ECE583 Final Project: Sketchpad++
Press L/C/X to initiate a line/circle/CCW circle from cursor position. Click to finish it (for circles, click to set the radius and then click to set the arc length). Press A to zoom in S to zoom out at cursor location. While hovering over a point, press M to move it. While hovering over a line, press E to initiate an equal length constraint and then click on the other line you would like to constrain. Use the P key to do the same for parallel line constraints. While hovering over any element, press D to delete it. While hovering over a line, press H to enforce it to be horizontal or V to enforce it to be vertical. Press T to tick parallel, horizontal, and vertical constraint enforcement.