Around a year ago today, I began writing an extensive UI framework for Windows Mobile. It turned out great, however I continually run into the limitations and performance issues of GDI/GDI+ on mobile devices. One of the steps I wanted to take into really improving performance was to utilize the hardware acceleration that we will begin to see in the new wave of Windows Mobile devices; in my case the HTC Touch Diamond.
The first step towards that end is to utilize one of the two 3D APIs available on the Windows Mobile platform. Direct3D Mobile .NET was not a reasonable option: it has limited support and is supposedly being phased out in Windows Mobile 7. In addition, the D3DM implementation on the HTC Touch Diamond is a just a wrapper around OpenGL ES... I find it a little distasteful that than an operating system specific 3D API is actually just a wrapper around a cross platform 3D API, hehe. And on the other hand, OpenGL ES does not have a managed API.
In My Humble Opinion, UI development should generally be in managed code. Although unmanaged code undoubtedly provides superior performance, the developer sacrifices too much of the ease and speed of managed development.
For that reason, I've started work on a managed wrapper for OpenGL ES: I now have a working set of wrappers for OpenGL ES. I won't take all the credit though. Most of the PInvokes were mass imported via the PInvoke Interop Assistant written by Jared Parsons.
For those wanting to learn OpenGL, I highly recommend reading the NeHe OpenGL series. It's the best OpenGL tutorial on the Internet; I've practically had it book marked for 8 years.
Future work will include converting the various OpenGL constants into enums (I.e., GL_TRIANGLES, GL_TEXTURE0, etc) so that arguments are not so loosely typed.
- The sample uses floating point math, so not all devices may support it.
- If your device does not have an implementation of OpenGL ES (hardware or software), you can get the free software implementation, Vincent 3D. Just drop the libgles_cm.dll into your \Windows directory. Vincent 3D is a fixed point implementation, so it does not support the sample either. I will probably convert the sample to fixed point eventually.