Mirrors/yuzu
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

GPU: Implement frameskip and remove forced framebuffer swap hack.

Browse source
This commit is contained in:
bunnei 2014-12-26 21:40:17 -05:00
parent a2005d0657
commit 3b9d181b8e
7 changed files with 47 additions and 27 deletions
Download patch file Download diff file Expand all files Collapse all files

63
src/core/hw/gpu.cpp
View file

@ -21,10 +21,14 @@ namespace GPU {
Regs g_regs;
static u64 frame_ticks = 0; ///< 268MHz / 60 frames per second
static u32 cur_line = 0; ///< Current vertical screen line
static u64 last_frame_ticks = 0; ///< CPU tick count from last frame
static u64 last_update_tick = 0; ///< CPU ticl count from last GPU update
bool g_skip_frame = false; ///< True if the current frame was skipped
static u64 frame_ticks = 0; ///< 268MHz / gpu_refresh_rate frames per second
static u64 line_ticks = 0; ///< Number of ticks for a screen line
static u32 cur_line = 0; ///< Current screen line
static u64 last_update_tick = 0; ///< CPU ticl count from last GPU update
static u64 frame_count = 0; ///< Number of frames drawn
static bool last_skip_frame = false; ///< True if the last frame was skipped
template <typename T>
inline void Read(T &var, const u32 raw_addr) {
@ -178,38 +182,40 @@ template void Write<u8>(u32 addr, const u8 data);
void Update() {
auto& framebuffer_top = g_regs.framebuffer_config[0];
// Update the frame after a certain number of CPU ticks have elapsed. This assumes that the
// active frame in memory is always complete to render. There also may be issues with this
// becoming out-of-synch with GSP synchrinization code (as follows). At this time, this seems to
// be the most effective solution for both homebrew and retail applications. With retail, this
// could be moved below (and probably would guarantee more accurate synchronization). However,
// primitive homebrew relies on a vertical blank interrupt to happen inevitably (regardless of a
// threading reschedule).
if ((Core::g_app_core->GetTicks() - last_frame_ticks) > (GPU::frame_ticks)) {
VideoCore::g_renderer->SwapBuffers();
last_frame_ticks = Core::g_app_core->GetTicks();
}
// Synchronize GPU on a thread reschedule: Because we cannot accurately predict a vertical
// blank, we need to simulate it. Based on testing, it seems that retail applications work more
// accurately when this is signalled between thread switches.
if (HLE::g_reschedule) {
u64 current_ticks = Core::g_app_core->GetTicks();
u64 line_ticks = (GPU::frame_ticks / framebuffer_top.height) * 16;
u32 num_lines = static_cast<u32>((current_ticks - last_update_tick) / line_ticks);
//// Synchronize line...
if ((current_ticks - last_update_tick) >= line_ticks) {
// Synchronize line...
if (num_lines > 0) {
GSP_GPU::SignalInterrupt(GSP_GPU::InterruptId::PDC0);
cur_line++;
last_update_tick += line_ticks;
cur_line += num_lines;
last_update_tick += (num_lines * line_ticks);
}
// Synchronize frame...
if (cur_line >= framebuffer_top.height) {
cur_line = 0;
VideoCore::g_renderer->SwapBuffers();
frame_count++;
last_skip_frame = g_skip_frame;
g_skip_frame = (frame_count & Settings::values.frame_skip) != 0;
// Swap buffers based on the frameskip mode, which is a little bit tricky. When
// a frame is being skipped, nothing is being rendered to the internal framebuffer(s).
// So, we should only swap frames if the last frame was rendered. The rules are:
// - If frameskip == 0 (disabled), always swap buffers
// - If frameskip == 1, swap buffers every other frame (starting from the first frame)
// - If frameskip > 1, swap buffers every frameskip^n frames (starting from the second frame)
if ((((Settings::values.frame_skip != 1) ^ last_skip_frame) && last_skip_frame != g_skip_frame) ||
Settings::values.frame_skip == 0) {
VideoCore::g_renderer->SwapBuffers();
}
GSP_GPU::SignalInterrupt(GSP_GPU::InterruptId::PDC1);
}
}
@ -217,10 +223,6 @@ void Update() {
/// Initialize hardware
void Init() {
frame_ticks = 268123480 / Settings::values.gpu_refresh_rate;
cur_line = 0;
last_update_tick = last_frame_ticks = Core::g_app_core->GetTicks();
auto& framebuffer_top = g_regs.framebuffer_config[0];
auto& framebuffer_sub = g_regs.framebuffer_config[1];
@ -249,6 +251,13 @@ void Init() {
framebuffer_sub.color_format = Regs::PixelFormat::RGB8;
framebuffer_sub.active_fb = 0;
frame_ticks = 268123480 / Settings::values.gpu_refresh_rate;
line_ticks = (GPU::frame_ticks / framebuffer_top.height);
cur_line = 0;
last_update_tick = Core::g_app_core->GetTicks();
last_skip_frame = false;
g_skip_frame = false;
LOG_DEBUG(HW_GPU, "initialized OK");
}