C / C++ / MFC

Panning -Zooming-Centering 2d shapes

9-Jun-03 23:15

Omar Alvi wrote:
does it depend upon the size of the address bus of the cpu

Yes, but there are some issues. Under DOS or Windows before Win95, a pointer was 16 bits. Under Win95 or later, a pointer is 32 bits (although under 64-bit Windows it's 64 bits). Even though it may be the same computer. The PentiumIII and later processors actually have an address bus larger than 32 bits (From memory I think it's 36 bits), but the OS does not use it all at the moment, so a pointer is still only 32 bits.

Ryan

Being little and getting pushed around by big guys all my life I guess I compensate by pushing electrons and holes around. What a bully I am, but I do enjoy making subatomic particles hop at my bidding - Roger Wright (2^nd April 2003, The Lounge)

Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late - John Nichol "Point Of Impact"

ninpo9-Jun-03 4:50

ninpo

9-Jun-03 4:50

I have been working on this for about 3 weeks and have not got any where. Perhaps someone out there can send me in the right direction. The Big picture I'm after is, given a length and width (of a 2d shape)Draw the shape to the screen centered and given a little margin, and be able to drag the mouse across the screen and it will display the XY in the status menu (have the code for this done but numbers are wrong....just need the formulas to calculate it), and finally to be able to Zoom or Pan.

Thats the total direction I'm heading, but I believe the panning and zooming in MFC is real easy by just setting the SetViewExtents and by moving the view origin around (again that is what I believe)

What I've been banging my head against the wall with is this centering aspects of the shape. (AS A SIDE NOTE: I want the units to be real ie if I have a rectangle that is 5.25x1.25 in or mm then use those such that when I do my magic calculations then the cursor gives you those positions as you move the cursor over it)

Anyway, back to the orignal, This is the code I have been playing with in my Ondraw functin:

(CPoint apt is the length and width of the rectangle) if I change these I want the shape to be drawn centered

CTestHelpDoc* pDoc = GetDocument();
ASSERT_VALID(pDoc);
m_pDC=NULL;

CPoint apt;
apt.x=5250; //5.25*1000
apt.y=1250;//1.25*1000 units scaled by 1000

CRect arect;
GetClientRect(&arect);
pDC->SetMapMode(MM_ISOTROPIC);//MM_HIENGLISH
int m_iView=(int)(viewextents);

pDC->SetWindowExt(m_iView,m_iView);

int m_iSize=0;
if(arect.right>arect.bottom)
m_iSize=int(arect.right*scalefac);
else
m_iSize=int(arect.bottom*scalefac);

double testX=apt.x/viewextents;
double testY=apt.y/viewextents;

double m_RatioX= testX * m_iSize;
double m_RatioY= testY * m_iSize;

int Rx,Ry;
// Rx=(m_iSize-m_RatioX)/2;
// Ry=arect.bottom-(arect.bottom-m_RatioY)/2;
Rx=(((double)apt.x*((double)arect.right/viewextents))+arect.right)/4;
Ry=m_RatioY/2;

pDC->SetViewportExt(m_iSize,-m_iSize);
// pDC->SetViewportExt(viewextents/2,-viewextents/2);
// pDC->SetViewportExt(testX,-testY);
// pDC->SetViewportExt(arect.right,-arect.bottom);

// pDC->SetViewportOrg(m_iSize/2,m_iSize/2);
pDC->SetViewportOrg(arect.right/2,arect.bottom/2);

// pDC->SetViewportOrg(Rx,Ry);
// pDC->SetViewportOrg(m_RatioX,m_RatioY);
// pDC->SetViewportOrg(m_RatioX,m_RatioY);
// pDC->SetViewportOrg(testX/8,testY/1.4);

// pDC->OffsetViewportOrg(-apt.x,-apt.y);
pDC->OffsetViewportOrg(-Rx,Ry);
// pDC->OffsetViewportOrg(-m_RatioX*1.3,m_RatioY*2.0);

pDC->Rectangle(0,0,apt.x,apt.y);

//Orgin
pDC->MoveTo(0,0);
pDC->LineTo(0,50);
pDC->MoveTo(0,0);
pDC->LineTo(50,0);

I need to set this up correct so when I go after the mousemove to update the status pains with the locatin in real units that they work correctly as well as have it ready for zooming and panning.

Thanks in advance!

-Eric

How to import the addressbook of the Cuteftp to my program?

kindows9-Jun-03 4:38

kindows

9-Jun-03 4:38

I want to develop a FTP client like Cuteftp,and want to share my addressbook with the cuteftp, so I need to know the structure of the addressbook of the cuteftp. Who knows it or where can I find the explanation of the structure of the addressbook?
Thank you very much!

Which API can set a image file as wallpaper?

white jungle9-Jun-03 4:35

white jungle

9-Jun-03 4:35

I do have MSDN.But I don't know which keyword I can use to look for it!

Re: Which API can set a image file as wallpaper?

Ryan Binns9-Jun-03 4:43

Re: Which API can set a image file as wallpaper?

9-Jun-03 4:43

SystemParametersInfo() with the SPI_SETDESK_WALLPAPER option. However, this is a temporary change (it disappears after a reboot). To make it permanent, you'll also have to change the registry. The key to look at is "HKEY_CURRENT_USER\Control Panel\Desktop\Wallpaper".

Remember that this only works if web-view is disabled for the desktop, and Windows can only show BMP images when web-view is disabled.

Hope this helps

Ryan

Being little and getting pushed around by big guys all my life I guess I compensate by pushing electrons and holes around. What a bully I am, but I do enjoy making subatomic particles hop at my bidding - Roger Wright (2^nd April 2003, The Lounge)

Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late - John Nichol "Point Of Impact"

kindows9-Jun-03 4:44

kindows

9-Jun-03 4:44

Try SystemParametersInfo

Re: Which API can set a image file as wallpaper?

Sardaukar9-Jun-03 22:02

Sardaukar

9-Jun-03 22:02

[MSDN October 2001]

IActiveDesktop::SetWallpaper
Sets the wallpaper for the Active Desktop.

HRESULT SetWallpaper(
LPCWSTR pwszWallpaper,
DWORD dwReserved
);

Parameters
pwszWallpaper
String value containing the file name of the wallpaper to be set.
dwReserved
Reserved. Must be set to zero.
Return Values
Returns S_OK if successful, or an OLE error code otherwise.

See Also
IActiveDesktop

Requirements
Version 4.71 and later of Shell32.dll

Windows NT/2000: Requires Windows 2000 (or Windows NT 4.0 with Internet Explorer 4.0 or later).
Windows 95/98/Me: Requires Windows 98 (or Windows 95 with Internet Explorer 4.0 or later).
Header: Declared in Shlobj.h.

So it should work from IE 4.0+. Hope it helps.

For a lower version, try SystemParametersInfo:

BOOL SystemParametersInfo(
UINT uiAction, // system parameter to retrieve or set
UINT uiParam, // depends on action to be taken
PVOID pvParam, // depends on action to be taken
UINT fWinIni // user profile update option
);

SPI_SETDESKWALLPAPER
Sets the desktop wallpaper.

The value of the pvParam parameter determines the new wallpaper.
To specify a wallpaper bitmap, set pvParam to point to a null-terminated string containing the name of a bitmap file.

Setting pvParam to "" removes the wallpaper.
Setting pvParam to SETWALLPAPER_DEFAULT or NULL reverts to the default wallpaper.

Basic understanding question...

CherezZaboro9-Jun-03 4:32

CherezZaboro

9-Jun-03 4:32

Using WSAEvents winsock notifications... Under what circumstances would a client get FD_WRITE and FD_CONNECT at the same time? I mean WSAEnumNetworkEvents gives me 0x12(18) in WSANETWORKEVENTS::lNetworkEvents which to me looks like FD_CONNECT|FD_WRITE.
Confused | :confused:

That throws me off pretty bad.

valikac9-Jun-03 6:35

9-Jun-03 6:35

Upon an initial connection, the server will trigger both FD_CONNECT and FD_WRITE events.

Kuphryn

CherezZaboro9-Jun-03 7:02

CherezZaboro

9-Jun-03 7:02

Thanks! OK I get it. Now is there any chance or a situation when I will NOT recv the FD_CONNECT notification. May be when ::connect returns success right away - without WSAWOULDBLOCK?
MSDN help is vague on this.

valikac9-Jun-03 7:22

9-Jun-03 7:22

connect() is a blocking winsock API. If it returns immediately, then yes there is a possibility the process will not receive FD_CONNECT.

Kuphryn

CherezZaboro9-Jun-03 7:36

CherezZaboro

9-Jun-03 7:36

That's strange..
My MSDN in connect() article says:

<br />
For connection-oriented, nonblocking sockets, it is often not possible to complete the connection immediately. In such a case, this function returns the error WSAEWOULDBLOCK. However, the operation proceeds.<br />
<br />
When the success or failure outcome becomes known, it may be reported in one of two ways, depending on how the client registers for notification.<br />
<br />
If the client uses the select function, success is reported in the writefds set and failure is reported in the exceptfds set.<br />
If the client uses the functions WSAAsyncSelect or WSAEventSelect, the notification is announced with FD_CONNECT and the error code associated with the FD_CONNECT indicates either success or a specific reason for failure.<br />

It actualy feels just like WSAConnect and I get notification most of the time but not always.
Should I switch to WSAConnect or what?

valikac9-Jun-03 7:39

Re: Layered window problem

9-Jun-03 7:39

Yes, I highly recommend WSAConnect(). I am not familiar with connect() because I always use WSAConnect() under non-blocking I/O model.

Kuphryn

Layered window problem

Bedas9-Jun-03 4:21

Bedas

9-Jun-03 4:21

Hello,
I'm using the SetLayeredWindowAttributes() function for
setting transparency of a frame window. It works fine but
all window childs (edit boxes, combo boxes ...) are
transparent too. Is it possible to make childs opaque but
with preserving parent transparency ?

Thank you.

Bedas

Ryan Binns9-Jun-03 4:37

Re: Layered window problem

9-Jun-03 4:37

You could try calling SetLayeredWindowAttributes() for each child window, but I don't think it would work. I may be wrong though.

Ryan

Being little and getting pushed around by big guys all my life I guess I compensate by pushing electrons and holes around. What a bully I am, but I do enjoy making subatomic particles hop at my bidding - Roger Wright (2^nd April 2003, The Lounge)

Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late - John Nichol "Point Of Impact"

Bedas10-Jun-03 0:31

Bedas

10-Jun-03 0:31

Thank you, but unfortunately it doesn't work.

Re: Layered window problem

Ryan Binns10-Jun-03 0:51

10-Jun-03 0:51

I didn't think it would. I think you're attempting something that Windows does not support. You might have to implement the transparency yourself if you really need this feature. It's not standard and may very well confuse some users.

Ryan

Being little and getting pushed around by big guys all my life I guess I compensate by pushing electrons and holes around. What a bully I am, but I do enjoy making subatomic particles hop at my bidding - Roger Wright (2^nd April 2003, The Lounge)

Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late - John Nichol "Point Of Impact"

List Control

User 98859-Jun-03 3:49

User 9885

9-Jun-03 3:49

I have a list control with LVS_OWNERDATA style set. This creates one problem for me. When an item is inserted or deleted, the selected index remains the same, but the item at the index may have changed due to the change in the underlying list.

I wanted to know whether anyone else faced this problem, and what was done to rectify it.

My article on a reference-counted smart pointer that supports polymorphic objects and raw pointers

modified 29-Aug-18 21:01pm.

Re: List Control

valikac9-Jun-03 6:37

9-Jun-03 6:37

How does the program determine which items are selected? One solution is to determine the selected items in the on item change handler. Thus, item insertion will cause windows to send an item change message.

Kuphryn

Re: List Control

User 98859-Jun-03 6:56

User 9885

9-Jun-03 6:56

I use

int index = GetNextItem(previous_index, LVNI_SELECTED);

to get the selected item.

With the OWNERDATA style, I don't have to insert items into the list view control using InsertItem. Rather, I just add items in the underlying container and call SetItemCount() on the control with the number of items.

Say, I was at index 0, and a new item was added at the top of the container. Now the selected index is still 0, but the item that is at that index is the new item. The same problem occurs when the container is sorted.

The only option I can think of now, is to get the object that is in the container at the index before changing it, and then find the index of same object in the modified container, and selecting that item from the code, and then make sure that the item is visible.

I was looking for an easier solution to this Big Grin | :-D

My article on a reference-counted smart pointer that supports polymorphic objects and raw pointers

modified 29-Aug-18 21:01pm.

Re: List Control

valikac9-Jun-03 7:26

Re: Getting text into Word

9-Jun-03 7:26

One solution is to update the index database that holds the selected items. Here is one example.

Selected indices:
2
3
5
8
10
13
15

- insert new item at index 0

Now using STL, one solution is to determine where the item was inserted and update the index database.

Updated selected indices:
3
4
6
9
11
12
16

Kuphryn

Getting text into Word

Martyn Pearson9-Jun-03 3:32

Martyn Pearson

9-Jun-03 3:32

I am trying to get RTF text into an MS Word document, using automation. I have a method which works fine, whereby I write the rtf to the file, then call the Range object's InsertFile() method. However, this is a little slow, to say the least.

Any ideas on how I could transfer my text quicker?

Thanks in advance!

Ryan Binns9-Jun-03 4:24