I have Microsoft''s Picture It! software and it allows you to grab a point on a picture and drag it around. Does anyone here know how I might be able to accomplish this myself?

on mousedown event:

obtain x and y from mouse.
find out which point is closest to that and store it''s id.
set a global flag indicating "dragging" is true.

on mousemove event:

if "dragging" is true, AND if the id has a value >= 0, set the x and z (or whatever you want) of the point stored in the id to the x and y value of the mouse (maybe transform them, depending on the mode you are in (glOrtho?))

on mouseup event:
set "dragging" to false
set id to e.g. -1, indicating no point is selected for dragging (optional)

Sorry I wasn''t perfectly clear there. I don''t mean the whole picture, I mean drag a small part of the picture to distort it

Try something like

draw picture as texture on high density gridselect start pointselect end pointget drag direction vectorscale down direction vector by something like    dx = dx / picture_width;    dy = dy / picture_height;for each vertex on grid    get distance from start point    if the vertex is in range of tool (it has some kind of too_radius)        use some gaussina or sinus based function to calculate force based on radius. something like force = cos( radius / tool_radius * Pi * 0.5f );        apply (force * direction vector) to texture coordinatesrepeat  

You should never let your fears become the boundaries of your dreams.

[edited by - _DarkWIng_ on February 5, 2004 3:37:16 AM]