Merge branch 'high-resolution-timer-2' into next

src/d_clisrv.c

@@ -4847,14 +4847,14 @@ void TryRunTics(tic_t realtics)
 			{
 				DEBFILE(va("============ Running tic %d (local %d)\n", gametic, localgametic));
 
-				ps_tictime = I_GetTimeMicros();
+				ps_tictime = I_GetPreciseTime();
 
 				G_Ticker((gametic % NEWTICRATERATIO) == 0);
 				ExtraDataTicker();
 				gametic++;
 				consistancy[gametic%BACKUPTICS] = Consistancy();
 
-				ps_tictime = I_GetTimeMicros() - ps_tictime;
+				ps_tictime = I_GetPreciseTime() - ps_tictime;
 
 				// Leave a certain amount of tics present in the net buffer as long as we've ran at least one tic this frame.
 				if (client && gamestate == GS_LEVEL && leveltime > 3 && neededtic <= gametic + cv_netticbuffer.value)

src/d_main.c

@@ -413,7 +413,7 @@ static void D_Display(void)
 
 			if (!automapactive && !dedicated && cv_renderview.value)
 			{
-				ps_rendercalltime = I_GetTimeMicros();
+				ps_rendercalltime = I_GetPreciseTime();
 				if (players[displayplayer].mo || players[displayplayer].playerstate == PST_DEAD)
 				{
 					topleft = screens[0] + viewwindowy*vid.width + viewwindowx;
@@ -460,7 +460,7 @@ static void D_Display(void)
 					if (postimgtype2)
 						V_DoPostProcessor(1, postimgtype2, postimgparam2);
 				}
-				ps_rendercalltime = I_GetTimeMicros() - ps_rendercalltime;
+				ps_rendercalltime = I_GetPreciseTime() - ps_rendercalltime;
 			}
 
 			if (lastdraw)
@@ -474,7 +474,7 @@ static void D_Display(void)
 				lastdraw = false;
 			}
 
-			ps_uitime = I_GetTimeMicros();
+			ps_uitime = I_GetPreciseTime();
 
 			if (gamestate == GS_LEVEL)
 			{
@@ -487,7 +487,7 @@ static void D_Display(void)
 		}
 		else
 		{
-			ps_uitime = I_GetTimeMicros();
+			ps_uitime = I_GetPreciseTime();
 		}
 	}
 
@@ -529,7 +529,7 @@ static void D_Display(void)
 
 	CON_Drawer();
 
-	ps_uitime = I_GetTimeMicros() - ps_uitime;
+	ps_uitime = I_GetPreciseTime() - ps_uitime;
 
 	//
 	// wipe update
@@ -615,9 +615,9 @@ static void D_Display(void)
 			M_DrawPerfStats();
 		}
 
-		ps_swaptime = I_GetTimeMicros();
+		ps_swaptime = I_GetPreciseTime();
 		I_FinishUpdate(); // page flip or blit buffer
-		ps_swaptime = I_GetTimeMicros() - ps_swaptime;
+		ps_swaptime = I_GetPreciseTime() - ps_swaptime;
 	}
 }
 

src/doomtype.h

@@ -379,4 +379,8 @@ Needed for some lua shenanigans.
 #define FIELDFROM( type, field, have, want ) \
 	(void *)((intptr_t)(field) - offsetof (type, have) + offsetof (type, want))
 
+#ifdef HAVE_SDL
+typedef UINT64 precise_t;
+#endif
+
 #endif //__DOOMTYPE__

src/hardware/hw_batching.c

@@ -248,12 +248,12 @@ void HWR_RenderBatches(void)
 	}
 
 	// sort polygons
-	ps_hw_batchsorttime = I_GetTimeMicros();
+	ps_hw_batchsorttime = I_GetPreciseTime();
 	if (cv_glshaders.value && gl_shadersavailable)
 		qsort(polygonIndexArray, polygonArraySize, sizeof(unsigned int), comparePolygons);
 	else
 		qsort(polygonIndexArray, polygonArraySize, sizeof(unsigned int), comparePolygonsNoShaders);
-	ps_hw_batchsorttime = I_GetTimeMicros() - ps_hw_batchsorttime;
+	ps_hw_batchsorttime = I_GetPreciseTime() - ps_hw_batchsorttime;
 	// sort order
 	// 1. shader
 	// 2. texture
@@ -261,7 +261,7 @@ void HWR_RenderBatches(void)
 	// 4. colors + light level
 	// not sure about what order of the last 2 should be, or if it even matters
 
-	ps_hw_batchdrawtime = I_GetTimeMicros();
+	ps_hw_batchdrawtime = I_GetPreciseTime();
 
 	currentShader = polygonArray[polygonIndexArray[0]].shader;
 	currentTexture = polygonArray[polygonIndexArray[0]].texture;
@@ -446,7 +446,7 @@ void HWR_RenderBatches(void)
 	polygonArraySize = 0;
 	unsortedVertexArraySize = 0;
 
-	ps_hw_batchdrawtime = I_GetTimeMicros() - ps_hw_batchdrawtime;
+	ps_hw_batchdrawtime = I_GetPreciseTime() - ps_hw_batchdrawtime;
 }
 
 

src/hardware/hw_main.c

@@ -147,11 +147,11 @@ static angle_t gl_aimingangle;
 static void HWR_SetTransformAiming(FTransform *trans, player_t *player, boolean skybox);
 
 // Render stats
-int ps_hw_skyboxtime = 0;
-int ps_hw_nodesorttime = 0;
-int ps_hw_nodedrawtime = 0;
-int ps_hw_spritesorttime = 0;
-int ps_hw_spritedrawtime = 0;
+precise_t ps_hw_skyboxtime = 0;
+precise_t ps_hw_nodesorttime = 0;
+precise_t ps_hw_nodedrawtime = 0;
+precise_t ps_hw_spritesorttime = 0;
+precise_t ps_hw_spritedrawtime = 0;
 
 // Render stats for batching
 int ps_hw_numpolys = 0;
@@ -161,8 +161,8 @@ int ps_hw_numshaders = 0;
 int ps_hw_numtextures = 0;
 int ps_hw_numpolyflags = 0;
 int ps_hw_numcolors = 0;
-int ps_hw_batchsorttime = 0;
-int ps_hw_batchdrawtime = 0;
+precise_t ps_hw_batchsorttime = 0;
+precise_t ps_hw_batchdrawtime = 0;
 
 boolean gl_init = false;
 boolean gl_maploaded = false;
@@ -4654,7 +4654,7 @@ static void HWR_CreateDrawNodes(void)
 	// that is already lying around. This should all be in some sort of linked list or lists.
 	sortindex = Z_Calloc(sizeof(size_t) * (numplanes + numpolyplanes + numwalls), PU_STATIC, NULL);
 
-	ps_hw_nodesorttime = I_GetTimeMicros();
+	ps_hw_nodesorttime = I_GetPreciseTime();
 
 	for (i = 0; i < numplanes; i++, p++)
 	{
@@ -4709,9 +4709,9 @@ static void HWR_CreateDrawNodes(void)
 		}
 	}
 
-	ps_hw_nodesorttime = I_GetTimeMicros() - ps_hw_nodesorttime;
+	ps_hw_nodesorttime = I_GetPreciseTime() - ps_hw_nodesorttime;
 
-	ps_hw_nodedrawtime = I_GetTimeMicros();
+	ps_hw_nodedrawtime = I_GetPreciseTime();
 
 	// Okay! Let's draw it all! Woo!
 	HWD.pfnSetTransform(&atransform);
@@ -4748,7 +4748,7 @@ static void HWR_CreateDrawNodes(void)
 		}
 	}
 
-	ps_hw_nodedrawtime = I_GetTimeMicros() - ps_hw_nodedrawtime;
+	ps_hw_nodedrawtime = I_GetPreciseTime() - ps_hw_nodedrawtime;
 
 	numwalls = 0;
 	numplanes = 0;
@@ -6017,10 +6017,10 @@ void HWR_RenderPlayerView(INT32 viewnumber, player_t *player)
 	if (viewnumber == 0) // Only do it if it's the first screen being rendered
 		HWD.pfnClearBuffer(true, false, &ClearColor); // Clear the Color Buffer, stops HOMs. Also seems to fix the skybox issue on Intel GPUs.
 
-	ps_hw_skyboxtime = I_GetTimeMicros();
+	ps_hw_skyboxtime = I_GetPreciseTime();
 	if (skybox && drawsky) // If there's a skybox and we should be drawing the sky, draw the skybox
 		HWR_RenderSkyboxView(viewnumber, player); // This is drawn before everything else so it is placed behind
-	ps_hw_skyboxtime = I_GetTimeMicros() - ps_hw_skyboxtime;
+	ps_hw_skyboxtime = I_GetPreciseTime() - ps_hw_skyboxtime;
 
 	{
 		// do we really need to save player (is it not the same)?
@@ -6132,7 +6132,7 @@ void HWR_RenderPlayerView(INT32 viewnumber, player_t *player)
 
 	ps_numbspcalls = 0;
 	ps_numpolyobjects = 0;
-	ps_bsptime = I_GetTimeMicros();
+	ps_bsptime = I_GetPreciseTime();
 
 	validcount++;
 
@@ -6170,7 +6170,7 @@ void HWR_RenderPlayerView(INT32 viewnumber, player_t *player)
 	}
 #endif
 
-	ps_bsptime = I_GetTimeMicros() - ps_bsptime;
+	ps_bsptime = I_GetPreciseTime() - ps_bsptime;
 
 	if (cv_glbatching.value)
 		HWR_RenderBatches();
@@ -6186,12 +6186,12 @@ void HWR_RenderPlayerView(INT32 viewnumber, player_t *player)
 
 	// Draw MD2 and sprites
 	ps_numsprites = gl_visspritecount;
-	ps_hw_spritesorttime = I_GetTimeMicros();
+	ps_hw_spritesorttime = I_GetPreciseTime();
 	HWR_SortVisSprites();
-	ps_hw_spritesorttime = I_GetTimeMicros() - ps_hw_spritesorttime;
-	ps_hw_spritedrawtime = I_GetTimeMicros();
+	ps_hw_spritesorttime = I_GetPreciseTime() - ps_hw_spritesorttime;
+	ps_hw_spritedrawtime = I_GetPreciseTime();
 	HWR_DrawSprites();
-	ps_hw_spritedrawtime = I_GetTimeMicros() - ps_hw_spritedrawtime;
+	ps_hw_spritedrawtime = I_GetPreciseTime() - ps_hw_spritedrawtime;
 
 #ifdef NEWCORONAS
 	//Hurdler: they must be drawn before translucent planes, what about gl fog?

src/hardware/hw_main.h

@@ -116,11 +116,11 @@ extern FTransform atransform;
 
 
 // Render stats
-extern int ps_hw_skyboxtime;
-extern int ps_hw_nodesorttime;
-extern int ps_hw_nodedrawtime;
-extern int ps_hw_spritesorttime;
-extern int ps_hw_spritedrawtime;
+extern precise_t ps_hw_skyboxtime;
+extern precise_t ps_hw_nodesorttime;
+extern precise_t ps_hw_nodedrawtime;
+extern precise_t ps_hw_spritesorttime;
+extern precise_t ps_hw_spritedrawtime;
 
 // Render stats for batching
 extern int ps_hw_numpolys;
@@ -130,8 +130,8 @@ extern int ps_hw_numshaders;
 extern int ps_hw_numtextures;
 extern int ps_hw_numpolyflags;
 extern int ps_hw_numcolors;
-extern int ps_hw_batchsorttime;
-extern int ps_hw_batchdrawtime;
+extern precise_t ps_hw_batchsorttime;
+extern precise_t ps_hw_batchdrawtime;
 
 extern boolean gl_init;
 extern boolean gl_maploaded;

src/i_system.h

@@ -46,7 +46,13 @@ UINT32 I_GetFreeMem(UINT32 *total);
 */
 tic_t I_GetTime(void);
 
-int I_GetTimeMicros(void);// provides microsecond counter for render stats
+/**	\brief	Returns precise time value for performance measurement.
+  */
+precise_t I_GetPreciseTime(void);
+
+/**	\brief	Returns the difference between precise times as microseconds.
+  */
+int I_PreciseToMicros(precise_t);
 
 /**	\brief	The I_Sleep function
 

src/lua_hooklib.c

@@ -25,7 +25,7 @@
 
 #include "m_perfstats.h"
 #include "d_netcmd.h" // for cv_perfstats
-#include "i_system.h" // I_GetTimeMicros
+#include "i_system.h" // I_GetPreciseTime
 
 static UINT8 hooksAvailable[(hook_MAX/8)+1];
 
@@ -481,7 +481,7 @@ void LUAh_ThinkFrame(void)
 			continue;
 
 		if (cv_perfstats.value == 3)
-			time_taken = I_GetTimeMicros();
+			time_taken = I_GetPreciseTime();
 		PushHook(gL, hookp);
 		if (lua_pcall(gL, 0, 0, 1)) {
 			if (!hookp->error || cv_debug & DBG_LUA)
@@ -492,7 +492,7 @@ void LUAh_ThinkFrame(void)
 		if (cv_perfstats.value == 3)
 		{
 			lua_Debug ar;
-			time_taken = I_GetTimeMicros() - time_taken;
+			time_taken = I_GetPreciseTime() - time_taken;
 			// we need the function, let's just retrieve it again
 			PushHook(gL, hookp);
 			lua_getinfo(gL, ">S", &ar);

src/m_anigif.c

@@ -18,7 +18,7 @@
 #include "z_zone.h"
 #include "v_video.h"
 #include "i_video.h"
-#include "i_system.h" // I_GetTimeMicros
+#include "i_system.h" // I_GetPreciseTime
 #include "m_misc.h"
 #include "st_stuff.h" // st_palette
 
@@ -53,8 +53,8 @@ static RGBA_t *gif_framepalette = NULL;
 
 static FILE *gif_out = NULL;
 static INT32 gif_frames = 0;
-static UINT32 gif_prevframeus = 0; // "us" is microseconds
-static UINT32 gif_delayus = 0;
+static precise_t gif_prevframetime = 0;
+static UINT32 gif_delayus = 0; // "us" is microseconds
 static UINT8 gif_writeover = 0;
 
 
@@ -608,7 +608,7 @@ static void GIF_framewrite(void)
 		{
 			// golden's attempt at creating a "dynamic delay"
 			UINT16 mingifdelay = 10; // minimum gif delay in milliseconds (keep at 10 because gifs can't get more precise).
-			gif_delayus += (I_GetTimeMicros() - gif_prevframeus); // increase delay by how much time was spent between last measurement
+			gif_delayus += I_PreciseToMicros(I_GetPreciseTime() - gif_prevframetime); // increase delay by how much time was spent between last measurement
 
 			if (gif_delayus/1000 >= mingifdelay) // delay is big enough to be able to effect gif frame delay?
 			{
@@ -711,7 +711,7 @@ static void GIF_framewrite(void)
 	}
 	fwrite(gifframe_data, 1, (p - gifframe_data), gif_out);
 	++gif_frames;
-	gif_prevframeus = I_GetTimeMicros();
+	gif_prevframetime = I_GetPreciseTime();
 }
 
 
@@ -739,7 +739,7 @@ INT32 GIF_open(const char *filename)
 
 	GIF_headwrite();
 	gif_frames = 0;
-	gif_prevframeus = I_GetTimeMicros();
+	gif_prevframetime = I_GetPreciseTime();
 	gif_delayus = 0;
 	return 1;
 }

src/m_perfstats.h

@@ -16,17 +16,17 @@
 #include "lua_script.h"
 #include "p_local.h"
 
-extern int ps_tictime;
+extern precise_t ps_tictime;
 
-extern int ps_playerthink_time;
-extern int ps_thinkertime;
+extern precise_t ps_playerthink_time;
+extern precise_t ps_thinkertime;
 
-extern int ps_thlist_times[];
+extern precise_t ps_thlist_times[];
 
-extern int ps_checkposition_calls;
+extern int       ps_checkposition_calls;
 
-extern int ps_lua_thinkframe_time;
-extern int ps_lua_mobjhooks;
+extern precise_t ps_lua_thinkframe_time;
+extern int       ps_lua_mobjhooks;
 
 typedef struct
 {

src/p_tick.c

@@ -22,7 +22,7 @@
 #include "lua_script.h"
 #include "lua_hook.h"
 #include "m_perfstats.h"
-#include "i_system.h" // I_GetTimeMicros
+#include "i_system.h" // I_GetPreciseTime
 
 // Object place
 #include "m_cheat.h"
@@ -323,7 +323,7 @@ static inline void P_RunThinkers(void)
 	size_t i;
 	for (i = 0; i < NUM_THINKERLISTS; i++)
 	{
-		ps_thlist_times[i] = I_GetTimeMicros();
+		ps_thlist_times[i] = I_GetPreciseTime();
 		for (currentthinker = thlist[i].next; currentthinker != &thlist[i]; currentthinker = currentthinker->next)
 		{
 #ifdef PARANOIA
@@ -331,7 +331,7 @@ static inline void P_RunThinkers(void)
 #endif
 			currentthinker->function.acp1(currentthinker);
 		}
-		ps_thlist_times[i] = I_GetTimeMicros() - ps_thlist_times[i];
+		ps_thlist_times[i] = I_GetPreciseTime() - ps_thlist_times[i];
 	}
 
 }
@@ -658,11 +658,11 @@ void P_Ticker(boolean run)
 
 		LUAh_PreThinkFrame();
 
-		ps_playerthink_time = I_GetTimeMicros();
+		ps_playerthink_time = I_GetPreciseTime();
 		for (i = 0; i < MAXPLAYERS; i++)
 			if (playeringame[i] && players[i].mo && !P_MobjWasRemoved(players[i].mo))
 				P_PlayerThink(&players[i]);
-		ps_playerthink_time = I_GetTimeMicros() - ps_playerthink_time;
+		ps_playerthink_time = I_GetPreciseTime() - ps_playerthink_time;
 	}
 
 	// Keep track of how long they've been playing!
@@ -677,18 +677,18 @@ void P_Ticker(boolean run)
 
 	if (run)
 	{
-		ps_thinkertime = I_GetTimeMicros();
+		ps_thinkertime = I_GetPreciseTime();
 		P_RunThinkers();
-		ps_thinkertime = I_GetTimeMicros() - ps_thinkertime;
+		ps_thinkertime = I_GetPreciseTime() - ps_thinkertime;
 
 		// Run any "after all the other thinkers" stuff
 		for (i = 0; i < MAXPLAYERS; i++)
 			if (playeringame[i] && players[i].mo && !P_MobjWasRemoved(players[i].mo))
 				P_PlayerAfterThink(&players[i]);
 
-		ps_lua_thinkframe_time = I_GetTimeMicros();
+		ps_lua_thinkframe_time = I_GetPreciseTime();
 		LUAh_ThinkFrame();
-		ps_lua_thinkframe_time = I_GetTimeMicros() - ps_lua_thinkframe_time;
+		ps_lua_thinkframe_time = I_GetPreciseTime() - ps_lua_thinkframe_time;
 	}
 
 	// Run shield positioning

src/r_main.c

@@ -34,7 +34,7 @@
 #include "m_random.h" // quake camera shake
 #include "r_portal.h"
 #include "r_main.h"
-#include "i_system.h" // I_GetTimeMicros
+#include "i_system.h" // I_GetPreciseTime
 
 #ifdef HWRENDER
 #include "hardware/hw_main.h"
@@ -100,17 +100,17 @@ lighttable_t *zlight[LIGHTLEVELS][MAXLIGHTZ];
 extracolormap_t *extra_colormaps = NULL;
 
 // Render stats
-int ps_prevframetime = 0;
-int ps_rendercalltime = 0;
-int ps_uitime = 0;
-int ps_swaptime = 0;
+precise_t ps_prevframetime = 0;
+precise_t ps_rendercalltime = 0;
+precise_t ps_uitime = 0;
+precise_t ps_swaptime = 0;
 
-int ps_bsptime = 0;
+precise_t ps_bsptime = 0;
 
-int ps_sw_spritecliptime = 0;
-int ps_sw_portaltime = 0;
-int ps_sw_planetime = 0;
-int ps_sw_maskedtime = 0;
+precise_t ps_sw_spritecliptime = 0;
+precise_t ps_sw_portaltime = 0;
+precise_t ps_sw_planetime = 0;
+precise_t ps_sw_maskedtime = 0;
 
 int ps_numbspcalls = 0;
 int ps_numsprites = 0;
@@ -1498,9 +1498,9 @@ void R_RenderPlayerView(player_t *player)
 	ProfZeroTimer();
 #endif
 	ps_numbspcalls = ps_numpolyobjects = ps_numdrawnodes = 0;
-	ps_bsptime = I_GetTimeMicros();
+	ps_bsptime = I_GetPreciseTime();
 	R_RenderBSPNode((INT32)numnodes - 1);
-	ps_bsptime = I_GetTimeMicros() - ps_bsptime;
+	ps_bsptime = I_GetPreciseTime() - ps_bsptime;
 	ps_numsprites = visspritecount;
 #ifdef TIMING
 	RDMSR(0x10, &mycount);
@@ -1511,9 +1511,9 @@ void R_RenderPlayerView(player_t *player)
 //profile stuff ---------------------------------------------------------
 	Mask_Post(&masks[nummasks - 1]);
 
-	ps_sw_spritecliptime = I_GetTimeMicros();
+	ps_sw_spritecliptime = I_GetPreciseTime();
 	R_ClipSprites(drawsegs, NULL);
-	ps_sw_spritecliptime = I_GetTimeMicros() - ps_sw_spritecliptime;
+	ps_sw_spritecliptime = I_GetPreciseTime() - ps_sw_spritecliptime;
 
 
 	// Add skybox portals caused by sky visplanes.
@@ -1521,7 +1521,7 @@ void R_RenderPlayerView(player_t *player)
 		Portal_AddSkyboxPortals();
 
 	// Portal rendering. Hijacks the BSP traversal.
-	ps_sw_portaltime = I_GetTimeMicros();
+	ps_sw_portaltime = I_GetPreciseTime();
 	if (portal_base)
 	{
 		portal_t *portal;
@@ -1561,17 +1561,17 @@ void R_RenderPlayerView(player_t *player)
 			Portal_Remove(portal);
 		}
 	}
-	ps_sw_portaltime = I_GetTimeMicros() - ps_sw_portaltime;
+	ps_sw_portaltime = I_GetPreciseTime() - ps_sw_portaltime;
 
-	ps_sw_planetime = I_GetTimeMicros();
+	ps_sw_planetime = I_GetPreciseTime();
 	R_DrawPlanes();
-	ps_sw_planetime = I_GetTimeMicros() - ps_sw_planetime;
+	ps_sw_planetime = I_GetPreciseTime() - ps_sw_planetime;
 
 	// draw mid texture and sprite
 	// And now 3D floors/sides!
-	ps_sw_maskedtime = I_GetTimeMicros();
+	ps_sw_maskedtime = I_GetPreciseTime();
 	R_DrawMasked(masks, nummasks);
-	ps_sw_maskedtime = I_GetTimeMicros() - ps_sw_maskedtime;
+	ps_sw_maskedtime = I_GetPreciseTime() - ps_sw_maskedtime;
 
 	free(masks);
 }

src/r_main.h

@@ -78,17 +78,17 @@ boolean R_DoCulling(line_t *cullheight, line_t *viewcullheight, fixed_t vz, fixe
 
 // Render stats
 
-extern int ps_prevframetime;// time when previous frame was rendered
-extern int ps_rendercalltime;
-extern int ps_uitime;
-extern int ps_swaptime;
+extern precise_t ps_prevframetime;// time when previous frame was rendered
+extern precise_t ps_rendercalltime;
+extern precise_t ps_uitime;
+extern precise_t ps_swaptime;
 
-extern int ps_bsptime;
+extern precise_t ps_bsptime;
 
-extern int ps_sw_spritecliptime;
-extern int ps_sw_portaltime;
-extern int ps_sw_planetime;
-extern int ps_sw_maskedtime;
+extern precise_t ps_sw_spritecliptime;
+extern precise_t ps_sw_portaltime;
+extern precise_t ps_sw_planetime;
+extern precise_t ps_sw_maskedtime;
 
 extern int ps_numbspcalls;
 extern int ps_numsprites;

src/sdl/i_system.c

@@ -54,12 +54,6 @@ typedef LPVOID (WINAPI *p_MapViewOfFile) (HANDLE, DWORD, DWORD, DWORD, SIZE_T);
 #include <fcntl.h>
 #endif
 
-#if defined (_WIN32)
-DWORD TimeFunction(int requested_frequency);
-#else
-int TimeFunction(int requested_frequency);
-#endif
-
 #include <stdio.h>
 #ifdef _WIN32
 #include <conio.h>
@@ -2044,112 +2038,36 @@ ticcmd_t *I_BaseTiccmd2(void)
 	return &emptycmd2;
 }
 
-#if defined (_WIN32)
-static HMODULE winmm = NULL;
-static DWORD starttickcount = 0; // hack for win2k time bug
-static p_timeGetTime pfntimeGetTime = NULL;
-
-// ---------
-// I_GetTime
-// Use the High Resolution Timer if available,
-// else use the multimedia timer which has 1 millisecond precision on Windowz 95,
-// but lower precision on Windows NT
-// ---------
-
-DWORD TimeFunction(int requested_frequency)
-{
-	DWORD newtics = 0;
-	// this var acts as a multiplier if sub-millisecond precision is asked but is not available
-	int excess_frequency = requested_frequency / 1000;
-
-	if (!starttickcount) // high precision timer
-	{
-		LARGE_INTEGER currtime; // use only LowPart if high resolution counter is not available
-		static LARGE_INTEGER basetime = {{0, 0}};
-
-		// use this if High Resolution timer is found
-		static LARGE_INTEGER frequency;
-
-		if (!basetime.LowPart)
-		{
-			if (!QueryPerformanceFrequency(&frequency))
-				frequency.QuadPart = 0;
-			else
-				QueryPerformanceCounter(&basetime);
-		}
-
-		if (frequency.LowPart && QueryPerformanceCounter(&currtime))
-		{
-			newtics = (INT32)((currtime.QuadPart - basetime.QuadPart) * requested_frequency
-				/ frequency.QuadPart);
-		}
-		else if (pfntimeGetTime)
-		{
-			currtime.LowPart = pfntimeGetTime();
-			if (!basetime.LowPart)
-				basetime.LowPart = currtime.LowPart;
-			if (requested_frequency > 1000)
-				newtics = currtime.LowPart - basetime.LowPart * excess_frequency;
-			else
-				newtics = (currtime.LowPart - basetime.LowPart)/(1000/requested_frequency);
-		}
-	}
-	else
-	{
-		if (requested_frequency > 1000)
-			newtics = (GetTickCount() - starttickcount) * excess_frequency;
-		else
-			newtics = (GetTickCount() - starttickcount)/(1000/requested_frequency);
-	}
-
-	return newtics;
-}
-
-static void I_ShutdownTimer(void)
-{
-	pfntimeGetTime = NULL;
-	if (winmm)
-	{
-		p_timeEndPeriod pfntimeEndPeriod = (p_timeEndPeriod)(LPVOID)GetProcAddress(winmm, "timeEndPeriod");
-		if (pfntimeEndPeriod)
-			pfntimeEndPeriod(1);
-		FreeLibrary(winmm);
-		winmm = NULL;
-	}
-}
-#else
 //
 // I_GetTime
 // returns time in 1/TICRATE second tics
 //
 
-// millisecond precision only
-int TimeFunction(int requested_frequency)
-{
-	static Uint64 basetime = 0;
-		   Uint64 ticks = SDL_GetTicks();
+static Uint64 timer_frequency;
 
-	if (!basetime)
-		basetime = ticks;
+static double tic_frequency;
+static Uint64 tic_epoch;
 
-	ticks -= basetime;
+tic_t I_GetTime(void)
+{
+	static double elapsed;
 
-	ticks = (ticks*requested_frequency);
+	const Uint64 now = SDL_GetPerformanceCounter();
 
-	ticks = (ticks/1000);
+	elapsed += (now - tic_epoch) / tic_frequency;
+	tic_epoch = now; // moving epoch
 
-	return ticks;
+	return (tic_t)elapsed;
 }
-#endif
 
-tic_t I_GetTime(void)
+precise_t I_GetPreciseTime(void)
 {
-	return TimeFunction(NEWTICRATE);
+	return SDL_GetPerformanceCounter();
 }
 
-int I_GetTimeMicros(void)
+int I_PreciseToMicros(precise_t d)
 {
-	return TimeFunction(1000000);
+	return (int)(d / (timer_frequency / 1000000.0));
 }
 
 //
@@ -2157,26 +2075,11 @@ int I_GetTimeMicros(void)
 //
 void I_StartupTimer(void)
 {
-#ifdef _WIN32
-	// for win2k time bug
-	if (M_CheckParm("-gettickcount"))
-	{
-		starttickcount = GetTickCount();
-		CONS_Printf("%s", M_GetText("Using GetTickCount()\n"));
-	}
-	winmm = LoadLibraryA("winmm.dll");
-	if (winmm)
-	{
-		p_timeEndPeriod pfntimeBeginPeriod = (p_timeEndPeriod)(LPVOID)GetProcAddress(winmm, "timeBeginPeriod");
-		if (pfntimeBeginPeriod)
-			pfntimeBeginPeriod(1);
-		pfntimeGetTime = (p_timeGetTime)(LPVOID)GetProcAddress(winmm, "timeGetTime");
-	}
-	I_AddExitFunc(I_ShutdownTimer);
-#endif
-}
-
+	timer_frequency = SDL_GetPerformanceFrequency();
+	tic_epoch       = SDL_GetPerformanceCounter();
 
+	tic_frequency   = timer_frequency / (double)NEWTICRATE;
+}
 
 void I_Sleep(void)
 {