From 617b6cd987a80e139e57fbb4b997bebcd587590b Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Sat, 15 Feb 2020 09:22:30 +0100
Subject: [PATCH] - use floats for sprite depth sorting in the hardware
 renderer.

Fixed point is clearly insufficient here.
---
 src/rendering/hwrenderer/scene/hw_drawlist.cpp  | 7 +++----
 src/rendering/hwrenderer/scene/hw_drawstructs.h | 6 +++---
 src/rendering/hwrenderer/scene/hw_sprites.cpp   | 2 +-
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/src/rendering/hwrenderer/scene/hw_drawlist.cpp b/src/rendering/hwrenderer/scene/hw_drawlist.cpp
index a5a6d7b1d..37ff4006b 100644
--- a/src/rendering/hwrenderer/scene/hw_drawlist.cpp
+++ b/src/rendering/hwrenderer/scene/hw_drawlist.cpp
@@ -585,10 +585,9 @@ inline int HWDrawList::CompareSprites(SortNode * a,SortNode * b)
 	HWSprite * s1= sprites[drawitems[a->itemindex].index];
 	HWSprite * s2= sprites[drawitems[b->itemindex].index];
 
-	int res = s1->depth - s2->depth;
-
-	if (res != 0) return -res;
-	else return reverseSort? s2->index-s1->index : s1->index-s2->index;
+	if (s1->depth < s2->depth) return 1;
+	if (s1->depth > s2->depth) return -1;
+	return reverseSort? s2->index-s1->index : s1->index-s2->index;
 }
 
 //==========================================================================
diff --git a/src/rendering/hwrenderer/scene/hw_drawstructs.h b/src/rendering/hwrenderer/scene/hw_drawstructs.h
index 5550a2d46..4c9730844 100644
--- a/src/rendering/hwrenderer/scene/hw_drawstructs.h
+++ b/src/rendering/hwrenderer/scene/hw_drawstructs.h
@@ -354,7 +354,7 @@ public:
 
 	int translation;
 	int index;
-	int depth;
+	float depth;
 	int vertexindex;
 
 	float topclip;
@@ -366,15 +366,15 @@ public:
 	float vt,vb;
 	float x1,y1,z1;
 	float x2,y2,z2;
+	float trans;
+	int dynlightindex;
 
 	FMaterial *gltexture;
-	float trans;
 	AActor * actor;
 	particle_t * particle;
 	TArray<lightlist_t> *lightlist;
 	DRotator Angles;
 
-	int dynlightindex;
 
 	void SplitSprite(HWDrawInfo *di, sector_t * frontsector, bool translucent);
 	void PerformSpriteClipAdjustment(AActor *thing, const DVector2 &thingpos, float spriteheight);
diff --git a/src/rendering/hwrenderer/scene/hw_sprites.cpp b/src/rendering/hwrenderer/scene/hw_sprites.cpp
index d2104c7d1..4d44f29ef 100644
--- a/src/rendering/hwrenderer/scene/hw_sprites.cpp
+++ b/src/rendering/hwrenderer/scene/hw_sprites.cpp
@@ -903,7 +903,7 @@ void HWSprite::Process(HWDrawInfo *di, AActor* thing, sector_t * sector, area_t
 		gltexture = nullptr;
 	}
 
-	depth = FloatToFixed((x - vp.Pos.X) * vp.TanCos + (y - vp.Pos.Y) * vp.TanSin);
+	depth = (float)((x - vp.Pos.X) * vp.TanCos + (y - vp.Pos.Y) * vp.TanSin);
 
 	// light calculation