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fix: move code in scheduler to ppu

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This commit is contained in:
Rekai Nyangadzayi Musuka
2022-03-15 04:34:13 -03:00
parent bdea19f280
commit 48679fa4ca
2 changed files with 63 additions and 82 deletions
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90
src/scheduler.zig
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@@ -1,7 +1,5 @@
const std = @import("std");
const pollBlankingDma = @import("bus/dma.zig").pollBlankingDma;
const Bus = @import("Bus.zig");
const Arm7tdmi = @import("cpu.zig").Arm7tdmi;
@@ -32,92 +30,18 @@ pub const Scheduler = struct {
}
pub fn handleEvent(self: *Self, cpu: *Arm7tdmi, bus: *Bus) void {
const should_handle = if (self.queue.peek()) |e| self.tick >= e.tick else false;
const stat = &bus.ppu.dispstat;
const vcount = &bus.ppu.vcount;
const irq = &bus.io.irq;
if (should_handle) {
const event = self.queue.remove();
// log.debug("Handle {} @ tick = {}", .{ event.kind, self.tick });
if (self.queue.removeOrNull()) |event| {
switch (event.kind) {
.HeatDeath => {
log.err("A u64 overflowered. This *actually* should never happen.", .{});
unreachable;
},
.HBlank => {
// The End of a Hblank (During Draw or Vblank)
const old_scanline = vcount.scanline.read();
const scanline = (old_scanline + 1) % 228;
vcount.scanline.write(scanline);
stat.hblank.unset();
// Perform Vc == VcT check
const coincidence = scanline == stat.vcount_trigger.read();
stat.coincidence.write(coincidence);
if (coincidence and stat.vcount_irq.read()) {
irq.coincidence.set();
cpu.handleInterrupt();
}
if (scanline < 160) {
// Transitioning to another Draw
self.push(.Draw, self.tick + (240 * 4));
} else {
// Transitioning to a Vblank
if (scanline == 160) {
stat.vblank.set();
if (stat.vblank_irq.read()) {
irq.vblank.set();
cpu.handleInterrupt();
}
// See if Vblank DMA is present and not enabled
pollBlankingDma(bus, .VBlank);
}
if (scanline == 227) stat.vblank.unset();
self.push(.VBlank, self.tick + (240 * 4));
}
},
.Draw => {
// The end of a Draw
// The end of a VDraw
bus.ppu.drawScanline();
// Transitioning to a Hblank
if (bus.ppu.dispstat.hblank_irq.read()) {
bus.io.irq.hblank.set();
cpu.handleInterrupt();
}
// See if Hblank DMA is present and not enabled
pollBlankingDma(bus, .HBlank);
bus.ppu.dispstat.hblank.set();
self.push(.HBlank, self.tick + (68 * 4));
},
.VBlank => {
// The end of a Vblank
// Transitioning to a Hblank
if (bus.ppu.dispstat.hblank_irq.read()) {
bus.io.irq.hblank.set();
cpu.handleInterrupt();
}
// See if Hblank DMA is present and not enabled
pollBlankingDma(bus, .HBlank);
bus.ppu.dispstat.hblank.set();
self.push(.HBlank, self.tick + (68 * 4));
bus.ppu.handleHDrawEnd(cpu);
},
.TimerOverflow => |id| {
// log.warn("TIM{} Overflowed", .{id});
switch (id) {
0 => bus.io.tim0.handleOverflow(cpu, &bus.io),
1 => bus.io.tim1.handleOverflow(cpu, &bus.io),
@@ -125,6 +49,8 @@ pub const Scheduler = struct {
3 => bus.io.tim3.handleOverflow(cpu, &bus.io),
}
},
.HBlank => bus.ppu.handleHBlankEnd(cpu), // The end of a HBlank
.VBlank => bus.ppu.handleHDrawEnd(cpu), // The end of a VBlank
}
}
}
@@ -153,9 +79,9 @@ pub const Scheduler = struct {
}
pub fn nextTimestamp(self: *Self) u64 {
if (self.queue.peek()) |e| {
return e.tick;
} else unreachable;
if (self.queue.peek()) |e| return e.tick;
unreachable; // There's always the HeatDeath event scheduled
}
};