From 526a9e4b66abaf83eb6b1aaa3e93375acd87b830 Mon Sep 17 00:00:00 2001
From: sfan5 <sfan5@live.de>
Date: Wed, 24 Jul 2019 23:15:28 +0200
Subject: [PATCH] Let ENABLE_GLES appear in cmake_config.h and change its
 functionality

---
 README.md             |  2 +-
 src/CMakeLists.txt    | 31 ++++++++++++++++++++++---------
 src/cmake_config.h.in |  1 +
 3 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/README.md b/README.md
index 83676a866..fcc7fec67 100644
--- a/README.md
+++ b/README.md
@@ -220,7 +220,7 @@ General options and their default values:
     ENABLE_CURSES=ON           - Build with (n)curses; Enables a server side terminal (command line option: --terminal)
     ENABLE_FREETYPE=ON         - Build with FreeType2; Allows using TTF fonts
     ENABLE_GETTEXT=ON          - Build with Gettext; Allows using translations
-    ENABLE_GLES=OFF            - Search for Open GLES headers & libraries and use them
+    ENABLE_GLES=OFF            - Build for OpenGL ES instead of OpenGL (requires support by Irrlicht)
     ENABLE_LEVELDB=ON          - Build with LevelDB; Enables use of LevelDB map backend
     ENABLE_POSTGRESQL=ON       - Build with libpq; Enables use of PostgreSQL map backend (PostgreSQL 9.5 or greater recommended)
     ENABLE_REDIS=ON            - Build with libhiredis; Enables use of Redis map backend
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index cb920e875..2627a0b97 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -102,10 +102,18 @@ if(BUILD_CLIENT AND ENABLE_SOUND)
 endif()
 
 
-option(ENABLE_GLES "Enable OpenGL ES support" FALSE)
+option(ENABLE_GLES "Use OpenGL ES instead of OpenGL" FALSE)
 mark_as_advanced(ENABLE_GLES)
 if(ENABLE_GLES)
-	find_package(OpenGLES2)
+	find_package(OpenGLES2 REQUIRED)
+elseif()
+	if(NOT WIN32) # Unix probably
+		set(OPENGL_GL_PREFERENCE "LEGACY" CACHE STRING
+			"See CMake Policy CMP0072 for reference. GLVND is broken on some nvidia setups")
+		set(OpenGL_GL_PREFERENCE ${OPENGL_GL_PREFERENCE})
+
+		find_package(OpenGL REQUIRED)
+	endif()
 endif()
 
 
@@ -275,11 +283,6 @@ else()
 			find_package(X11 REQUIRED)
 		endif(NOT HAIKU)
 
-		set(OPENGL_GL_PREFERENCE "LEGACY" CACHE STRING
-			"See CMake Policy CMP0072 for reference. GLVND is broken on some nvidia setups")
-		set(OpenGL_GL_PREFERENCE ${OPENGL_GL_PREFERENCE})
-
-		find_package(OpenGL REQUIRED)
 		find_package(JPEG REQUIRED)
 		find_package(BZip2 REQUIRED)
 		find_package(PNG REQUIRED)
@@ -519,7 +522,6 @@ if(BUILD_CLIENT)
 		${PROJECT_NAME}
 		${ZLIB_LIBRARIES}
 		${IRRLICHT_LIBRARY}
-		${OPENGL_LIBRARIES}
 		${JPEG_LIBRARIES}
 		${BZIP2_LIBRARIES}
 		${PNG_LIBRARIES}
@@ -529,7 +531,6 @@ if(BUILD_CLIENT)
 		${LUA_LIBRARY}
 		${GMP_LIBRARY}
 		${JSON_LIBRARY}
-		${OPENGLES2_LIBRARIES}
 		${PLATFORM_LIBS}
 		${CLIENT_PLATFORM_LIBS}
 	)
@@ -543,6 +544,18 @@ if(BUILD_CLIENT)
 			${client_LIBS}
 		)
 	endif()
+	if(ENABLE_GLES)
+		target_link_libraries(
+			${PROJECT_NAME}
+			${OPENGLES2_LIBRARIES}
+			${EGL_LIBRARIES}
+		)
+	else()
+		target_link_libraries(
+			${PROJECT_NAME}
+			${OPENGL_LIBRARIES}
+		)
+	endif()
 	if(USE_GETTEXT)
 		target_link_libraries(
 			${PROJECT_NAME}
diff --git a/src/cmake_config.h.in b/src/cmake_config.h.in
index 81b8c2695..cb54cb488 100644
--- a/src/cmake_config.h.in
+++ b/src/cmake_config.h.in
@@ -26,6 +26,7 @@
 #cmakedefine01 USE_SPATIAL
 #cmakedefine01 USE_SYSTEM_GMP
 #cmakedefine01 USE_REDIS
+#cmakedefine01 ENABLE_GLES
 #cmakedefine01 HAVE_ENDIAN_H
 #cmakedefine01 CURSES_HAVE_CURSES_H
 #cmakedefine01 CURSES_HAVE_NCURSES_H