Added code for rotating the PSprite, courtesy of IvanDobrovski.

- However, the XY offsets are relative as a result.This must be made toggleable.

src/playsim/p_pspr.cpp

@@ -142,8 +142,6 @@ DEFINE_FIELD(DPSprite, oldscalex)
 DEFINE_FIELD(DPSprite, oldscaley)
 DEFINE_FIELD(DPSprite, rotation)
 DEFINE_FIELD(DPSprite, oldrotation)
-DEFINE_FIELD(DPSprite, PivotPercent)
-DEFINE_FIELD(DPSprite, PivotScreen)
 DEFINE_FIELD(DPSprite, firstTic)
 DEFINE_FIELD(DPSprite, Tics)
 DEFINE_FIELD(DPSprite, Translation)
@@ -157,6 +155,7 @@ DEFINE_FIELD_BIT(DPSprite, Flags, bMirror, PSPF_MIRROR)
 DEFINE_FIELD_BIT(DPSprite, Flags, bPlayerTranslated, PSPF_PLAYERTRANSLATED)
 DEFINE_FIELD_BIT(DPSprite, Flags, bPivotPercent, PSPF_PIVOTPERCENT)
 DEFINE_FIELD_BIT(DPSprite, Flags, bPivotScreen, PSPF_PIVOTSCREEN)
+DEFINE_FIELD_BIT(DPSprite, Flags, bPivotOffsetRel, PSPF_PIVOTOFFSETREL)
 
 //------------------------------------------------------------------------
 //
@@ -185,7 +184,8 @@ DPSprite::DPSprite(player_t *owner, AActor *caller, int id)
   oldpx(.0), oldpy(.0),
   oldrotation(.0),
   PivotPercent(true),
-  PivotScreen(false)
+  PivotScreen(false),
+  PivotOffsetRel(false)
 {
 	alpha = 1;
 	Renderstyle = STYLE_Normal;

src/playsim/p_pspr.h

@@ -73,6 +73,7 @@ enum PSPFlags
 	PSPF_PLAYERTRANSLATED = 1 << 10,
 	PSPF_PIVOTPERCENT	= 1 << 11,
 	PSPF_PIVOTSCREEN	= 1 << 12,
+	PSPF_PIVOTOFFSETREL	= 1 << 13,
 };
 
 class DPSprite : public DObject
@@ -101,6 +102,7 @@ public:
 
 	bool PivotScreen;		// If true, the pivot is based on the entire screen width/height instead of the image's dimensions/position.
 	bool PivotPercent;		// If true, the pivot goes between [0.0, 1.0]. Otherwise, it's a pixel position offset from the image size.
+	bool PivotOffsetRel;	// If true, x & y are relative to rotation. Otherwise, x is left/right and y is up/down.
 	double px, py;			// pivot points
 	double oldpx, oldpy;	
 	double rotation;		// How much rotation to apply.