From 223279ebd99a08ed9300ebaaf2a79dc9e0692483 Mon Sep 17 00:00:00 2001
From: cutealien <cutealien@dfc29bdd-3216-0410-991c-e03cc46cb475>
Date: Tue, 22 Dec 2020 21:14:45 +0000
Subject: [PATCH] Make it possible again to enable ES1 on Linux. Seems Debian
 11 adds it back. Thanks @TheBrokenRail for patch. Hidden in comments for
 patch #322: https://sourceforge.net/p/irrlicht/patches/322

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/branches/ogl-es@6175 dfc29bdd-3216-0410-991c-e03cc46cb475
---
 include/IrrCompileConfig.h     | 20 +++++++++++---------
 source/Irrlicht/COGLESCommon.h | 10 +++++-----
 2 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/include/IrrCompileConfig.h b/include/IrrCompileConfig.h
index 643b011b..6c004bd0 100644
--- a/include/IrrCompileConfig.h
+++ b/include/IrrCompileConfig.h
@@ -227,22 +227,24 @@ define out. */
 	#endif
 #endif
 
-
-// Debian 10 removed support for GLES1 in mesa.
-// Can't tell about other Linux platforms or a way to test if it's still available,
-// so removing OGLES1 support on Linux now to allow compiling to work by default.
-#if defined(_IRR_LINUX_PLATFORM_) && !defined(_IRR_ANDROID_PLATFORM_)
-#define NO_IRR_COMPILE_WITH_OGLES1_
-#endif
-
 //! Define _IRR_COMPILE_WITH_OGLES1_ to compile the Irrlicht engine with OpenGL ES 1.1.
 /** If you do not wish the engine to be compiled with OpenGL ES 1.1, comment this
-define out. */
+define out.
+Currently only enabled on Android by default.
+Depending on platform you may have to enable _IRR_OGLES1_USE_KHRONOS_API_HEADERS_ as well when using it.
+*/
+#if defined(_IRR_ANDROID_PLATFORM_)
 #define _IRR_COMPILE_WITH_OGLES1_
+#endif
 #ifdef NO_IRR_COMPILE_WITH_OGLES1_
 #undef _IRR_COMPILE_WITH_OGLES1_
 #endif
 
+#ifdef _IRR_COMPILE_WITH_OGLES1_
+//! Define _IRR_OGLES1_USE_KHRONOS_API_HEADERS_ to use the OpenGL ES headers from the Debian Khronos-api package
+//#define _IRR_OGLES1_USE_KHRONOS_API_HEADERS_
+#endif
+
 //! Define required options for OpenGL ES 1.1 drivers.
 #if defined(_IRR_COMPILE_WITH_OGLES1_)
 #if defined(_IRR_COMPILE_WITH_WINDOWS_DEVICE_) || defined(_IRR_COMPILE_WITH_X11_DEVICE_) || defined(_IRR_COMPILE_WITH_ANDROID_DEVICE_)
diff --git a/source/Irrlicht/COGLESCommon.h b/source/Irrlicht/COGLESCommon.h
index c7988f7a..7086522f 100644
--- a/source/Irrlicht/COGLESCommon.h
+++ b/source/Irrlicht/COGLESCommon.h
@@ -12,14 +12,14 @@
 #if defined(_IRR_COMPILE_WITH_IOS_DEVICE_)
 #include <OpenGLES/ES1/gl.h>
 #include <OpenGLES/ES1/glext.h>
-#elif defined(_IRR_COMPILE_WITH_ANDROID_DEVICE_)
-#include <GLES/gl.h>
-#include <GLES/glext.h>
-#include <EGL/eglplatform.h>
-#else
+#elif defined(_IRR_OGLES1_USE_KHRONOS_API_HEADERS_)
 #include <khronos-api/GLES/gl.h>
 #include <EGL/eglplatform.h>
 typedef char GLchar;
+#else	// or only when defined(_IRR_COMPILE_WITH_ANDROID_DEVICE_) ?
+#include <GLES/gl.h>
+#include <GLES/glext.h>
+#include <EGL/eglplatform.h>
 #if defined(_IRR_OGLES1_USE_EXTPOINTER_)
 #include "gles-ext.h"
 #endif