Project 1 Interactive 2D Geometry

Code:

https://github.com/CyberHolmes/CSCI5607/tree/main/Project1

Implemented Features:

Required Features:

• • (5) Translating only when the user drags on the square's interior (but not on the edge or outside the square)

  • (5) Scaling the square when the user drags on the corners

  • (10) Rotating the square when the user drags on the edges

  • (10) Texture the square with an image loaded from a PPM file

  • (5) Significantly brighten the image on the square (without distorting the colors)

  • (5) Pressing ‘r’, resets the square’s position, scale, and orientation

Extra Features:

• • (5) Changing something visually when the user presses the keyboard

  • (5) Supporting a triangle (in addition to a square)

  • (5) Animating the square (without needing user input)

  • (5) Multiple squares

Controls:

• 'r' - reset

• 'b' - brighten / un-brighten the image

• 'left arrow' - change image from square to triangle

• 'right arrow' - change image from triangle to square

• 'space' - start / stop animation

• 'm' - display multiple images (4 additional images)

• 'escape' - quit program <implemented in starter code>

• 'f' - full screen <implemented in starter code>

Description:

In this project, I expanded upon the starter code and implemented rotation, scaling, triangle support, animation, brightening the image, displaying multiple images and more key controls. It took me a while to figure out how to make scaling and rotation smooth. Implementing the triangle support also took some thoughts. The simple animation did not take too much time since I took 5611 class. There was one intermittent hidden bug in the geom library that causes the image to disappear briefly when click on the edge just right. The bug is that dot(Line2D.normalized(), Line2D.normalized()) may return a number that is just above 1. And this in turn cause the angle(Line2D, Line2D) = acos(dot(Line2D.normalized(), Line2D.normalized())) to return nan. The fix is simple once the cause is clear: clamp the dot product to [-1,1]. Because this bug causes the artifact very rarely, I only became aware of it when I started taking videos. It is fixed now.