From 6131b80f03fcd30f3f003c1793deb77bcad7ef6e Mon Sep 17 00:00:00 2001
From: fickleheart <fickle@tinted.red>
Date: Sun, 1 Dec 2019 12:34:25 -0600
Subject: [PATCH] I don't like your sprite clipping fix, so here's mine

---
 src/hardware/hw_main.c | 49 +++++++++++++++++++++++-------------------
 src/r_things.c         |  6 +-----
 2 files changed, 28 insertions(+), 27 deletions(-)

diff --git a/src/hardware/hw_main.c b/src/hardware/hw_main.c
index 31ea0760..2965d7fc 100644
--- a/src/hardware/hw_main.c
+++ b/src/hardware/hw_main.c
@@ -3245,20 +3245,22 @@ static void HWR_SplitSprite(gr_vissprite_t *spr)
 		baseWallVerts[0].t = baseWallVerts[1].t = gpatch->max_t;
 	}
 
-	// if it has a dispoffset, push it a little towards the camera
-	if (spr->dispoffset)
-	{
-		float co = -gr_viewcos*(0.05f*spr->dispoffset);
-		float si = -gr_viewsin*(0.05f*spr->dispoffset);
-		baseWallVerts[0].z = baseWallVerts[3].z = baseWallVerts[0].z+si;
-		baseWallVerts[1].z = baseWallVerts[2].z = baseWallVerts[1].z+si;
-		baseWallVerts[0].x = baseWallVerts[3].x = baseWallVerts[0].x+co;
-		baseWallVerts[1].x = baseWallVerts[2].x = baseWallVerts[1].x+co;
-	}
-
 	// Let dispoffset work first since this adjust each vertex
 	HWR_RotateSpritePolyToAim(spr, baseWallVerts);
 
+	// push it toward the camera to mitigate floor-clipping sprites
+	{
+		float sprdist = sqrtf((spr->x1 - gr_viewx)*(spr->x1 - gr_viewx) + (spr->z1 - gr_viewy)*(spr->z1 - gr_viewy) + (spr->ty - gr_viewz)*(spr->ty - gr_viewz));
+		float distfact = ((2.0f*spr->dispoffset) + 20.0f) / sprdist;
+		size_t i;
+		for (i = 0; i < 4; i++)
+		{
+			baseWallVerts[i].x += (gr_viewx - baseWallVerts[i].x)*distfact;
+			baseWallVerts[i].z += (gr_viewy - baseWallVerts[i].z)*distfact;
+			baseWallVerts[i].y += (gr_viewz - baseWallVerts[i].y)*distfact;
+		}
+	}
+
 	realtop = top = baseWallVerts[3].y;
 	realbot = bot = baseWallVerts[0].y;
 	towtop = baseWallVerts[3].t;
@@ -3598,20 +3600,23 @@ static void HWR_DrawSprite(gr_vissprite_t *spr)
 		HWR_DrawSpriteShadow(spr, gpatch, this_scale);
 	}
 
-	// if it has a dispoffset, push it a little towards the camera
-	if (spr->dispoffset)
-	{
-		float co = -gr_viewcos*(0.05f*spr->dispoffset);
-		float si = -gr_viewsin*(0.05f*spr->dispoffset);
-		wallVerts[0].z = wallVerts[3].z = wallVerts[0].z+si;
-		wallVerts[1].z = wallVerts[2].z = wallVerts[1].z+si;
-		wallVerts[0].x = wallVerts[3].x = wallVerts[0].x+co;
-		wallVerts[1].x = wallVerts[2].x = wallVerts[1].x+co;
-	}
-
 	// Let dispoffset work first since this adjust each vertex
+	// ...nah
 	HWR_RotateSpritePolyToAim(spr, wallVerts);
 
+	// push it toward the camera to mitigate floor-clipping sprites
+	{
+		float sprdist = sqrtf((spr->x1 - gr_viewx)*(spr->x1 - gr_viewx) + (spr->z1 - gr_viewy)*(spr->z1 - gr_viewy) + (spr->ty - gr_viewz)*(spr->ty - gr_viewz));
+		float distfact = ((2.0f*spr->dispoffset) + 20.0f) / sprdist;
+		size_t i;
+		for (i = 0; i < 4; i++)
+		{
+			wallVerts[i].x += (gr_viewx - wallVerts[i].x)*distfact;
+			wallVerts[i].z += (gr_viewy - wallVerts[i].z)*distfact;
+			wallVerts[i].y += (gr_viewz - wallVerts[i].y)*distfact;
+		}
+	}
+
 	// This needs to be AFTER the shadows so that the regular sprites aren't drawn completely black.
 	// sprite lighting by modulating the RGB components
 	/// \todo coloured
diff --git a/src/r_things.c b/src/r_things.c
index 97b22c13..f933cb8c 100644
--- a/src/r_things.c
+++ b/src/r_things.c
@@ -259,11 +259,7 @@ static boolean R_AddSingleSpriteDef(const char *sprname, spritedef_t *spritedef,
 			//BP: we cannot use special tric in hardware mode because feet in ground caused by z-buffer
 			if (rendermode != render_none) // not for psprite
 				spritecachedinfo[numspritelumps].topoffset += 4<<FRACBITS;
-			
-			// Idea, how about we do it like literally every hardware renderer ever?
-			if (rendermode == render_opengl)
-				spritecachedinfo[numspritelumps].topoffset += 5<<FRACBITS;
-				
+
 			// Being selective with this causes bad things. :( Like the special stage tokens breaking apart.
 			/*if (rendermode != render_none // not for psprite
 			 && SHORT(patch.topoffset)>0 && SHORT(patch.topoffset)<SHORT(patch.height))