Re: [Linux-fbdev-devel] [PATCH][FBDEV]: fb_putcs() and fb_setfont() methods

From: James Simmons (jsimmons@infradead.org)
Date: Thu Jan 09 2003 - 13:09:58 EST


> :-) I did not want prolong the discussion, but...
>
> Geert is correct that the functions are generic. The fb_putcs() and
> fb_setfont() can be compared to Tile blitting. Tile blitting is a
> common operation in some games such as Warcraft, Starcraft, and most
> RPG's. I'm think there is Tile Blitting support in DirectFB.
>
> In a tile-based game, the basic unit is a Tile which is just a bitmap
> with a predefined width and height. The game has several tiles stored in
> memory each with it's own unique id. To draw the background/layer, a
> TileMap is constructed which is basically another array. Its format is
> something like this - TileMap[x] = y which means draw Tile y at screen
> position x.
>
> In the fbcon perspective, we can think of each character as a Tile, and
> fontdata as the collection of tiles. fb_char.data is basically a
> TileMap. Of course, tile blitting in games is more complicated than
> this, since games have multiple layers for the background, so layer
> position, transparency, etc has to be considered.
>
> So maybe if we can rename fb_putcs() to fb_tileblit(), fb_setfont() to
> fb_loadtiles(), struct fb_chars to struct fb_tilemap and struct
> fb_fontdata to struct fb_tiledata, maybe it will be more acceptable?
>
> It can be even be expanded by including fb_tiledata.depth
> fb_tiledata.cmap so we can support multi-colored tiled blitting.

This I have no problem with. I'm willing to accept this. As long as data
from the console layer is not touched. As for loadtiles one thing I like
to address is memory allocation. It probable is good idea to do things
like place the tile data in buffers allocated by pci_alloc_consistent.
The other fear is it will only support so many tiles.

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