Introduction to Qt Widgets (Part 43) - Coordinate Transformations

With your current knowledge of QPainter, you would likely have a hard time if I asked you to draw an analog clock. Obviously, you know you can draw a line between two points with drawLine, but how do you determine these two points for say the 5 o'clock marker?

To the rescue comes coordinate transformations, which is the topic of this episode.

Links:

00:00 Introduction
00:44 Translate
01:21 Scale
01:35 Shear
02:04 Rotate
02:20 drawRotatedText
06:50 QTransform
08:12 Example with QTransform
9:54 QMatrix doesn't exists anymore
10:13 Perspective Projection
12:13 Analog clock
13:40 Ad: Migrating from Raspberry Pie to Banana Pie
14:02 Analog clock continued
19:50 Making the y axis point upwards
22:49 What's up next

All 'Introduction to Qt Widgets - Module 2' videos:

All 'Introduction to Qt Widgets - Module 3' videos:

All 'Introduction to Qt Widgets - Module 4' videos:

All 'Introduction to Qt Widgets - Module 5' videos:

All 'Introduction to Qt Widgets - Module 6' videos:

About the host:
The video is presented by Jesper Pedersen, who started with Qt back when Qt was widgets only and the version was 1.44, which gives him 21 years of experience with Qt. Since 2000 he has taught almost 100 Qt classes, ranging from Qt Widgets to QML. Heck, Jesper even taught a few classes on QTopia Core — Trolltech's initial attempt at creating a phone stack. Today Jesper holds a fancy business title, but that doesn't prevent him from coding both in his job and in his spare time.

About KDAB:

KDAB experts regularly take time out to deliver KDAB’s world class training, in-house or at open enrolment courses around the world. We are the market leaders for training in Qt, OpenGL and C++.