mirror of
https://github.com/hrydgard/ppsspp.git
synced 2024-10-06 18:33:34 +00:00
129 lines
4.0 KiB
C++
129 lines
4.0 KiB
C++
// Frame timing
|
|
//
|
|
// A frame on the main thread should look a bit like this:
|
|
//
|
|
// 1. -- Wait for the right time to start the frame (alternatively, see this is step 8).
|
|
// 2. Sample inputs (on some platforms, this is done continouously during step 3)
|
|
// 3. Run CPU
|
|
// 4. Submit GPU commands (there's no reason to ever wait before this).
|
|
// 5. -- Wait for the right time to present
|
|
// 6. Send Present command
|
|
// 7. Do other end-of-frame stuff
|
|
//
|
|
// To minimize latency, we should *maximize* 1 and *minimize* 5 (while still keeping some margin to soak up hitches).
|
|
// Additionally, if too many completed frames have been buffered up, we need a feedback mechanism, so we can temporarily
|
|
// artificially increase 1 in order to "catch the CPU up".
|
|
//
|
|
// There are some other things that can influence the frame timing:
|
|
// * Unthrottling. If vsync is off or the backend can change present mode dynamically, we can simply disable all waits during unthrottle.
|
|
// * Frame skipping. This gets complicated.
|
|
// * The game not actually asking for flips, like in static loading screens
|
|
|
|
#include "Common/Profiler/Profiler.h"
|
|
#include "Common/Log.h"
|
|
#include "Common/TimeUtil.h"
|
|
|
|
#include "Core/RetroAchievements.h"
|
|
#include "Core/CoreParameter.h"
|
|
#include "Core/Core.h"
|
|
#include "Core/Config.h"
|
|
#include "Core/HW/Display.h"
|
|
#include "Core/FrameTiming.h"
|
|
|
|
FrameTiming g_frameTiming;
|
|
|
|
void WaitUntil(double now, double timestamp) {
|
|
#ifdef _WIN32
|
|
while (time_now_d() < timestamp) {
|
|
sleep_ms(1); // Sleep for 1ms on this thread
|
|
}
|
|
#else
|
|
const double left = timestamp - now;
|
|
if (left > 0.0 && left < 3.0) {
|
|
usleep((long)(left * 1000000));
|
|
}
|
|
#endif
|
|
}
|
|
|
|
inline Draw::PresentMode GetBestImmediateMode(Draw::PresentMode supportedModes) {
|
|
if (supportedModes & Draw::PresentMode::MAILBOX) {
|
|
return Draw::PresentMode::MAILBOX;
|
|
} else {
|
|
return Draw::PresentMode::IMMEDIATE;
|
|
}
|
|
}
|
|
|
|
void FrameTiming::Reset(Draw::DrawContext *draw) {
|
|
if (g_Config.bVSync || !(draw->GetDeviceCaps().presentModesSupported & (Draw::PresentMode::MAILBOX | Draw::PresentMode::IMMEDIATE))) {
|
|
presentMode = Draw::PresentMode::FIFO;
|
|
presentInterval = 1;
|
|
} else {
|
|
presentMode = GetBestImmediateMode(draw->GetDeviceCaps().presentModesSupported);
|
|
presentInterval = 0;
|
|
}
|
|
}
|
|
|
|
void FrameTiming::DeferWaitUntil(double until, double *curTimePtr) {
|
|
_dbg_assert_(until > 0.0);
|
|
waitUntil_ = until;
|
|
curTimePtr_ = curTimePtr;
|
|
}
|
|
|
|
void FrameTiming::PostSubmit() {
|
|
if (waitUntil_ != 0.0) {
|
|
WaitUntil(time_now_d(), waitUntil_);
|
|
if (curTimePtr_) {
|
|
*curTimePtr_ = waitUntil_;
|
|
curTimePtr_ = nullptr;
|
|
}
|
|
waitUntil_ = 0.0;
|
|
}
|
|
}
|
|
|
|
Draw::PresentMode ComputePresentMode(Draw::DrawContext *draw, int *interval) {
|
|
_assert_(draw);
|
|
|
|
Draw::PresentMode mode = Draw::PresentMode::FIFO;
|
|
|
|
if (draw->GetDeviceCaps().presentModesSupported & (Draw::PresentMode::IMMEDIATE | Draw::PresentMode::MAILBOX)) {
|
|
// Switch to immediate if desired and possible.
|
|
bool wantInstant = false;
|
|
if (!g_Config.bVSync) {
|
|
wantInstant = true;
|
|
}
|
|
|
|
if (PSP_CoreParameter().fastForward) {
|
|
wantInstant = true;
|
|
}
|
|
if (PSP_CoreParameter().fpsLimit != FPSLimit::NORMAL) {
|
|
int limit;
|
|
if (PSP_CoreParameter().fpsLimit == FPSLimit::CUSTOM1)
|
|
limit = g_Config.iFpsLimit1;
|
|
else if (PSP_CoreParameter().fpsLimit == FPSLimit::CUSTOM2)
|
|
limit = g_Config.iFpsLimit2;
|
|
else
|
|
limit = PSP_CoreParameter().analogFpsLimit;
|
|
|
|
// For an alternative speed that is a clean factor of 60, the user probably still wants vsync.
|
|
// TODO: Should take the user's display refresh rate into account...
|
|
if (limit == 0 || (limit >= 0 && limit != 15 && limit != 30 && limit != 60)) {
|
|
wantInstant = true;
|
|
}
|
|
}
|
|
|
|
if (wantInstant && g_Config.bVSync && !draw->GetDeviceCaps().presentInstantModeChange) {
|
|
// If in vsync mode (which will be FIFO), and the backend can't switch immediately,
|
|
// stick to FIFO.
|
|
wantInstant = false;
|
|
}
|
|
|
|
// The outer if checks that instant modes are available.
|
|
if (wantInstant) {
|
|
mode = GetBestImmediateMode(draw->GetDeviceCaps().presentModesSupported);
|
|
}
|
|
}
|
|
|
|
*interval = (mode == Draw::PresentMode::FIFO) ? 1 : 0;
|
|
return mode;
|
|
}
|