Pressure sensitivity

Boudewijn Rempt boud at
Thu Jan 22 14:32:28 CET 2004

On Thursday 22 January 2004 14:28, Patrick Julien wrote:

> > * Wiping the layer between paint operations or recreating it might be
> > costly.
> Wiping it would be yes

So deleting the temporary layer after blitting and creating a new one would be 

> > * How costly is compositing only the dirty rect of the temporary
> > layer? I mean, is bitBlting from a section of a layer onto another layer
> > not very expensive?
> Well, yes and no, it's less costly that blitting the entire layer but
> obviously more costly than not doing any work :)

Well, it might have been more difficult to determine which tiles to blit 
instead of just looping through everything.

> > * Memory consumption... Currently, if I paint a line along the edges of a
> > large canvas, only the edge tiles will get dirtied and included in the
> > undo list, I guess. But if I use a big overlay layer, and blt the dirty
> > rect to the destination layer, all tiles will get dirtied. It might be
> > possible to optimize this, but I don't look forward to that: that would
> > be very complicated.
> Hmm, maybe not, I have to think about the implications of this, we might
> cut this down if the tiles in the source layer don't exist, then obviously
> we don't need to do anything.  However, this could have far reaching side
> effects.

But it would be an interesting improvement... I don't think this is something 
I should mess with myself -- I'll leave that to you :-).

Boudewijn Rempt |

More information about the kimageshop mailing list