Computer Graphics Applications in OpenGL

This repository is a showcase of my computer graphics assignments which were developed using:

• OpenGL v3.3 (Core Profile)
  • The version was manually set. If your GPU does not support this version, the applications will not work.
• GLFW v3.3.8, for creating windows and retrieving input
• GLEW v2.1.0, for accessing modern OpenGL API
• ImGui v1.88 (docking branch), for drawing basic GUI components
• FreeType v2.12.1, for better looking fonts for ImGui
• MagicEnum v0.8.1, for converting integer OpenGL errors into strings and for serializing enums
• stb-image.h v2.27 from the STB library, for importing images in C++, was used for importing texture assets
• tinyfiledialogs v3.8.8, for creating file dialogs for save & load purposes for the 1st assignment

Requirements

You need to have

• C++ 17

minimum installed to run the applications, in addition to the minimum OpenGL version stated above. With a small change in the ErrorManager class, you can run the applications in other compilers, such as GCC, CLang etc, because that class uses the following MSVC instrinsic statement:

//  In ErrorManager.h
// ... Some macros defined before
// At line 6:
#define GENERAL_BREAK() __debugbreak()
#endif
// Other macros and function definitions contn'd

If you are using MSVC compiler, you need to have Visual Studio 2017 installed minimum, although using Visual Studio 2022 is reccommended.

Applications

2D Vector-based Geometric Paint Application

Figure 1: 2D Vector-based Geometric Paint Application

• Features:
  • Drawing predefined shapes, rectangulars and equilateral triangles
  • Changing the drawing color using a HSV color picker, as well as support for transparent shapes
  • 2D selection system, which supports single and multiple selection
    • Drawing a rectangle box around selected multiple shapes, in addition to highlighting any selected shape by drawing edges of the shape
  • Moving a selected shape, does not support moving multiple shapes
  • Removing shapes
    • Supports removing multiple shapes if there are multiple selections
    • Clears both the undo and redo stack
  • Support for drawing convex polygons
    • Drawing a line whenever a vertex is being added, from the previous created vertex to the current mouse position
    • Also the polygon is drawn if there are at least 3 vertices
  • Selection pane, which controls:
    • Changing the colour of the shape
    • Rotation of the shape, with buttons and a slider float. Rrotation with the slider float does not support undo/redo
  • Support for undo/redo for the following operations:
    • Drawing a predefined shape, or finishing a polygon shape
    • Moving a shape
    • Rotating a shape
  • Interactive 2D Camera:
    • Zooming, minimum zoom is 50 %, maximum zoom is 1000 %. The values can be changed very easily.
    • Zooming towards mouse position - the world coordinate the cursor is poingting to won't change while zooming
    • Camera movement and zoom also works when:
      • a selection is being made
      • a predefined shape is being drawn
      • a vertex is added to a polygon
      • a shape is being moved
  • Support for copying selected shapes, and pasting shapes that are copied towards the mouse position

Modeling and Animating Randomly Generated Tree Models

Figure 2: Modeling and Animating Randomly Generated Tree Models Demo

• Features:
  • A simple 3D camera to move around the scene, using raw, pitch and roll angles
  • Rendering hierarchical models, such as a tree, and changing the orientation and position of the model
  • Smooth shading using the Phong model, along with textures
  • Randomly generating hierarchical models so that these models look more like a tree
  • Mouse picking for selecting a part of the model, or anything entity in the drawlist
    • Also supports selection highlighting by rendering the green channel only (smoothly shaded entities only)

Realistic Rendering of Parametric Surfaces

Figure 3: Realistic Rendering of Parametric Surfaces Demo

• Features:
  • 3D camera which can zoom in and out
  • Generating parametric surfaces
  • Bump Mapping
  • Display options:
    • Wireframe
    • Gouraud Shaded, bump mapping and shading per vertex
    • Phong Shaded, bump mapping and shading per fragment
  • Parameter tuning on the fly for shading and curve parameters

Remarks

Huge shoutout to TheCherno, whom I followed his OpenGL series to implement my basic OpenGL framework for the assignments.