[nostalgia] Setup Glad as GL loader

src/nostalgia/core/glfw/core.cpp

@@ -2,9 +2,9 @@
  * Copyright 2016 - 2022 Gary Talent (gary@drinkingtea.net). All rights reserved.
  */
 
+#include <glad/glad.h>
 #include <GLFW/glfw3.h>
 
-#include <nostalgia/core/config.hpp>
 #include <nostalgia/core/gfx.hpp>
 #include <nostalgia/core/input.hpp>
 #include <nostalgia/core/userland/gfx.hpp>

src/nostalgia/core/glfw/gfx.cpp

@@ -2,6 +2,7 @@
  * Copyright 2016 - 2022 Gary Talent (gary@drinkingtea.net). All rights reserved.
  */
 
+#include <glad/glad.h>
 #include <GLFW/glfw3.h>
 #include <imgui_impl_glfw.h>
 
@@ -109,6 +110,9 @@ ox::Error initGfx(Context *ctx) noexcept {
 	glfwSetKeyCallback(id->window, handleGlfwKeyEvent);
 	glfwSetWindowUserPointer(id->window, ctx);
 	glfwMakeContextCurrent(id->window);
+	if (!gladLoadGLES2Loader(reinterpret_cast<GLADloadproc>(glfwGetProcAddress))) {
+		return OxError(2, "Could not init Glad");
+	}
 	if constexpr(config::ImGuiEnabled) {
 		IMGUI_CHECKVERSION();
 		ImGui::CreateContext();