Week 3: Drawing on the Canvas and Creating Timers

Question 1

How do computers draw?

Answer 1

Computer monitor - 2D grid of piles stored in a frame buffer

Computers update the monitor based on the frame buffer at a rate of 60-72 times a second - this is the refresh rate

Applications register with the computer a special function called a “draw handler”

The draw handler updates the canvass using a collection of commands.

Question 2

How are coordinates measured on a canvas?

Answer 2

Grid starts in top left corner at [0, 0] and accepts [x, y] coordinates (height in pixels, width in pixels) which increase in value as they move from left to right and top to bottom.

Question 3

When drawing text in Python, how do the positional coordinates relate to where the text is drawn?

Answer 3

The positional coordinates will be at the bottom left of the text entered; important to remember for positioning text.