Dispstat = .{ .raw = 0x0000_0000 },
vcount: ty.Vcount = .{ .raw = 0x0000_0000 },
} = .{},
powcnt: ty.PowCnt = .{ .raw = 0x0000_0000 },
};
pub fn init(allocator: Allocator, vram: *Vram) !@This() {
@@ -42,22 +52,21 @@ pub const Ppu = struct {
pub fn drawScanline(self: *@This(), bus: *System.Bus9) void {
if (self.io.powcnt.engine2d_a.read())
self.engines[0].drawScanline(bus, &self.fb, &self.io.powcnt);
self.engines[0].drawScanline(bus, &self.fb, &self.io);
if (self.io.powcnt.engine2d_b.read())
self.engines[1].drawScanline(bus, &self.fb, &self.io.powcnt);
self.engines[1].drawScanline(bus, &self.fb, &self.io);
}
/// HDraw -> HBlank
pub fn onHdrawEnd(self: *@This(), scheduler: *Scheduler, late: u64) void {
inline for (&self.engines) |*engine| {
std.debug.assert(engine.dispstat.hblank.read() == false);
std.debug.assert(engine.dispstat.vblank.read() == false);
std.debug.assert(self.io.nds9.dispstat.hblank.read() == false);
std.debug.assert(self.io.nds9.dispstat.vblank.read() == false);
// TODO: Signal HBlank IRQ
self.io.nds9.dispstat.hblank.set();
self.io.nds7.dispstat.hblank.set();
engine.dispstat.hblank.set();
}
// TODO: Signal HBlank IRQ
const dots_in_hblank = 99;
scheduler.push(.{ .nds9 = .hblank }, dots_in_hblank * cycles_per_dot -| late);
@@ -65,14 +74,13 @@ pub const Ppu = struct {
// VBlank -> HBlank (Still VBlank)
pub fn onVblankEnd(self: *@This(), scheduler: *Scheduler, late: u64) void {
inline for (&self.engines) |*engine| {
std.debug.assert(!engine.dispstat.hblank.read());
std.debug.assert(engine.vcount.scanline.read() == 262 or engine.dispstat.vblank.read());
std.debug.assert(!self.io.nds9.dispstat.hblank.read());
std.debug.assert(self.io.nds9.vcount.scanline.read() == 262 or self.io.nds9.dispstat.vblank.read());
// TODO: Signal HBlank IRQ
self.io.nds9.dispstat.hblank.set();
self.io.nds7.dispstat.hblank.set();
engine.dispstat.hblank.set();
}
// TODO: Signal HBlank IRQ
const dots_in_hblank = 99;
scheduler.push(.{ .nds9 = .hblank }, dots_in_hblank * cycles_per_dot -| late);
@@ -82,28 +90,29 @@ pub const Ppu = struct {
pub fn onHblankEnd(self: *@This(), scheduler: *Scheduler, late: u64) void {
const scanline_total = 263; // 192 visible, 71 blanking
std.debug.assert(self.engines[0].vcount.scanline.read() == self.engines[1].vcount.scanline.read());
const prev_scanline = self.io.nds9.vcount.scanline.read();
const scanline = (prev_scanline + 1) % scanline_total;
inline for (&self.engines) |*engine| {
const prev_scanline = engine.vcount.scanline.read();
const scanline = (prev_scanline + 1) % scanline_total;
self.io.nds9.vcount.scanline.write(scanline);
self.io.nds7.vcount.scanline.write(scanline);
engine.vcount.scanline.write(scanline);
engine.dispstat.hblank.unset();
self.io.nds9.dispstat.hblank.unset();
self.io.nds7.dispstat.hblank.unset();
const coincidence = scanline == engine.dispstat.lyc.read();
engine.dispstat.coincidence.write(coincidence);
{
const coincidence = scanline == self.io.nds9.dispstat.lyc.read();
self.io.nds9.dispstat.coincidence.write(coincidence);
}
{
const coincidence = scanline == self.io.nds7.dispstat.lyc.read();
self.io.nds7.dispstat.coincidence.write(coincidence);
}
const scanline = self.engines[0].vcount.scanline.read();
// TODO: LYC == LY IRQ
if (scanline < 192) {
inline for (&self.engines) |*engine| {
std.debug.assert(engine.dispstat.vblank.read() == false);
std.debug.assert(engine.dispstat.hblank.read() == false);
}
std.debug.assert(self.io.nds9.dispstat.vblank.read() == false);
std.debug.assert(self.io.nds9.dispstat.hblank.read() == false);
// Draw Another Scanline
const dots_in_hdraw = 256;
@@ -114,17 +123,17 @@ pub const Ppu = struct {
// Transition from Hblank to Vblank
self.fb.swap();
inline for (&self.engines) |*engine|
engine.dispstat.vblank.set();
self.io.nds9.dispstat.vblank.set();
self.io.nds7.dispstat.vblank.set();
// TODO: Signal VBlank IRQ
}
if (scanline == 262) {
inline for (&self.engines) |*engine| {
engine.dispstat.vblank.unset();
std.debug.assert(engine.dispstat.vblank.read() == (scanline != 262));
}
self.io.nds9.dispstat.vblank.unset();
self.io.nds7.dispstat.vblank.unset();
std.debug.assert(self.io.nds9.dispstat.vblank.read() == (scanline != 262));
}
const dots_in_vblank = 256;