Sign In Start Free Trial
Account

Add to playlist

Create a Playlist

Modal Close icon
You need to login to use this feature.
  • Android Application Development Cookbook
  • Toc
  • feedback
Android Application Development Cookbook

Android Application Development Cookbook

By : Boyer, Mew
4.5 (6)
close
Android Application Development Cookbook

Android Application Development Cookbook

4.5 (6)
By: Boyer, Mew

Overview of this book

The Android OS has the largest installation base of any operating system in the world; there has never been a better time to learn Android development to write your own applications, or to make your own contributions to the open source community! This “cookbook” will make it easy for you to jump to a topic of interest and get what you need to implement the feature in your own application. If you are new to Android and learn best by “doing,” then this book will provide many topics of interest. Starting with the basics of Android development, we move on to more advanced concepts, and we’ll guide you through common tasks developers struggle to solve. The first few chapters cover the basics including Activities, Layouts, Widgets, and the Menu. From there, we cover fragments and data storage (including SQLite), device sensors, the camera, and GPS. Then we move on more advanced topics such as graphics and animation (including OpenGL), multi-threading with AsyncTask, and Internet functionality with Volley. We’ll also demonstrate Google Maps and Google Cloud Messaging (also known as Push Notifications) using the Google API Library. Finally, we’ll take a look at several online services designed especially for Android development. Take your application big-time with full Internet web services without having to become a server admin by leveraging the power of Backend as a Service (BaaS) providers.
Table of Contents (17 chapters)
close
16
Index

Applying Projection and Camera View while drawing


As we saw in the previous recipe, when we draw our shape to the screen, the shape is skewed by the screen orientation. The reason for this is because, by default, OpenGL assumes a perfectly square screen. We mentioned before, the default screen coordinates for the top right is (1,1,0) and bottom left is (-1,-1,0).

Since most device screens are not perfectly square, we need to map the display coordinates to match our physical device. In OpenGL, we do this with Projection. This recipe will show how to use Projection to match the GLSurfaceView coordinates with the device coordinates. Along with the Projection, we'll also show how to set the Camera View. Here's a screenshot showing the final result:

Getting ready

Create a new project in Android Studio and call it: ProjectionAndCamera. Use the default Phone & Tablet options and select Empty Activity when prompted for Activity Type.

This recipe builds on the previous recipe Drawing shapes on the...

bookmark search playlist font-size

Change the font size

margin-width

Change margin width

day-mode

Change background colour

Close icon Search
Country selected

Close icon Your notes and bookmarks

Delete Bookmark

Modal Close icon
Are you sure you want to delete it?
Cancel
Yes, Delete