feat: create window

.vscode/settings.json

@@ -73,5 +73,6 @@
     "streambuf": "cpp",
     "cinttypes": "cpp",
     "typeinfo": "cpp"
-  }
+  },
+  "C_Cpp.errorSquiggles": "Disabled"
 }

.vscode/tasks.json

@@ -9,7 +9,9 @@
                 "-std=c++17",
                 "-I${workspaceFolder}/dependencies/include",
                 "-L${workspaceFolder}/dependencies/library",
-                "-Wall",                                 "${workspaceFolder}/Engine/engine/*.cpp",
+                "-Wall",      
+                "${workspaceFolder}/Engine/engine/*.hpp",                           
+                "${workspaceFolder}/Engine/engine/*.cpp",
                 "${workspaceFolder}/Engine/engine/glad.c",
                 "-o",
                 "${workspaceFolder}/Engine/engine/match", "-lglut", "-lglfw", "-lGLU", "-lGL", "-lm",

Engine/engine/constants.hpp

@@ -0,0 +1,14 @@
+#ifndef CONSTANTS_HPP
+#include <iostream>
+#include <string_view>
+
+namespace constants 
+{
+    // best practice is to use inline constexpr std::string_view but glfwCreateWindow takes only char* as input
+    inline const char* MAIN_WINDOW_NAME { "Match" }; 
+    inline constexpr int MAIN_WINDOW_WIDTH { 800 };
+    inline constexpr int MAIN_WINDOW_HEIGHT { 600 };
+
+}
+
+#endif

Engine/engine/match.cpp

@@ -1,3 +1,4 @@
+#ifndef MAIN_CPP
 
 #include <glad/glad.h>
 #include <GLFW/glfw3.h>
@@ -5,29 +6,98 @@
 #include <glad/glad.h>
 #include <GLFW/glfw3.h>
 #include <iostream>
-int main()
-{
-    glfwInit();
+#include "constants.hpp"
+
+void configureGLFW() {
+    // first argument tells us what option to configure
+    // second is to what we set the value of this option
+    // see: https://www.glfw.org/docs/latest/window.html#window_hints
     glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
     glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
     glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
-    //glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
-    
+    // we set GLFW to 3.3 CORE
+    // core profile gives us access to smaller subset of OGL without backwards compatible features
 
-    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
-if (window == NULL)
-{
-    std::cout << "Failed to create GLFW window" << std::endl;
-    glfwTerminate();
-    return -1;
+    // if we are on Mac OS X we need this for our code to work
+    #ifdef __APPLE__
+        glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
+    #endif
 }
-glfwMakeContextCurrent(window);
 
+void instantiateGLFWwindow() {
+    // Initialize GLFW
+    glfwInit();
+    configureGLFW();
+}
 
-if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
+GLFWwindow* createWindowObject() {
+    // First two arguments are width and height 
+    // Third is the name of the window
+    // We ignore last two
+    GLFWwindow* window = glfwCreateWindow(constants::MAIN_WINDOW_WIDTH, constants::MAIN_WINDOW_HEIGHT, constants::MAIN_WINDOW_NAME, NULL, NULL);
+    return window;
+}
+
+int initializeGLAD() 
 {
-    std::cout << "Failed to initialize GLAD" << std::endl;
-    return -1;
-}    
+    // we load address of OGL OS-specific function pointers
+    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
+    {
+        std::cout << "Failed to initialize GLAD" << std::endl;
+        return -1;
+    }    
     return 0;
-}
+}
+
+// resizes viewport when user resizes window
+void framebuffer_size_callback(GLFWwindow* window, int width, int height)
+{
+    glViewport(0, 0, width, height);
+}  
+
+void viewPort(GLFWwindow* window)
+{
+    // We tell OGL size of rendering window
+    // First two define left corner of window
+    // 3th and 4th width and height of rendering window
+    // we could set them to be smaller than window dimension, ogl rendering will be then displayed in smaller window
+    glViewport(0, 0, constants::MAIN_WINDOW_WIDTH, constants::MAIN_WINDOW_HEIGHT);
+    // processed coordinates are between -1 and 1 so here we map:
+    // (-1 to 1) to (0, constants::MAIN_WINDOW_WIDTH) and (0, constants::MAIN_WINDOW_HEIGHT)
+    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);  
+    // we call framebuffer_size_callback on every window resize
+}
+
+void renderLoop(GLFWwindow* window)
+{
+    while(!glfwWindowShouldClose(window))
+    {
+        glfwSwapBuffers(window);
+        glfwPollEvents();    
+    }
+}
+
+int main()
+{
+    instantiateGLFWwindow();
+
+    GLFWwindow* window = createWindowObject();
+    // function returns GLFWWindow object
+    
+    if (window == NULL)
+    {
+        std::cout << "Failed to create GLFW window" << std::endl;
+        glfwTerminate();
+        return -1;
+    }
+    // we make context of this window main context of current thread
+    glfwMakeContextCurrent(window);
+    
+    if(initializeGLAD() == -1) return -1;
+    viewPort(window);
+    renderLoop(window);
+
+    return 0;
+}
+
+#endif