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I want to draw an open line which smoothly passes several (or any number of) points.
those points are set by user with mouse clicking.
do you know any formula suitable for c++ code to draw the smooth line passing all of those points?
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includeh10 wrote: want to draw an open line which smoothly passes several (or any number of) points.
A line, or straight line, can be described as an infinitely thin, infinitely long, perfectly straight curve.
Three or more points that lie on the same line are called collinear.
So for you, if the user clicks on different points that are not collinear than it won't be possible for you to connect this points using one single line. You would need to store the points in an array (or whatever you prefer) and then draw a line betweent the consecutive points.
You could prefer a curve if you want to connect these points but a single line won't do it, unless and until the points are collinear.
Somethings seem HARD to do, until we know how to do them.
 _AnShUmAn_
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Use a spline!
You can implement it with polynomial expression joining 3 or 4 points each time and then join the splines obtained to get a continuos line.
Cheers,
Russell
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I is what I am thinking.
Any existing code or formula to get related params for >=3 (4 or more is prefered) points?
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Here you can fine some interesting formula
http://www.codeproject.com/useritems/SplineInterpolation.asp
Cheers,
Russell
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A modelless dialog with child property is created on a main dialog,just like notepad with find dialog been opened,except the modeless dialog has a List Control.
now do it like this:
set focus(click the left mouse button) to the List Control(if the List Control's tab order is not 1) firstly,secondly, minimize the main dialog, then restore it.
now you will find the problem: the List Control remains not refreshing!
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eat_union wrote: the List Control remains not refreshing!
What does this mean ?
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the List Control remains not refreshing
means that the List Control does not be displayed.
I'm a chinese.
I'm so sorry to my poor english.
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eat_union wrote: the List Control remains not refreshing
means that the List Control does not be displayed.
How you are creating list box ? One place its creation could be in in WM_INITDIALOG handler.
eat_union wrote: I'm so sorry to my poor english.
Never mind. You can count me one with you. 
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You need to show , how you have created list box ?
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Oh ! I'm not able to reproduce said behaviour. May be you can try it with other application. And see the difference.
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thanks for your help!
I do the same operation in another simple project, and the problem cant not be reproduced too,
I will try to find my fault.
thanks.
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That's cool. All the best. Do post, when you find ,what you was doing wrong.
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Yes it can be refreshed correctly.
Probably you mean redraw, not refresh. Anyway, it's the programmer's job to handle WM_ACTIVATE, WM_SETFOCUS etc.
Could be a SetRedraw with FALSE without a SetRedraw with TRUE?
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yes, i mean that the List Control disappeared.
when the main dialog being restored, i add some code:
<br />
CDialog::OnSysCommand(nID, lParam);<br />
if (SC_RESTORE == (nID & 0xFFF0) && hRefresh)
::RedrawWindow(hRefresh, 0, 0, RDW_FRAME | RDW_INVALIDATE);<br />
now, program is solved, but i want to know why.
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Check with spy++ the list size and visibility while the main dialog is minimized.
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If you use of RedrawWindow what happens
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It's a MFC bug, I think.
first, I should say "List Control remains not refreshing" means "List Control disappeared".
I'm sorry to my poor english!
In order to produce the problem, the main dialog must has a tab control(Last time, I forgot to explain), and the modelless dialog must covers total or part of the tab control.
I can solve the problem(use RedrawWindow to force the List Control Repaint when main dialog be restored),but I want to know why.
will you please have a try, and I'm sure you'll get the problem.
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This is not an MFC bug. Listbox controls have nothing to do with MFC.
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hello all:
i want to use the 'avi/wav file source filter' in my filtergraph,but the method AddSourceFilter(...) by graphbuilder add the filter 'file source filter' in the filterchain,how can i change that,and to configure the filepath for my 'avi/wav file source filter'.
sorry for my poor english
thanks in advance
henry
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What part is giving you trouble?
File Source (Async) Filter
CLSID = CLSID_AsyncReader
Category = CLSID_LegacyAmFilterCategory
File Source (URL) Filter
CLSID = CLSID_URLReader
Category = CLSID_LegacyAmFilterCategory
If you've added the file source filter then use its IFileSourceFilter interface's Load() method
to get the filter to load the file.
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hi this is ramesh .
i am writing a small win32 appl..i am using hierarchical stucture of check boxes in it(Tree view)
the functionality i badly needed is if i select a root item the child checkboxes should also get selected. could u help me to solve this problem??
if u have any example applications could u send me??
my mail id is sramesh21@gmail.com .
thanks in advance.
regards,
ramesh s
ramesh s
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