From 37884cfdbffeea150f3a8f72bc37b1e9d2541584 Mon Sep 17 00:00:00 2001
From: Rudolf Polzer <divVerent@xonotic.org>
Date: Sat, 16 Jul 2011 12:15:57 +0200
Subject: [PATCH] when compressing textures, check whether DXT3 or DXT5 is
 better, and use that (slower, better)

---
 misc/tools/cached-converter.sh | 47 +++++++++++++++++++++++++++++-----
 1 file changed, 41 insertions(+), 6 deletions(-)

diff --git a/misc/tools/cached-converter.sh b/misc/tools/cached-converter.sh
index 642edb10..f1e535e6 100755
--- a/misc/tools/cached-converter.sh
+++ b/misc/tools/cached-converter.sh
@@ -14,8 +14,8 @@ set -e
 : ${del_src:=false}
 : ${git_src_repo:=}
 : ${dds_noalpha:=dxt1}
-: ${dds_prealpha:=dxt4}
-: ${dds_sepalpha:=dxt5}
+: ${dds_prealpha:=dxt2 dxt4}
+: ${dds_sepalpha:=dxt3 dxt5}
 
 selfprofile_t0=`date +%s`
 selfprofile_step=init
@@ -143,13 +143,48 @@ cached()
 	selfprofile convert_finished
 }
 
+pickdxta()
+{
+	pd_t=$1; shift
+	pd_d=$1; shift
+	pd_i=$1; shift
+	pd_o=$1; shift
+	for pd_dd in $pd_d; do
+		if [ -f "$pd_o".dds ]; then
+			"$meprefix"compress-texture "$pd_t" "$pd_dd" "$pd_i" "$pd_o".tmp.dds "$@"
+			pd_psnr_tmp=`compare -channel alpha -metric PSNR "$pd_i" "$pd_o".tmp.dds NULL:`
+			echo >&2 "$pd_dd: $pd_psnr_tmp dB"
+			pd_psnr_diff=`echo "($pd_psnr_tmp) - ($pd_psnr)" | bc -l`
+			case "$pd_psnr_diff" in
+				-*|0)
+					# tmp is smaller or equal
+					# smaller PSNR is worse
+					# no action
+					;;
+				*)
+					# tmp is larger
+					# larger PSNR is better
+					pd_psnr=$pd_psnr_tmp
+					mv "$pd_o".tmp.dds "$pd_o"
+					echo >&2 "PICKED (better)"
+					;;
+			esac
+		else
+			"$meprefix"compress-texture "$pd_t" "$pd_dd" "$pd_i" "$pd_o" "$@"
+			pd_psnr=`compare -channel alpha -metric PSNR "$pd_i" "$pd_o" NULL:`
+			echo >&2 "$pd_dd: $pd_psnr dB"
+			echo >&2 "PICKED (first)"
+		fi
+	done
+}
+
 reduce_jpeg2_dds()
 {
 	i=$1; shift
 	ia=$1; shift
 	o=$1; shift; shift 
 	convert "$i" "$ia" -compose CopyOpacity -composite "$tmpdir/x.tga" && \
-	"$meprefix"compress-texture "$dds_tool" "$dds_sepalpha" "$tmpdir/x.tga" "$o" $1
+	pickdxta "$dds_tool" "$dds_sepalpha" "$tmpdir/x.tga" "$o" $1
 }
 
 reduce_jpeg2_dds_premul()
@@ -158,7 +193,7 @@ reduce_jpeg2_dds_premul()
 	ia=$1; shift
 	o=$1; shift; shift 
 	convert "$i" "$ia" -compose CopyOpacity -composite "$tmpdir/x.tga" && \
-	"$meprefix"compress-texture "$dds_tool" "$dds_prealpha" "$tmpdir/x.tga" "$o" $1
+	pickdxta "$dds_tool" "$dds_prealpha" "$tmpdir/x.tga" "$o" $1
 }
 
 reduce_jpeg2_jpeg2()
@@ -218,7 +253,7 @@ reduce_rgba_dds()
 	i=$1; shift; shift
 	o=$1; shift; shift
 	convert "$i" "$tmpdir/x.tga" && \
-	"$meprefix"compress-texture "$dds_tool" "$dds_sepalpha" "$tmpdir/x.tga" "$o" $1
+	pickdxta "$dds_tool" "$dds_sepalpha" "$tmpdir/x.tga" "$o" $1
 }
 
 reduce_rgba_dds_premul()
@@ -226,7 +261,7 @@ reduce_rgba_dds_premul()
 	i=$1; shift; shift
 	o=$1; shift; shift
 	convert "$i" "$tmpdir/x.tga" && \
-	"$meprefix"compress-texture "$dds_tool" "$dds_prealpha" "$tmpdir/x.tga" "$o" $1
+	pickdxta "$dds_tool" "$dds_prealpha" "$tmpdir/x.tga" "$o" $1
 }
 
 reduce_rgba_jpeg2()
-- 
2.39.2