Getting Started

First of all, make sure you follow the installation instructions here.

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GLFW and OpenGL (with glew)

GLEngine uses GLFW 3.3 for platform-independent window and input handling, and glew 2.1.0 for including modern OpenGL functionality. They must be included in the following order:

#include <GL/glew.h>
#include <GLFW/glfw3.h>

Tip

Any time you want to use GLFW or OpenGL methods or defines, simply importing GLEngine/include/graphics/graphics.hpp will include everything for you in the right order.

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Creating Windows

If you want to manually handle the creation and destruction of GLFW windows, please take a look at the following: GLFW Window Guide

GLEngine contains it's own system for creating and handling one or multiple GLFW windows called the WindowHandler. You should only create one of these per application. The following snippet shows you how to create your own WindowHandler (initializing GLFW for you) and then create your own window.

WindowHandler windowHandler = WindowHandler();
// Initialize GLFW and WindowHandler

std::vector<int> windowHintNames = std::vector<int>();
std::vector<int> windowHintValues = std::vector<int>();

windowHintNames.push_back(GLFW_RESIZABLE);
windowHintValues.push_back(GL_FALSE); // Turn off resizing

windowHintNames.push_back(GLFW_CONTEXT_VERSION_MAJOR);
windowHintValues.push_back(3); // OpenGL version 3.x

windowHintNames.push_back(GLFW_CONTEXT_VERSION_MINOR);
windowHintValues.push_back(3); // OpenGL version x.3
// Together these two window hints set the Window to use OpenGL version 3.3

GLFWwindow *window; = windowHandler.CreateWindow(1280, 720, "Window Title", 
nullptr, nullptr, windowHintNames, windowHintValues);

See the WindowHandler reference for more details

Every window holds a reference to it's own OpenGL version, as the OpenGL context at any time in your application is based on what window you are rendering to.

Note

CreateWindow will call glfwMakeContentCurrent on the GLFWwindow* it is creating for you. When you want to manually switch the glfw context, you have to call glfwMakeContextCurrent(yourWindow) yourself.

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Initializing glew

At any point after the initialization of GLFW, you can initialize glew. This can be achieved with the following code (eventually this will be handled by the renderer):

GLenum err = glewInit();
if (GLEW_OK != err)
{
    std::cout << "Error: " << glewGetErrorString(err) << std::endl;
}

Note

Please note that you should try to use GLEngine's logging (with spdlog) when possible. See the engine and application logging section.

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Engine and Application Logging

GLEngine utilizes spdlog to handle all of it's logging. CPPModelLibrary also does.
This is because spdlog handles two important features: Rust-lang like formatting, and level based logging: meaning that all logging can separated into different levels of importance (and colors!).