From 9e3b89c54f238a6eb2a18472d885e683c14043f7 Mon Sep 17 00:00:00 2001
From: toaster <rollerorbital@gmail.com>
Date: Sat, 23 Jul 2022 21:48:05 +0100
Subject: [PATCH] R_DrawVisSprite adjustments

* Backport the fix to an interp-based crash caused by using a combination of interpolated and uninterpolated scale in renderer calculations.
* Between this and the last commit, I attempted a refactor of this and associated functions in order to find the cause of the above crash. Committed are the changes which resulted in increased performance.
---
 src/r_things.c | 39 ++++++++++-----------------------------
 src/r_things.h |  2 ++
 2 files changed, 12 insertions(+), 29 deletions(-)

diff --git a/src/r_things.c b/src/r_things.c
index c5308562..e8086f8b 100644
--- a/src/r_things.c
+++ b/src/r_things.c
@@ -697,19 +697,6 @@ void R_DrawMaskedColumn(column_t *column)
 			// quick fix... something more proper should be done!!!
 			if (ylookup[dc_yl])
 				colfunc();
-			else if (colfunc == R_DrawColumn_8
-#ifdef USEASM
-			|| colfunc == R_DrawColumn_8_ASM || colfunc == R_DrawColumn_8_MMX
-#endif
-			)
-			{
-				static INT32 first = 1;
-				if (first)
-				{
-					CONS_Debug(DBG_RENDER, "WARNING: avoiding a crash in %s %d\n", __FILE__, __LINE__);
-					first = 0;
-				}
-			}
 		}
 		column = (column_t *)((UINT8 *)column + column->length + 4);
 	}
@@ -768,19 +755,6 @@ static void R_DrawFlippedMaskedColumn(column_t *column, INT32 texheight)
 			// Still drawn by R_DrawColumn.
 			if (ylookup[dc_yl])
 				colfunc();
-			else if (colfunc == R_DrawColumn_8
-#ifdef USEASM
-			|| colfunc == R_DrawColumn_8_ASM || colfunc == R_DrawColumn_8_MMX
-#endif
-			)
-			{
-				static INT32 first = 1;
-				if (first)
-				{
-					CONS_Debug(DBG_RENDER, "WARNING: avoiding a crash in %s %d\n", __FILE__, __LINE__);
-					first = 0;
-				}
-			}
 			Z_Free(dc_source);
 		}
 		column = (column_t *)((UINT8 *)column + column->length + 4);
@@ -801,7 +775,7 @@ static void R_DrawVisSprite(vissprite_t *vis)
 #endif
 	fixed_t frac;
 	patch_t *patch = W_CacheLumpNum(vis->patch, PU_CACHE);
-	fixed_t this_scale = vis->mobj->scale;
+	fixed_t this_scale = vis->thingscale;
 	INT32 x1, x2;
 	INT64 overflow_test;
 
@@ -932,8 +906,11 @@ static void R_DrawVisSprite(vissprite_t *vis)
 #if 1
 	// Something is occasionally setting 1px-wide sprites whose frac is exactly the width of the sprite, causing crashes due to
 	// accessing invalid column info. Until the cause is found, let's try to correct those manually...
-	while (frac + vis->xiscale*(vis->x2-vis->x1) > SHORT(patch->width)<<FRACBITS && vis->x2 >= vis->x1)
-		vis->x2--;
+	{
+		fixed_t temp = ((frac + vis->xiscale*(vis->x2-vis->x1))>>FRACBITS) - SHORT(patch->width);
+		if (temp > 0)
+			vis->x2 -= temp;
+	}
 #endif
 
 	for (dc_x = vis->x1; dc_x <= vis->x2; dc_x++, frac += vis->xiscale)
@@ -1482,6 +1459,8 @@ static void R_ProjectSprite(mobj_t *thing)
 		vis->scale += scalestep*(vis->x1 - x1);
 	}
 
+	vis->thingscale = interp.scale;
+
 	//Fab: lumppat is the lump number of the patch to use, this is different
 	//     than lumpid for sprites-in-pwad : the graphics are patched
 	vis->patch = sprframe->lumppat[rot];
@@ -1697,6 +1676,8 @@ static void R_ProjectPrecipitationSprite(precipmobj_t *thing)
 	vis->startfrac = 0;
 	vis->xiscale = iscale;
 
+	vis->thingscale = interp.scale;
+
 	if (vis->x1 > x1)
 		vis->startfrac += vis->xiscale*(vis->x1-x1);
 
diff --git a/src/r_things.h b/src/r_things.h
index 697cde25..b80ffa71 100644
--- a/src/r_things.h
+++ b/src/r_things.h
@@ -159,6 +159,8 @@ typedef struct vissprite_s
 	boolean vflip; // Flip vertically
 	boolean isScaled;
 	INT32 dispoffset; // copy of info->dispoffset, affects ordering but not drawing
+
+	fixed_t thingscale;
 } vissprite_t;
 
 // A drawnode is something that points to a 3D floor, 3D side, or masked