diff --git a/Makefile b/Makefile
index 124b70a..e26ddfc 100755
--- a/Makefile
+++ b/Makefile
@@ -1,21 +1,38 @@
-CC = g++
-CFLAGS = -Iinclude -Wall -g
-LDFLAGS = -lSDL2 -lGL -lGLEW
+CC=clang++
+current_directory=$(shell pwd)
 
-SRC = src/main.cpp src/sdl.cpp
-OBJ = $(SRC:.cpp=.o)
-EXEC = opengl-app
+FRAMEWORKS=-framework OpenGL -framework Cocoa -framework IOKit -framework CoreVideo
 
-all: $(EXEC)
+CFLAGS=-std=c++11
+CFLAGS+=-I$(current_directory)
+CFLAGS+=-I$(current_directory)/../external
+
+LDFLAGS=-L$(current_directory)/../lib
+LDFLAGS+=-lglfw3
+LDFLAGS+=-lGLEW
+
+SOURCES=$(wildcard *.cpp)
+OBJECTS=$(patsubst %.cpp, %.o, $(SOURCES))
 
-$(EXEC): $(OBJ)
-	$(CC) -o $@ $^ $(LDFLAGS)
 
 %.o: %.cpp
-	$(CC) $(CFLAGS) -c $< -o $@
+	$(CC) $(CFLAGS) -c -o $@ $^
 
+default: debug
+
+app: $(OBJECTS)
+	$(CC) $(CFLAGS) $(LDFLAGS) $(FRAMEWORKS) -o $@ $(OBJECTS)
+
+# Define debug and -g enables debug symbols
+debug: CFLAGS+=-DDEBUG -g
+debug: app
+
+release: app
+
+.PHONY: clean
 clean:
-	rm -f $(OBJ) $(EXEC)
+	rm -f *.o app
 
-run: all
-	./$(EXEC)
\ No newline at end of file
+.PHONY: debugger
+debugger: debug
+	PATH=/usr/bin /usr/bin/lldb ./app
\ No newline at end of file
diff --git a/src/IndexBuffer.cpp b/src/IndexBuffer.cpp
index 74c7fe6..1cf66db 100644
--- a/src/IndexBuffer.cpp
+++ b/src/IndexBuffer.cpp
@@ -4,7 +4,7 @@
 IndexBuffer::IndexBuffer(const unsigned int* data, unsigned int count)
   : m_Count(count)
 {
-  //ASSERT(sizeof(unsigned int) == sizeof(GLuint));
+  ASSERT(sizeof(unsigned int) == sizeof(GLuint));
   //
   GLCall(glGenBuffers(1, &m_RendererID));
   GLCall(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_RendererID)); //select buffer called 'buffer'
diff --git a/src/IndexBuffer.h b/src/IndexBuffer.h
index 3b663e4..d37125f 100644
--- a/src/IndexBuffer.h
+++ b/src/IndexBuffer.h
@@ -2,9 +2,6 @@
 
 class IndexBuffer 
 {
-private:
-    unsigned int m_RendererID;
-    unsigned int m_Count;
 public:
   IndexBuffer(const unsigned int* data, unsigned int count);
   ~IndexBuffer();
@@ -13,4 +10,7 @@ public:
   void Unbind() const;
 
   inline unsigned int GetCount() const { return m_Count; }
+private:
+    unsigned int m_RendererID;
+    unsigned int m_Count;
 };
diff --git a/src/Renderer.h b/src/Renderer.h
index 4bc906f..8de98da 100644
--- a/src/Renderer.h
+++ b/src/Renderer.h
@@ -32,6 +32,6 @@
   x;\
   ASSERT(GLLogCall())
 
-
+#define INT2VOIDP(i) (void*)(uintptr_t)(i)
 void GLClearError();
 bool GLLogCall();
diff --git a/src/VertexArray.cpp b/src/VertexArray.cpp
index c933449..d33885e 100644
--- a/src/VertexArray.cpp
+++ b/src/VertexArray.cpp
@@ -1,7 +1,5 @@
 #include "VertexArray.h"
-#include "VertexBuffer.h"
 #include "Renderer.h"
-#include "VertexBufferLayout.h"
 
 VertexArray::VertexArray()
 {
@@ -21,13 +19,13 @@ void VertexArray::AddBuffer(const VertexBuffer& vb, const VertexBufferLayout& la
 {
   Bind();
   vb.Bind();
-  const auto& elements = layout.GetElements();
-  GLsizei offset = 0;
+  const std::vector<VertexBufferElement> elements = layout.GetElements();
+  unsigned int offset = 0;
   for (unsigned int i = 0; i < elements.size(); i++) {
-    const auto& element = elements[i];
-    GLCall(glEnableVertexAttribArray(i));
-    GLCall(glVertexAttribPointer(i, element.count, element.type, element.normalized, layout.GetStride(), (const void*)offset));
-    offset += element.count * VertexBufferElement::GetSizeOfType(element.type);
+      const auto& element = elements[i];
+      GLCall(glEnableVertexAttribArray(i));
+      GLCall( glVertexAttribPointer(i, element.count, element.type, element.normalized,layout.GetStride(), INT2VOIDP(offset)) );
+      offset += element.count * VertexBufferElement::GetSizeOfType(element.type);
     }
 }
 
diff --git a/src/VertexBufferLayout.h b/src/VertexBufferLayout.h
index 27b18ba..dff1701 100644
--- a/src/VertexBufferLayout.h
+++ b/src/VertexBufferLayout.h
@@ -1,6 +1,7 @@
 #ifndef VERTEXBUFFERLAYOUT_H
 #define VERTEXBUFFERLAYOUT_H
 #include <vector>
+#include <GL/glew.h>
 #include "Renderer.h"
 struct VertexBufferElement {
     unsigned int type;
diff --git a/src/sdl.cpp b/src/sdl.cpp
index bf76e53..0602e2f 100644
--- a/src/sdl.cpp
+++ b/src/sdl.cpp
@@ -13,6 +13,11 @@
 #include <string>
 #include <sstream>
 
+#include "Renderer.h"
+#include "VertexBuffer.h"
+#include "VertexArray.h"
+#include "IndexBuffer.h"
+
 #if defined(_MSC_VER)  // Microsoft Visual C++
     #include <intrin.h>
     #define DEBUG_BREAK() __debugbreak()
@@ -58,7 +63,7 @@ SdlWindow::SdlWindow(const char* title, int width, int height)
     r(0.5f),
     location(),
     increment(0.05f),
-    ib(nullptr, 0)
+    ib(nullptr,6)
 {
   // 1. Set attributes
     SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
@@ -115,24 +120,30 @@ SdlWindow::SdlWindow(const char* title, int width, int height)
       2, 3, 0
   };
 
-  unsigned int vao; //vertext array object
-  GLCall(glGenVertexArrays(1, &vao));
-  GLCall(glBindVertexArray(vao));
+  //unsigned int vao; //vertext array object
+  //GLCall(glGenVertexArrays(1, &vao));
+  //GLCall(glBindVertexArray(vao));
 
   VertexArray va;
   VertexBuffer vb(positions, 4 * 2 * sizeof(float));
+  ib = IndexBuffer(indices, 6);
+
   VertexBufferLayout layout;
   layout.Push<float>(2);
+
   va.AddBuffer(vb, layout);
   
-  IndexBuffer ib(indices, 6); 
-
   ShaderProgramSource source = parseShader("res/shaders/Basic.shader");
+
+  std::cout << "VERTEX" << std::endl << source.VertexSource << std::endl;
+  std::cout << "FRAGMENT" << std::endl << source.FragmentSource << std::endl;
+
   unsigned int m_ShaderID = createShader(source.VertexSource, source.FragmentSource);
   GLCall(glUseProgram(m_ShaderID));
   
-  GLCall(int location = glGetUniformLocation(m_ShaderID, "u_Color"));
+  GLCall(unsigned int location = glGetUniformLocation(m_ShaderID, "u_Color"));
   ASSERT(location != -1); // -1 is an error
+
   GLCall(glUniform4f(location, 0.8f, 0.3f, 0.8f, 1.0f));
 
   GLCall(glBindVertexArray(0));
@@ -165,7 +176,6 @@ SdlWindow::~SdlWindow() {
         shader = 0;
     }
 
-  delete &ib;
   SDL_Quit();
 }