PropGFX

Update?

computer guy — Thu, 22 Apr 2010 10:01:20

Hey guys,

Any chance of getting some updated photographs of the board?

3D Rendering

Owen — Sun, 24 Feb 2008 15:53:14

No, I'm not asking if the PropGFX will do 3D.

Instead, I'm conjecturing about using the PropGFX as the 2D chip behind a 3D renderer.

One of my (Non µC) hobies is 3D, whether it be hardware or software rendered. Now, I'm conjecturing about making an MCU do 3D rendering and then passing the drawing off to a PropGFX. 3D rendering on the prop is quite difficult, mainly because the prop lacks hardware MUL/DIV. Instead, I was thinking of teaming the prop up with something more capable in that area, and the thought occured to use one of the 16-Bit PICs (PIC24/dsPIC) as the rasterizer to which a stream of triangles is sent. The rasterizer then scans along each triangle, and converts it into a seires of HLINES, which are sent off to the PropGFX. In this case, as many cogs as possible in the PropGFX should be dedicated to processing HLines

I'm still working out whether, to acheive decent framerates, 1 or 2 dsPICs would be needed (one to do the triangle rasterizing, and one to do the depth sorting and matrix transformations)

The main complexity on the 2D side with 3D rendering is that the display has got to be a framebuffer, not tiled. I think the highest the prop could feasibly do is 256x[256|192]x16 col, but, this doesn't leave much colour space, which is also very important in representing depth

I wonder whether the fillrate would be higher using the "Inter-Prop Bus" or DMA fed serial for this... Hmm... (This also depends on, I suppose, how much of the DMA buffer is consumed with incoming triangles)

PropGFX's New Function

Baggers — Sun, 4 Nov 2007 21:57:38

Here's the latest on what's I've just added to PropGFX functionality , it's still early stages yet, as it's not double buffered, and I also need to sort the list on the hybrid side before sending it to the PropGFX.
When it's double buffered it'll draw a LOT more also, otherwise it'd be tearing the as it displays the image in this vid, and there's still some more optimisations that I know I can make to it so keep watching

It's for the 256 Colour Bitmap Mode, ( 128x96 res ) as I have enough ram on the PropGFX to double buffer the display, so I'll be able to have many many polys . well many many for a small microcontroller anyway

let me know what you think.

Baggers.

PropGFX Prototype Pictures

Coley — Wed, 17 Oct 2007 01:29:12

OK, here is the prototype board for the PropGFX graphics co-processor, you can see it attached to a Hybrid

Component Parts of PropGFX

Initial Power On Splash Screen (PAL Composite Video)

SD Boot Loader Running on Hybrid, displayed by Prop GFX (PAL Composite Video)

Scroll down with keyboard to select application (PAL Composite Video)

Et Voila! Instant Retro Goodness! (PAL Composite Video)

PropGFX Peliminary Specification

Coley — Mon, 15 Oct 2007 22:39:10

Processor

Parallax Propeller P8X32A-Q44 44 Pin QFP @ 96MHz (6Mhz * 16PLL) - 32K EEPROM

Video Signal Generator

Analog AD724 RGB Video Encoder
Composite Video Jack
S-Video DIN

Footprint

Hybrid / Hydra compatible expansion riser card
DIP40 Layout for other uControllers and rapid prototyping

Sprite Engine

32 Sprites on screen ( for now! )
16 Colours per Sprite each with it's own 16 Colour Palette
Sprites can be 8, 16, 24 or 32 pixels wide and any height.
Flippable in both X and Y

Screen Modes

256 * 192, 16 Colour Bitmap
256 * 224, 16 Colour Bitmap
128 * 96, 256 Colour Bitmap
128 * 96, 32768 Colour Bitmap
DXT1 16Bit Real Time Decompression http://www.propgfx.co.uk/forum/Blah.pl?b-pb/m-1192203749/s-new/#num23

Each bitmap mode can be reduced by 8 pixels in X, Y or X & Y for smooth scrolling

Character Map mode - 16 Colour per Character, 16 Palettes per Screen & 768 Characters per Screen
Characters are flippable in both X and Y

Movie Player Mode - 120 * 96, 256 Colour, 25 FPS (each frame can have it's own 256 colour palette)

Also in the pipeline is a 4 Bit character mode, with 4 Bit character overlay.....

All modes are switchable on the fly with software switches