World: r3wp
[View] discuss view related issues
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Maxim 25-May-2009 [8934x4] | that's the demo I was talking about ;-) |
so you don't mind if I use that code in my own projects? | |
first use will be to build a keyframe editor, which will be distributed with liquid-paint, with MIT license. | |
(for spline-based animation curves.) | |
Geomol 25-May-2009 [8938x2] | Use as you like. |
do you know of an algorythm (expressed in code, not in math) that can give me the ellipse with two supplied coordinates. center and one point which touches the ellipse? Isn't there an infinite number of ways, you can do that? | |
Maxim 25-May-2009 [8940x2] | thanks! for the spline code, with a few changes, one in three points should pass directly through the point and the two other points will be used as tangeants. |
its not really obvious... I'm not a math expert, even if I've done some pretty cool 3D engines (crowd simulation, for example) it takes me a lot of time to get the math part of things done when its question of doing math mix and match. | |
Geomol 25-May-2009 [8942] | Let's say, you have center and a point with same y-coordinate as center. So it's just horizontal out from the center. Now the ellipse can be any height, so you can make infinite many ellipses with those two points. |
Maxim 25-May-2009 [8943] | I did whole evening of research on the ellipse and didn't find a single exact procedure to do it... some math dr have done their thesis just on finding ways to calculate its arc len ! though I think its possible to resolve the two foci based on the angle and distance of the point we want to pass through the arc, all the math needed to get to the proper major and minor axis (eventually equating to what people call the x and y radius) is pretty intensive. |
Geomol 25-May-2009 [8944] | In DPaint (and Canvas RPaint), you specify center and corner of ellipse. It's then not rotated. After specifying size this way with two points, you can rotate it. |
Maxim 25-May-2009 [8945x2] | yes but the corner is not *ON* the line, its equal to the major and minor axis of the elipse. |
if I where to drag one of those points to an angle of 30 degres, I still want the arc to touch my point. | |
Geomol 25-May-2009 [8947] | Yup, but you can't make just one ellipse with center and point on the ellipse. |
Maxim 25-May-2009 [8948] | there is definitely a way to calculate it mathematically, but there are so many steps, I get lost in the procedure to get to it. |
Geomol 25-May-2009 [8949x2] | :-) Think of my example with center and point horizontal out from the center. What height should your ellipse be? |
The problem is not, that it's hard. It's impossible. | |
Maxim 25-May-2009 [8951] | in that case, its can be treated as a special case... like a like since one of the axis is = 0 just like the up vector of a 3d object cannot be (0,0,0) |
Geomol 25-May-2009 [8952] | Ah, I now think, I understand, what you want. It's like the arc drawing routine, where you want the point to be on the line. Same thing with ellipse. |
Maxim 25-May-2009 [8953x2] | but if x and y axis aren't = 0 then the angle of the point, can let you calculate the two foci, which are relation to x/y. |
yep. | |
Geomol 25-May-2009 [8955] | And you don't want the ellipse rotated at first? |
Maxim 25-May-2009 [8956x5] | for an arc drawing its a bit simpler, since by using three points, you actually get points directly on the line. |
yep. rotation I can deal separately, using an actual separate rotation value | |
(after) | |
re-reading... my answer is ambiguous.... I mean that I don't need rotation as part of the arc on point algorythm. | |
do you think you can pull it off? | |
Geomol 25-May-2009 [8961x2] | I'm still not convinced, it can be done. That there is only one solution. Try Canvas RPaint: do http://www.fys.ku.dk/~niclasen/rebol/canvas099.r And draw two points. Then start an ellipse in one point. Can you see, you can make infinite many ellipses going through the other point? |
Even if they're not rotated. You need to put some restrictions on your ellipse to only have one solution. | |
Maxim 25-May-2009 [8963x5] | its funny, yep... now that I try doing it interactively, I realise, that you must know 2 out of 3 values to resolve an ellipse... |
the funny part is that my vectorial app lets me try it out just like yours, but I didn't get to that point in my head. well, it was a nice dream while it lasted ;-) | |
btw, rpaint is really nice. | |
I really like the look of the tool selection is it just a button rotated 180 degres? | |
LOL "workbench" in the menu... | |
Geomol 25-May-2009 [8968] | The selection effect is not just a button rotated 180, but took some drawing. :-) |
Maxim 25-May-2009 [8969] | it really is perfect. probably some of the most polished rebol GUI work I've seen so far. |
Geomol 25-May-2009 [8970] | Thanks! :-) |
Dockimbel 25-May-2009 [8971] | I agree, that's very good and high quality work. Nice tribute to the Amiga. |
Graham 15-Jun-2009 [8972x2] | Is there a way to dynamically turn a field into info and back again ... so to prevent users from editing various fields on an as required basis? |
Hope VID+ has a way to dynamically disable/ghost out widgets .... | |
Chris 15-Jun-2009 [8974] | Switch out 'feel objects and visual facets, unfocus, then 'show? (trying to recall if that's right...) |
Graham 15-Jun-2009 [8975] | should be easier! |
Maxim 15-Jun-2009 [8976] | Oldes/graham here is a complete application which shows you how to build and affect a face with a ghost effect. ---------------------------------- rebol [] ghost-blk: [ ghost-data: none ghost: func [][ self/ghost-data: make self [] self/image: img: to-image self effect: [ merge grayscale contrast -50 ] ;size: img/size edge: text: feel: pane: none show self ] regenerate: func [/local attr][ foreach attr [image effect feel edge text feel pane][ set in self attr get in ghost-data attr ] ghost-data: none show self ] ] stylize/master compose/only [ field: field with ghost-blk button: button with ghost-blk btn: btn with ghost-blk scroller: scroller with ghost-blk ] view layout [ across toggle "btn" [either face/data [my-btn/ghost][my-btn/regenerate]] toggle "button" [either face/data [my-button/ghost][my-button/regenerate]] toggle "field" [either face/data [my-field/ghost][my-field/regenerate]] toggle "scroller" [either face/data [my-scroller/ghost][my-scroller/regenerate]] return my-btn: btn "yippe" my-button: button "ka" my-field: field "yay" my-scroller: scroller 100x20 ] |
Graham 15-Jun-2009 [8977] | Very nice Max |
Maxim 15-Jun-2009 [8978x3] | you can easily adapt this for rebgui by simply replacing the feel related code above by whatever rebgui uses. |
thanks. | |
wrote this in 5 minutes... I always wonder why people complain about VID . its very easy to manipulate and control. | |
Graham 15-Jun-2009 [8981] | sure :) |
Maxim 16-Jun-2009 [8982x2] | anyone know of an official way to push a rebol view window back on top of all windows on the display? |
right now I am closing windows and reopening them... but if a pop-up is displayed, I'm getting strange results. | |
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