Oleg Kobchenko wrote: > I am not suggesting to use a VRML layer. I try to say > that in the design of VRML seasoned 3D professionals > already solved those problems and their _ideas_ can be used.
I had not understood that that's what you were doing. Thanks for correcting me. > I believe this topic is about user input interaction > as opposed to model representation or rendering. > What do you mean by 'flat'? I had been talking about representation. This was a somewhat generic comment on the quality of the imagery I saw. I don't know if that was a VRML issue or an application issue but given the context you had intended this is a moot point. >> But I think that what I'm asking for is much simpler. It could >> be broken down into two more general operations: >> >> (1) The ability to supply a small image to use as the mouse >> cursor (for cross platform portability this would either have >> to be a bit map or there would have to be some way of discovering >> the limitations of the platform). Alternatively, it might be >> adequate to have a set of (abstractly defined) cursors one of >> which is picked by numeric index. I've seen systems use both >> mechanisms, I don't care which is documented as long as I can >> make the thing transparent. > > I thought you were talking about a 3D cursor, which is not > an image, but a 3D object, a manipulator, which can, for example > grab things. If that's a plain bitmap, than how is it different > from a regular screen cursor? The bitmap (or other image) would be for the OS mouse cursor. If I can make the OS mouse cursor be an image where all pixels are transparent, I am then free to render an alternative "mouse cursor" inside the opengl control. If I do this right, it will seem seamless to the user, though obviously it's somewhat more complicated from a programmer's point of view. >> ever is under the mouse at the time. So it could be generally >> useful if J would let me say: when the cursor is over this >> graphical element, the cursor looks like (specified value). And >> maybe assign a priority to that to allow the user to implement >> different concepts (does the button take priority over the form, > > J and even OpenGL layer wouldn't be able to link cursor > shape with position over an object, it's application's job. > OpenGL may only help make a hit test. > > BTW, in VRML there is just such feature, called Anchor: > if you hover over an anchor-enclosed geometry, cursor changes, > just like over a hyperlink on a web page. Quite true. But I was talking about a change in J -- in the 2 dimensional OS windowing enviroment. For example, consider an elementary J form: coinsert 'jgl3' [ require 'gl3' A=: 0 : 0 pc a; xywh 0 _1 50 50;cc g isigraph ws_clipchildren ws_clipsiblings; xywh 56 6 34 11;cc b1 button;cn "button 1"; xywh 56 20 34 11;cc b2 button;cn "button 2"; xywh 56 35 34 11;cc b3 button;cn "button 3"; xywh 55 51 34 11;cc b4 button;cn "button 4"; pas 6 6;pcenter; rem form end; ) a_g_paint=: 3 : 0 glClear GL_COLOR_BUFFER_BIT glaSwapBuffers'' ) a_run=: 3 : 0 wd A glaRC'' wd 'pshow;' ) a_close=: 3 : 0 wd'pclose' ) Now imagine I could set the appearance of the OS mouse cursor which is used when the mouse is over some form or form element. Hypothetically, the following set of commands might arrange so that when the mouse was over the opengl control it was transparent, when the mouse was over the top button, it was a cross hair, except that temporarily during "expensive calculation" the mouse is an hour glass when it's anywhere over the form. wd 'setMouse c 1 g *',mouseClear wd 'setMouse c 1 b1 *',mouseHand wd 'setMouse p 2 a *',mouseWaiting expensive calculation wd 'setMouse p 0 a *',mouseNormal This potential feature would a j form editor feature, which you could use for any j control. My application might be using it in the context of an opengl control, but nothing limits its use to my context. Does this make sense? To recap -- what I'm looking for from the J environment is: (1) Ability to set the displayed mouse image for an element of a J form. (2) Ability to control the position the OS mouse. (3) Support for more keys and mice buttons. Everything else I've written in this thread is just my idea of motivation, it's not something I'm asking someone else to implement. Thanks, -- Raul ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
