restructure work

engine/Backend/Backend.cpp

@@ -0,0 +1,99 @@
+
+#include "Backend.h"
+
+namespace engine::Backend
+{
+    GLFWwindow* window;
+    int SCREEN_WIDTH = 1920;
+    int SCREEN_HEIGHT = 1080;
+
+    bool Init(const char* title, int width = SCREEN_WIDTH, int height = SCREEN_HEIGHT)
+    {
+        SCREEN_WIDTH = width;
+        SCREEN_HEIGHT = height;
+
+        // Initialize GLFW
+        glfwInit();
+        glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+        glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+        glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+
+        // Create GLFW Window
+        window = glfwCreateWindow(SCREEN_WIDTH, SCREEN_HEIGHT, title, NULL, NULL);
+        if (window == NULL)
+        {
+            std::cout << "Failed to create GLFW window" << std::endl;
+            glfwTerminate();
+            return false;
+        }
+        glfwMakeContextCurrent(window);
+
+        // Initialize GLAD
+        if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
+        {
+            std::cout << "Failed to initialize GLAD" << std::endl;
+            return false;
+        }
+
+        // Initialize Viewport & setup resize callback
+        glViewport(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT);
+        glfwSetFramebufferSizeCallback(window, window_resize_callback);
+        glfwSetCursorPosCallback(window, mouse_callback);
+        glfwSetScrollCallback(window, scroll_callback);
+
+        // depth testing
+        glEnable(GL_DEPTH_TEST);
+
+        return true;
+    }
+
+
+    void PreFrame()
+    {
+        // Input processing
+        processInput(window);
+
+        // Depth buffer
+        glClearColor(0, 0, 0, 1);
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+    }
+
+    void PostFrame()
+    {
+        // Call events & swap buffers
+        glfwSwapBuffers(window);
+        glfwPollEvents();
+    }
+
+    void Cleanup()
+    {
+        glfwTerminate();
+    }
+
+    bool isWindowOpen()
+    {
+        return !glfwWindowShouldClose(window);
+    }
+
+    void window_resize_callback(GLFWwindow* window2, int width, int height)
+    {
+        glViewport(0, 0, width, height);
+        SCREEN_WIDTH = width;
+        SCREEN_HEIGHT = height;
+    }
+
+    void processInput(GLFWwindow* window2)
+    {
+        // Close on Escape
+        if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
+            glfwSetWindowShouldClose(window, true);
+    }
+
+    void mouse_callback(GLFWwindow* window2, double xposIn, double yposIn)
+    {
+    }
+
+    void scroll_callback(GLFWwindow* window2, double xoffset, double yoffset)
+    {
+    }
+}