add iOS support

engine/pch.h

@@ -4,14 +4,28 @@
 #define USE_SAMPLER 1
 
 #ifdef __APPLE__
-    #include <OpenGL/gl3.h>
-    #include <OpenGL/gl3ext.h>
+
+    #include "TargetConditionals.h"
+    #if TARGET_OS_IPHONE && TARGET_IPHONE_SIMULATOR
+        #define TARGET_OS_IOS 1
+        #define __IOS__ 1
+        #include <CoreFoundation/CoreFoundation.h>
+        #include <OpenGLES/ES3/gl.h>
+        #include <OpenGLES/ES3/glext.h>
+        #define SHADER_VERSION "#version 300 es\n"
+    #elif TARGET_OS_IPHONE
+    // define something for iphone
+    #else
+        #define TARGET_OS_OSX 1
+        #include <OpenGL/gl3.h>
+        #include <OpenGL/gl3ext.h>
+        #define SHADER_VERSION "#version 150\n"
+    #endif
+
     #include <sys/stat.h>
     #include <sys/types.h>
     #include <dirent.h>
 
-    #define SHADER_VERSION "#version 150\n"
-
 #elif __ANDROID__
     #include <EGL/egl.h>
     #include <EGL/eglext.h>
@@ -22,7 +36,7 @@
     #include <android/log.h>
     #include <android_native_app_glue.h>
 
-#define SHADER_VERSION "#version 300 es\n"
+    #define SHADER_VERSION "#version 300 es\n"
 
 #elif _WIN32
     #define _USE_MATH_DEFINES