main.cpp

/* Hello GLFW
*  Based on https://www.glfw.org/docs/3.3/quick.html
*/

#include "main.h"
#include <glad/glad.h>
#include <GLFW/glfw3.h>

#include <imgui/imgui.h>
#include <imgui/imgui_impl_glfw.h>
#include <imgui/imgui_impl_opengl3.h>

#include <thread>

using namespace std;

GLFWwindow* window;

/**
 * A helper function for terminating the program
 */
void terminate(int errorCode) {
	cout << "Closing application";
	//Close GLFW
	glfwTerminate();
	//Exit
	exit(errorCode);
}


/**
 * A callback function for GLFW to execute when an internal error occurs with the
 * library.
 */
void error_callback(int error, const char* description)
{
	fprintf(stderr, "Error: %s\n", description);
}


void setStyle(){
	ImGuiStyle* style = &ImGui::GetStyle();
	ImVec4* colors = style->Colors;

	colors[ImGuiCol_Text] = ImVec4(0.92f, 0.92f, 0.92f, 1.00f);
	colors[ImGuiCol_TextDisabled] = ImVec4(0.44f, 0.44f, 0.44f, 1.00f);
	colors[ImGuiCol_WindowBg] = ImVec4(0.06f, 0.06f, 0.06f, 1.00f);
	colors[ImGuiCol_PopupBg] = ImVec4(0.08f, 0.08f, 0.08f, 0.94f);
	colors[ImGuiCol_Border] = ImVec4(0.51f, 0.36f, 0.15f, 1.00f);
	colors[ImGuiCol_BorderShadow] = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
	colors[ImGuiCol_FrameBg] = ImVec4(0.11f, 0.11f, 0.11f, 1.00f);
	colors[ImGuiCol_FrameBgHovered] = ImVec4(0.51f, 0.36f, 0.15f, 1.00f);
	colors[ImGuiCol_FrameBgActive] = ImVec4(0.78f, 0.55f, 0.21f, 1.00f);
	colors[ImGuiCol_TitleBg] = ImVec4(0.51f, 0.36f, 0.15f, 1.00f);
	colors[ImGuiCol_TitleBgActive] = ImVec4(0.91f, 0.64f, 0.13f, 1.00f);
	colors[ImGuiCol_TitleBgCollapsed] = ImVec4(0.00f, 0.00f, 0.00f, 0.51f);
	colors[ImGuiCol_MenuBarBg] = ImVec4(0.11f, 0.11f, 0.11f, 1.00f);
	colors[ImGuiCol_ScrollbarBg] = ImVec4(0.06f, 0.06f, 0.06f, 0.53f);
	colors[ImGuiCol_ScrollbarGrab] = ImVec4(0.21f, 0.21f, 0.21f, 1.00f);
	colors[ImGuiCol_ScrollbarGrabHovered] = ImVec4(0.47f, 0.47f, 0.47f, 1.00f);
	colors[ImGuiCol_ScrollbarGrabActive] = ImVec4(0.81f, 0.83f, 0.81f, 1.00f);
	colors[ImGuiCol_CheckMark] = ImVec4(0.78f, 0.55f, 0.21f, 1.00f);
	colors[ImGuiCol_SliderGrab] = ImVec4(0.91f, 0.64f, 0.13f, 1.00f);
	colors[ImGuiCol_SliderGrabActive] = ImVec4(0.91f, 0.64f, 0.13f, 1.00f);
	colors[ImGuiCol_Button] = ImVec4(0.51f, 0.36f, 0.15f, 1.00f);
	colors[ImGuiCol_ButtonHovered] = ImVec4(0.91f, 0.64f, 0.13f, 1.00f);
	colors[ImGuiCol_ButtonActive] = ImVec4(0.78f, 0.55f, 0.21f, 1.00f);
	colors[ImGuiCol_Header] = ImVec4(0.51f, 0.36f, 0.15f, 1.00f);
	colors[ImGuiCol_HeaderHovered] = ImVec4(0.91f, 0.64f, 0.13f, 1.00f);
	colors[ImGuiCol_HeaderActive] = ImVec4(0.93f, 0.65f, 0.14f, 1.00f);
	colors[ImGuiCol_ResizeGrip] = ImVec4(0.21f, 0.21f, 0.21f, 1.00f);
	colors[ImGuiCol_ResizeGripHovered] = ImVec4(0.91f, 0.64f, 0.13f, 1.00f);
	colors[ImGuiCol_ResizeGripActive] = ImVec4(0.78f, 0.55f, 0.21f, 1.00f);
	colors[ImGuiCol_PlotLines] = ImVec4(0.61f, 0.61f, 0.61f, 1.00f);
	colors[ImGuiCol_PlotLinesHovered] = ImVec4(1.00f, 0.43f, 0.35f, 1.00f);
	colors[ImGuiCol_PlotHistogram] = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
	colors[ImGuiCol_PlotHistogramHovered] = ImVec4(1.00f, 0.60f, 0.00f, 1.00f);
	colors[ImGuiCol_TextSelectedBg] = ImVec4(0.26f, 0.59f, 0.98f, 0.35f);

	style->FramePadding = ImVec2(4, 2);
	style->ItemSpacing = ImVec2(10, 2);
	style->IndentSpacing = 12;
	style->ScrollbarSize = 10;

	style->WindowRounding = 4;
	style->FrameRounding = 4;
	style->ScrollbarRounding = 6;
	style->GrabRounding = 4;

	style->WindowTitleAlign = ImVec2(1.0f, 0.5f);

	style->DisplaySafeAreaPadding = ImVec2(4, 4);

}

void setGuiScale(float guiScale) {
	int fbw, fbh, ww, wh;
	glfwGetFramebufferSize(window, &fbw, &fbh);
	glfwGetWindowSize(window, &ww, &wh);

	float pixelRatio = fbw / ww;

	ImGui::GetIO().FontGlobalScale = guiScale / pixelRatio;
}

int main()
{
	//Attempt to initialize GLFW
	if (!glfwInit())
	{
		//Initialization failed
		cerr << "GLFW initialization failed :(";
		//Use the terminate() function to safely close the application
		terminate(1);
	}

	// Decide GL+GLSL versions
#if __APPLE__
	// GL 3.2 + GLSL 150
	const char* glsl_version = "#version 150";
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);  // 3.2+ only
	glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);            // Required on Mac
#else
	// GL 3.0 + GLSL 130
	const char* glsl_version = "#version 130";
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
	//glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);  // 3.2+ only
	//glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);            // 3.0+ only
#endif

	//Set GLFW's error callback function
	glfwSetErrorCallback(error_callback);

	//GLFW creates a window and its OpenGL context with the next function
	window = glfwCreateWindow(640, 480, "Hello window :)", NULL, NULL);

	//Check for errors (which would happen if creating a window fails
	if (!window)
	{
		// Window or OpenGL context creation failed
		cerr << "GLFW failed to create a window and/or OpenGL context :(";
		//Use the terminate() function to safely close the application
		terminate(1);
	}

	//Window creation was successful. Continue
	glfwMakeContextCurrent(window);
	glfwSwapInterval(1); // Enable vsync

	if (!gladLoadGL()) {
		// GLAD failed
		cerr << "GLAD failed to initialize :(";
		//Use the terminate() function to safely close the application
		terminate(1);
	}



    // Setup Dear ImGui context
	IMGUI_CHECKVERSION();
	ImGui::CreateContext();
	ImGuiIO& io = ImGui::GetIO(); (void)io;
	ImGui_ImplGlfw_InitForOpenGL(window, true);
	ImGui_ImplOpenGL3_Init(glsl_version);
	setStyle();

	bool show_test_window = true;
	bool show_another_window = false;
	ImVec4 clear_color = ImColor(60, 55, 15);

	//Set scale based on scale of monitor
	GLFWmonitor* monitor = glfwGetPrimaryMonitor();
	float scale = 2.f;
	glfwGetMonitorContentScale(monitor, &scale, nullptr);

	//The render loop
	while (!glfwWindowShouldClose(window))
	{
		glfwPollEvents();
		ImGui_ImplOpenGL3_NewFrame();
		ImGui_ImplGlfw_NewFrame();
		ImGui::NewFrame();

		ImGui::ShowDemoWindow(&show_test_window);

		//ImGui::SetNextWindowSize(ImVec2(320,240));
		ImGui::Begin("Another Window", &show_another_window);
		ImGui::Text("Hello");
		if (ImGui::Button("Push me", ImVec2(128, 32))) {
			ImGui::Text("Ouch, not so hard!");
		}

		//Gui rendering size
		ImGui::SliderFloat("Display scale", &scale, 1, 3);
		setGuiScale(scale);

		ImGui::End();

		// Rendering
		ImGui::Render();
		int display_w, display_h;
		glfwGetFramebufferSize(window, &display_w, &display_h);
		glViewport(0, 0, display_w, display_h);
		glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
		glClear(GL_COLOR_BUFFER_BIT);
		ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());

		glfwSwapBuffers(window);
	}

	// Cleanup
	ImGui_ImplOpenGL3_Shutdown();
	ImGui_ImplGlfw_Shutdown();
	ImGui::DestroyContext();
	glfwDestroyWindow(window);
	glfwTerminate();
	return 0;
}