// IRQ
public override void OnPPUScanlineTick()
{
// In frame signal
irq_current_inframe = (NesEmu.IsInRender() && NesEmu.IsRenderingOn()) ? 0x40 : 0x00;
if (irq_current_inframe == 0)
{
irq_current_inframe = 0x40;
irq_current_counter = 0;
irq_pending = 0;
NesEmu.IRQFlags &= ~NesEmu.IRQ_BOARD;
}
else
{
irq_current_counter++;
if (irq_current_counter == irq_line)
{
irq_pending = 0x80; // IRQ pending flag is raised *regardless* of whether or not IRQs are enabled.
if (irq_enable == 0x80) // Trigger an IRQ on the 6502 if both this flag *and* the IRQ enable flag is set.
{
NesEmu.IRQFlags |= NesEmu.IRQ_BOARD;
}
}
}
}