Snap light level to software values (32 levels)

* New properties `exactlightlevel` and `lightlevel` in `lightlevel_t`

src/lua_baselib.c

@@ -1810,9 +1810,10 @@ static int lib_pFadeLight(lua_State *L)
 	INT32 destvalue = (INT32)luaL_checkinteger(L, 2);
 	INT32 speed = (INT32)luaL_checkinteger(L, 3);
 	boolean ticbased = lua_optboolean(L, 4);
+	boolean exactlightlevel = lua_optboolean(L, 5);
 	NOHUD
 	INLEVEL
-	P_FadeLight(tag, destvalue, speed, ticbased);
+	P_FadeLight(tag, destvalue, speed, ticbased, exactlightlevel);
 	return 0;
 }
 

src/p_lights.c

@@ -15,6 +15,7 @@
 #include "doomdef.h"
 #include "doomstat.h" // gametic
 #include "p_local.h"
+#include "r_main.h" // LIGHTSEGSHIFT
 #include "r_state.h"
 #include "z_zone.h"
 #include "m_random.h"
@@ -331,9 +332,10 @@ glow_t *P_SpawnAdjustableGlowingLight(sector_t *minsector, sector_t *maxsector,
   * \param speed     Speed of the fade; the change to the ligh
   *                  level in each sector per tic.
   * \param ticbased  Use a specific duration for the fade, defined by speed
+  * \param exactlightlevel Do not snap to software values (for OpenGL)
   * \sa T_LightFade
   */
-void P_FadeLightBySector(sector_t *sector, INT32 destvalue, INT32 speed, boolean ticbased)
+void P_FadeLightBySector(sector_t *sector, INT32 destvalue, INT32 speed, boolean ticbased, boolean exactlightlevel)
 {
 	lightlevel_t *ll;
 
@@ -353,6 +355,8 @@ void P_FadeLightBySector(sector_t *sector, INT32 destvalue, INT32 speed, boolean
 
 	ll->sector = sector;
 	ll->destlevel = destvalue;
+	ll->exactlightlevel = exactlightlevel;
+	ll->lightlevel = sector->lightlevel;
 
 	if (ticbased)
 	{
@@ -370,12 +374,12 @@ void P_FadeLightBySector(sector_t *sector, INT32 destvalue, INT32 speed, boolean
 	}
 }
 
-void P_FadeLight(INT16 tag, INT32 destvalue, INT32 speed, boolean ticbased)
+void P_FadeLight(INT16 tag, INT32 destvalue, INT32 speed, boolean ticbased, boolean exactlightlevel)
 {
 	INT32 i;
 	// search all sectors for ones with tag
 	for (i = -1; (i = P_FindSectorFromTag(tag, i)) >= 0 ;)
-		P_FadeLightBySector(&sectors[i], destvalue, speed, ticbased);
+		P_FadeLightBySector(&sectors[i], destvalue, speed, ticbased, exactlightlevel);
 }
 
 /** Fades the light level in a sector to a new value.
@@ -385,47 +389,66 @@ void P_FadeLight(INT16 tag, INT32 destvalue, INT32 speed, boolean ticbased)
   */
 void T_LightFade(lightlevel_t *ll)
 {
+	boolean stillfading = false;
+	INT16 lightlevel = ll->lightlevel;
+
 	if (ll->duration >= 0) // tic-based
 	{
+		stillfading = !(gametic - ll->firsttic >= ll->duration);
 		if (gametic - ll->firsttic >= ll->duration)
 		{
-			ll->sector->lightlevel = (INT16)ll->destlevel; // set to dest lightlevel
+			lightlevel = (INT16)ll->destlevel; // set to dest lightlevel
 			P_RemoveLighting(ll->sector); // clear lightingdata, remove thinker
 		}
 		else if (!((gametic - ll->firsttic) % ll->interval))
 		{
 			if (ll->speed < 0)
-				ll->sector->lightlevel = max(ll->sector->lightlevel + (INT16)ll->speed, (INT16)ll->destlevel);
+				lightlevel = max(lightlevel + (INT16)ll->speed, (INT16)ll->destlevel);
 			else
-				ll->sector->lightlevel = min(ll->sector->lightlevel + (INT16)ll->speed, (INT16)ll->destlevel);
+				lightlevel = min(lightlevel + (INT16)ll->speed, (INT16)ll->destlevel);
 		}
-		return;
 	}
-
+	else // x/tic speed-based
-	if (ll->sector->lightlevel < ll->destlevel)
 	{
-		// increase the lightlevel
+		if (lightlevel < ll->destlevel)
-		if (ll->sector->lightlevel + ll->speed >= ll->destlevel)
 		{
-			// stop changing light level
+			// increase the lightlevel
-			ll->sector->lightlevel = (INT16)ll->destlevel; // set to dest lightlevel
+			if (lightlevel + ll->speed >= ll->destlevel)
+			{
+				// stop changing light level
+				lightlevel = (INT16)ll->destlevel; // set to dest lightlevel
 
-			P_RemoveLighting(ll->sector); // clear lightingdata, remove thinker
+				P_RemoveLighting(ll->sector); // clear lightingdata, remove thinker
+			}
+			else
+			{
+				stillfading = true;
+				lightlevel = (INT16)(lightlevel + (INT16)ll->speed); // move lightlevel
+			}
 		}
 		else
-			ll->sector->lightlevel = (INT16)(ll->sector->lightlevel + (INT16)ll->speed); // move lightlevel
+		{
+			// decrease lightlevel
+			if (lightlevel - ll->speed <= ll->destlevel)
+			{
+				// stop changing light level
+				lightlevel = (INT16)ll->destlevel; // set to dest lightlevel
+
+				P_RemoveLighting(ll->sector); // clear lightingdata, remove thinker
+			}
+			else
+			{
+				stillfading = true;
+				lightlevel = (INT16)(lightlevel - (INT16)ll->speed); // move lightlevel
+			}
+		}
 	}
+
+	// Snap light level to software values
+	if (!stillfading || ll->exactlightlevel)
+		ll->sector->lightlevel = lightlevel;
 	else
-	{
+		ll->sector->lightlevel = (lightlevel >> LIGHTSEGSHIFT) << LIGHTSEGSHIFT;
-		// decrease lightlevel
-		if (ll->sector->lightlevel - ll->speed <= ll->destlevel)
-		{
-			// stop changing light level
-			ll->sector->lightlevel = (INT16)ll->destlevel; // set to dest lightlevel
 
-			P_RemoveLighting(ll->sector); // clear lightingdata, remove thinker
+	ll->lightlevel = lightlevel;
-		}
-		else
-			ll->sector->lightlevel = (INT16)(ll->sector->lightlevel - (INT16)ll->speed); // move lightlevel
-	}
 }

src/p_saveg.c

@@ -1542,6 +1542,8 @@ static void SaveLightlevelThinker(const thinker_t *th, const UINT8 type)
 	WRITEINT32(save_p, ht->duration);
 	WRITEUINT32(save_p, ht->interval);
 	WRITEUINT32(save_p, (UINT32)ht->firsttic);
+	WRITEUINT8(save_p, (UINT8)ht->exactlightlevel);
+	WRITEINT16(save_p, ht->lightlevel);
 }
 
 //
@@ -2518,6 +2520,8 @@ static inline void LoadLightlevelThinker(actionf_p1 thinker)
 	ht->duration = READINT32(save_p);
 	ht->interval = READUINT32(save_p);
 	ht->firsttic = (tic_t)READUINT32(save_p);
+	ht->exactlightlevel = (boolean)READUINT8(save_p);
+	ht->lightlevel = READINT16(save_p);
 	if (ht->sector)
 		ht->sector->lightingdata = ht;
 	P_AddThinker(&ht->thinker);

src/p_spec.c

@@ -2781,7 +2781,8 @@ static void P_ProcessLineSpecial(line_t *line, mobj_t *mo, sector_t *callsec)
 			P_FadeLight(line->tag,
 				(line->flags & ML_BLOCKMONSTERS) ? max(min(sides[line->sidenum[0]].textureoffset>>FRACBITS, 255), 0) : line->frontsector->lightlevel,
 				(line->flags & ML_BLOCKMONSTERS) ? max(sides[line->sidenum[0]].rowoffset>>FRACBITS, 0) : P_AproxDistance(line->dx, line->dy)>>FRACBITS,
-				(line->flags & ML_NOCLIMB));
+				(line->flags & ML_NOCLIMB),
+				(line->flags & ML_TFERLINE));
 			break;
 
 		case 421: // Stop lighting effect in tagged sectors

src/p_spec.h

@@ -143,6 +143,10 @@ typedef struct
 	INT32 duration;    ///< If <0, do not use tic-based behavior. If 0, set instantly. If >0, fade lasts this duration.
 	UINT32 interval;   ///< Interval to deduct light level
 	tic_t firsttic;    ///< First gametic to count from
+
+	// Snap to software values
+	boolean exactlightlevel; ///< Use exact values for OpenGL
+	INT16 lightlevel;        ///< Internal counter for fading
 } lightlevel_t;
 
 #define GLOWSPEED 8
@@ -161,8 +165,8 @@ strobe_t * P_SpawnAdjustableStrobeFlash(sector_t *minsector, sector_t *maxsector
 void T_Glow(glow_t *g);
 glow_t *P_SpawnAdjustableGlowingLight(sector_t *minsector, sector_t *maxsector, INT32 length);
 
-void P_FadeLightBySector(sector_t *sector, INT32 destvalue, INT32 speed, boolean ticbased);
+void P_FadeLightBySector(sector_t *sector, INT32 destvalue, INT32 speed, boolean ticbased, boolean exactlightlevel);
-void P_FadeLight(INT16 tag, INT32 destvalue, INT32 speed, boolean ticbased);
+void P_FadeLight(INT16 tag, INT32 destvalue, INT32 speed, boolean ticbased, boolean exactlightlevel);
 void T_LightFade(lightlevel_t *ll);
 
 typedef enum