OPENGL: Allow runtime specification of OpenGL mode.

Formerly, we required that the OpenGL mode was fixed at compile time. Now we
allow the code to work with whatever it is given at runtime.

It is still possible to force a context type on compile time.

1 files changed, 74 insertions, 26 deletions

diff --git a/configure b/configure
index 8d465bc37c..2367466a7c 100755
--- a/configure
+++ b/configure
@@ -133,8 +133,7 @@ _png=auto
 _theoradec=auto
 _faad=auto
 _fluidsynth=auto
-_opengl=auto
-_opengles=no
+_opengl_mode=auto
 _readline=auto
 _freetype2=auto
 _taskbar=auto
@@ -940,6 +939,14 @@ Optional Features:
   --enable-verbose-build   enable regular echoing of commands during build
                            process
   --disable-bink           don't build with Bink video support
+  --opengl-mode=MODE       OpenGL (ES) mode to use for OpenGL output [auto]
+                           available modes: auto for autodetection
+                                            none for disabling any OpenGL usage
+                                            any for runtime detection
+                                            gl for forcing OpenGL
+                                            gles for forcing OpenGL ES
+                           WARNING: only specify this manually if you know what
+                           you are doing!
 
 Optional Libraries:
   --with-alsa-prefix=DIR   Prefix where alsa is installed (optional)
@@ -964,9 +971,6 @@ Optional Libraries:
   --with-mpeg2-prefix=DIR  Prefix where libmpeg2 is installed (optional)
   --enable-mpeg2           enable mpeg2 codec for cutscenes [autodetect]
 
-  --disable-opengl         disable OpenGL (ES) support [autodetect]
-  --enable-opengles        enable forced OpenGL ES mode [disabled]
-
   --with-jpeg-prefix=DIR   Prefix where libjpeg is installed (optional)
   --disable-jpeg           disable JPEG decoder [autodetect]
 
@@ -1071,12 +1075,11 @@ for ac_option in $@; do
 	--disable-updates)        _updates=no     ;;
 	--enable-libunity)        _libunity=yes   ;;
 	--disable-libunity)       _libunity=no    ;;
-	--enable-opengl)          _opengl=yes     ;;
-	--disable-opengl)         _opengl=no      ;;
-	--enable-opengles)        _opengles=yes   ;;
-	--disable-opengles)       _opengles=no    ;;
 	--enable-bink)            _bink=yes       ;;
 	--disable-bink)           _bink=no        ;;
+	--opengl-mode=*)
+		_opengl_mode=`echo $ac_option | cut -d '=' -f 2`
+		;;
 	--enable-verbose-build)   _verbose_build=yes ;;
 	--enable-plugins)         _dynamic_modules=yes ;;
 	--default-dynamic)        _plugins_default=dynamic ;;
@@ -2658,8 +2661,7 @@ if test -n "$_host"; then
 			_sdlconfig=sdl2-config
 			# OpenGL(ES) support is mature enough as to be the best option on
 			# the Raspberry Pi, so it's enabled by default.
-			_opengl=yes
-			_opengles=yes
+			_opengl_mode=gles
 			;;
 		dreamcast)
 			append_var DEFINES "-DDISABLE_DEFAULT_SAVEFILEMANAGER"
@@ -2988,8 +2990,7 @@ if test -n "$_host"; then
 			_timidity=no
 			_vkeybd=yes
 			# Tizen relies on the OpenGL ES output thus we always enable it.
-			_opengl=yes
-			_opengles=yes
+			_opengl_mode=gles
 			;;
 		webos)
 			_backend="webos"
@@ -4150,35 +4151,82 @@ echocheck "OpenGL"
 
 case $_backend in
 	openpandora)
-		# Only enable OpenGL ES on the OpanPandora if --enable-opengl is passed in explicitly.
-		if test "$_opengl" = yes ; then
-			_opengl=yes
-			_opengles=yes
+		# Only enable OpenGL ES on the OpanPandora if --opengl-mode=gles is passed in explicitly.
+		if test "$_opengl_mode" = "gles" ; then
 			append_var LIBS "-lGLES_CM -lEGL -lX11"
+		else
+			_opengl_mode=none
 		fi
 		;;
 esac
 
-if test "$_opengl" = auto ; then
+if test "$_opengl_mode" = auto ; then
 	case $_backend in
 		sdl)
-			_opengl=yes
+			case $_sdlversion in
+				1.2.*)
+					# Stock SDL 1.2 only supports OpenGL contexts.
+					_opengl_mode=gl
+					;;
+
+				2.0.*)
+					# SDL2 supports both OpenGL + OpenGL ES contexts.
+					# However, Mac OS X only allows OpenGL context creation at
+					# this time, thus we limit us to OpenGL on that platform.
+					case $_host_os in
+						darwin*)
+							_opengl_mode=gl
+							;;
+
+						*)
+							_opengl_mode=any
+							;;
+					esac
+					;;
+			esac
+			;;
+
+		tizen)
+			# Tizen always runs in GLES mode
+			_opengl_mode=gles
 			;;
 
 		*)
-			_opengl=no
+			_opengl_mode=none
 			;;
 	esac
 fi
 
-if test "$_opengles" = "yes" ; then
-	echo "yes (OpenGL ES)"
-else
-	echo "$_opengl"
-fi
+_opengl=yes
+case $_opengl_mode in
+	auto)
+		# This case should never occur but better safe than sorry.
+		echo "no"
+		_opengl=no
+		;;
+
+	none)
+		echo "no"
+		_opengl=no
+		;;
+
+	any)
+		echo "yes (runtime detection)"
+		add_line_to_config_h "#undef USE_GLES_MODE"
+		;;
+
+	gl)
+		echo "yes (OpenGL)"
+		add_line_to_config_h "#define USE_GLES_MODE 0"
+		;;
+
+	gles)
+		echo "yes (OpenGL ES)"
+		add_line_to_config_h "#define USE_GLES_MODE 1"
+		;;
+esac
 
 define_in_config_if_yes "$_opengl" "USE_OPENGL"
-define_in_config_if_yes "$_opengles" "USE_GLES"
 
 #
 # Check for nasm