1 files changed, 37 insertions, 24 deletions

diff --git a/src/main.cpp b/src/main.cpp
index bd9dee0..fcddf80 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -16,7 +16,7 @@
 #include "window.hpp"
 
 void signal_handler(int signal_num) {
-	printf("Received signal: %d - shutting down\n", signal_num);
+	fprintf(stdout, "Received signal: %d - shutting down\n", signal_num);
 	pkeSettings.isGameRunning = false;
 }
 
@@ -29,7 +29,7 @@ void Tick(double delta) {
 int main() { 
 	signal(SIGTERM, signal_handler);
 
-	printf("PKE ENTERING\n");
+	fprintf(stdout, "PKE ENTERING\n");
 	try {
 		AM_Init();
 		Game_Init();
@@ -49,8 +49,10 @@ int main() {
 
 			glfwPollEvents();
 
+			int64_t nsAheadHolder = 0.0;
 			if (nsAhead > 0) {
-				std::this_thread::sleep_until(lastTimePoint + GameTimeDuration(nsAhead + 1));
+				nsAheadHolder = nsAhead;
+				std::this_thread::sleep_for(GameTimeDuration(nsAhead));
 				nsAhead = 0;
 			}
 			if (vidMode.refreshRate != pkeSettings.targetFPS) {
@@ -59,23 +61,23 @@ int main() {
 			}
 
 			GameTimePoint currentTimePoint = pkeSettings.steadyClock.now();
-			double deltaThisTick = (currentTimePoint - lastTimePoint).count() / NANO_DENOM_DOUBLE;
+			double deltaThisTick = ((currentTimePoint - lastTimePoint).count() - nsAheadHolder) / NANO_DENOM_DOUBLE;
 			deltaThisTick = std::min(deltaThisTick, pkeSettings.minimumDeltaPerFrame);
-			deltaTillNextRender -= deltaThisTick;
-			bool shouldRender = deltaTillNextRender < deltaThisTick;
 			lastTimePoint = currentTimePoint;
 
-			if (shouldRender) {
-				if (deltaTillNextRender > 0.0 && deltaThisTick < pkeSettings.deltaPerFrame) {
-					/*
-					 * We are ahead of schedule && the current tick is faster than our target FPS.
-					 *  Simulate the extra time we are ahead and prepare to sleep the difference
-					 *  before the next tick.
-					 */
-					nsAhead = std::ceil(deltaTillNextRender * NANO_DENOM_DOUBLE);
-					deltaThisTick += deltaTillNextRender;
-				}
-				deltaTillNextRender += pkeSettings.deltaPerFrame;
+			deltaTillNextRender -= deltaThisTick;
+			bool shouldRender = pkeSettings.graphicsSettings.isFramerateUnlocked || deltaTillNextRender <= 0.0;
+
+			if (deltaTillNextRender > 0.0 && deltaTillNextRender - deltaThisTick <= 0.0) {
+				/*
+				 * We are ahead of the render schedule
+				 * && the current tick's speed would put us behind schedule next tick.
+				 *  Simulate the extra time we are ahead and prepare to sleep the difference
+				 *  before the next tick.
+				 */
+				nsAhead = std::ceil(deltaTillNextRender * NANO_DENOM_DOUBLE);
+				deltaThisTick += deltaTillNextRender;
+				shouldRender = true;
 			}
 
 			tickCount += 1;
@@ -83,11 +85,22 @@ int main() {
 
 			if (shouldRender) {
 				Render();
+				double msBehind = deltaTillNextRender * -1000;
+				int64_t behindCount = 0;
+				while (deltaTillNextRender < pkeSettings.deltaPerFrame) {
+					behindCount += 1;
+					deltaTillNextRender += pkeSettings.deltaPerFrame;
+				}
+				if (behindCount > 2) {
+					fprintf(stderr, "[PKE::main] late render - simulated ahead: %fms - delta behind: %fms - missed frames:%ld\n", nsAheadHolder / (NANO_DENOM_DOUBLE / 1000), msBehind, behindCount - 1);
+					fflush(stderr);
+				}
 			}
 
-			if (shouldRender == false && (currentTimePoint - lastLogTimePoint).count() > std::chrono::nanoseconds::period::den) {
+			if ((currentTimePoint - lastLogTimePoint).count() > std::chrono::nanoseconds::period::den) {
 				lastLogTimePoint = currentTimePoint;
-				printf("TPS: ~%ld - actual:%ld\n", int64_t(1 / deltaThisTick), tickCount);
+				fprintf(stdout, "TPS: ~%ld - actual:%ld\n", int64_t(1 / deltaThisTick), tickCount);
+				fflush(stdout);
 				tickCount = 0;
 			}
 
@@ -97,13 +110,13 @@ int main() {
 		vkDeviceWaitIdle(vkDevice);
 
 	} catch (const std::exception &exc) {
-		printf("EXCEPTION: %s\n", exc.what());
+		fprintf(stdout, "EXCEPTION: %s\n", exc.what());
 	} catch (const char *err) {
-		printf("UNHANDLED EXCEPTION: %s\n", err);
+		fprintf(stdout, "UNHANDLED EXCEPTION: %s\n", err);
 	} catch (...) {
-		printf("UNHANDLED EXCEPTION\n");
+		fprintf(stdout, "UNHANDLED EXCEPTION\n");
 	}
-	printf("PKE SHUTDOWN INITIATED\n");
+	fprintf(stdout, "PKE SHUTDOWN INITIATED\n");
 	Game_Teardown();
 	Event_Teardown();
 	EntityType_Teardown();
@@ -112,6 +125,6 @@ int main() {
 	AM_Teardown();
 	DestroyWindow();
 	Pke_DebugPrint();
-	printf("PKE EXITING\n");
+	fprintf(stdout, "PKE EXITING\n");
 	return 0;
 }