HWA blending text blitter

[Pixelthief]

Is there any way that the text blitter could be given an alpha transparency in HWA mode, rather than rendering it in software? IE right now it draws individual character transparency, and its very, very slow compared to HWA alphas. So is there any substitute or trick to allow it to draw semitransparent but not tax a CPU?

Basically, I have an arbitrarily sized background in my project, normally 512x512. I want this to be able to parallax and tile, up to the smallest multiple after 512x512 on each dimension. I can accomplish this with a text blitter by breaking it into fragment tiles and tiling an extra 2 tiles on each dimension (ie 1 top 1 bottom) and having a small offset as it blits, allowing it to scroll smoothly while giving me control over ratios for parallaxing, and making tiling quite easy.

I haven't found any other objects that can come close to this, but the biggest drawback so far has been that the text blitter cannot do much of any effect in HWA beyond simple blitting, which at least is optimized now. But is there any way to do something even the least bit beyond that like semitransparency? Or is there another public extension that could be more apt for parallax backgrounds?



.... or is the text blitter's semitransparency already done HWA and I'm just paranoid?

[Pixelthief]

Hrmm from what I understand, the character image object is both dev exclusive and is not HWA optimized, and even if it was I'm not sure it would be beyond what the text blitter can do. I tried the Background Images Object, but while it could easily pattern and run fast, it can't do transparency and wasn't quite as robust as the text blitter. Blah


hey, I was just dorking around with this and I realized- Couldn't I do this with just an active picture object? I've been using these horridly complicated text blitter methods, but all I'm really doing is loading a simple graphic, and the offsets already wrap and can be transparent.


but eh, one thing I'm concerned about- how would I tile active picture objects? I could just cut it back and force 512x512 images, but if it was any bigger, would I have to load the image into each object? In which case would it be redundantly loading the same image into memory multiple times? Bleh. Actually since that could never total up to more than 512x512, probably doesn't matter.

Seems like every time I post a question here, I answer it before anyone else can. :S

[Fanotherpg]

This is why I always love to read your comments cause they are full of knowledge and self explanatory.

[Yves]

Is there any way that the text blitter could be given an alpha transparency in HWA mode, rather than rendering it in software? IE right now it draws individual character transparency, and its very, very slow compared to HWA alphas. So is there any substitute or trick to allow it to draw semitransparent but not tax a CPU?

I don't see what you mean. I took a look at the source code and I don't see why it would be slow, this object seems correctly optimized for MMF2 HWA. Could you post an example?

[Pixelthief]

Hrmm well the examples would be too complicated, but the HWA incompatibility isn't hard to test. Just adding any HWA effect, or RGB coefficient, or Alpha coefficient- does nothing. Only the built in "Callback: Character Transparency" will do anything. And maybe that is indeed using HWA and I'm just imagining things, but the rest of the options certainly don't work.

Bear in mind thats using callbacks to blit images, so it could be possible its piping the texture before blitting?