Gain insights into computer graphics with Python's Pycairo library. Learn about pixel vs. vector graphics, create complex shapes, work with transforms, text, gradients, and more for VR and game development.

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Pycairo

In this course, you will use Python’s Pycairo library to draw complex shapes. So if you have an appetite for virtual reality, or game development, then this course will serve you well.

You will start with basic concepts like: What is the difference between pixel and vector graphics? After that, you will learn to make basic drawings and then you will move on to complex shapes. Throughout, you will cover important concepts like transform and state, working with text, gradients, and a whole lot more.

By the time you finish this course, you will have a powerful new library at your disposal, and you’ll be able to construct beautiful graphics that users will love.

Computer Graphics in Python and Pycairo

In the previous lessons, we used the `rectangle` function. Generally, though, if we need to create any other type of shape, we construct it with separate lines and curves. Let’s start by drawing a simple straight line. Here is how a line is drawn on a surface:


# Lines
Pycairo uses the idea of a current point when drawing shapes. This makes it easy to create common shapes, such as polygons, which are formed through the end-to-end joining of lines or curves.

import cairo

# Set up surface
surface = cairo.ImageSurface(cairo.FORMAT_RGB24, 600, 400)
ctx = cairo.Context(surface)
ctx.set_source_rgb(0.8, 0.8, 0.8)
ctx.paint()

# Draw a line
ctx.move_to(100, 100)
ctx.line_to(500, 300)
ctx.set_source_rgb(1, 0, 0)
ctx.set_line_width(10)
ctx.stroke()

Let’s look at the code given above, in detail.
- Initially, the path is empty and the current point is undefined.
- The `move_to` function sets the current point to (100, 100).
- The `line_to` function adds a line to the path from the current point to the specified point (500,
300). It also sets the current point to the new value (500, 300).

We set the color and line width, and then we stroke the path to draw the line. This code will give the following result:


Get introduced to open and closed shapes with Pycairo.

Introduction

Introduction to Vector Graphics

Basic Drawing Operations

Paths and Complex Shapes

Computer Color

Transforms and State

Working with Text

Gradients and Image Fills

Clipping, Masking and Compositing

Surfaces and Output Formats

Integration with Other Libraries

Conclusion

Open and Closed Shapes

Lines