1 files changed, 70 insertions, 0 deletions
diff --git a/core/src/Entrypoint/OpenGL2.cpp b/core/src/Entrypoint/OpenGL2.cpp
new file mode 100644
index 0000000..de13a02
--- /dev/null
+++ b/core/src/Entrypoint/OpenGL2.cpp
@@ -0,0 +1,70 @@
+#include "OpenGL2.hpp"
+
+#include <glad/glad.h>
+
+#include <GLFW/glfw3.h>
+#include <backend/imgui_impl_glfw.h>
+#include <backend/imgui_impl_opengl2.h>
+#include <imgui.h>
+#include <stdexcept>
+
+OpenGL2Backend::OpenGL2Backend() {
+#if IMGUI_INCLUDE_OPENGL2_BACKEND
+	glfwSetErrorCallback(GlfwErrorCallback);
+	if (!glfwInit()) {
+		throw std::runtime_error("Failed to initialize GLFW.");
+	}
+
+	mWindow = glfwCreateWindow(1280, 720, "Cplt", nullptr, nullptr);
+	if (mWindow == nullptr) {
+		throw std::runtime_error("Failed to create GLFW window.");
+	}
+	glfwMakeContextCurrent(mWindow);
+	glfwSwapInterval(1); // Enable vsync
+
+	if (gladLoadGLLoader((GLADloadproc)glfwGetProcAddress) == 0) {
+		throw std::runtime_error("Failed to initialize OpenGL.");
+	}
+
+	IMGUI_CHECKVERSION();
+	ImGui::CreateContext();
+
+	ImGui_ImplGlfw_InitForOpenGL(mWindow, true);
+	ImGui_ImplOpenGL2_Init();
+#else
+	throw std::runtime_error("Backend opengl2 is not available in this build.\n");
+#endif
+}
+
+OpenGL2Backend::~OpenGL2Backend() {
+	ImGui_ImplOpenGL2_Shutdown();
+	ImGui_ImplGlfw_Shutdown();
+	ImGui::DestroyContext();
+
+	glfwDestroyWindow(mWindow);
+	glfwTerminate();
+}
+
+void OpenGL2Backend::BeginFrame() {
+	glfwPollEvents();
+
+	ImGui_ImplOpenGL2_NewFrame();
+	ImGui_ImplGlfw_NewFrame();
+	ImGui::NewFrame();
+}
+
+void OpenGL2Backend::EndFrame() {
+	int displayWidth, displayHeight;
+	glfwGetFramebufferSize(mWindow, &displayWidth, &displayHeight);
+	glViewport(0, 0, displayWidth, displayHeight);
+
+	const ImVec4 kClearColor = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
+	glClearColor(kClearColor.x * kClearColor.w, kClearColor.y * kClearColor.w, kClearColor.z * kClearColor.w, kClearColor.w);
+	glClear(GL_COLOR_BUFFER_BIT);
+
+	ImGui::Render();
+	ImGui_ImplOpenGL2_RenderDrawData(ImGui::GetDrawData());
+
+	glfwMakeContextCurrent(mWindow);
+	glfwSwapBuffers(mWindow);
+}