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GDC: Programming The PSP Report
By David Smith
3/25/2004
This morning's presentation by Sony Computer Entertainment America executive vice president Andrew House introduced Sony's PSP handheld to a more mainstream audience. Later in the afternoon, SCEA senior development engineer David Coombes and software engineer Peter Young got down to brass tacks, delivering a detailed presentation on "Programming the PlayStation Portable." Much of the session was naturally aimed right over the head of the average gamer, but our GDC correspondents did their best to keep up and learn some new details about the hardware and what it will make possible.
The PSP's screen specifications are well-known -- 24-bit color, 480 pixels by 272 pixels for a 16:9 widescreen aspect ration -- but Coombes pointed out that the wider aspect affects game design in some notable ways. The wider view offers more peripheral vision in a 3D game and a bigger playfield in a 2D game, as well as extra space to fit elements of the graphical user interface. Early feedback from developers, he said, indicates that this "massively affects gameplay."
The system's 3D hardware, Coombes said, is "closer to PS2 and in some ways superior to PS2 in feature set." As Andrew House pointed out at Sony's keynote address, it supports more effects and features in hardware, making it easier to program for. Unlike the PS2, it's a "closed" system for developers, meaning that they'll always have to program through a thin API, but the loss of flexibility in that regard is balanced by ease of use.
On the animation side, the PSP supports vertex blending in hardware -- morph blending for detailed facial animations, vertex skinning and weighting for the realistic movement of bodies and the surfaces around them. Its pixel pipeline has numerous features that we'd better avoid talking about in detail for fear of tripping over our tech-speak -- alpha-blending, stencil buffers, hardware lighting, and so forth.
One subject Coombes touched on that programmers haven't explored in detail as yet is the PSP's support for methods of generating parametric surfaces. A parametric surface is a 3D surface defined by an equation, rather than a collection of polygons defined by their vertices -- if you remember your algebra, it's the difference between a set of values and the equation that defines the curve going through them. The PSP supports Bezier patches and other methods for more drawing these kinds of surfaces more efficiently, as Ken Kutaragi illustrated in his presentation on the PSP last year, but the potential of this aspect of the system's design has yet to be fully documented.
Ascending closer to the surface of the system, and issues laymen can get a slightly better handle on, Coombes addressed some questions about the PSP's sound hardware and video playback capabilities. The mention of 7.1-channel surround sound support in Sony's earlier spec lists raised a few eyebrows, but he brought that speculation a little closer to earth -- the PSP will have only ordinary stereo sound output (whether with its speakers or headphones), and sound development for the system will use the same tools developers are familiar with from the PS2. The PSP's H.246 video codec support, meanwhile, will play back movies from both the UMD drive and users' Memory Sticks, so you won't be limited to watching commercially-released UMD movies.
In a break with its practice on the PlayStation and PS2, Sony will keep a tight control over the production of UMD discs, Coombes said. Developers will not, in fact, have UMD writers -- their debug hardware will let them test their games on DVD-Rs, and Sony will accept final code submitted on DVD-Rs as well, keeping UMD manufacturing in-house. It's not clear what practical effect this will have on developers -- it might make no difference at all, if the development hardware is easy enough to use -- but it does indicate that Sony is very serious about using the UMD as a check against leaks and piracy.
Coombes then connected a rather interesting series of dots related to the PSP's connectivity and peripheral capabilities. Its 802.11b wireless connection will let PSPs connect peer-to-peer in close proximity, and a client-server relationship with a PSP will be possible as well. The PSP will thus be able to exchange data with a PC and even connect to the Internet. Its USB ports will enable connections with other kinds of devices, like cameras and global positioning systems -- Sony is apparently "very interested" in the possibilities offered by GPS utilities.
After Coombes concluded the technical half of the presentation, Sony's Peter Young came forward to discuss the logistics and scheduling of the PSP development effort. Young tempered the news about the hardware's capabilities with a warning that development for PSP is much more like developing for PS2 than developing for previous handhelds. Budgets and team sizes will need to be comparable to current PS2 development projects. However, he assured that Sony's APIs and other developer support will be very helpful, and that while 3D programmers will be an absolute necessity, sharing many kinds of assets -- from art to AI and physics code -- with console projects will be common.
Young outlined the timetable for PSP development in a little more detail than in earlier presentations. At present, Sony has a PC-based PSP emulator. Later in the spring, more complete software development kits will go out to developers, with a compiler and debugger (based on the GCC graphical interface), development libraries, and a high-level graphics library called GUMO with sample code for developers to work with.
At E3 2004, we'll see a complete selection of demos from Sony, which may or may not run on genuine PSP hardware, depending on how Sony's schedule develops in the coming months. For certain, hardware development systems will be available this summer. Then the schedule progresses as we've already reported -- game demos at the Tokyo Game Show in September, a retail launch in Japan by the end of the calendar year, and the North American and European launches by the end of March 2005.
