From 1e3886b872c286e385013a8878e34c09f6da23fd Mon Sep 17 00:00:00 2001
From: Rudolf Polzer <divverent@xonotic.org>
Date: Thu, 5 Apr 2012 16:27:14 +0200
Subject: [PATCH] add a shader-preprocessor (like cpp)

---
 scripts/ex2x.shader        |   2 +-
 scripts/shader-audit.sh    |   2 +-
 scripts/shader-cpp.sh      | 164 +++++++++++++++++++++++++++++++++++++
 scripts/shader-parser.subr |   6 +-
 4 files changed, 171 insertions(+), 3 deletions(-)
 create mode 100644 scripts/shader-cpp.sh

diff --git a/scripts/ex2x.shader b/scripts/ex2x.shader
index 0069b1a0..ecd6b0d8 100644
--- a/scripts/ex2x.shader
+++ b/scripts/ex2x.shader
@@ -1,4 +1,4 @@
-textures/ex2x/base-yellowpaint
+textures/exx/base-yellowpaint
 {
 	qer_editorimage textures/ex2x/base/base_yellowpaint.tga
 	
diff --git a/scripts/shader-audit.sh b/scripts/shader-audit.sh
index 196d5703..c583f0ee 100755
--- a/scripts/shader-audit.sh
+++ b/scripts/shader-audit.sh
@@ -483,7 +483,7 @@ parse_shaderfile_pre()
 	esac
 }
 
-parse_shaders
+parse_shaders *.shader
 
 textures_avail=`( cd ..; find textures/ -type f -not -name '*.sh' -not -name '*_norm.*' -not -name '*_glow.*' -not -name '*_gloss.*' -not -name '*_reflect.*' -not -name '*.xcf' -not -name '*.txt' ) | while IFS= read -r T; do shader_normalize "$T"; done | sort -u`
 textures_used=`echo "${textures_used#$LF}" | sort -u`
diff --git a/scripts/shader-cpp.sh b/scripts/shader-cpp.sh
new file mode 100644
index 00000000..202987ad
--- /dev/null
+++ b/scripts/shader-cpp.sh
@@ -0,0 +1,164 @@
+#!/bin/sh
+
+case "$0" in
+	*/*)
+		cd "${0%/*}"
+		;;
+esac
+
+. ./shader-parser.subr
+
+LF="
+"
+TAB="	"
+
+parse_shader_pre()
+{
+	shadertext=
+	shaderconds=
+}
+parse_conditional()
+{
+	shaderconds="$shaderconds$LF$*"
+}
+parse_shader_line()
+{
+	case "$1" in
+		'#if')
+			parse_conditional $2 $3
+			;;
+	esac
+	shadertext="$shadertext$LF$TAB$*"
+}
+parse_shaderstage_pre()
+{
+	shadertext="$shadertext$LF$TAB{"
+}
+parse_shaderstage_line()
+{
+	case "$1" in
+		'#if')
+			parse_conditional $2 $3
+			;;
+	esac
+	shadertext="$shadertext$LF$TAB$TAB$*"
+}
+parse_shaderstage_post()
+{
+	shadertext="$shadertext$LF$TAB}"
+}
+# note: the conds are what is FALSE, not TRUE
+shaderkill()
+{
+	parseALLtheconds=$conds
+	while :; do
+		case "$parseALLtheconds" in
+			'')
+				break
+				;;
+			*$LF*)
+				thiscond=${parseALLtheconds%%$LF*}
+				parseALLtheconds=${parseALLtheconds#*$LF}
+				;;
+			*)
+				thiscond=$parseALLtheconds
+				parseALLtheconds=
+				;;
+		esac
+		[ -n "$thiscond" ] || continue
+		echo "$TAB""dpshaderkillifcvar $thiscond"
+	done
+}
+preprocess()
+{
+	condstack=
+	echo "$shadertext" | while IFS= read -r L; do
+		[ -n "$L" ] || continue
+		set -- $L
+		k=$1
+		shift
+		case "$k" in
+			'#if')
+				case "$LF$conds$LF" in
+					*"$LF$*$LF"*)
+						condstack=0$condstack
+						;;
+					*)
+						condstack=1$condstack
+						;;
+				esac
+				;;
+			'#else')
+				case "$condstack" in
+					0)
+						condstack=1${condstack#0}
+						;;
+					1)
+						condstack=0${condstack#1}
+						;;
+				esac
+				;;
+			'#endif')
+				condstack=${condstack#?}
+				;;
+			*)
+				case "$condstack" in
+					*0*)
+						;;
+					*)
+						echo "$L"
+						;;
+				esac
+				;;
+		esac
+	done
+}
+conditionalize()
+{
+	case "$1" in
+		'')
+			# no conditions
+			echo "$parsing_shader"
+			echo "{"
+			shaderkill
+			preprocess
+			echo "}"
+			return
+			;;
+		*$LF*)
+			# many conditions
+			firstcond="${1%%$LF*}"
+			restcond="${1#*$LF}"
+			;;
+		*)
+			firstcond=$1
+			restcond=
+			;;
+	esac
+	(
+		conds="$conds$LF$firstcond"
+		conditionalize "$restcond"
+	)
+	(
+		set -- $firstcond
+		case "$2" in
+			'==') op='!=' ;;
+			'!=') op='==' ;;
+			'>') op='<=' ;;
+			'<') op='>=' ;;
+			'>=') op='<' ;;
+			'<=') op='>' ;;
+		esac
+		set -- "$1" "$op" "$3"
+		conds="$conds$LF$*"
+		conditionalize "$restcond"
+	)
+}
+parse_shader_post()
+{
+	allconds=`echo "$shaderconds" | sort -u | grep .`
+	conds=
+	conditionalize "$allconds"
+}
+
+parse_shaders "$@"
diff --git a/scripts/shader-parser.subr b/scripts/shader-parser.subr
index ea964572..ef82832f 100644
--- a/scripts/shader-parser.subr
+++ b/scripts/shader-parser.subr
@@ -30,6 +30,8 @@ parse_shaderstage()
 			'}')
 				break
 				;;
+			'')
+				;;
 			*)
 				parse_shaderstage_line "$shaderparser_L" "$shaderparser_A1" "$shaderparser_Aother"
 				;;
@@ -61,6 +63,8 @@ parse_shader()
 			'}')
 				break
 				;;
+			'')
+				;;
 			*)
 				parse_shader_line "$shaderparser_L" "$shaderparser_A1" "$shaderparser_Aother"
 				;;
@@ -109,7 +113,7 @@ shaderparser_strip_comments()
 parse_shaders()
 {
 	shaderparser_t=`mktemp || echo ".temp"`
-	for shaderparser_X in *.shader; do
+	for shaderparser_X in "$@"; do
 		shaderparser_strip_comments < "$shaderparser_X" > "$shaderparser_t"
 		parsing_shaderfile="$shaderparser_X"
 		parse_shaderfile < "$shaderparser_t"
-- 
2.39.2