From ff576182c4da852bbdefa77c9a9a7ee7f5d23fcb Mon Sep 17 00:00:00 2001
From: Karl <karl.bittner@hexaquo.at>
Date: Fri, 30 Apr 2021 22:40:42 +0200
Subject: [PATCH] Make Application create a GLFW Window

---
 cpp/Application.cpp            | 13 +++++++---
 cpp/RenderBackend.cpp          | 44 ++++++++++++++++++++++++++++++++++
 include/Gedeng/Input.h         | 27 ++++++++++++++++++---
 include/Gedeng/RenderBackend.h | 31 ++++++++++++++++++++++++
 4 files changed, 109 insertions(+), 6 deletions(-)
 create mode 100644 cpp/RenderBackend.cpp
 create mode 100644 include/Gedeng/RenderBackend.h

diff --git a/cpp/Application.cpp b/cpp/Application.cpp
index 2573ca7..723195b 100644
--- a/cpp/Application.cpp
+++ b/cpp/Application.cpp
@@ -1,21 +1,28 @@
 #include "Gedeng/Application.h"
-#include "Gedeng/Time.h"
+#include "Gedeng/Input.h"
 #include "Gedeng/Logger.h"
+#include "Gedeng/RenderBackend.h"
+#include "Gedeng/Time.h"
 
 namespace Gedeng {
 
 void Application::run() {
+    // Setup Rendering
+    // FIXME: Make these parameters variable, maybe move this to a different function
+    RenderBackend::initialize_window(1920, 1080, String("Application"));
+    Input::initialize(RenderBackend::get_window());
+
     unsigned long previous_time_ms = Time::get_time_ms();
     unsigned long time_until_fixed_update_ms = 0.0;
 
-    while (true) {
+    while (!RenderBackend::does_window_want_to_close()) {
         unsigned long current_time_ms = Time::get_time_ms();
         unsigned long elapsed_time_ms = current_time_ms - previous_time_ms;
 
         previous_time_ms = current_time_ms;
         time_until_fixed_update_ms += elapsed_time_ms;
 
-        // Process Input
+        Input::poll_input();
 
         // Update fixed time step
         while (time_until_fixed_update_ms >= MS_PER_UPDATE) {
diff --git a/cpp/RenderBackend.cpp b/cpp/RenderBackend.cpp
new file mode 100644
index 0000000..48bc929
--- /dev/null
+++ b/cpp/RenderBackend.cpp
@@ -0,0 +1,44 @@
+#include "Gedeng/RenderBackend.h"
+
+namespace Gedeng {
+
+void RenderBackend::initialize_window(unsigned int width, unsigned int height, String title) {
+    glfwInit();
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+
+#ifdef __APPLE__
+    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
+#endif
+
+    window = glfwCreateWindow(width, height, title, NULL, NULL);
+    glfwMakeContextCurrent(window);
+    gladLoadGLLoader((GLADloadproc)glfwGetProcAddress);
+}
+
+bool RenderBackend::is_window_created() {
+    return window != nullptr;
+}
+
+void RenderBackend::set_depth_test_enabled(bool enabled) {
+    if (enabled) {
+        glEnable(GL_DEPTH_TEST);
+    } else {
+        glDisable(GL_DEPTH_TEST);
+    }
+}
+
+bool RenderBackend::does_window_want_to_close() {
+    return glfwWindowShouldClose(window);
+}
+
+GLFWwindow *RenderBackend::get_window() {
+    return window;
+}
+
+void RenderBackend::render() {
+    glfwSwapBuffers(window);
+}
+
+} // namespace Gedeng
\ No newline at end of file
diff --git a/include/Gedeng/Input.h b/include/Gedeng/Input.h
index 374ab37..b304615 100644
--- a/include/Gedeng/Input.h
+++ b/include/Gedeng/Input.h
@@ -1,13 +1,32 @@
 #pragma once
 
+// Must be the first include
+#include <glad/glad.h>
+
+// Other includes
+#include <GLFW/glfw3.h>
+
+#include "RenderBackend.h"
 #include <map>
 
 namespace Gedeng {
 
 class Input {
-
   public:
-    inline static std::map<int, bool> keys_down;
+    static void initialize(GLFWwindow *window) {
+        glfwSetKeyCallback(window, key_callback);
+    }
+
+    // FIXME: Ignore warnings produced by these unused variables -- they're required for the callback to work
+    static void key_callback(GLFWwindow *window, int key, int scancode, int action, int mods) {
+        if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS) glfwSetWindowShouldClose(window, GLFW_TRUE);
+
+        Input::set_key_down(key, action == GLFW_RELEASE ? false : true);
+    }
+
+    static void poll_input() {
+        glfwPollEvents();
+    }
 
     static void set_key_down(int key, bool down) {
         keys_down[key] = down;
@@ -16,6 +35,8 @@ class Input {
     static bool is_key_down(int key) {
         return keys_down[key];
     }
+
+    inline static std::map<int, bool> keys_down;
 };
 
-}
\ No newline at end of file
+} // namespace Gedeng
\ No newline at end of file
diff --git a/include/Gedeng/RenderBackend.h b/include/Gedeng/RenderBackend.h
new file mode 100644
index 0000000..ab05cd1
--- /dev/null
+++ b/include/Gedeng/RenderBackend.h
@@ -0,0 +1,31 @@
+#pragma once
+
+// Must be the first include
+#include <glad/glad.h>
+
+// Other includes
+#include <GLFW/glfw3.h>
+
+#include "Gedeng/String.h"
+
+namespace Gedeng {
+
+class RenderBackend {
+  private:
+    static inline GLFWwindow *window;
+
+  public:
+    static void initialize_window(unsigned int width, unsigned int height, String title);
+
+    static bool is_window_created();
+
+    static void set_depth_test_enabled(bool enabled);
+
+    static bool does_window_want_to_close();
+
+    static GLFWwindow *get_window();
+
+    static void render();
+};
+
+} // namespace Gedeng
\ No newline at end of file