From fffc03c4e4aae7abd319d7508c800672d220803f Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Fri, 12 Nov 2021 15:30:52 -0500
Subject: [PATCH] Propagates time to the audio subsystem.
---
Machines/Amiga/Amiga.cpp | 4 ++++
Machines/Amiga/Audio.cpp | 12 ++++++++----
Machines/Amiga/Audio.hpp | 15 +++++++++++++--
Machines/Amiga/Chipset.cpp | 9 +++++++--
Machines/Amiga/Chipset.hpp | 4 +++-
5 files changed, 35 insertions(+), 9 deletions(-)
diff --git a/Machines/Amiga/Amiga.cpp b/Machines/Amiga/Amiga.cpp
index ee638f454..dcaefae53 100644
--- a/Machines/Amiga/Amiga.cpp
+++ b/Machines/Amiga/Amiga.cpp
@@ -166,6 +166,10 @@ class ConcreteMachine:
return access_delay;
}
+ void flush() {
+ chipset_.flush();
+ }
+
private:
CPU::MC68000::Processor<ConcreteMachine, true> mc68000_;
diff --git a/Machines/Amiga/Audio.cpp b/Machines/Amiga/Audio.cpp
index 4a9ece054..d64f5b2fb 100644
--- a/Machines/Amiga/Audio.cpp
+++ b/Machines/Amiga/Audio.cpp
@@ -7,12 +7,16 @@
//
#include "Audio.hpp"
+
+#define LOG_PREFIX "[Audio] "
+#include "../../Outputs/Log.hpp"
+
#include <cassert>
using namespace Amiga;
bool Audio::advance(int channel) {
- if(channels_[channel].samples_remaining || !channels_[channel].length) {
+ if(channels_[channel].has_data || !channels_[channel].length) {
return false;
}
@@ -40,10 +44,10 @@ void Audio::set_volume(int channel, uint16_t volume) {
void Audio::set_data(int channel, uint16_t data) {
assert(channel >= 0 && channel < 4);
- if(!channels_[channel].samples_remaining) {
+ if(!channels_[channel].has_data) {
channels_[channel].period_counter = channels_[channel].period;
}
- channels_[channel].samples_remaining = 2;
+ channels_[channel].has_data = true;
channels_[channel].data = data;
}
@@ -57,7 +61,7 @@ void Audio::set_channel_enables(uint16_t enables) {
void Audio::set_modulation_flags(uint16_t) {
}
-void Audio::run_for(HalfCycles) {
+void Audio::run_for([[maybe_unused]] Cycles duration) {
// TODO:
//
// Check whether any channel's period counter is exhausted and, if
diff --git a/Machines/Amiga/Audio.hpp b/Machines/Amiga/Audio.hpp
index 84c5aafb7..e595cf2fb 100644
--- a/Machines/Amiga/Audio.hpp
+++ b/Machines/Amiga/Audio.hpp
@@ -28,7 +28,7 @@ class Audio: public DMADevice<4> {
/// Standard JustInTimeActor item; allows this class to track the
/// amount of time between other events.
- void run_for(HalfCycles);
+ void run_for(Cycles);
/// Sets the total number of words to fetch for the given channel.
void set_length(int channel, uint16_t);
@@ -58,7 +58,7 @@ class Audio: public DMADevice<4> {
// The data latch plus a count of unused samples
// in the latch, which will always be 0, 1 or 2.
uint16_t data = 0x0000;
- int samples_remaining = 0;
+ bool has_data = false;
// Number of words remaining in DMA data.
uint16_t length = 0;
@@ -73,6 +73,17 @@ class Audio: public DMADevice<4> {
// Indicates whether DMA is enabled for this channel.
bool dma_enabled = false;
+
+ // Replicates the Hardware Reference Manual state machine;
+ // comments indicate which of the documented states each
+ // label refers to.
+ enum class State {
+ Disabled, // 000
+ WaitingForDummyDMA, // 001
+ WaitingForDMA, // 101
+ PlayingHigh, // 010
+ PlayingLow, // 011
+ } state_;
} channels_[4];
};
diff --git a/Machines/Amiga/Chipset.cpp b/Machines/Amiga/Chipset.cpp
index 083aa0e49..3dbf31217 100644
--- a/Machines/Amiga/Chipset.cpp
+++ b/Machines/Amiga/Chipset.cpp
@@ -140,6 +140,9 @@ template <int cycle> void Chipset::output() {
constexpr int blank3 = 7 + burst;
static_assert(blank3 == 43);
+ // Advance audio.
+ audio_ += Cycles(1);
+
// Trigger any sprite loads encountered.
constexpr auto dcycle = cycle << 1;
for(int c = 0; c < 8; c += 2) {
@@ -444,8 +447,6 @@ template <bool stop_on_cpu> int Chipset::advance_slots(int first_slot, int last_
template <bool stop_on_cpu> Chipset::Changes Chipset::run(HalfCycles length) {
Changes changes;
- // TODO: incorporate audio timing here or deeper.
-
// This code uses 'pixels' as a measure, which is equivalent to one pixel clock time,
// or half a cycle.
auto pixels_remaining = length.as<int>();
@@ -1286,3 +1287,7 @@ uint16_t Chipset::Mouse::get_position() {
declared_position_[0]
);
}
+
+void Chipset::flush() {
+ audio_.flush();
+}
diff --git a/Machines/Amiga/Chipset.hpp b/Machines/Amiga/Chipset.hpp
index 67cd477f8..d9bc70493 100644
--- a/Machines/Amiga/Chipset.hpp
+++ b/Machines/Amiga/Chipset.hpp
@@ -102,6 +102,8 @@ class Chipset: private ClockingHint::Observer {
return keyboard_;
}
+ void flush();
+
private:
friend class DMADeviceBase;
@@ -309,7 +311,7 @@ class Chipset: private ClockingHint::Observer {
// MARK: - Audio.
- JustInTimeActor<Audio> audio_;
+ JustInTimeActor<Audio, Cycles> audio_;
// MARK: - Serial port.