Video looks good.

So lets look at the slow painting problem. Do some horsepower tests for me IF you can.
We will slowly disable segments of your painting to see where all the horsepower
is going by doing a speed-test on each of the below steps.

0> I cant see any, but if there are any wait commands WITHIN a single terrain
calculations, disable them. Waits between terrains is OK. Dont speed test this step.

1> Disable ONLY the pixel_for_bmap and pixel_to_bmap COMMANDS.
Just the individual LINES, not chunks of code.
We still want all the height and color CALCULATIONS to take place.

2> Now disable ALL the COLOR/PIXEL calculations as well, leaving the height calcs in.

3> Next disable all the HEIGHT calculations as well.
All that should be left is the bmap_lock and bmap_unlock's, and bmp_create's.

4> Next disable all the BMAP_CREATEs if you can find a way. Maybe create a
single global 512x512 bmap and just keep re-using it in place of the bmap_creates.
All that should be left is the bmap_lock and bmap_unlock's.

5> Finally, disable all the bmap_locks and bmap_unlocks.

Post the approximate results (in seconds) that you can measure for each step.
Until we know which PART is eating CPU, it going to be hard to optimise.
Also please do all the steps if you can. Dont stop just because it appears
that you've found 'the one', later-step results may be important too.
If you need to skip a step because it is just not possible code-wise, then so be it...

Also ... can you use shaders? Do you own a 'high' enough version of gamestudio?



Any of this is "unlikely" to help me, as I wont be doing any REAL painting.
My map isnt random. It comes from a monster height-map. (16384*12288 ATM and may grow)
So I plan on storing a simple color mask for using with a multi-tex shader in it too.
The simple color mask (128x128) get loaded at the same time I load my vertex heights(128x28),
and "blurred" into a 512x512 texture that the multi-tex shader will use.
At LOD-change time those heights will get lerped up into a 256x256 terrain
if it is LOD_0 or down to 32x32 for an LOD_3 terrain.



And I can say concisely that the textures WILL completely free their memory when
you use BOTH bmap_purge then bmap_remove. (dunno about ptr_remove though)