From bf8bb383ab1a39240c0a3e34ec8caa7c1a5bbdac Mon Sep 17 00:00:00 2001
From: Jaime Passos <lazymyuutsu@gmail.com>
Date: Wed, 14 Oct 2020 21:20:37 -0300
Subject: [PATCH] Simplify the floor splat clipping code a bit

---
 src/r_splats.c | 59 +++++++++++++++++++++++++++-----------------------
 src/r_splats.h |  1 -
 src/r_things.c |  4 +++-
 3 files changed, 35 insertions(+), 29 deletions(-)

diff --git a/src/r_splats.c b/src/r_splats.c
index ce45446d0..efcd6ea98 100644
--- a/src/r_splats.c
+++ b/src/r_splats.c
@@ -24,8 +24,6 @@ struct rastery_s *prastertab; // for ASM code
 static struct rastery_s rastertab[MAXVIDHEIGHT];
 static void prepare_rastertab(void);
 
-UINT8 ds_splatclip[MAXVIDWIDTH];
-
 // ==========================================================================
 //                                                               FLOOR SPLATS
 // ==========================================================================
@@ -147,7 +145,8 @@ static void rasterize_segment_tex(INT32 x1, INT32 y1, INT32 x2, INT32 y2, INT32
 void R_RenderFloorSplat(floorsplat_t *pSplat, vector2_t *verts, vissprite_t *vis)
 {
 	// rasterizing
-	INT32 miny = viewheight + 1, maxy = 0, y, x1, ry1, x2, y2, i, xclip;
+	INT32 miny = viewheight + 1, maxy = 0;
+	INT32 y, x1, ry1, x2, y2, i;
 	fixed_t offsetx = 0, offsety = 0;
 	fixed_t step;
 
@@ -289,6 +288,8 @@ void R_RenderFloorSplat(floorsplat_t *pSplat, vector2_t *verts, vissprite_t *vis
 
 	for (y = miny; y <= maxy; y++)
 	{
+		boolean cliptab[MAXVIDWIDTH+1];
+
 		x1 = rastertab[y].minx>>FRACBITS;
 		x2 = rastertab[y].maxx>>FRACBITS;
 
@@ -304,8 +305,34 @@ void R_RenderFloorSplat(floorsplat_t *pSplat, vector2_t *verts, vissprite_t *vis
 
 		if (x1 < 0)
 			x1 = 0;
-		if (x2 >= vid.width)
-			x2 = vid.width - 1;
+		if (x2 >= viewwidth)
+			x2 = viewwidth - 1;
+
+		if (x1 >= viewwidth || x2 < 0)
+			continue;
+
+		for (i = x1; i <= x2; i++)
+			cliptab[i] = (y >= mfloorclip[i]);
+
+		// clip left
+		while (cliptab[x1])
+		{
+			x1++;
+			if (x1 >= viewwidth)
+				break;
+		}
+
+		// clip right
+		i = x2;
+
+		while (i > x1)
+		{
+			if (cliptab[i])
+				x2 = i-1;
+			i--;
+			if (i < 0)
+				break;
+		}
 
 		ds_colormap = vis->colormap;
 		ds_translation = R_GetSpriteTranslation(vis);
@@ -320,28 +347,6 @@ void R_RenderFloorSplat(floorsplat_t *pSplat, vector2_t *verts, vissprite_t *vis
 				ds_colormap = &vis->extra_colormap->colormap[ds_colormap - colormaps];
 		}
 
-		R_ClipVisSprite(vis, x1-1, x2+1, drawsegs, NULL);
-		memset(ds_splatclip, 0, sizeof(ds_splatclip));
-
-		if (x2 >= x1 && x1 < viewwidth && x1 >= 0)
-		{
-			for (xclip = x1; xclip <= x2; xclip++)
-			{
-				if (y >= mfloorclip[xclip])
-					ds_splatclip[xclip] = 1;
-			}
-		}
-
-		while (ds_splatclip[x1])
-			x1++;
-		i = x2;
-		while (i > x1)
-		{
-			if (ds_splatclip[i])
-				x2 = i-1;
-			i--;
-		}
-
 		if (!pSplat->tilted)
 		{
 			angle = (viewangle + pSplat->angle)>>ANGLETOFINESHIFT;
diff --git a/src/r_splats.h b/src/r_splats.h
index b0707e95b..ba5052fc9 100644
--- a/src/r_splats.h
+++ b/src/r_splats.h
@@ -44,7 +44,6 @@ typedef struct floorsplat_s
 } floorsplat_t;
 
 void R_RenderFloorSplat(floorsplat_t *pSplat, vector2_t *verts, vissprite_t *vis);
-extern UINT8 ds_splatclip[MAXVIDWIDTH];
 #endif
 
 #endif /*__R_SPLATS_H__*/
diff --git a/src/r_things.c b/src/r_things.c
index e8c00b86b..6c1d8a879 100644
--- a/src/r_things.c
+++ b/src/r_things.c
@@ -3213,7 +3213,9 @@ void R_ClipSprites(drawseg_t* dsstart, portal_t* portal)
 	for (; clippedvissprites < visspritecount; clippedvissprites++)
 	{
 		vissprite_t *spr = R_GetVisSprite(clippedvissprites);
-		R_ClipVisSprite(spr, spr->x1, spr->x2, dsstart, portal);
+		INT32 x1 = (spr->cut & SC_SPLAT) ? 0 : spr->x1;
+		INT32 x2 = (spr->cut & SC_SPLAT) ? viewwidth : spr->x2;
+		R_ClipVisSprite(spr, x1, x2, dsstart, portal);
 	}
 }