World: r3wp

not sure the event system allows this.

Shouldn't it?

In windows, if I do this then the left mouse down is interrupted 
by the right mouse click

In rebol, the only thing that stops a left mouse drag is left mouse 
up.

How does the event system work?

Surely we can fix this.

I'm not sure if it's easy to fix. Cyphre would know whether it's 
possible.

How do I get in contact with him?

He is usually offline in the weekend, but he may come online tomorrow.

beware though, that this may not be fixable.

I think it's been asked for a few times in the past ...

There is a hotkit file that can be modified to add ALT support but 
then you need to create pass-thru scenarios for general window meta 
commands if you want the application to behave normally - eg ALT-F4 
etc.

s/hotkit/hostkit*

Nicolas: It looks in R2 the scenario you described doesn't work (don't 
ask me why, I have no access to the R2 sources). But in R3 you can 
normally detect the RMB while LMB is down.

does anyone have documentation for the R2 SHAPE subdialect within 
draw?


the rebol.com does doesn't have ANY information on them... and i'm 
totally at loss in trying to figure it out... its just creating random 
shapes for me right now.

eh? Lots of examples http://www.rebol.com/docs/draw-ref.html

Does Rebol support holy images? http://synapse-ehr.com/forums/showthread.php?133-VID-delete-area

try an alpha instead of white.

If you cut part of an image out, the rest of the image collapses 
in.

If you had a requirement to log a user out of an application after 
a period of inactivity... what's the best way to do this?

I don't know of a single best way. One of the key elements, though, 
is determining what constitues "activity". If you have a central 
command dispatch loop of some kind, and every command that indicates 
activity goes through that makes it easier. Then you probably have 
some kind of default state that is used when the app starts up, and 
you revert to that. Of course, if you have useful state that you 
throw away the user won't be happy.

Hmm... so no way to monitor view events

You could have the remote client app monitor its own View events, 
and when there are some within 5 minutes, send a "I'm still here" 
message to the server. If the server doesn't receive any of those 
for an hour, then logout that client.

Graham: >> help insert-event-func

thanks .. so I can use insert-event-func to monitor global events 
and just pass them on.  If I don't get any user events I can lock 
the screen until the user types in a password

perhaps you can set a rate on the window face.

I already have one that sends a heart beat to the server

you can also patch the wake-event for even more control, but insert-event-func 
should be sufficient for your needs.

In general, using chroma keying is it possible to vary the level 
of transparency?


I've been playing with cyphre's "Transparency window under View" 
script  and I do not seem to be able to change transparency levels 
when using chroma keys.


I know this script is using window's user32.dll and it's not using 
draw to do the effect.

it will depend on what you mean by "chroma keying".   most people 
in the PC world interpret it as a single color value becomes 100% 
transparent (like a .bmp).


in the VFX world chroma keying is a range using an alpha channel 
mask (like a .png, for example).  so yes it is possible.  


IIRC, windows supports an alpha plane to manage the transparency, 
but I have not played with this myself yet.

R2's chroma key effect  uses a single color as the transparency. 
 so you'd need to build an alpha image using a range based on luma 
or some other more complex algorithm... which you can easily find 
on the net.

usually, you pick a center point, and decide on a range.  you can 
filter out the transparency with additional parameters like luma, 
saturation and things like that.  

basically adding or removing from each previous step, until you get 
the alpha channel mask you want.

I wanted to create a near transparent window onto another windows 
app so I could draw/sketch over it like they do on tv during a football 
game.


playing with Cyphre's script the transparency works on the whole 
window including title bars and borders.
 

Perhaps I could use a chrome key to get full transparency on the 
area I want to see throught to and lay over that a draw based semi-transparent 
object to draw on....I'll do some experimenting.


Else I will need to make the whole project Rebol and not use this 
"cheat"

Anyone play around with particle/plasma generators on rebol...I think 
I remember a script that had like a plasma effect.


I want to try and mimick fire and smoke....does not have to be super 
realistic....

is this done as an interactive process?

game engines use this simple system.


-create very transparent images with a gaussian fall off.  actually 
give the prefered shape to your image... so if you want a triangle-like 
flame, generate a smooth triangle with alpha/color falloff.

-create a block which will store a list of pairs, each one holds 
the position of a single "particle"

the idea is that points are inserted/removed in lifo order, with 
the order determining age.

decide on a number of particles, lets say   count: 20

decide on a particle life time... lets say  life: 10

then go over the list, picking up count amount of particles at at 
time with life number of interations.
the life iteration is used to calculate age: life / life-counter

then based on age, move the particles according to some simple randomized 
algorithm.  try to use something to ground their direction... sometimes 
refering to previous particles allows you to make movement constant... 
so lets say:


new-position: current-particle + 0x5 + random  either greater? last-particle/x 
current-particle/x [5][-5]

then move the particle to the appropriate position in the face.

as they spread out, they will disapear.

all is left, is to add/remove new pairs to your list, basically, 
the last iteration knocks off old particles from the list and inserts 
new ones at your fire origin.

if you want smoke, just add the "dying" particles to a second list, 
using the same process, to animate them but with a bigger/softer 
image.  

the dying fire becomes the birth of the smoke.

for the particles, either pregenerate (and simply offset) small faces 
with an transparent image or build an AGG block at each refresh.

you can even blur aging particles by adding an effects block to them 
as they age.  but that will probably kill the refreh

they only unknown is how many particles you can have before view 
really starts to slow down

also make sure to only call show on the region of your graphics which 
will really contain particles... there no point in blitting the whole 
house if only the window is on fire.

the plasma effect you saw used repetitive blur to an image, with 
new particles added and some offset added to the previous image.

the problem with this is that you cannot change the color and the 
fact that the whole image gets faded.

it could work if R2's effect system also managed the alpha channel 
but it doesn't AFAIK.

Hope this helps!