2D Viewer

This repository contains a small viewer library (C++ and OpenGL2) encapsulating window, and input handling, primitive, and graphical user interface (ImGui/ImPlot) rendering.
I wrote it originally for visualizing physically based simulation approaches (mass-spring systems, rigid-bodies, SPH, etc.). Over the years it has been used for teaching purposes, e.g. practical assignments, at my university.

It has the following in-source external dependencies: glfw, glm, imgui, implot, stb_image.

Minimal Example

The Viewer class provides the interface to configure window/render behaviour and to register callbacks for the following events:

• init: is called after the opengl context is initialized
• shutdown: is called right before the opengl context is destroyed
• key: triggered if a key is pressed or released
• mouseButton: triggered if a mouse button is pressed or released
• update: called before rendering (once per frame)
• draw: used to submit render calls (points, lines, quads, triangles, circles, ...)
• gui: used to draw/respond to user-interface via ImGui and ImPlot

    Viewer viewer;
    viewer.mWindow.title = "Example";
    viewer.mWindow.width = 1280;
    viewer.mWindow.height = 720;
    viewer.mWindow.vsync = true;
    viewer.mWindow.mHDPI = false;

    /* install callback functions for events */
    viewer.onUpdate([](Window& window, double dt){ });
    viewer.onDraw([](Window& window, double dt){ });
    viewer.onGui([](Window& window, double dt){ });
    viewer.onMouseButton([](Window& window, Mouse& mouse, int button, int mod, bool press){ });
    viewer.onKey([](Window& window, Keyboard& keyboard, int key, int mod, bool press){ });
 
    /* start viewer (OpenGL context is created, use drawcommands and loading functions only in callbacks) */
    viewer.run();

See demo/demo.cpp for a detailed overview of the libraries functionalities.

Examples

Assignments for a physically-based simulation course (mass-spring systems, rigid-body simulation, stable fluid, finite element method).