From 2be2133d7f56dd79fb6f626c8d7e32ea355c733b Mon Sep 17 00:00:00 2001
From: Sam Lantinga <slouken@libsdl.org>
Date: Thu, 27 Sep 2012 11:29:13 -0700
Subject: [PATCH] Turned the X11 mode extension environment variables into
 hints so they can be more easily set from applications.

---
 include/SDL_hints.h          | 35 ++++++++++++++++++++++++++++++++++-
 src/video/x11/SDL_x11modes.c | 13 +++++++------
 2 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/include/SDL_hints.h b/include/SDL_hints.h
index 7500ee701..aff3602ba 100644
--- a/include/SDL_hints.h
+++ b/include/SDL_hints.h
@@ -118,7 +118,40 @@ extern "C" {
  *  By default SDL does not sync screen surface updates with vertical refresh.
  */
 #define SDL_HINT_RENDER_VSYNC               "SDL_RENDER_VSYNC"
-	
+
+/**
+ *  \brief  A variable controlling whether the X11 VidMode extension should be used.
+ *
+ *  This variable can be set to the following values:
+ *    "0"       - Disable XVidMode
+ *    "1"       - Enable XVidMode
+ *
+ *  By default SDL will use XVidMode if it is available.
+ */
+#define SDL_HINT_VIDEO_X11_XVIDMODE         "SDL_VIDEO_X11_XVIDMODE"
+
+/**
+ *  \brief  A variable controlling whether the X11 Xinerama extension should be used.
+ *
+ *  This variable can be set to the following values:
+ *    "0"       - Disable Xinerama
+ *    "1"       - Enable Xinerama
+ *
+ *  By default SDL will use Xinerama if it is available.
+ */
+#define SDL_HINT_VIDEO_X11_XINERAMA         "SDL_VIDEO_X11_XINERAMA"
+
+/**
+ *  \brief  A variable controlling whether the X11 XRandR extension should be used.
+ *
+ *  This variable can be set to the following values:
+ *    "0"       - Disable XRandR
+ *    "1"       - Enable XRandR
+ *
+ *  By default SDL will use XRandR if it is available.
+ */
+#define SDL_HINT_VIDEO_X11_XRANDR           "SDL_VIDEO_X11_XRANDR"
+
 /**
  *  \brief  A variable controlling whether the idle timer is disabled on iOS.
  *
diff --git a/src/video/x11/SDL_x11modes.c b/src/video/x11/SDL_x11modes.c
index cfab6e71d..ef6e08a7b 100755
--- a/src/video/x11/SDL_x11modes.c
+++ b/src/video/x11/SDL_x11modes.c
@@ -22,6 +22,7 @@
 
 #if SDL_VIDEO_DRIVER_X11
 
+#include "SDL_hints.h"
 #include "SDL_x11video.h"
 
 /*#define X11MODES_DEBUG*/
@@ -270,10 +271,10 @@ CheckXinerama(Display * display, int *major, int *minor)
     *major = *minor = 0;
 
     /* Allow environment override */
-    env = getenv("SDL_VIDEO_X11_XINERAMA");
+    env = SDL_GetHint(SDL_HINT_VIDEO_X11_XINERAMA);
     if (env && !SDL_atoi(env)) {
 #ifdef X11MODES_DEBUG
-        printf("Xinerama disabled due to environment variable\n");
+        printf("Xinerama disabled due to hint\n");
 #endif
         return SDL_FALSE;
     }
@@ -311,10 +312,10 @@ CheckXRandR(Display * display, int *major, int *minor)
     *major = *minor = 0;
 
     /* Allow environment override */
-    env = getenv("SDL_VIDEO_X11_XRANDR");
+    env = SDL_GetHint(SDL_HINT_VIDEO_X11_XRANDR);
     if (env && !SDL_atoi(env)) {
 #ifdef X11MODES_DEBUG
-        printf("XRandR disabled due to environment variable\n");
+        printf("XRandR disabled due to hint\n");
 #endif
         return SDL_FALSE;
     }
@@ -350,10 +351,10 @@ CheckVidMode(Display * display, int *major, int *minor)
     *major = *minor = 0;
 
     /* Allow environment override */
-    env = getenv("SDL_VIDEO_X11_XVIDMODE");
+    env = SDL_GetHint(SDL_HINT_VIDEO_X11_XVIDMODE);
     if (env && !SDL_atoi(env)) {
 #ifdef X11MODES_DEBUG
-        printf("XVidMode disabled due to environment variable\n");
+        printf("XVidMode disabled due to hint\n");
 #endif
         return SDL_FALSE;
     }