Lines
The drawing of lines holds a very special place in my heart on my computer graphics learning journey. While you were back in school learning about Cartesian coordinates, you most likely also learned how to draw a straight line and that the relationship of the y coordinate to the x coordinate is as follows:
Where m is the gradient (or slope) and c is the y-intercept. The gradient refers to how vertical or horizontal the line appears. A perfectly horizontal line has a gradient of 0, whereas a perfectly vertical line has a gradient of infinity. The y-intercept is the value on the y axis (where x = 0) that the line crosses.
Note
For a refresher on the ways to represent a line mathematically, see https://en.wikipedia.org/wiki/Linear_equation.
Exploring line equations makes more sense when you can see them on the screen and investigate the effect of modifying their variables. Lucky for us, there is freely available software on the web that can help...
