From 946d207c560ec1ba216f2f1edea7810c033bca1b Mon Sep 17 00:00:00 2001
From: helixhorned <helixhorned@1a8010ca-5511-0410-912e-c29ae57300e0>
Date: Thu, 16 May 2013 21:54:56 +0000
Subject: [PATCH] Polymodes: make flipping closer to classic.

This fixes cases A and B in test_tileoffsets.map.

git-svn-id: https://svn.eduke32.com/eduke32@3778 1a8010ca-5511-0410-912e-c29ae57300e0
---
 polymer/eduke32/build/src/polymer.c  | 41 ++++++++++++++--------------
 polymer/eduke32/build/src/polymost.c |  3 +-
 2 files changed, 22 insertions(+), 22 deletions(-)

diff --git a/polymer/eduke32/build/src/polymer.c b/polymer/eduke32/build/src/polymer.c
index 1de22f4fe..5ea85c8a6 100644
--- a/polymer/eduke32/build/src/polymer.c
+++ b/polymer/eduke32/build/src/polymer.c
@@ -3546,7 +3546,7 @@ static inline void  polymer_scansprites(int16_t sectnum, spritetype* localtsprit
 
 void                polymer_updatesprite(int32_t snum)
 {
-    int32_t         curpicnum, xsize, ysize, tilexoff, tileyoff, xoff, yoff, i, j, cs;
+    int32_t         curpicnum, xsize, ysize, tilexoff, tileyoff, xoff, yoff, i, j;
     spritetype      *tspr = tspriteptr[snum];
     float           xratio, yratio, ang, f;
     float           spos[3];
@@ -3554,12 +3554,13 @@ void                polymer_updatesprite(int32_t snum)
     uint8_t         flipu, flipv;
     _prsprite       *s;
 
+    const uint32_t cs = tspr->cstat;
+    const uint32_t alignmask = (cs & SPR_ALIGN_MASK);
+
     if (pr_verbosity >= 3) OSD_Printf("PR : Updating sprite %i...\n", snum);
 
     if (tspr->owner < 0 || tspr->picnum < 0) return;
 
-    cs = tspr->cstat;
-
     if (prsprites[tspr->owner] == NULL)
     {
         prsprites[tspr->owner] = (_prsprite *) Bcalloc(sizeof(_prsprite), 1);
@@ -3661,28 +3662,26 @@ void                polymer_updatesprite(int32_t snum)
     inbuffer = vertsprite;
 
     {
-        // Initially set flipu and flipv.
-        const uint8_t xflip = !!(tspr->cstat & SPR_XFLIP);
-        const uint8_t yflip = !!(tspr->cstat & SPR_YFLIP);
-        const uint8_t flooraligned = ((tspr->cstat & SPR_ALIGN_MASK)==SPR_FLOOR);
+        const uint8_t xflip = !!(cs & SPR_XFLIP);
+        const uint8_t yflip = !!(cs & SPR_YFLIP);
+        const uint8_t flooraligned = (alignmask==SPR_FLOOR);
 
+        // Initially set flipu and flipv.
         flipu = (xflip ^ flooraligned);
         flipv = (yflip && !flooraligned);
-    }
 
-    if (pr_billboardingmode && (tspr->cstat & SPR_ALIGN_MASK)==0)
-    {
-        // do surgery on the face tspr to make it look like a wall sprite
-        tspr->cstat |= 16;
-        tspr->ang = (viewangle + 1024) & 2047;
-    }
+        if (pr_billboardingmode && alignmask==0)
+        {
+            // do surgery on the face tspr to make it look like a wall sprite
+            tspr->cstat |= 16;
+            tspr->ang = (viewangle + 1024) & 2047;
+        }
 
-    if (flipu) {
-        xoff = -xoff;
-    }
+        if (flipu)
+            xoff = -xoff;
 
-    if (flipv) {
-        yoff = -yoff;
+        if (yflip && alignmask!=0)
+            yoff = -yoff;
     }
 
     switch (tspr->cstat & SPR_ALIGN_MASK)
@@ -3743,7 +3742,7 @@ void                polymer_updatesprite(int32_t snum)
 
     polymer_computeplane(&s->plane);
 
-    if ((cs & SPR_ALIGN_MASK) && (pr_vbos > 0))
+    if (alignmask && (pr_vbos > 0))
     {
         bglBindBufferARB(GL_ARRAY_BUFFER_ARB, s->plane.vbo);
         bglBufferSubDataARB(GL_ARRAY_BUFFER_ARB, 0, 4 * sizeof(GLfloat) * 5, s->plane.buffer);
@@ -3755,7 +3754,7 @@ void                polymer_updatesprite(int32_t snum)
         s->plane.vbo = 0;
     }
 
-    if (tspr->cstat & SPR_ALIGN_MASK)
+    if (alignmask)
     {
         int32_t curpriority = 0;
 
diff --git a/polymer/eduke32/build/src/polymost.c b/polymer/eduke32/build/src/polymost.c
index fa54f59b7..2750f969d 100644
--- a/polymer/eduke32/build/src/polymost.c
+++ b/polymer/eduke32/build/src/polymost.c
@@ -3835,7 +3835,8 @@ void polymost_drawsprite(int32_t snum)
     case 0: //Face sprite
         //Project 3D to 2D
         if (globalorientation&4) xoff = -xoff;
-        if (globalorientation&8) yoff = -yoff;
+        // NOTE: yoff not negated not for y flipping, unlike wall and floor
+        // aligned sprites.
 
         sx0 = (float)(tspr->x-globalposx);
         sy0 = (float)(tspr->y-globalposy);