DRS updates

* Introduce drs_skip_frame flag, skip DRS after resolution switch, wipe, save
  game, window event.

* Move V_InitFlexTranTable to R_Init (don't want to skip DRS for it).

* Disable DRS when menu is active.

* Tweak DRS parameters.

src/am_map.c

@@ -575,14 +575,6 @@ static void AM_clearLastMark(void)
 
 void AM_enableSmoothLines(void)
 {
-  static boolean precalc_once = true;
-
-  if (precalc_once && map_smooth_lines)
-  {
-    V_InitFlexTranTable();
-    precalc_once = false;
-  }
-
   AM_drawFline = map_smooth_lines ? AM_drawFline_Smooth : AM_drawFline_Vanilla;
 }
 

src/d_main.c

@@ -388,7 +388,7 @@ void D_Display (void)
     }
   while (!done);
 
-  I_ResetTargetRefresh(); // reset after wipe
+  drs_skip_frame = true; // skip DRS after wipe
 }
 
 //

src/g_game.c

@@ -59,6 +59,7 @@
 #include "m_snapshot.h"
 #include "m_swap.h" // [FG] LONG
 #include "i_input.h"
+#include "i_video.h"
 #include "m_array.h"
 
 #define SAVEGAMESIZE  0x20000
@@ -2155,6 +2156,8 @@ static void G_DoSaveGame(void)
   if (name) free(name);
 
   M_SetQuickSaveSlot(savegameslot);
+
+  drs_skip_frame = true;
 }
 
 static void G_DoLoadGame(void)

src/i_video.c

@@ -108,6 +108,8 @@ boolean screenvisible = true;
 
 boolean window_focused = true;
 
+boolean drs_skip_frame;
+
 void *I_GetSDLWindow(void)
 {
     return screen;
@@ -249,6 +251,8 @@ static void HandleWindowEvent(SDL_WindowEvent *event)
         default:
             break;
     }
+
+    drs_skip_frame = true;
 }
 
 // [FG] fullscreen toggle from Chocolate Doom 3.0
@@ -471,7 +475,7 @@ static void UpdateRender(void)
     }
 }
 
-static uint64_t frametime_withoutpresent;
+static uint64_t frametime_start, frametime_withoutpresent;
 static int targetrefresh;
 
 static void ResetResolution(int height);
@@ -482,13 +486,18 @@ void I_DynamicResolution(void)
     static int frame_counter;
     static double averagepercent;
 
-    if (resolution_mode != RES_DRS || frametime_withoutpresent == 0 ||
-        // Skip if frame time is too long (e.g. window event).
-        frametime_withoutpresent > 100000)
+    if (resolution_mode != RES_DRS || frametime_withoutpresent == 0 || menuactive)
     {
         return;
     }
 
+    if (drs_skip_frame)
+    {
+        frametime_start = frametime_withoutpresent = 0;
+        drs_skip_frame = false;
+        return;
+    }
+
     // 1.25 milliseconds for SDL render present
     double target = (1.0 / targetrefresh) - 0.00125;
     double actual = frametime_withoutpresent / 1000000.0;
@@ -498,9 +507,8 @@ void I_DynamicResolution(void)
     #define DRS_MIN_HEIGHT 400
     #define DRS_DELTA 0.1
     #define DRS_GREATER (1 + DRS_DELTA)
-    #define DRS_LESS (1 - DRS_DELTA)
-    // 50px step to make scaling artefacts less noticeable.
-    #define DRS_STEP (SCREENHEIGHT / 4)
+    #define DRS_LESS (1 - DRS_DELTA / 10.0)
+    #define DRS_STEP (SCREENHEIGHT / 2)
 
     int newheight = 0;
     int oldheight = video.height;
@@ -513,7 +521,7 @@ void I_DynamicResolution(void)
 
     if (actualpercent > DRS_GREATER)
     {
-        double reduction = (actualpercent - DRS_GREATER ) * 0.2;
+        double reduction = (actualpercent - DRS_GREATER ) * 0.4;
         newheight = (int)MAX(DRS_MIN_HEIGHT, oldheight - oldheight * reduction);
     }
     else if (averagepercent < DRS_LESS && frame_counter > targetrefresh)
@@ -553,8 +561,6 @@ static void CreateUpscaledTexture(boolean force);
 
 void I_FinishUpdate(void)
 {
-    static uint64_t frametime_start;
-
     if (noblit)
     {
         return;
@@ -1090,6 +1096,8 @@ static void ResetResolution(int height)
     I_InitDiskFlash();
 
     I_Printf(VB_DEBUG, "ResetResolution: %dx%d", video.width, video.height);
+
+    drs_skip_frame = true;
 }
 
 static void CreateUpscaledTexture(boolean force)
@@ -1206,8 +1214,6 @@ static void ResetLogicalSize(void)
 
 void I_ResetTargetRefresh(void)
 {
-    frametime_withoutpresent = 0; // skip DRS one frame
-
     if (uncapped)
     {
         targetrefresh = (fpslimit >= TICRATE) ? fpslimit : native_refresh_rate;

src/i_video.h

@@ -69,6 +69,8 @@ void I_ToggleVsync(void); // [JN] Calls native SDL vsync toggle
 
 void I_DynamicResolution(void);
 
+extern boolean drs_skip_frame;
+
 extern char *sdl_renderdriver;
 
 extern boolean use_vsync;  // killough 2/8/98: controls whether vsync is called

src/r_main.c

@@ -29,7 +29,7 @@
 #include "r_voxel.h"
 #include "i_video.h"
 #include "v_video.h"
-#include "am_map.h"
+#include "v_flextran.h"
 #include "st_stuff.h"
 
 // killough: viewangleoffset is a legacy from the pre-v1.2 days, when Doom
@@ -557,6 +557,7 @@ void R_Init (void)
   R_InitLightTables();
   R_InitSkyMap();
   R_InitTranslationTables();
+  V_InitFlexTranTable();
 
   // [FG] spectre drawing mode
   R_SetFuzzColumnMode();