From 382234971681efd4f91ac7211cc9bf40f39ba0dc Mon Sep 17 00:00:00 2001
From: Rudolf Polzer <divVerent@gmail.com>
Date: Thu, 18 Mar 2021 05:19:31 -0700
Subject: [PATCH] Add support for the "crunch" texture compression tool.

---
 misc/tools/cached-converter.sh |  8 +++++++-
 misc/tools/compress-texture    | 20 +++++++++++++++++---
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/misc/tools/cached-converter.sh b/misc/tools/cached-converter.sh
index 9fbdf240..ec976351 100755
--- a/misc/tools/cached-converter.sh
+++ b/misc/tools/cached-converter.sh
@@ -396,25 +396,31 @@ for F in "$@"; do
 			;;
 	esac
 
-	# configure S2TC
+	# Specific hacks for normalmaps.
 	case "$f" in
 		./maps/*/lm_[0-9][0-9][0-9][13579]) # deluxemap
 			export S2TC_COLORDIST_MODE=NORMALMAP
 			export S2TC_RANDOM_COLORS=256
 			export S2TC_REFINE_COLORS=LOOP
 			export S2TC_DITHER_MODE=NONE
+			# Engine ignores alpha channel on these, so we can use the DXT1 black encoding.
+			export CRUNCH_TEXTYPEFLAGS='-gamma 1.0 -renormalize -rtopmip -uniformMetrics -usetransparentindicesforblack'
 			;;
 		*_norm)
 			export S2TC_COLORDIST_MODE=NORMALMAP
 			export S2TC_RANDOM_COLORS=256
 			export S2TC_REFINE_COLORS=LOOP
 			export S2TC_DITHER_MODE=NONE
+			# Alpha channel here means height.
+			export CRUNCH_TEXTYPEFLAGS='-gamma 1.0 -renormalize -rtopmip -uniformMetrics'
 			;;
 		*)
 			export S2TC_COLORDIST_MODE=SRGB_MIXED
 			export S2TC_RANDOM_COLORS=64
 			export S2TC_REFINE_COLORS=LOOP
 			export S2TC_DITHER_MODE=FLOYDSTEINBERG
+			# Color channel-like images - consider as sRGB.
+			export CRUNCH_TEXTYPEFLAGS='-gamma 2.2'
 			;;
 	esac
 
diff --git a/misc/tools/compress-texture b/misc/tools/compress-texture
index 9e3b58e5..418d8e5c 100755
--- a/misc/tools/compress-texture
+++ b/misc/tools/compress-texture
@@ -17,8 +17,8 @@ f=
 
 fourcchack=
 case "$tool" in
-	compressonator-dxtc)
-		# we still have to preprocess the image to premultiply alpha, as it seems
+	compressonator-dxtc|crunch)
+		# We still have to preprocess the image to premultiply alpha, as it seems
 		case "$format" in
 			dxt2)
 				fourcchack=DXT2
@@ -30,7 +30,8 @@ case "$tool" in
 				;;
 		esac
 		;;
-	*)
+	compressonator-atic|nvcompress|s2tc)
+		# These tools don't support DXT2/4 at all.
 		case "$format" in
 			dxt2)
 				fourcchack=DXT2
@@ -42,6 +43,9 @@ case "$tool" in
 				;;
 		esac
 		;;
+	*)
+		echo >&2 "Please figure out the DXT2/DXT4 story for $tool."
+		;;
 esac
 
 if [ -n "$fourcchack" ]; then
@@ -93,6 +97,16 @@ case "$tool" in
 		esac
 		s2tc_compress $f "$@" -i "$src" -o "$dst"
 		;;
+	crunch)
+		case "$format" in
+			dxt1) f="-DXT1" ;;
+			dxt2) f="-DXT2" ;;
+			dxt3) f="-DXT3" ;;
+			dxt4) f="-DXT4" ;;
+			dxt5) f="-DXT5" ;;
+		esac
+		crunch $f "$@" -noprogress -nostats -quality 255 -mipMode Generate -dxtQuality uber $CRUNCH_TEXTYPEFLAGS -file "$src" -out "$dst"
+		;;
 esac
 
 if [ -n "$fourcchack" ]; then
-- 
2.39.2