Added window resize callback

functionality.cpp

@@ -278,6 +278,38 @@ void destroyVAO(GLuint &VAO) {
     //delete VAO
 	glDeleteVertexArrays(1, &VAO);
 }
+/**
+ * @brief Resize frame to keep aspect ratio.
+ * 
+ * @param window 
+ * @param width 
+ * @param height 
+ */
+void framebuffer_size_callback(GLFWwindow* window, int width, int height) {
+    //set difference values
+	int widthDifference = width - 1024;
+	int heightDifference = height - 1024;
+    //set scene size and position according to width and height difference
+	if(widthDifference > 0 && heightDifference > 0) {
+		glViewport((widthDifference / 2) - (heightDifference / 2), 0, (width - widthDifference) + heightDifference, height);
+	} else if(widthDifference < 0 && heightDifference < 0) {
+		glViewport(-(heightDifference / 2), -(widthDifference / 2), (width + heightDifference), (height + widthDifference)); //wrong
+	} else if(widthDifference > 0 && heightDifference < 0) {
+		glViewport((widthDifference / 2) - (heightDifference / 2), 0, (width - widthDifference) + heightDifference, height);
+	} else if(widthDifference < 0 && heightDifference > 0) {
+		glViewport(0, -(widthDifference / 2) + (heightDifference / 2), width, (height + widthDifference) - heightDifference);
+	} else {
+		if(widthDifference > 0) {
+			glViewport((widthDifference / 2), 0, (width - widthDifference), height);
+		} else if(widthDifference < 0) {
+			glViewport(0, -(widthDifference / 2), width, (height + widthDifference));
+		} else if(heightDifference > 0) {
+			glViewport(0, (heightDifference / 2), width, (height - heightDifference));
+		} else if(heightDifference < 0) {
+			glViewport(-(heightDifference / 2), 0, (width + heightDifference), height);
+		}
+	}
+}
 /**
  * @brief Eanable capture of debug output.
  * 

header/functionality.h

@@ -15,6 +15,7 @@ GLuint loadModel(const std::string path, const std::string file, int &size);
 GLuint loadTexture(const std::string &filepath, const GLuint slot);
 GLuint createVAO(const std::vector<GLfloat> &arr, const std::vector<GLuint> &arr_indices);
 void destroyVAO(GLuint &VAO);
+void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void enableDebug();
 void GLAPIENTRY messageCallback(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar* message, const void* userParam);
 #endif

main.cpp

@@ -37,6 +37,11 @@ int main() {
 	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
 	//create window
 	GLFWwindow* window = glfwCreateWindow(1024, 1024, "Landscape", nullptr, nullptr);
+	//set framebuffer size data
+	int framebufferWidth = 0, framebufferHeight = 0;
+	glfwGetFramebufferSize(window, &framebufferWidth, &framebufferHeight);
+	//declare framebuffer size callback
+	glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 	//setting the OpenGL context to the window
 	glfwMakeContextCurrent(window);
 	//enable capture of cursor and focus it on the middle while hiding the icon