S60 3rd Edition SDK for Symbian OS
Example Applications Guide

OpenGL ES Hierarchy Example

1. About this Example
2. Prerequisites
3. Design and Implementation


1. About this Example

This example demonstrates hierarchical programming using OpenGL ES glPushMatrix(…) and glPopMatrix(…). The user can rotate either the elbow or the fingers of a robotic arm by turning the joystick left or right. Pressing the joystick button down changes the point of rotation.

This example can be extended to any kind of OpenGL ES application, but you might want to look at the other example applications as well for how to use other, different kinds of, OpenGL ES features.

Only classes used by this example are the basic UI framework baseclasses. Open GL ES itself is pure C method call API and doesn't use classes.


2. Prerequisites

To build and run this example you need to have the S60 SDK installed and working correctly on your computer. You also need basic understanding on how to build S60 applications.

To work with this example application you need basic understanding on how to build S60 applications and basic undestanding of how Symbian (or COE) UI and application framework works. Also basic knowledge on OpenGL or OpenGL ES is required if you wish to modify the example.


3. Design and Implementation

All the different elements are drawn using the same origin-centered cube, the side length of which is two. Every time we draw a cube, the origin is in the middle of that cube, and in order to rotate the cube, for example, around a particular side, we first have to move the origin to that side of the cube. There is a helper function, which draws a 3D coordinate system. Try to call it from different points in the hierarchy to visualize the current location of the origin.

3.1 Capabilities

The application has capability NONE as it only needs the rights to execute and access to the screen.

3.2 ScalableUI

All Open GL ES examples support various screen modes. The examples also support changing the screen size while the application is running. Note that this support must be coded in the application and this code resides in the container's SizeChanged() method.


This inheritance list is sorted roughly, but not completely, alphabetically:


© Nokia 2006

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