1. Yes, we have one parameter we call "flow" that does what your GIF shows. We also have a parameter called "opacity" that does what you want to do. To create a brush that behaves the way you want do the following: open brush settings panel (located on the upper right of the screen), go to the "flow" tab, change "flow pressure" to 100%, go to the opacity tab and change "opacity pressure" to 0%.
(we need to improve the brush settings)
2. Yes, use the same brush settings as described above. You can click on "tip" (round circle for standard brush) to change brush tip.
3. We might open source the brush format in the future.
4. Maybe in a distant future. The problem with plugins is that you have one more API to keep backward compatible.
Thanks for testing Leonardo! Please feel free to email me if you have any more questions or feedback: henning.tegen 'at' getleonardo.com
I am the main developer of a new painting application called Leonardo ( http://www.getleonardo.com ) which include this feature for our native .LEO file format.
I haven't developed that much on Linux so I can't really compare. Visual Studio for Windows which I mostly use is really good in my opinion.
Leonardo use as little OS specific stuff as possible to make porting easy so going from Windows to Mac (and maybe Linux in the future) shouldn't be that hard.
Thanks. Sublime Text has been one of the many inspirations for Leonardo! :)
The trick Leonardo use to be this fast is that your screen only has a fixed amount of pixels and it is enough to update does pixels super fast for the application to feel fast. Then you have a lot more time to update the rest of the pixels.
This makes Leonardo kind of "resolution independent" and is always super fast whatever the canvas size and brush diameter. On top of this we also have a streaming mechanism of tiles between RAM and file so that you never run out of memory.
I am the lead developer of a application called Leonardo that we hope will be a future "Photoshop killer" when it comes to digital painting: http://www.getleonardo.com The main focus for us is speed and Leonardo is way faster then any other application including Photoshop (and it is still raster based).
Leonardo is not finished yet, but it is possible to sign up on out beta list.
We are currently working on a application with similar features called Leonardo although Leonardo is streamlined for digital painting, not photo editing.
Leonardo is still at least 6 months away from being released but all the features like "unlimited canvas", "instant painting" and handling of "huge files" are already in place.
Unfortunately there is no video right now showing the "unlimited canvas" and "instant painting", but I can make one within the next couple of hours... :)