winmain: reworked main loop for smoother frame times.

imgui_sdl: added handling for device lost.
midi: load PINBALL.MID in uppercase and using absolute path.
Added UPS/FPS options, by default 120/60.

SpaceCadetPinball/imgui_sdl.cpp

@@ -100,6 +100,12 @@ namespace
 
 			Clean();
 		}
+
+		void Reset()
+		{
+			Order.clear();
+			Container.clear();
+		}
 	private:
 		void Clean()
 		{
@@ -149,6 +155,7 @@ namespace
 	struct Device
 	{
 		SDL_Renderer* Renderer;
+		bool CacheWasInvalidated = false;
 
 		struct ClipRect
 		{
@@ -522,6 +529,14 @@ namespace
 
 namespace ImGuiSDL
 {
+	static int ImGuiSDLEventWatch(void* userdata, SDL_Event* event) {
+		if (event->type == SDL_RENDER_TARGETS_RESET) {
+			// Device lost event, applies to DirectX and some mobile devices.
+			CurrentDevice->CacheWasInvalidated = true;
+		}
+		return 0;
+	}
+
 	void Initialize(SDL_Renderer* renderer, int windowWidth, int windowHeight)
 	{
 		ImGuiIO& io = ImGui::GetIO();
@@ -531,6 +546,12 @@ namespace ImGuiSDL
 		ImGui::GetStyle().WindowRounding = 0.0f;
 		ImGui::GetStyle().AntiAliasedFill = false;
 		ImGui::GetStyle().AntiAliasedLines = false;
+		ImGui::GetStyle().ChildRounding = 0.0f;
+		ImGui::GetStyle().PopupRounding = 0.0f;
+		ImGui::GetStyle().FrameRounding = 0.0f;
+		ImGui::GetStyle().ScrollbarRounding = 0.0f;
+		ImGui::GetStyle().GrabRounding = 0.0f;
+		ImGui::GetStyle().TabRounding = 0.0f;
 
 		// Loads the font texture.
 		unsigned char* pixels;
@@ -545,6 +566,7 @@ namespace ImGuiSDL
 		io.Fonts->TexID = (void*)texture;
 
 		CurrentDevice = new Device(renderer);
+		SDL_AddEventWatch(ImGuiSDLEventWatch, nullptr);
 	}
 
 	void Deinitialize()
@@ -555,10 +577,17 @@ namespace ImGuiSDL
 		delete texture;
 
 		delete CurrentDevice;
+		SDL_DelEventWatch(ImGuiSDLEventWatch, nullptr);
 	}
 
 	void Render(ImDrawData* drawData)
 	{
+		if (CurrentDevice->CacheWasInvalidated) {
+			CurrentDevice->CacheWasInvalidated = false;
+			CurrentDevice->GenericTriangleCache.Reset();
+			CurrentDevice->UniformColorTriangleCache.Reset();
+		}
+
 		SDL_BlendMode blendMode;
 		SDL_GetRenderDrawBlendMode(CurrentDevice->Renderer, &blendMode);
 		SDL_SetRenderDrawBlendMode(CurrentDevice->Renderer, SDL_BLENDMODE_BLEND);

SpaceCadetPinball/midi.cpp

@@ -59,7 +59,11 @@ int midi::music_init()
 		return music_init_ft();
 	}
 
-	currentMidi = Mix_LoadMUS(pinball::get_rc_string(156, 0));
+	// File name is in lower case, while game data is in upper case.
+	std::string fileName = pinball::get_rc_string(156, 0);
+	std::transform(fileName.begin(), fileName.end(), fileName.begin(), [](unsigned char c) { return std::toupper(c); });
+	auto midiPath = pinball::make_path_name(fileName);
+	currentMidi = Mix_LoadMUS(midiPath.c_str());
 	return currentMidi != nullptr;
 }
 
@@ -329,7 +333,7 @@ std::vector<uint8_t>* midi::MdsToMidi(std::string file)
 		midiBytes.insert(midiBytes.end(), metaEndTrack, metaEndTrack + 4);
 
 		// Set final MTrk size
-		auto lengthBE = SwapByteOrderInt((uint32_t)midiBytes.size() - sizeof header - sizeof track);
+		auto lengthBE = SwapByteOrderInt(static_cast<uint32_t>(midiBytes.size()) - sizeof header - sizeof track);
 		auto lengthData = reinterpret_cast<const uint8_t*>(&lengthBE);
 		std::copy_n(lengthData, 4, midiBytes.begin() + lengthPos);
 	}

SpaceCadetPinball/options.cpp

@@ -100,6 +100,11 @@ void options::init()
 	ImGui::GetIO().FontGlobalScale = get_float("UI Scale", 1.0f);
 	Options.Resolution = get_int("Screen Resolution", -1);
 	Options.LinearFiltering = get_int("Linear Filtering", true);
+	Options.FramesPerSecond = std::min(MaxFps, std::max(MinUps, get_int("Frames Per Second", DefFps)));
+	Options.UpdatesPerSecond = std::min(MaxUps, std::max(MinUps, get_int("Updates Per Second", DefUps)));
+	Options.UpdatesPerSecond = std::max(Options.UpdatesPerSecond, Options.FramesPerSecond);
+
+	winmain::UpdateFrameRate();
 
 	Sound::Enable(0, 7, Options.Sounds);
 
@@ -125,6 +130,8 @@ void options::uninit()
 	set_int("Uniform scaling", Options.UniformScaling);
 	set_float("UI Scale", ImGui::GetIO().FontGlobalScale);
 	set_int("Linear Filtering", Options.LinearFiltering);
+	set_int("Frames Per Second", Options.FramesPerSecond);
+	set_int("Updates Per Second", Options.UpdatesPerSecond);
 }
 
 

SpaceCadetPinball/options.h

@@ -49,12 +49,17 @@ struct optionsStruct
 	int Resolution;
 	bool UniformScaling;
 	bool LinearFiltering;
+	int FramesPerSecond;
+	int UpdatesPerSecond;
 };
 
 
 class options
 {
 public:
+	// Original does ~120 updates per second.
+	static constexpr int MaxUps = 360, MaxFps = MaxUps, MinUps = 60, MinFps = MinUps,
+	                     DefUps = 120, DefFps = 60;
 	static optionsStruct Options;
 
 	static void init();

SpaceCadetPinball/pb.cpp

@@ -214,24 +214,27 @@ void pb::ballset(int x, int y)
 	ball->Speed = maths::normalize_2d(&ball->Acceleration);
 }
 
-int pb::frame(int time)
+void pb::frame(int dtMilliSec)
 {
-	if (time > 100)
+	
-		time = 100;
+	if (dtMilliSec > 100)
-	float timeMul = time * 0.001f;
+		dtMilliSec = 100;
-	if (!mode_countdown(time))
+	if (dtMilliSec <= 0)
+		return;
+	float dtMicroSec = dtMilliSec * 0.001f;
+	if (!mode_countdown(dtMilliSec))
 	{
-		time_next = time_now + timeMul;
+		time_next = time_now + dtMicroSec;
-		timed_frame(time_now, timeMul, true);
+		timed_frame(time_now, dtMicroSec, true);
 		time_now = time_next;
-		time_ticks += time;
+		time_ticks += dtMilliSec;
 		if (nudge::nudged_left || nudge::nudged_right || nudge::nudged_up)
 		{
-			nudge::nudge_count = timeMul * 4.0f + nudge::nudge_count;
+			nudge::nudge_count = dtMicroSec * 4.0f + nudge::nudge_count;
 		}
 		else
 		{
-			auto nudgeDec = nudge::nudge_count - timeMul;
+			auto nudgeDec = nudge::nudge_count - dtMicroSec;
 			if (nudgeDec <= 0.0f)
 				nudgeDec = 0.0;
 			nudge::nudge_count = nudgeDec;
@@ -249,7 +252,6 @@ int pb::frame(int time)
 				MainTable->tilt(time_now);
 		}
 	}
-	return 1;
 }
 
 void pb::timed_frame(float timeNow, float timeDelta, bool drawBalls)

SpaceCadetPinball/pb.h

@@ -48,7 +48,7 @@ public:
 	static void toggle_demo();
 	static void replay_level(int demoMode);
 	static void ballset(int x, int y);
-	static int frame(int time);
+	static void frame(int dtMilliSec);
 	static void timed_frame(float timeNow, float timeDelta, bool drawBalls);
 	static void window_size(int* width, int* height);
 	static void pause_continue();

SpaceCadetPinball/pch.h

@@ -27,6 +27,7 @@
 #include <algorithm>
 #include <cstring>
 #include <string>
+#include <thread>
 
 #define SDL_MAIN_HANDLED
 #include "SDL.h"

SpaceCadetPinball/winmain.cpp

@@ -10,8 +10,6 @@
 #include "render.h"
 #include "Sound.h"
 
-const double TargetFps = 60, TargetFrameTime = 1000 / TargetFps;
-
 SDL_Window* winmain::MainWindow = nullptr;
 SDL_Renderer* winmain::Renderer = nullptr;
 ImGuiIO* winmain::ImIO = nullptr;
@@ -28,8 +26,6 @@ int winmain::last_mouse_y;
 int winmain::mouse_down;
 int winmain::no_time_loss;
 
-DWORD winmain::then;
-DWORD winmain::now;
 bool winmain::restart = false;
 
 gdrv_bitmap8 winmain::gfr_display{};
@@ -42,15 +38,8 @@ bool winmain::HighScoresEnabled = true;
 bool winmain::DemoActive = false;
 char* winmain::BasePath;
 std::string winmain::FpsDetails;
-
+double winmain::UpdateToFrameRatio;
-
+winmain::DurationMs winmain::TargetFrameTime;
-uint32_t timeGetTimeAlt()
-{
-	auto now = std::chrono::high_resolution_clock::now();
-	auto duration = now.time_since_epoch();
-	auto millis = std::chrono::duration_cast<std::chrono::milliseconds>(duration).count();
-	return static_cast<uint32_t>(millis);
-}
 
 int winmain::WinMain(LPCSTR lpCmdLine)
 {
@@ -167,28 +156,29 @@ int winmain::WinMain(LPCSTR lpCmdLine)
 	else
 		pb::replay_level(0);
 
-	DWORD updateCounter = 300u, frameCounter = 0, prevTime = 0u;
+	DWORD dtHistoryCounter = 300u, updateCounter = 0, frameCounter = 0;
-	then = timeGetTimeAlt();
 
-	double sdlTimerResMs = 1000.0 / static_cast<double>(SDL_GetPerformanceFrequency());
+	auto frameStart = Clock::now();
-	auto frameStart = static_cast<double>(SDL_GetPerformanceCounter());
+	double frameDuration = TargetFrameTime.count(), UpdateToFrameCounter = 0;
+	DurationMs sleepRemainder(0);
+	auto prevTime = frameStart;
 	while (true)
 	{
-		if (!updateCounter)
-		{
-			updateCounter = 300;
 		if (DispFrameRate)
 		{
-				auto curTime = timeGetTimeAlt();
+			auto curTime = Clock::now();
-				if (prevTime)
+			if (curTime - prevTime > DurationMs(1000))
 			{
 				char buf[60];
-					auto elapsedSec = static_cast<float>(curTime - prevTime) * 0.001f;
+				auto elapsedSec = DurationMs(curTime - prevTime).count() * 0.001;
 				snprintf(buf, sizeof buf, "Updates/sec = %02.02f Frames/sec = %02.02f ",
-					         300.0f / elapsedSec, frameCounter / elapsedSec);
+				         updateCounter / elapsedSec, frameCounter / elapsedSec);
 				SDL_SetWindowTitle(window, buf);
 				FpsDetails = buf;
-					frameCounter = 0;
+				frameCounter = updateCounter = 0;
+				prevTime = curTime;
+			}
+		}
 
 		if (DispGRhistory)
 		{
@@ -212,17 +202,13 @@ int winmain::WinMain(LPCSTR lpCmdLine)
 				gdrv::create_bitmap(&gfr_display, 400, 15, 400, false);
 			}
 
+			if (!dtHistoryCounter)
+			{
+				dtHistoryCounter = 300;
 				gdrv::copy_bitmap(&render::vscreen, 300, 10, 0, 30, &gfr_display, 0, 0);
 				gdrv::fill_bitmap(&gfr_display, 300, 10, 0, 0, 0);
 			}
 		}
-				prevTime = curTime;
-			}
-			else
-			{
-				prevTime = 0;
-			}
-		}
 
 		if (!ProcessWindowMessages() || bQuit)
 			break;
@@ -230,54 +216,34 @@ int winmain::WinMain(LPCSTR lpCmdLine)
 		if (has_focus)
 		{
 			if (mouse_down)
-			{
-				now = timeGetTimeAlt();
-				if (now - then >= 2)
 			{
 				int x, y;
 				SDL_GetMouseState(&x, &y);
 				pb::ballset(last_mouse_x - x, y - last_mouse_y);
 				SDL_WarpMouseInWindow(window, last_mouse_x, last_mouse_y);
 			}
-			}
 			if (!single_step)
 			{
-				auto curTime = timeGetTimeAlt();
+				auto deltaT = static_cast<int>(frameDuration);
-				now = curTime;
+				frameDuration -= deltaT;
-				if (no_time_loss)
+				pb::frame(deltaT);
-				{
-					then = curTime;
-					no_time_loss = 0;
-				}
-
-				if (curTime == then)
-				{
-					SDL_Delay(8);
-				}
-				else if (pb::frame(curTime - then))
-				{
 				if (gfr_display.BmpBufPtr1)
 				{
-						auto deltaT = now - then + 10;
+					auto deltaTPal = deltaT + 10;
-						auto fillChar = static_cast<uint8_t>(deltaT);
+					auto fillChar = static_cast<uint8_t>(deltaTPal);
-						if (deltaT > 236)
+					if (deltaTPal > 236)
 					{
 						fillChar = 1;
 					}
-						gdrv::fill_bitmap(&gfr_display, 1, 10, 300 - updateCounter, 0, fillChar);
+					gdrv::fill_bitmap(&gfr_display, 1, 10, 300 - dtHistoryCounter, 0, fillChar);
-					}
+					--dtHistoryCounter;
-					--updateCounter;
-					then = now;
 				}
+				updateCounter++;
 			}
 
-			auto frameEnd = static_cast<double>(SDL_GetPerformanceCounter());
+			if (UpdateToFrameCounter >= UpdateToFrameRatio)
-			auto elapsedMs = (frameEnd - frameStart) * sdlTimerResMs;
-			if (elapsedMs >= TargetFrameTime)
 			{
-				// Keep track of remainder, limited to one frame time.
+				UpdateToFrameCounter -= UpdateToFrameRatio;
-				frameStart = frameEnd - std::min(elapsedMs - TargetFrameTime, TargetFrameTime) / sdlTimerResMs;
-
 				ImGui_ImplSDL2_NewFrame();
 				ImGui::NewFrame();
 
@@ -299,6 +265,28 @@ int winmain::WinMain(LPCSTR lpCmdLine)
 				SDL_ClearError();
 				printf("SDL Error: %s\n", sdlError);
 			}
+
+			auto updateEnd = Clock::now();
+			auto targetTimeDelta = TargetFrameTime - DurationMs(updateEnd - frameStart) - sleepRemainder;
+
+			TimePoint frameEnd;
+			if (targetTimeDelta > DurationMs::zero())
+			{
+				std::this_thread::sleep_for(targetTimeDelta);
+				frameEnd = Clock::now();
+				sleepRemainder = DurationMs(frameEnd - updateEnd) - targetTimeDelta;
+			}
+			else
+			{
+				frameEnd = updateEnd;
+				sleepRemainder = DurationMs(0);
+			}
+
+			// Limit duration to 2 * target time
+			frameDuration = std::min(frameDuration + DurationMs(frameEnd - frameStart).count(),
+			                         2 * TargetFrameTime.count());
+			frameStart = frameEnd;
+			UpdateToFrameCounter++;
 		}
 	}
 
@@ -430,7 +418,7 @@ void winmain::RenderUi()
 				}
 				ImGui::EndMenu();
 			}
-			if (ImGui::BeginMenu("Window"))
+			if (ImGui::BeginMenu("Graphics"))
 			{
 				if (ImGui::MenuItem("Uniform Scaling", nullptr, options::Options.UniformScaling))
 				{
@@ -440,8 +428,35 @@ void winmain::RenderUi()
 				{
 					options::toggle(Menu1::WindowLinearFilter);
 				}
-				ImGui::DragFloat("", &ImIO->FontGlobalScale, 0.005f, 0.8f, 5,
+				ImGui::DragFloat("UI Scale", &ImIO->FontGlobalScale, 0.005f, 0.8f, 5,
-				                 "UI Scale %.2f", ImGuiSliderFlags_AlwaysClamp);
+				                 "%.2f", ImGuiSliderFlags_AlwaysClamp);
+				ImGui::Separator();
+
+				auto changed = false;
+				if (ImGui::MenuItem("Set Default UPS/FPS"))
+				{
+					changed = true;
+					options::Options.UpdatesPerSecond = options::DefUps;
+					options::Options.FramesPerSecond = options::DefFps;
+				}
+				if (ImGui::DragInt("UPS", &options::Options.UpdatesPerSecond, 1, options::MinUps, options::MaxUps,
+				                   "%d", ImGuiSliderFlags_AlwaysClamp))
+				{
+					changed = true;
+					options::Options.FramesPerSecond = std::min(options::Options.UpdatesPerSecond,
+					                                            options::Options.FramesPerSecond);
+				}
+				if (ImGui::DragInt("FPS", &options::Options.FramesPerSecond, 1, options::MinFps, options::MaxFps,
+				                   "%d", ImGuiSliderFlags_AlwaysClamp))
+				{
+					changed = true;
+					options::Options.UpdatesPerSecond = std::max(options::Options.UpdatesPerSecond,
+					                                             options::Options.FramesPerSecond);
+				}
+				if (changed)
+				{
+					UpdateFrameRate();
+				}
 
 				ImGui::EndMenu();
 			}
@@ -760,3 +775,11 @@ void winmain::Restart()
 	SDL_Event event{SDL_QUIT};
 	SDL_PushEvent(&event);
 }
+
+void winmain::UpdateFrameRate()
+{
+	// UPS >= FPS
+	auto fps = options::Options.FramesPerSecond, ups = options::Options.UpdatesPerSecond;
+	UpdateToFrameRatio = static_cast<double>(ups) / fps;
+	TargetFrameTime = DurationMs(1000.0 / ups);
+}

SpaceCadetPinball/winmain.h

@@ -1,8 +1,44 @@
 #pragma once
 #include "gdrv.h"
 
+struct SdlTickClock
+{
+	using duration = std::chrono::milliseconds;
+	using rep = duration::rep;
+	using period = duration::period;
+	using time_point = std::chrono::time_point<SdlTickClock>;
+	static constexpr bool is_steady = true;
+
+	static time_point now() noexcept
+	{
+		return time_point{duration{SDL_GetTicks()}};
+	}
+};
+
+struct SdlPerformanceClock
+{
+	using duration = std::chrono::duration<uint64_t, std::nano>;
+	using rep = duration::rep;
+	using period = duration::period;
+	using time_point = std::chrono::time_point<SdlPerformanceClock>;
+	static constexpr bool is_steady = true;
+
+	static time_point now() noexcept
+	{
+		const auto freq = SDL_GetPerformanceFrequency();
+		const auto ctr = SDL_GetPerformanceCounter();
+		const auto whole = (ctr / freq) * period::den;
+		const auto part = (ctr % freq) * period::den / freq;
+		return time_point(duration(whole + part));
+	}
+};
+
 class winmain
 {
+	using Clock = SdlPerformanceClock; // Or std::chrono::steady_clock.
+	using DurationMs = std::chrono::duration<double, std::milli>;
+	using TimePoint = std::chrono::time_point<Clock>;
+
 public:
 	static std::string DatFileName;
 	static int single_step;
@@ -24,16 +60,18 @@ public:
 	static void pause();
 	static void Restart();
 	static bool RestartRequested() { return restart; }
+	static void UpdateFrameRate();
 private:
 	static int return_value, bQuit, DispFrameRate, DispGRhistory, activated;
 	static int has_focus, mouse_down, last_mouse_x, last_mouse_y, no_time_loss;
-	static DWORD then, now;
 	static gdrv_bitmap8 gfr_display;
 	static std::string FpsDetails;
 	static bool restart;
 	static bool ShowAboutDialog;
 	static bool ShowImGuiDemo;
 	static bool ShowSpriteViewer;
+	static double UpdateToFrameRatio;
+	static DurationMs TargetFrameTime;
 
 	static void RenderUi();
 };