Textures

This activity has the following desired goals:

• Learning to stroke and fill figures using textures (A, M).
• Learning to apply the above ideas to make pleasing drawings (M, T).

Step 0

Save the above image in any folder on your computer. Let’s say that the full path/name of the folder is path/folder.

Step 1

Type in the following code and run it:

cleari()
setBackground(black)
setSpeed(fast)
val b1 = cm.texture("path/folder/brush1.png", 0, 0)
setPenColor(b1)
setPenThickness(18)
repeatFor(0 to 19) { n =>
    forward(200 - n * 10)
    right(90)
}

Q1a What is the color of the lines made by the above program?

Q1b What is the thickness of the lines made by the program?

Q1c How many lines does the program make?

Q1d What is the length of the longest line?

Q1e What is the length of the shortest line?

Explanation

Wherever you can use a color or gradient in your program (for backgrounds, for pens, and for fills), you can also use a texture.

Function description:

• cm.texture("image-file", x, y) - creates a texture out of the given image. The texture is anchored at the given (x, y) coordinate.

Step 2

Type in the following code and run it:

cleari()
setBackground(black)
setSpeed(fast)
val b1 = cm.texture("path/folder/brush1.png", 0, 0)
setFillColor(b1)
setPenThickness(2)
setPenColor(black)
repeatFor(0 to 19) { n =>
    println(n * 10)
    forward(200 - n * 10)
    right(90)
}

Q2a The program above makes a drawing that is similar to the drawing made by the program in Step 1. But it makes a drawing in a very different way. Explain the difference.

Exercise

• Download a texture off the internet by, for example, doing a google search - https://www.google.com/search?q=texture, clicking on the Images link, and selecting a texture that you like.
• Use this texture to make a drawing of your choice. You can use the texture for either filling or stroking (i.e. setting pen color) of your drawing.