From d0246cfdcce3268e02ae240b6185f45875a97324 Mon Sep 17 00:00:00 2001
From: sfan5 <sfan5@live.de>
Date: Thu, 25 Jul 2019 19:55:40 +0200
Subject: [PATCH] Clean up FindOpenGLES2.cmake

---
 cmake/Modules/FindOpenGLES2.cmake | 86 +++++++++----------------------
 1 file changed, 24 insertions(+), 62 deletions(-)

diff --git a/cmake/Modules/FindOpenGLES2.cmake b/cmake/Modules/FindOpenGLES2.cmake
index a8622f3b2..a47126705 100644
--- a/cmake/Modules/FindOpenGLES2.cmake
+++ b/cmake/Modules/FindOpenGLES2.cmake
@@ -1,6 +1,4 @@
 #-------------------------------------------------------------------
-# This file is stolen from part of the CMake build system for OGRE (Object-oriented Graphics Rendering Engine) http://www.ogre3d.org/
-#
 # The contents of this file are placed in the public domain. Feel
 # free to make use of it in any way you like.
 #-------------------------------------------------------------------
@@ -16,26 +14,18 @@
 #  EGL_INCLUDE_DIR  - the EGL include directory
 #  EGL_LIBRARIES    - Link these to use EGL
 
-# Win32, Apple, and Android are not tested!
+# Win32 and Apple are not tested!
 # Linux tested and works
 
 if(WIN32)
-	if(CYGWIN)
-		find_path(OPENGLES2_INCLUDE_DIR GLES2/gl2.h)
-		find_library(OPENGLES2_LIBRARY libGLESv2)
-	else()
-		if(BORLAND)
-			set(OPENGLES2_LIBRARY import32 CACHE STRING "OpenGL ES 2.x library for Win32")
-		else()
-			# TODO
-			# set(OPENGLES_LIBRARY ${SOURCE_DIR}/Dependencies/lib/release/libGLESv2.lib CACHE STRING "OpenGL ES 2.x library for win32"
-		endif()
-	endif()
+	find_path(OPENGLES2_INCLUDE_DIR GLES2/gl2.h)
+	find_library(OPENGLES2_LIBRARY libGLESv2)
 elseif(APPLE)
 	create_search_paths(/Developer/Platforms)
 	findpkg_framework(OpenGLES2)
 	set(OPENGLES2_LIBRARY "-framework OpenGLES")
 else()
+	# Unix
 	find_path(OPENGLES2_INCLUDE_DIR GLES2/gl2.h
 		PATHS /usr/openwin/share/include
 			/opt/graphics/OpenGL/include
@@ -47,55 +37,34 @@ else()
 		NAMES GLESv2
 		PATHS /opt/graphics/OpenGL/lib
 			/usr/openwin/lib
-			/usr/shlib /usr/X11R6/lib
+			/usr/X11R6/lib
 			/usr/lib
 	)
 
-	if(NOT BUILD_ANDROID)
-		find_path(EGL_INCLUDE_DIR EGL/egl.h
-			PATHS /usr/openwin/share/include
-				/opt/graphics/OpenGL/include
-				/usr/X11R6/include
-				/usr/include
-		)
+	include(FindPackageHandleStandardArgs)
+	find_package_handle_standard_args(OPENGLES2 DEFAULT_MSG OPENGLES2_LIBRARY OPENGLES2_INCLUDE_DIR)
 
-		find_library(EGL_LIBRARY
-			NAMES EGL
-			PATHS /opt/graphics/OpenGL/lib
-				/usr/openwin/lib
-				/usr/shlib
-				/usr/X11R6/lib
-				/usr/lib
-		)
+	find_path(EGL_INCLUDE_DIR EGL/egl.h
+		PATHS /usr/openwin/share/include
+			/opt/graphics/OpenGL/include
+			/usr/X11R6/include
+			/usr/include
+	)
 
-		# On Unix OpenGL usually requires X11.
-		# It doesn't require X11 on OSX.
+	find_library(EGL_LIBRARY
+		NAMES EGL
+		PATHS /opt/graphics/OpenGL/lib
+			/usr/openwin/lib
+			/usr/X11R6/lib
+			/usr/lib
+	)
 
-		if(OPENGLES2_LIBRARY)
-			if(NOT X11_FOUND)
-				include(FindX11)
-			endif()
-			if(X11_FOUND)
-				set(OPENGLES2_LIBRARIES ${X11_LIBRARIES})
-			endif()
-		endif()
-	endif()
+	include(FindPackageHandleStandardArgs)
+	find_package_handle_standard_args(EGL DEFAULT_MSG EGL_LIBRARY EGL_INCLUDE_DIR)
 endif()
 
-set(OPENGLES2_LIBRARIES ${OPENGLES2_LIBRARIES} ${OPENGLES2_LIBRARY})
-
-if(BUILD_ANDROID)
-	if(OPENGLES2_LIBRARY)
-		set(EGL_LIBRARIES)
-		set(OPENGLES2_FOUND TRUE)
-	endif()
-else()
-	if(OPENGLES2_LIBRARY AND EGL_LIBRARY)
-		set(OPENGLES2_LIBRARIES ${OPENGLES2_LIBRARY} ${OPENGLES2_LIBRARIES})
-		set(EGL_LIBRARIES ${EGL_LIBRARY} ${EGL_LIBRARIES})
-		set(OPENGLES2_FOUND TRUE)
-	endif()
-endif()
+set(OPENGLES2_LIBRARIES ${OPENGLES2_LIBRARY})
+set(EGL_LIBRARIES ${EGL_LIBRARY})
 
 mark_as_advanced(
 	OPENGLES2_INCLUDE_DIR
@@ -103,10 +72,3 @@ mark_as_advanced(
 	EGL_INCLUDE_DIR
 	EGL_LIBRARY
 )
-
-if(OPENGLES2_FOUND)
-	message(STATUS "Found system OpenGL ES 2 library: ${OPENGLES2_LIBRARIES}")
-else()
-	set(OPENGLES2_LIBRARIES "")
-endif()
-