Replaced deprecated gluPerspective()

src/SDLSystem.cpp

 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <cmath>
 
 #ifdef MEMEORY_TEST
 #   include "memeory_test.h"
 
 	glMatrixMode(GL_PROJECTION);
 	glLoadIdentity();
-	gluPerspective(m_fovY, aspect, m_clipNear, m_clipFar);
+
+    // gluPerspective is deprecated!
+	// gluPerspective(m_fovY, aspect, m_clipNear, m_clipFar);
+    // fix: http://stackoverflow.com/a/2417756
+    GLfloat fH = tan(float(m_fovY / 360.0f * 3.14159f) ) * m_clipNear;
+    GLfloat fW = fH * aspect;
+    glFrustum(-fW, fW, -fH, fH, m_clipNear, m_clipFar);
 
 	glMatrixMode(GL_MODELVIEW);
 	glLoadIdentity();

src/System.cpp

 #include <sys/types.h>
 #include <string.h>
 #include <stdarg.h>
+#include <cmath>
 
 #ifdef USING_OPENGL
 #ifdef __APPLE__
 	glLoadIdentity();
 
 	// Adjust clipping
-	gluPerspective(m_fovY, ((GLdouble)w)/((GLdouble)h), m_clipNear, m_clipFar);
+    // gluPerspective is deprecated!
+	// gluPerspective(m_fovY, ((GLdouble)w)/((GLdouble)h), m_clipNear, m_clipFar);
+    // Fix: http://stackoverflow.com/a/2417756
+    GLfloat fH = tan(float(m_fovY / 360.0f * 3.14159f)) * m_clipNear;
+    GLfloat fW = fH * ((GLdouble)w)/((GLdouble)h);
+    glFrustum(-fW, fW, -fH, fH, m_clipNear, m_clipFar);
+
 	glMatrixMode(GL_MODELVIEW);
 }