So frame interpolation is incoming.

This is a huge change, but it sets up all the interpolation things and handles view and things.

Sectors/segs are done, except I introduced a clipping bug. That will come in very soon.

Line scrollers are simple from here.

src/doom/d_main.c

@@ -215,8 +215,8 @@ boolean D_Display (void)
     boolean			redrawsbar;
 	patch_t*		pausepatch;
 
-	boolean ispaused = paused
-		|| 	( gamestate == GS_LEVEL && !demoplayback && dashboardactive && dashboardpausesplaysim && ( solonetgame || !netgame ) );
+	boolean ispaused = renderpaused = ( paused
+										|| 	( gamestate == GS_LEVEL && !demoplayback && dashboardactive && dashboardpausesplaysim && ( solonetgame || !netgame ) ) );
 
 	M_PROFILE_PUSH( __FUNCTION__, __FILE__, __LINE__ );
 
@@ -492,6 +492,8 @@ boolean D_GrabMouseCallback(void)
 //  D_RunFrame
 //
 
+uint64_t frametime = 0;
+
 void D_RunFrame()
 {
 	uint64_t nowtime;
@@ -504,6 +506,7 @@ void D_RunFrame()
 
 	boolean dofinishupdate = true;
 
+	uint64_t start = I_GetTimeUS();
 	M_ProfileNewFrame();
 	M_PROFILE_PUSH( __FUNCTION__, __FILE__, __LINE__ );
 
@@ -557,6 +560,8 @@ void D_RunFrame()
 	{
 		I_FinishUpdate( NULL );
 	}
+
+	frametime = I_GetTimeUS() - start;
 }
 
 //

src/doom/d_player.h

@@ -92,6 +92,9 @@ typedef struct player_s
     // bounded/scaled total momentum.
     fixed_t         	bob;	
 
+	rend_fixed_t prevviewz;
+	rend_fixed_t currviewz;
+
     // This is only used between levels,
     // mo->health is used during levels.
     int			health;	

src/doom/doomstat.h

@@ -150,6 +150,7 @@ extern  int32_t dashboardactive; // R&R Dashboard, powered by Dear ImGui
 extern  int32_t dashboardremappingkey;
 extern  int32_t dashboardpausesplaysim;
 extern  boolean	paused;		// Game Pause?
+extern  boolean	renderpaused;
 
 
 extern  boolean		viewactive;

src/doom/g_game.c

@@ -109,7 +109,8 @@ int32_t			gameflags;
 
 int             timelimit;
 
-boolean         paused; 
+boolean         paused;
+boolean			renderpaused;
 boolean         sendpause;             	// send a pause event next tic 
 boolean         sendsave;             	// send a save event next tic 
 boolean         usergame;               // ok to save / end game 
@@ -859,8 +860,8 @@ boolean G_Responder (event_t* ev)
 
       case ev_mouse: 
         SetMouseButtons(ev->data1);
-	mousex = ev->data2*(mouseSensitivity+5)/10; 
-	mousey = ev->data3*(mouseSensitivity+5)/10; 
+	mousex += ev->data2*(mouseSensitivity+5)/10; 
+	mousey += ev->data3*(mouseSensitivity+5)/10; 
 	return true;    // eat events 
 
       case ev_joystick: 

src/doom/info.h

@@ -26,6 +26,7 @@
 
 typedef enum
 {
+	SPR_INVALID = -1,
     SPR_TROO,
     SPR_SHTG,
     SPR_PUNG,

src/doom/m_menu.c

@@ -2902,6 +2902,7 @@ void M_DashboardOptionsWindow( const char* itemname, void* data )
 	extern int32_t show_diskicon;
 	extern int32_t grabmouse;
 	extern int32_t novert;
+	extern int32_t enable_frame_interpolation;
 
 	controlsection_t*	currsection;
 
@@ -2925,6 +2926,17 @@ void M_DashboardOptionsWindow( const char* itemname, void* data )
 			igColumns( 2, "", false );
 			igSetColumnWidth( 0, columwidth );
 
+			igText( "Frame interpolation" );
+			igNextColumn();
+			WorkingBool = !!enable_frame_interpolation;
+			igPushIDPtr( &enable_frame_interpolation );
+			if( igCheckbox( "", &WorkingBool ) )
+			{
+				enable_frame_interpolation = (int32_t)WorkingBool;
+			}
+			igPopID();
+			igNextColumn();
+
 			igText( "Show text startup" );
 			igNextColumn();
 			WorkingBool = !!show_text_startup;

src/doom/p_mobj.c

@@ -558,11 +558,23 @@ P_SpawnMobj
     mobj->ceilingz = mobj->subsector->sector->ceilingheight;
 
     if (z == ONFLOORZ)
-	mobj->z = mobj->floorz;
+		mobj->z = mobj->floorz;
     else if (z == ONCEILINGZ)
-	mobj->z = mobj->ceilingz - mobj->info->height;
+		mobj->z = mobj->ceilingz - mobj->info->height;
     else 
-	mobj->z = z;
+		mobj->z = z;
+
+	mobj->curr.x = FixedToRendFixed( mobj->x );
+	mobj->curr.y = FixedToRendFixed( mobj->y );
+	mobj->curr.z = FixedToRendFixed( mobj->z );
+	mobj->curr.angle = mobj->angle;
+	mobj->curr.frame = -1;
+	mobj->curr.sprite = SPR_INVALID;
+
+	mobj->prev = mobj->curr;
+
+	mobj->curr.frame = mobj->frame;
+	mobj->curr.sprite = mobj->sprite;
 
     mobj->thinker.function.acp1 = (actionf_p1)P_MobjThinker;
 
@@ -604,7 +616,7 @@ void P_RemoveMobj (mobj_t* mobj)
     S_StopSound (mobj);
 
     // free block
-    P_RemoveThinker ((thinker_t*)mobj);
+    P_RemoveThinker (&mobj->thinker);
 }
 
 
@@ -731,6 +743,8 @@ void P_SpawnPlayer (mapthing_t* mthing)
     p->extralight = 0;
     p->fixedcolormap = 0;
     p->viewheight = VIEWHEIGHT;
+	p->viewz = mobj->z + p->viewheight;
+	p->prevviewz = p->currviewz = FixedToRendFixed( p->viewz );
 
     // setup gun psprite
     P_SetupPsprites (p);

src/doom/p_mobj.h

@@ -201,7 +201,7 @@ typedef struct mobjinstance_s
 	rend_fixed_t			x;
 	rend_fixed_t			y;
 	rend_fixed_t			z;
-	rend_fixed_t			angle;
+	angle_t					angle;
 	spritenum_t				sprite;
 	int32_t					frame;
 } mobjinstance_t;
@@ -227,6 +227,9 @@ typedef struct mobj_s
     spritenum_t		sprite;	// used to find patch_t and flip value
     int			frame;	// might be ORed with FF_FULLBRIGHT
 
+	mobjinstance_t curr;
+	mobjinstance_t prev;
+
     // Interaction info, by BLOCKMAP.
     // Links in blocks (if needed).
     struct mobj_s*	bnext;

src/doom/p_saveg.c

@@ -308,12 +308,15 @@ static void saveg_read_mobj_t(mobj_t *str)
 
     // fixed_t x;
     str->x = saveg_read32();
+	str->prev.x = str->curr.x = FixedToRendFixed( str->x );
 
     // fixed_t y;
     str->y = saveg_read32();
+	str->prev.y = str->y = FixedToRendFixed( str->y );
 
     // fixed_t z;
     str->z = saveg_read32();
+	str->prev.z = str->z = FixedToRendFixed( str->z );
 
     // struct mobj_s* snext;
     str->snext = saveg_readp();
@@ -323,12 +326,15 @@ static void saveg_read_mobj_t(mobj_t *str)
 
     // angle_t angle;
     str->angle = saveg_read32();
+	str->prev.angle = str->curr.angle = str->angle;
 
     // spritenum_t sprite;
     str->sprite = saveg_read_enum();
+	str->prev.sprite = str->curr.sprite = str->sprite;
 
     // int frame;
     str->frame = saveg_read32();
+	str->prev.frame = str->curr.frame = str->frame;
 
     // struct mobj_s* bnext;
     str->bnext = saveg_readp();
@@ -654,6 +660,7 @@ static void saveg_read_player_t(player_t *str)
 
     // fixed_t viewz;
     str->viewz = saveg_read32();
+	str->prevviewz = str->currviewz = FixedToRendFixed( str->viewz );
 
     // fixed_t viewheight;
     str->viewheight = saveg_read32();