News

By: Nick Evanson Aug 01, 2007

Beta stage for the Windows Vista's first service pack

Every few months, Microsoft updates its SDK (software development kit) for DirectX programmers - most of the time, it means nothing to the end-user and average gamer but the August 2007 update just release suggests that we should pay attention this time. Why?

The answer lies in the release notes with the August 2007 DirectX SDK - first of which is the announcement of Direct3D 10.1:

Direct3D 10.1 Tech Preview

Direct3D 10.1 is an incremental, side-by-side update to Direct3D 10.0 that provides a series of new rendering features that will be available in an upcoming generation of graphics hardware.

TextureCube Arrays which are dynamically indexable in shader code.
An updated shader model (shader model 4.1).
The ability to select the MSAA sample pattern for a resource from a palette of patterns, and retrieve the corresponding sample positions.
The ability to render to block-compressed textures.
More flexibility with respect to copying of resources.
Support for blending on all unorm and snorm formats.

This tech preview provides an early look at these features and the handful of new APIs that support them. The August 2007 Direct3D 10.1 Tech Preview requires the Windows Vista SP1 Beta which will be available to MSDN subscribers once it is publicly released.

So first of all, Service Pack 1 for Windows Vista has reached beta stage and anyone with a MSDN subscription can try it out. My recommendation would be to wait until its officially released, instead of risking borking your PC! The other important note is the changes to Direct3D, the graphics API. We're only just seeing D3D10 games on the market now, although DX10 hardware has been around for around 8 months now (notably quicker than the release of DX9 games after DX9 graphics card appeared). The new addition to D3D10 are only there to give API support for the forthcoming hardware from the likes of ATI, Intel and NVIDIA and given that the updates are only small tweaks to improve functionality and flexibiity (although this could help performance too), it means that the next round of GPUs will be speed, rather than feature, hikes over the last round.

XAudio2 Beta: New Cross-Platform Audio API

The August release includes Beta 1 of XAudio2. XAudio2 is a new cross-platform audio API (Windows and Xbox 360) that is based on the Xbox 360 XAudio API. XAudio2 is a low-level audio signal processing library for Windows XP and Windows Vista providing a fully modern audio pipeline, including:

Multi-channel and surround-sound support with full per-channel volume and mapping control.
Programmable, cross-platform DSP effects framework.
Per-voice filtering, arbitrary submixing, and multi-rate processing.
Multicore optimized, non-blocking API design.
Pluggable and generalized 3D spatialization support, with a full-featured implementation provided by the independent X3DAudio math library.

XAudio2 is designed to be the game-audio API that will replace DirectSound.

Audio in Vista, in terms of gaming at least, has been... well... a complete mess. Just in the same way that D3D10 is not in the least bit backwards compatible with anything non-D3D10, sound processing in Vista is just as "cut off from reality". This is because the HAL (hardware abstraction layer), a vital piece of coding between the program and hardware, that handled audio in DX9 is no longer present in DX10. With graphics, at least Vista has a version of D3D9 to use but no such luck for sound - basically, if a game uses DirectSound, DirectSound3D, EAX, etc and you run it in Vista, the processing will not be hardware accelerated by any sound card you might have. Fortunately using the CPU to process audio in games isn't super intensive (unlike graphics) but it's still a kick in the teeth to sound card manufacturers.

XAudio2 will be one solution to the problem but games will need to be written to take advantage of it, so it's not going to help with older titles. We should be rather thankful that OpenAL exists...

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