From bdb754b2573e40edd80177bcddf7961f4c629c23 Mon Sep 17 00:00:00 2001
From: cxgeorge <>
Date: Fri, 29 Jun 2001 02:25:19 +0000
Subject: [PATCH] use floating-point division in mipmap generation

---
 panda/src/dxgsg/dxTextureContext.cxx | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/panda/src/dxgsg/dxTextureContext.cxx b/panda/src/dxgsg/dxTextureContext.cxx
index 5d85038cec..dd1a700b8a 100644
--- a/panda/src/dxgsg/dxTextureContext.cxx
+++ b/panda/src/dxgsg/dxTextureContext.cxx
@@ -1669,9 +1669,16 @@ FillDDSurfTexturePixels(void) {
             DWORD src_row_bytelength=oldcurxsize*cPixelSize;
             DWORD two_src_row_bytelength=2*src_row_bytelength;
 
+        #ifdef GENMIPMAP_DO_INTEGER_DIV
             DWORD DivShift=2;
             if((oldcurxsize==1)||(oldcurysize==1))
                 DivShift = 1;
+        #else
+            float numpixels_per_filter=4.0f;
+            if((oldcurxsize==1)||(oldcurysize==1))
+                numpixels_per_filter=2.0f;                
+        #endif
+
             DWORD x_srcptr_inc = ((oldcurxsize==1)? cPixelSize: (2*cPixelSize));
 
             // box-filter shrink down, avg 4 pixels at a time
@@ -1691,8 +1698,11 @@ FillDDSurfTexturePixels(void) {
                             if(oldcurxsize>1)
                                 colr += *(pSrcWord+src_row_bytelength+cPixelSize+c);
                         }
-
-                        colr >>= DivShift;
+                        #ifdef GENMIPMAP_DO_INTEGER_DIV
+                           colr >>= DivShift;
+                        #else
+                           colr = (DWORD) ((((float)colr)/numpixels_per_filter)+0.5f);
+                        #endif
 
                         *(pDstWord+c)=(BYTE)colr;
                     }