Drawing with Text
In this laboratory, you will explore the use of text in GIMP drawings.
Start GIMP and MediaScript.
Create and show a 200x200 image named
Experiment 1: Drawing with text
(a) The image.draw-text! procedure allows you to draw
text in an image with a specified location and rotation. Try the
following expression to see what it does; then experiment with varying
(image.draw-text! canvas "hello" "Courier" 12 0 0 0)
(b) What do you think the following code will do? Make a prediction, then see
if your prediction is correct.
(image.draw-text! canvas "hello" "Arial" 16 100 100 (* pi 0))
(image.draw-text! canvas "hello" "Arial" 16 100 100 (* pi 0.5))
(image.draw-text! canvas "hello" "Arial" 16 100 100 (* pi 1))
(image.draw-text! canvas "hello" "Arial" 16 100 100 (* pi 1.5))
Experiment 2: Choosing a font
The font.list procedure works much like
color.list. Use it to obtain a list of all fonts; to
list fonts with
Times in their names; to find a
font that you like.
Choose any of the following explorations to do in (or after) class.
You need not do them in the order they are listed,
but some will take more time than others.
Some details are deliberately left unspecified for you to figure out.
They are all things I think you can figure out how to do based on what
you've already learned.
If you are particularly proud of your work, please email me your code for
possible extra credit.
Write a procedure, image.draw-whirled-text!,
to repeatedly draw the same text with the same
starting location, while varying the angle by which the text is rotated.
Use text as a stamp when drawing
Write a procedure,
image.draw-shadowed-text!, that produces
a 3D shadow effect by drawing the text first in black (for the shadow)
and then in another color, in slightly different positions.
For a different 3D effect,
write a recursive procedure to draw the same text in the same location
with a series of different font sizes.
Jitter the text: Write a procedure,
image.draw-jittered-text!, that draws
the same text several times in approximately the same location,
introducing a small random offset to the position each time.
Produce a contact sheet: The purpose of a contact sheet is to let you
compare different fonts. Write the same text in several different
locations, each time using a different font from a list of fonts provided
by the user.
text wave: Take a string and use numeric recursion
along with string-ref
to draw each character separately. Vary the vertical position of
each character by using the sin or
cos procedure (or some other interesting mathematical
function). You will also need to compute a horizontal position for each
character; it's easiest if you assume all characters are the same
ransom note effect: Take a string and use
numeric recursion along with string-ref
to draw each character separately. Randomly vary the position,
angle, font size, and/or font for each character.
Draw each character in the string using a different color. The color
could be algorithmically generated or selected from a list, based on
either the position of the character in the string or its
position in the ASCII collating sequence.
alphabet blocks, with a different colored square
behind each character.
Write a procedure to draw a personalized greeting card, with
text that includes the recipient's name, and also an interesting picture.
The picture could use any of the
techniques for making images you've learned about this semester.
You might make the picture look different for each different recipient,
perhaps by transforming the characters in the recipient's name
into integers and then using these integers as
parameters for the drawing procedures.
Any other interesting ideas?