Moderately Complex Example¶

This tutorial covers more of the features required to do useful rendering: setting colors, drawing multiple objects, etc.

Import the library¶

Most of the functionality you need are methods on the :class:Image object, so you import that directly:

from py_gd import Image

In this case,the image is created as 800x800 with the “xkcd” colorscheme:

img = Image(width=600, height=600, preset_colors='xkcd')

The xkcd colors are set to those named by a survey by Randall Monroe (py_gd only support 256 colors, so this is the first 256)

You can check what colors are set on the image with Image.get_color_names():

In [5]: img.get_color_names()
Out[5]:
['transparent',
 'white',
 'black',
 'red',
 'blue',
 'green',
 'purple',
 'pink',
 'brown',
 'light blue',
...

The first color (in this case transparent) is the default background color.

If you want a different background color, or to clear the whole image, you can call clear with the color you want.

img.clear(‘lilac’)

The Image class has a number of drawing methods.

To draw a line, you need to specify the start and end coordinates as (x, y) pairs. (0, 0) is at the top left, with x going down, and y going to the right.
You can specify the color by name: it must be one of the named colors set on the image.
Other parameters can be set as well. In the case of a line, the width can be set in pixels.

img.draw_line((0, 0), (600, 600), color=’red’, line_width=10)

This will draw a 10 pixel wide red line from the top left corner to the bottom right corner.

To draw a rectangle, you need to specify the upper left and bottom right corners.
You can specify the color by name: it must be one of the named colors set on the image.
Other parameters can be set as well. In the case of a line, the width can be set in pixels.

img.draw_line((0, 0), (600, 600), color=’red’, line_width=10)

This will draw a 10 pixel wide red line from the top left corner to the bottom right corner.

The image can be saved in a number of formats. BMP is the default. Other formats will be available dependingon how libgd was compiled.:

img.save("moderate_complex.png", 'png')