Merge branch 'fix-paper-roll' into 'next'

Fix papersprites being rotated incorrectly in Software when viewing them on the flipped side

See merge request !1770

src/r_things.c

@@ -1610,8 +1610,17 @@ static void R_ProjectSprite(mobj_t *thing)
 #ifdef ROTSPRITE
 	if (thing->rollangle
 	&& !(splat && !(thing->renderflags & RF_NOSPLATROLLANGLE)))
+	{
+		if (papersprite && ang >= ANGLE_180)
+		{
+			// Makes Software act much more sane like OpenGL
+			rollangle = R_GetRollAngle(InvAngle(thing->rollangle));
+		}
+		else
 		{
 			rollangle = R_GetRollAngle(thing->rollangle);
+		}
+
 		rotsprite = Patch_GetRotatedSprite(sprframe, (thing->frame & FF_FRAMEMASK), rot, flip, false, sprinfo, rollangle);
 
 		if (rotsprite != NULL)