krita overview

[Michael Thaler]

Hi,

> Some corrections...
> 
> In your document, you should really talk about QUANTUM, downscale and upscale.

Yes. It still needs some reiterations;-) But I learned a lot while writing it.

> KisPixelData...
> 	1) The owner flag indicates if the KisPixelData owns the the actual memory 
> pointer to by the QUANTUM array.  If so, delete[] gets called on it at 
> destruction time.

This is good to know. I should add this...

> 	2) stride is what you have to add to get to the next line, sometimes, even if 
> your KisPixelData is smaller, we have to fetch a bigger block of memory, 
> hence stride takes that into account, width does not.
> 
> 	So base + stride = line 2, but base + width might be line 2 or might be 
> outside the memory region you requested, but still inside the paint device.
> 
> KisTileCacheInterface, also used to help swapping, every tile would actually 
> put it's data in here for easy maintance, when you lock, we actually try to 
> get the data from here first, then from the swap interface.

Thanks for the explanation. This makes it clear.

> KisTileMgr
> 	KisScopedLock, might be a bug here, don't know, haven't looked at the code in 
> a while.

It is used quite often. I will look at KisScopedLock, maybe I
understand what it is for. 

> 
> KisRenderInterface
> 	What Java?

I meant that there was something like

intercaece KisRenderInterface
{
	...
}

class KisPaintDevice implements KisRenderInterface : KShared
{
	...
}

But this is not a C++ construct, but Java...

> kis_global.h, upscale and downscale do more than nothing, again I refer you to 
> the list.

In the case of 8 Bit per channel they do nothing, that's what I
meant. For 16 Bit they of course are important.

> Hey!  I find KisGuide interesting :)

It is, but not if you want to understand the basics of krita;-)

> Why do you need these new functions?

Because you told me, that the dirty flag is for rendering and
valid/invalid for memory management stuff, which is actually not the
case;-) 

(Just ordered Effective C++;-))

Take care,
Michael
-- 
We shall not cease from exploration, and the end of all our exploring 
will be to arrive where we started and know the place for the first time.