Add GL/EGL extension loader generator

1 files changed, 91 insertions, 0 deletions

diff --git a/glgen.sh b/glgen.sh
new file mode 100755
index 00000000..d9de6f9f
--- /dev/null
+++ b/glgen.sh
@@ -0,0 +1,91 @@
+#!/bin/sh
+
+# Generates a simple GL/EGL extension function loader.
+#
+# The input is a .txt file, with each function to load on its own line.
+# If a line starts with a -, it is optional, and will not cause the loader
+# to fail if it can't load the function. You'll need to check if that function
+# is NULL before using it.
+
+if [ $# -ne 2 ]; then
+	exit 1
+fi
+
+SPEC=$1
+OUT=$2
+
+BASE=$(basename "$SPEC" .txt)
+INCLUDE_GUARD=$(printf %s "$SPEC" | tr -c [:alnum:] _ | tr [:lower:] [:upper:])
+
+DECL=""
+DEFN=""
+LOADER=""
+
+DECL_FMT='extern %s %s;'
+DEFN_FMT='%s %s;'
+LOADER_FMT='%s = (%s)eglGetProcAddress("%s");'
+CHECK_FMT='if (!%s) {
+	wlr_log(L_ERROR, "Unable to load %s");
+	return false;
+}'
+
+while read -r COMMAND; do
+	[ ${COMMAND::1} = "-" ]
+	OPTIONAL=$?
+
+	COMMAND=${COMMAND#-}
+	if [ ${COMMAND: -2} = "WL" ]; then
+		FUNC_PTR_FMT='PFN%s'
+	else
+		FUNC_PTR_FMT='PFN%sPROC'
+	fi
+
+	FUNC_PTR=$(printf "$FUNC_PTR_FMT" "$COMMAND" | tr [:lower:] [:upper:])
+
+	DECL="$DECL$(printf "\n$DECL_FMT" "$FUNC_PTR" "$COMMAND")"
+	DEFN="$DEFN$(printf "\n$DEFN_FMT" "$FUNC_PTR" "$COMMAND")"
+	LOADER="$LOADER$(printf "\n$LOADER_FMT" "$COMMAND" "$FUNC_PTR" "$COMMAND")"
+
+	if [ $OPTIONAL -ne 0 ]; then
+		LOADER="$LOADER$(printf "\n$CHECK_FMT" "$COMMAND" "$COMMAND")"
+	fi
+done < $SPEC
+
+if [ ${OUT: -2} = '.h' ]; then
+	cat > $OUT << EOF
+	#ifndef $INCLUDE_GUARD
+	#define $INCLUDE_GUARD
+
+	#include <stdbool.h>
+
+	#include <EGL/egl.h>
+	#include <EGL/eglext.h>
+	#include <EGL/eglmesaext.h>
+	#include <GLES2/gl2.h>
+	#include <GLES2/gl2ext.h>
+
+	bool load_$BASE(void);
+	$DECL
+
+	#endif
+EOF
+elif [ ${OUT: -2} = '.c' ]; then
+	cat > $OUT << EOF
+	#include <wlr/util/log.h>
+	#include "$BASE.h"
+	$DEFN
+
+	bool load_$BASE(void) {
+		static bool done = false;
+		if (done) {
+			return true;
+		}
+	$LOADER
+
+		done = true;
+		return true;
+	}
+EOF
+else
+	exit 1
+fi