diff --git a/includes/learnopengl/shader_s.h b/includes/learnopengl/shader_s.h
index 93906d3..6c46f05 100644
--- a/includes/learnopengl/shader_s.h
+++ b/includes/learnopengl/shader_s.h
@@ -32,13 +32,13 @@ public:
             std::stringstream vShaderStream, fShaderStream;
             // read file's buffer contents into streams
             vShaderStream << vShaderFile.rdbuf();
-            fShaderStream << fShaderFile.rdbuf();		
+            fShaderStream << fShaderFile.rdbuf();
             // close file handlers
             vShaderFile.close();
             fShaderFile.close();
             // convert stream into string
-            vertexCode = vShaderStream.str();
-            fragmentCode = fShaderStream.str();			
+            vertexCode   = vShaderStream.str();
+            fragmentCode = fShaderStream.str();
         }
         catch (std::ifstream::failure e)
         {
@@ -96,10 +96,10 @@ public:
 private:
     // utility function for checking shader compilation/linking errors.
     // ------------------------------------------------------------------------
-    void checkCompileErrors(GLuint shader, std::string type)
+    void checkCompileErrors(unsigned int shader, std::string type)
     {
-        GLint success;
-        GLchar infoLog[1024];
+        int success;
+        char infoLog[1024];
         if (type != "PROGRAM")
         {
             glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
diff --git a/src/1.getting_started/1.1.hello_window/hello_window.cpp b/src/1.getting_started/1.1.hello_window/hello_window.cpp
index ee6d191..4a5f6f6 100644
--- a/src/1.getting_started/1.1.hello_window/hello_window.cpp
+++ b/src/1.getting_started/1.1.hello_window/hello_window.cpp
@@ -6,6 +6,10 @@
 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void processInput(GLFWwindow *window);
 
+// settings
+const unsigned int SCR_WIDTH = 1280;
+const unsigned int SCR_HEIGHT = 720;
+
 int main()
 {
     // glfw: initialize and configure
@@ -18,14 +22,14 @@ int main()
 
     // glfw window creation
     // --------------------
-    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
-    glfwMakeContextCurrent(window);
+    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
     if (window == NULL)
     {
         std::cout << "Failed to create GLFW window" << std::endl;
         glfwTerminate();
         return -1;
     }
+    glfwMakeContextCurrent(window);
     glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
     // glad: load all OpenGL function pointers
diff --git a/src/1.getting_started/1.2.hello_window_clear/hello_window_clear.cpp b/src/1.getting_started/1.2.hello_window_clear/hello_window_clear.cpp
index 30ecaee..dd98fd4 100644
--- a/src/1.getting_started/1.2.hello_window_clear/hello_window_clear.cpp
+++ b/src/1.getting_started/1.2.hello_window_clear/hello_window_clear.cpp
@@ -6,6 +6,10 @@
 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void processInput(GLFWwindow *window);
 
+// settings
+const unsigned int SCR_WIDTH = 1280;
+const unsigned int SCR_HEIGHT = 720;
+
 int main()
 {
     // glfw: initialize and configure
@@ -18,14 +22,14 @@ int main()
 
     // glfw window creation
     // --------------------
-    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
-    glfwMakeContextCurrent(window);
+    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
     if (window == NULL)
     {
         std::cout << "Failed to create GLFW window" << std::endl;
         glfwTerminate();
         return -1;
     }
+    glfwMakeContextCurrent(window);
     glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
     // glad: load all OpenGL function pointers
diff --git a/src/1.getting_started/2.1.hello_triangle/hello_triangle.cpp b/src/1.getting_started/2.1.hello_triangle/hello_triangle.cpp
index 8e5b515..ecfb59c 100644
--- a/src/1.getting_started/2.1.hello_triangle/hello_triangle.cpp
+++ b/src/1.getting_started/2.1.hello_triangle/hello_triangle.cpp
@@ -6,6 +6,10 @@
 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void processInput(GLFWwindow *window);
 
+// settings
+const unsigned int SCR_WIDTH = 1280;
+const unsigned int SCR_HEIGHT = 720;
+
 const char *vertexShaderSource = "#version 330 core\n"
     "layout (location = 0) in vec3 aPos;\n"
     "void main()\n"
@@ -13,10 +17,10 @@ const char *vertexShaderSource = "#version 330 core\n"
     "   gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
     "}\0";
 const char *fragmentShaderSource = "#version 330 core\n"
-    "out vec4 fragColor;\n"
+    "out vec4 FragColor;\n"
     "void main()\n"
     "{\n"
-    "   fragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
+    "   FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
     "}\n\0";
 
 int main()
@@ -31,14 +35,14 @@ int main()
 
     // glfw window creation
     // --------------------
-    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
-    glfwMakeContextCurrent(window);
+    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
     if (window == NULL)
     {
         std::cout << "Failed to create GLFW window" << std::endl;
         glfwTerminate();
         return -1;
     }
+    glfwMakeContextCurrent(window);
     glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
     // glad: load all OpenGL function pointers
diff --git a/src/1.getting_started/2.2.hello_triangle_indexed/hello_triangle_indexed.cpp b/src/1.getting_started/2.2.hello_triangle_indexed/hello_triangle_indexed.cpp
index cd2a2a0..47a846f 100644
--- a/src/1.getting_started/2.2.hello_triangle_indexed/hello_triangle_indexed.cpp
+++ b/src/1.getting_started/2.2.hello_triangle_indexed/hello_triangle_indexed.cpp
@@ -6,6 +6,10 @@
 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void processInput(GLFWwindow *window);
 
+// settings
+const unsigned int SCR_WIDTH = 1280;
+const unsigned int SCR_HEIGHT = 720;
+
 const char *vertexShaderSource = "#version 330 core\n"
     "layout (location = 0) in vec3 aPos;\n"
     "void main()\n"
@@ -13,10 +17,10 @@ const char *vertexShaderSource = "#version 330 core\n"
     "   gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
     "}\0";
 const char *fragmentShaderSource = "#version 330 core\n"
-    "out vec4 fragColor;\n"
+    "out vec4 FragColor;\n"
     "void main()\n"
     "{\n"
-    "   fragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
+    "   FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
     "}\n\0";
 
 int main()
@@ -31,14 +35,14 @@ int main()
 
     // glfw window creation
     // --------------------
-    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
-    glfwMakeContextCurrent(window);
+    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
     if (window == NULL)
     {
         std::cout << "Failed to create GLFW window" << std::endl;
         glfwTerminate();
         return -1;
     }
+    glfwMakeContextCurrent(window);
     glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
     // glad: load all OpenGL function pointers
diff --git a/src/1.getting_started/2.3.hello_triangle_exercise1/hello_triangle_exercise1.cpp b/src/1.getting_started/2.3.hello_triangle_exercise1/hello_triangle_exercise1.cpp
index a6eefa7..40ee6e9 100644
--- a/src/1.getting_started/2.3.hello_triangle_exercise1/hello_triangle_exercise1.cpp
+++ b/src/1.getting_started/2.3.hello_triangle_exercise1/hello_triangle_exercise1.cpp
@@ -6,6 +6,10 @@
 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void processInput(GLFWwindow *window);
 
+// settings
+const unsigned int SCR_WIDTH = 1280;
+const unsigned int SCR_HEIGHT = 720;
+
 const char *vertexShaderSource = "#version 330 core\n"
     "layout (location = 0) in vec3 aPos;\n"
     "void main()\n"
@@ -13,10 +17,10 @@ const char *vertexShaderSource = "#version 330 core\n"
     "   gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
     "}\0";
 const char *fragmentShaderSource = "#version 330 core\n"
-    "out vec4 fragColor;\n"
+    "out vec4 FragColor;\n"
     "void main()\n"
     "{\n"
-    "   fragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
+    "   FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
     "}\n\0";
 
 int main()
@@ -31,14 +35,14 @@ int main()
 
     // glfw window creation
     // --------------------
-    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
-    glfwMakeContextCurrent(window);
+    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
     if (window == NULL)
     {
         std::cout << "Failed to create GLFW window" << std::endl;
         glfwTerminate();
         return -1;
     }
+    glfwMakeContextCurrent(window);
     glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
     // glad: load all OpenGL function pointers
diff --git a/src/1.getting_started/2.4.hello_triangle_exercise2/hello_triangle_exercise2.cpp b/src/1.getting_started/2.4.hello_triangle_exercise2/hello_triangle_exercise2.cpp
index 994552e..7d57d7c 100644
--- a/src/1.getting_started/2.4.hello_triangle_exercise2/hello_triangle_exercise2.cpp
+++ b/src/1.getting_started/2.4.hello_triangle_exercise2/hello_triangle_exercise2.cpp
@@ -6,6 +6,10 @@
 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void processInput(GLFWwindow *window);
 
+// settings
+const unsigned int SCR_WIDTH = 1280;
+const unsigned int SCR_HEIGHT = 720;
+
 const char *vertexShaderSource = "#version 330 core\n"
     "layout (location = 0) in vec3 aPos;\n"
     "void main()\n"
@@ -13,10 +17,10 @@ const char *vertexShaderSource = "#version 330 core\n"
     "   gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
     "}\0";
 const char *fragmentShaderSource = "#version 330 core\n"
-    "out vec4 fragColor;\n"
+    "out vec4 FragColor;\n"
     "void main()\n"
     "{\n"
-    "   fragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
+    "   FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
     "}\n\0";
 
 int main()
@@ -31,14 +35,14 @@ int main()
 
     // glfw window creation
     // --------------------
-    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
-    glfwMakeContextCurrent(window);
+    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
     if (window == NULL)
     {
         std::cout << "Failed to create GLFW window" << std::endl;
         glfwTerminate();
         return -1;
     }
+    glfwMakeContextCurrent(window);
     glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
     // glad: load all OpenGL function pointers
diff --git a/src/1.getting_started/2.5.hello_triangle_exercise3/hello_triangle_exercise3.cpp b/src/1.getting_started/2.5.hello_triangle_exercise3/hello_triangle_exercise3.cpp
index 521d36e..af5471a 100644
--- a/src/1.getting_started/2.5.hello_triangle_exercise3/hello_triangle_exercise3.cpp
+++ b/src/1.getting_started/2.5.hello_triangle_exercise3/hello_triangle_exercise3.cpp
@@ -6,6 +6,10 @@
 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void processInput(GLFWwindow *window);
 
+// settings
+const unsigned int SCR_WIDTH = 1280;
+const unsigned int SCR_HEIGHT = 720;
+
 const char *vertexShaderSource = "#version 330 core\n"
     "layout (location = 0) in vec3 aPos;\n"
     "void main()\n"
@@ -13,16 +17,16 @@ const char *vertexShaderSource = "#version 330 core\n"
     "   gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
     "}\0";
 const char *fragmentShader1Source = "#version 330 core\n"
-    "out vec4 fragColor;\n"
+    "out vec4 FragColor;\n"
     "void main()\n"
     "{\n"
-    "   fragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
+    "   FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
     "}\n\0";
 const char *fragmentShader2Source = "#version 330 core\n"
-    "out vec4 fragColor;\n"
+    "out vec4 FragColor;\n"
     "void main()\n"
     "{\n"
-    "   fragColor = vec4(1.0f, 1.0f, 0.0f, 1.0f);\n"
+    "   FragColor = vec4(1.0f, 1.0f, 0.0f, 1.0f);\n"
     "}\n\0";
 
 
@@ -38,14 +42,14 @@ int main()
 
     // glfw window creation
     // --------------------
-    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
-    glfwMakeContextCurrent(window);
+    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
     if (window == NULL)
     {
         std::cout << "Failed to create GLFW window" << std::endl;
         glfwTerminate();
         return -1;
     }
+    glfwMakeContextCurrent(window);
     glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
     // glad: load all OpenGL function pointers
diff --git a/src/1.getting_started/3.1.shaders_uniform/shaders_uniform.cpp b/src/1.getting_started/3.1.shaders_uniform/shaders_uniform.cpp
index 0a703da..d4b3139 100644
--- a/src/1.getting_started/3.1.shaders_uniform/shaders_uniform.cpp
+++ b/src/1.getting_started/3.1.shaders_uniform/shaders_uniform.cpp
@@ -6,6 +6,10 @@
 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void processInput(GLFWwindow *window);
 
+// settings
+const unsigned int SCR_WIDTH = 1280;
+const unsigned int SCR_HEIGHT = 720;
+
 const char *vertexShaderSource ="#version 330 core\n"
     "layout (location = 0) in vec3 aPos;\n"
     "void main()\n"
@@ -14,11 +18,11 @@ const char *vertexShaderSource ="#version 330 core\n"
     "}\0";
 
 const char *fragmentShaderSource = "#version 330 core\n"
-    "out vec4 fragColor;\n"
+    "out vec4 FragColor;\n"
     "uniform vec4 ourColor;\n"
     "void main()\n"
     "{\n"
-    "   fragColor = ourColor;\n"
+    "   FragColor = ourColor;\n"
     "}\n\0";
 
 int main()
@@ -34,13 +38,13 @@ int main()
     // glfw window creation
     // --------------------
     GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
-    glfwMakeContextCurrent(window);
     if (window == NULL)
     {
         std::cout << "Failed to create GLFW window" << std::endl;
         glfwTerminate();
         return -1;
     }
+    glfwMakeContextCurrent(window);
     glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
     // glad: load all OpenGL function pointers
@@ -51,7 +55,6 @@ int main()
         return -1;
     }
 
-
     // build and compile our shader program
     // ------------------------------------
     // vertex shader
diff --git a/src/1.getting_started/3.2.shaders_interpolation/shaders_interpolation.cpp b/src/1.getting_started/3.2.shaders_interpolation/shaders_interpolation.cpp
index fec6bec..e4ad10f 100644
--- a/src/1.getting_started/3.2.shaders_interpolation/shaders_interpolation.cpp
+++ b/src/1.getting_started/3.2.shaders_interpolation/shaders_interpolation.cpp
@@ -6,6 +6,10 @@
 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void processInput(GLFWwindow *window);
 
+// settings
+const unsigned int SCR_WIDTH = 1280;
+const unsigned int SCR_HEIGHT = 720;
+
 const char *vertexShaderSource ="#version 330 core\n"
     "layout (location = 0) in vec3 aPos;\n"
     "layout (location = 1) in vec3 aColor;\n"
@@ -17,11 +21,11 @@ const char *vertexShaderSource ="#version 330 core\n"
     "}\0";
 
 const char *fragmentShaderSource = "#version 330 core\n"
-    "out vec4 fragColor;\n"
+    "out vec4 FragColor;\n"
     "in vec3 ourColor;\n"
     "void main()\n"
     "{\n"
-    "   fragColor = vec4(ourColor, 1.0f);\n"
+    "   FragColor = vec4(ourColor, 1.0f);\n"
     "}\n\0";
 
 int main()
@@ -36,14 +40,14 @@ int main()
 
     // glfw window creation
     // --------------------
-    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
-    glfwMakeContextCurrent(window);
+    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
     if (window == NULL)
     {
         std::cout << "Failed to create GLFW window" << std::endl;
         glfwTerminate();
         return -1;
     }
+    glfwMakeContextCurrent(window);
     glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
     // glad: load all OpenGL function pointers
@@ -54,7 +58,6 @@ int main()
         return -1;
     }
 
-
     // build and compile our shader program
     // ------------------------------------
     // vertex shader
diff --git a/src/1.getting_started/3.3.shaders_class/3.3.shader.fs b/src/1.getting_started/3.3.shaders_class/3.3.shader.fs
index 9f10653..bde012b 100644
--- a/src/1.getting_started/3.3.shaders_class/3.3.shader.fs
+++ b/src/1.getting_started/3.3.shaders_class/3.3.shader.fs
@@ -1,9 +1,9 @@
 #version 330 core
-out vec4 fragColor;
+out vec4 FragColor;
 
 in vec3 ourColor;
 
 void main()
 {
-    fragColor = vec4(ourColor, 1.0f);
+    FragColor = vec4(ourColor, 1.0f);
 }
\ No newline at end of file
diff --git a/src/1.getting_started/3.3.shaders_class/3.3.shader.vs b/src/1.getting_started/3.3.shaders_class/3.3.shader.vs
index a69d96b..feb3bfc 100644
--- a/src/1.getting_started/3.3.shaders_class/3.3.shader.vs
+++ b/src/1.getting_started/3.3.shaders_class/3.3.shader.vs
@@ -6,6 +6,6 @@ out vec3 ourColor;
 
 void main()
 {
-    gl_Position = vec4(aPos, 1.0f);
+    gl_Position = vec4(aPos, 1.0);
     ourColor = aColor;
 }
\ No newline at end of file
diff --git a/src/1.getting_started/3.3.shaders_class/shaders_class.cpp b/src/1.getting_started/3.3.shaders_class/shaders_class.cpp
index f69223c..dcb90e3 100644
--- a/src/1.getting_started/3.3.shaders_class/shaders_class.cpp
+++ b/src/1.getting_started/3.3.shaders_class/shaders_class.cpp
@@ -8,6 +8,10 @@
 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void processInput(GLFWwindow *window);
 
+// settings
+const unsigned int SCR_WIDTH = 1280;
+const unsigned int SCR_HEIGHT = 720;
+
 int main()
 {
     // glfw: initialize and configure
@@ -20,14 +24,14 @@ int main()
 
     // glfw window creation
     // --------------------
-    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
-    glfwMakeContextCurrent(window);
+    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
     if (window == NULL)
     {
         std::cout << "Failed to create GLFW window" << std::endl;
         glfwTerminate();
         return -1;
     }
+    glfwMakeContextCurrent(window);
     glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
     // glad: load all OpenGL function pointers
@@ -38,7 +42,6 @@ int main()
         return -1;
     }
 
-
     // build and compile our shader program
     // ------------------------------------
     Shader ourShader("3.3.shader.vs", "3.3.shader.fs"); // you can name your shader files however you like
@@ -50,7 +53,6 @@ int main()
          0.5f, -0.5f, 0.0f,  1.0f, 0.0f, 0.0f,  // bottom right
         -0.5f, -0.5f, 0.0f,  0.0f, 1.0f, 0.0f,  // bottom left
          0.0f,  0.5f, 0.0f,  0.0f, 0.0f, 1.0f   // top 
-
     };
 
     unsigned int VBO, VAO;
diff --git a/src/1.getting_started/4.1.textures/textures.cpp b/src/1.getting_started/4.1.textures/textures.cpp
index 85ebb85..1a96c88 100644
--- a/src/1.getting_started/4.1.textures/textures.cpp
+++ b/src/1.getting_started/4.1.textures/textures.cpp
@@ -10,6 +10,10 @@
 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void processInput(GLFWwindow *window);
 
+// settings
+const unsigned int SCR_WIDTH = 1280;
+const unsigned int SCR_HEIGHT = 720;
+
 int main()
 {
     // glfw: initialize and configure
@@ -22,14 +26,14 @@ int main()
 
     // glfw window creation
     // --------------------
-    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
-    glfwMakeContextCurrent(window);
+    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
     if (window == NULL)
     {
         std::cout << "Failed to create GLFW window" << std::endl;
         glfwTerminate();
         return -1;
     }
+    glfwMakeContextCurrent(window);
     glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
     // glad: load all OpenGL function pointers
@@ -93,8 +97,8 @@ int main()
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
     // load image, create texture and generate mipmaps
-    int width, height, nrComponents;
-    unsigned char *data = stbi_load(FileSystem::getPath("resources/textures/container.jpg").c_str(), &width, &height, &nrComponents, 0);
+    int width, height, nrChannels;
+    unsigned char *data = stbi_load(FileSystem::getPath("resources/textures/container.jpg").c_str(), &width, &height, &nrChannels, 0);
     if (data)
     {
         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
diff --git a/src/1.getting_started/4.2.textures_combined/textures_combined.cpp b/src/1.getting_started/4.2.textures_combined/textures_combined.cpp
index dde3a54..b84ff14 100644
--- a/src/1.getting_started/4.2.textures_combined/textures_combined.cpp
+++ b/src/1.getting_started/4.2.textures_combined/textures_combined.cpp
@@ -10,6 +10,10 @@
 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void processInput(GLFWwindow *window);
 
+// settings
+const unsigned int SCR_WIDTH = 1280;
+const unsigned int SCR_HEIGHT = 720;
+
 int main()
 {
     // glfw: initialize and configure
@@ -22,14 +26,14 @@ int main()
 
     // glfw window creation
     // --------------------
-    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
-    glfwMakeContextCurrent(window);
+    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
     if (window == NULL)
     {
         std::cout << "Failed to create GLFW window" << std::endl;
         glfwTerminate();
         return -1;
     }
+    glfwMakeContextCurrent(window);
     glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
     // glad: load all OpenGL function pointers
@@ -95,9 +99,9 @@ int main()
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
     // load image, create texture and generate mipmaps
-    int width, height, nrComponents;
+    int width, height, nrChannels;
     stbi_set_flip_vertically_on_load(true); // tell stb_image.h to flip loaded texture's on the y-axis.
-    unsigned char *data = stbi_load(FileSystem::getPath("resources/textures/container.jpg").c_str(), &width, &height, &nrComponents, 0);
+    unsigned char *data = stbi_load(FileSystem::getPath("resources/textures/container.jpg").c_str(), &width, &height, &nrChannels, 0);
     if (data)
     {
         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
@@ -119,7 +123,7 @@ int main()
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
     // load image, create texture and generate mipmaps
-    data = stbi_load(FileSystem::getPath("resources/textures/awesomeface.png").c_str(), &width, &height, &nrComponents, 0);
+    data = stbi_load(FileSystem::getPath("resources/textures/awesomeface.png").c_str(), &width, &height, &nrChannels, 0);
     if (data)
     {
         // note that the awesomeface.png has transparency and thus an alpha channel, so make sure to tell OpenGL the data type is of GL_RGBA
diff --git a/src/1.getting_started/4.3.textures_exercise2/textures_exercise2.cpp b/src/1.getting_started/4.3.textures_exercise2/textures_exercise2.cpp
index 362eecd..1d47272 100644
--- a/src/1.getting_started/4.3.textures_exercise2/textures_exercise2.cpp
+++ b/src/1.getting_started/4.3.textures_exercise2/textures_exercise2.cpp
@@ -10,6 +10,10 @@
 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void processInput(GLFWwindow *window);
 
+// settings
+const unsigned int SCR_WIDTH = 1280;
+const unsigned int SCR_HEIGHT = 720;
+
 int main()
 {
     // glfw: initialize and configure
@@ -22,14 +26,14 @@ int main()
 
     // glfw window creation
     // --------------------
-    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
-    glfwMakeContextCurrent(window);
+    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
     if (window == NULL)
     {
         std::cout << "Failed to create GLFW window" << std::endl;
         glfwTerminate();
         return -1;
     }
+    glfwMakeContextCurrent(window);
     glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
     // glad: load all OpenGL function pointers
@@ -40,7 +44,6 @@ int main()
         return -1;
     }
 
-
     // build and compile our shader zprogram
     // ------------------------------------
     Shader ourShader("4.2.texture_combined.vs", "4.2.texture_combined.fs");
@@ -96,9 +99,9 @@ int main()
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
     // load image, create texture and generate mipmaps
-    int width, height, nrComponents;
+    int width, height, nrChannels;
     stbi_set_flip_vertically_on_load(true); // tell stb_image.h to flip loaded texture's on the y-axis.
-    unsigned char *data = stbi_load(FileSystem::getPath("resources/textures/container.jpg").c_str(), &width, &height, &nrComponents, 0);
+    unsigned char *data = stbi_load(FileSystem::getPath("resources/textures/container.jpg").c_str(), &width, &height, &nrChannels, 0);
     if (data)
     {
         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
@@ -120,7 +123,7 @@ int main()
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
     // load image, create texture and generate mipmaps
-    data = stbi_load(FileSystem::getPath("resources/textures/awesomeface.png").c_str(), &width, &height, &nrComponents, 0);
+    data = stbi_load(FileSystem::getPath("resources/textures/awesomeface.png").c_str(), &width, &height, &nrChannels, 0);
     if (data)
     {
         // note that the awesomeface.png has transparency and thus an alpha channel, so make sure to tell OpenGL the data type is of GL_RGBA
@@ -142,7 +145,6 @@ int main()
     ourShader.setInt("texture2", 1);
 
 
-
     // render loop
     // -----------
     while (!glfwWindowShouldClose(window))
diff --git a/src/1.getting_started/4.4.textures_exercise3/textures_exercise3.cpp b/src/1.getting_started/4.4.textures_exercise3/textures_exercise3.cpp
index 26f884e..8fd1525 100644
--- a/src/1.getting_started/4.4.textures_exercise3/textures_exercise3.cpp
+++ b/src/1.getting_started/4.4.textures_exercise3/textures_exercise3.cpp
@@ -10,6 +10,10 @@
 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void processInput(GLFWwindow *window);
 
+// settings
+const unsigned int SCR_WIDTH = 1280;
+const unsigned int SCR_HEIGHT = 720;
+
 int main()
 {
     // glfw: initialize and configure
@@ -22,14 +26,14 @@ int main()
 
     // glfw window creation
     // --------------------
-    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
-    glfwMakeContextCurrent(window);
+    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
     if (window == NULL)
     {
         std::cout << "Failed to create GLFW window" << std::endl;
         glfwTerminate();
         return -1;
     }
+    glfwMakeContextCurrent(window);
     glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
     // glad: load all OpenGL function pointers
@@ -40,7 +44,6 @@ int main()
         return -1;
     }
 
-
     // build and compile our shader zprogram
     // ------------------------------------
     Shader ourShader("4.2.texture_combined.vs", "4.2.texture_combined.fs");
@@ -49,8 +52,8 @@ int main()
     // ------------------------------------------------------------------
     float vertices[] = {
         // positions          // colors           // texture coords (note that we changed them to 'zoom in' on our texture image)
-        0.5f,  0.5f, 0.0f,   1.0f, 0.0f, 0.0f,   0.55f, 0.55f, // top right
-        0.5f, -0.5f, 0.0f,   0.0f, 1.0f, 0.0f,   0.55f, 0.45f, // bottom right
+         0.5f,  0.5f, 0.0f,   1.0f, 0.0f, 0.0f,   0.55f, 0.55f, // top right
+         0.5f, -0.5f, 0.0f,   0.0f, 1.0f, 0.0f,   0.55f, 0.45f, // bottom right
         -0.5f, -0.5f, 0.0f,   0.0f, 0.0f, 1.0f,   0.45f, 0.45f, // bottom left
         -0.5f,  0.5f, 0.0f,   1.0f, 1.0f, 0.0f,   0.45f, 0.55f  // top left 
     };
@@ -96,9 +99,9 @@ int main()
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); // set texture filtering to nearest neighbor to clearly see the texels/pixels
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
     // load image, create texture and generate mipmaps
-    int width, height, nrComponents;
+    int width, height, nrChannels;
     stbi_set_flip_vertically_on_load(true); // tell stb_image.h to flip loaded texture's on the y-axis.
-    unsigned char *data = stbi_load(FileSystem::getPath("resources/textures/container.jpg").c_str(), &width, &height, &nrComponents, 0);
+    unsigned char *data = stbi_load(FileSystem::getPath("resources/textures/container.jpg").c_str(), &width, &height, &nrChannels, 0);
     if (data)
     {
         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
@@ -120,7 +123,7 @@ int main()
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); // set texture filtering to nearest neighbor to clearly see the texels/pixels
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
     // load image, create texture and generate mipmaps
-    data = stbi_load(FileSystem::getPath("resources/textures/awesomeface.png").c_str(), &width, &height, &nrComponents, 0);
+    data = stbi_load(FileSystem::getPath("resources/textures/awesomeface.png").c_str(), &width, &height, &nrChannels, 0);
     if (data)
     {
         // note that the awesomeface.png has transparency and thus an alpha channel, so make sure to tell OpenGL the data type is of GL_RGBA
@@ -136,13 +139,12 @@ int main()
     // tell opengl for each sampler to which texture unit it belongs to (only has to be done once)
     // -------------------------------------------------------------------------------------------
     ourShader.use(); // don't forget to activate/use the shader before setting uniforms!
-                     // either set it manually like so:
+    // either set it manually like so:
     glUniform1i(glGetUniformLocation(ourShader.ID, "texture1"), 0);
     // or set it via the texture class
     ourShader.setInt("texture2", 1);
 
 
-
     // render loop
     // -----------
     while (!glfwWindowShouldClose(window))
diff --git a/src/1.getting_started/4.5.textures_exercise4/textures_exercise4.cpp b/src/1.getting_started/4.5.textures_exercise4/textures_exercise4.cpp
index 28846f8..13bb81f 100644
--- a/src/1.getting_started/4.5.textures_exercise4/textures_exercise4.cpp
+++ b/src/1.getting_started/4.5.textures_exercise4/textures_exercise4.cpp
@@ -10,6 +10,10 @@
 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void processInput(GLFWwindow *window);
 
+// settings
+const unsigned int SCR_WIDTH = 1280;
+const unsigned int SCR_HEIGHT = 720;
+
 // stores how much we're seeing of either texture
 float mixValue = 0.2f;
 
@@ -25,14 +29,14 @@ int main()
 
     // glfw window creation
     // --------------------
-    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
-    glfwMakeContextCurrent(window);
+    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
     if (window == NULL)
     {
         std::cout << "Failed to create GLFW window" << std::endl;
         glfwTerminate();
         return -1;
     }
+    glfwMakeContextCurrent(window);
     glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
     // glad: load all OpenGL function pointers
@@ -99,9 +103,9 @@ int main()
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
     // load image, create texture and generate mipmaps
-    int width, height, nrComponents;
+    int width, height, nrChannels;
     stbi_set_flip_vertically_on_load(true); // tell stb_image.h to flip loaded texture's on the y-axis.
-    unsigned char *data = stbi_load(FileSystem::getPath("resources/textures/container.jpg").c_str(), &width, &height, &nrComponents, 0);
+    unsigned char *data = stbi_load(FileSystem::getPath("resources/textures/container.jpg").c_str(), &width, &height, &nrChannels, 0);
     if (data)
     {
         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
@@ -123,7 +127,7 @@ int main()
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
     // load image, create texture and generate mipmaps
-    data = stbi_load(FileSystem::getPath("resources/textures/awesomeface.png").c_str(), &width, &height, &nrComponents, 0);
+    data = stbi_load(FileSystem::getPath("resources/textures/awesomeface.png").c_str(), &width, &height, &nrChannels, 0);
     if (data)
     {
         // note that the awesomeface.png has transparency and thus an alpha channel, so make sure to tell OpenGL the data type is of GL_RGBA
@@ -145,7 +149,6 @@ int main()
     ourShader.setInt("texture2", 1);
 
 
-
     // render loop
     // -----------
     while (!glfwWindowShouldClose(window))