Merge pull request rougier#262 from joshuafc/patch-2

generate config.h while compile by cmake variable status, so user can get the macro which exists when build freetype-gl .

CMakeLists.txt

@@ -106,19 +106,20 @@ endif()
 find_package(Freetype REQUIRED)
 
 if(freetype-gl_WITH_GLEW)
-    add_definitions(-DWITH_GLEW=1)
+    set(FREETYPE_GL_USE_GLEW 1)
     find_package(GLEW REQUIRED)
 endif()
 
 if(freetype-gl_WITH_GLAD)
-    add_definitions(-DGL_WITH_GLAD)
+    set(GL_WITH_GLAD 1)
 endif()
 
 include_directories(
     ${OPENGL_INCLUDE_DIRS}
     ${FREETYPE_INCLUDE_DIRS}
     ${CMAKE_CURRENT_SOURCE_DIR}
     ${GLEW_INCLUDE_PATH}
+    ${PROJECT_BINARY_DIR}
 )
 
 if(MSVC)
@@ -127,9 +128,14 @@ if(MSVC)
 endif(MSVC)
 
 if(freetype-gl_USE_VAO)
-    add_definitions(-DFREETYPE_GL_USE_VAO)
+    set(FREETYPE_GL_USE_VAO 1)
 endif(freetype-gl_USE_VAO)
 
+configure_file (
+        "${PROJECT_SOURCE_DIR}/cmake/config.h.in"
+        "${PROJECT_BINARY_DIR}/config.h"
+)
+
 set(FREETYPE_GL_HDR
     distance-field.h
     edtaa3func.h
@@ -148,6 +154,7 @@ set(FREETYPE_GL_HDR
     vertex-attribute.h
     vertex-buffer.h
     freetype-gl-errdef.h
+    ${PROJECT_BINARY_DIR}/config.h
 )
 
 set(FREETYPE_GL_SRC

cmake/config.h.in

@@ -0,0 +1,5 @@
+// config.h is generated by cmake while build freetype-gl from template config.h.in by cmake variable status
+
+#cmakedefine FREETYPE_GL_USE_GLEW @FREETYPE_GL_USE_GLEW@
+#cmakedefine FREETYPE_GL_USE_VAO @FREETYPE_GL_USE_VAO@
+#cmakedefine GL_WITH_GLAD @GL_WITH_GLAD@

opengl.h

@@ -5,6 +5,7 @@
  */
 #ifndef __OPEN_GL_H__
 #define __OPEN_GL_H__
+#include "config.h"
 
 #if defined(GL_WITH_GLAD)
 #   include <glad/glad.h>
@@ -30,7 +31,7 @@
 #    include <GLES2/gl2.h>
 #  endif
 #else
-#if defined(WITH_GLEW)
+#if defined(FREETYPE_GL_USE_GLEW)
 #  include <GL/glew.h>
 #endif
 #  include <GL/gl.h>