Re: Problem understanding image rotation. - C / C++ / MFC Discussion Boards

Johpoke6-Oct-06 5:08

6-Oct-06 5:08

Would anyone know how to do this, or have any pointers on it:

using getpixel read a pixel on the screen, then do if 3<g<255

so="" basicly="" if="" a="" pixel="" contains="" hint="" of="" green="" execute="" some="" code?=""

thanks

="" johannes=""

<div="" class="ForumSig">/Johannes

Re: GetPixel

Mark Salsbery6-Oct-06 5:16

Mark Salsbery

6-Oct-06 5:16

if (GetGValue(GetPixel(hdc, xpos, ypos)) > 0)
{
execute some code
}

Re: GetPixel

Johpoke6-Oct-06 5:25

Johpoke

6-Oct-06 5:25

whats the hdc bit?

thanks

/Johannes

Re: GetPixel

Mark Salsbery6-Oct-06 5:31

Mark Salsbery

6-Oct-06 5:31

Handle to a device context for the screen.

HDC hdc = GetDC(0);

You asked about reading a pixel from the screen, yes?

Mark

Re: GetPixel

Hamid_RT6-Oct-06 19:49

Hamid_RT

6-Oct-06 19:49

Or you can use GetGValue(GetPixel(GetDC()->m_hDC,x,y)); Smile | :)

WhiteSky

Re: GetPixel

Mark Salsbery7-Oct-06 8:44

Mark Salsbery

7-Oct-06 8:44

>>Or you can use GetGValue(GetPixel(GetDC()->m_hDC,x,y));

But that's a window pixel, not a SCREEN pixel Poke tongue | ;-P

lol

Problem understanding image rotation.

Mark F.6-Oct-06 4:39

Mark F.

6-Oct-06 4:39

I have tried to rotate an image using GDI+ but I have trouble understanding how to do it. Some examples describe calling TranslateTransform() before calling RotateTransform(). The MSDN files are not clear on this. I do all the drawing in a CView from OnDraw().

I would really appreciate clarification on this.

Thanks!

"Eat till you're sleepy, sleep till you're hungry." - Mark

Re: Problem understanding image rotation.

Maximilien6-Oct-06 4:46

Maximilien

6-Oct-06 4:46

Disclaimer : I hate it when I cannot put into "good" words what I'm trying to explain.

Me think, you need to translate to the origin, otherwise, the image will be rotated around the origin, and if it's not it will be what you expect the rotation to be.

or, the image will not be rotated against its center point like you expect.

Maximilien Lincourt
Your Head A Splode - Strong Bad

Re: Problem understanding image rotation.

Mark F.6-Oct-06 4:48

Mark F.

6-Oct-06 4:48

Maximilien wrote:
Me think, you need to translate to the origin, otherwise, the image will be rotated around the origin, and if it's not it will be what you expect the rotation to be.

Are you suggesting that my image is there, but rotated out of the view (origin problem)?

"Complexity breeds problems. Keep it simple." - Mark

Re: Problem understanding image rotation.

Maximilien6-Oct-06 4:50

Maximilien

6-Oct-06 4:50

maybe.

Maximilien Lincourt
Your Head A Splode - Strong Bad

Re: Problem understanding image rotation.

Stephen Hewitt6-Oct-06 21:02

Stephen Hewitt

6-Oct-06 21:02

The rotation will be around the origin. You're probably after a rotation around the center of the image. Try something like this.

graphics.TranslateTransform(-cx, -cy);
graphics.RotateTransform(30.0f, MatrixOrderAppend);
graphics.TranslateTransform(cx, cy, MatrixOrderAppend);

Where cx and cy are the center of the image (the point you wish to rotate around). This code builds a transformation that effectively translates the image so that the point you want to rotate around is at the origin, rotates around the origin and then translates the image back to its proper location.

Steve

EnumDisplaySettings

viliam6-Oct-06 4:02

viliam

6-Oct-06 4:02

hi,
I am using function EnumDisplaySettings to get Windows resolution
like this:

DEVMODE dm;
dm.dmSize = sizeof(DEVMODE);
dm.dmDriverExtra = 0;
EnumDisplaySettings(NULL, ENUM_CURRENT_SETTINGS, &dm);

..and resolutin is in dm.dmPelsWidth and dm.dmPelsHeight

It works fine in WinXP - I am programming it, but
i need to run it on Windows 95 and even function return TRUE
the values in DEVMODE are nonsencical and probably random.

Does anyone solved this problem?
Or know any other function to get resolution in Win95
Thank you

viliam

Re: EnumDisplaySettings

David Crow6-Oct-06 4:17

David Crow

6-Oct-06 4:17

Why not use GetSystemMetrics()?

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

Can hook the window of a service with WH_CBT system hook? [modified]

lijian_41326-Oct-06 3:58

lijian_4132

6-Oct-06 3:58

I try to hook the window of a service with WH_CBT system hook, but it doesn't work.

Re: Can hook the window of a service with WH_CBT system hook?

Mark Salsbery6-Oct-06 4:52

Mark Salsbery

6-Oct-06 4:52

Not many services have windows Smile | :)

Mark

Re: Can hook the window of a service with WH_CBT system hook?

James Brown7-Oct-06 7:09

James Brown

7-Oct-06 7:09

you must be runing under the same desktop context in order to 'hook' a window this way. So your must be a service as well.

http://www.catch22.net

CFileDialog question

<color>Aljechin 6-Oct-06 3:28

<color>Aljechin

6-Oct-06 3:28

I am using CFileDialog to select multiple files. When I select single file, the member function GetPathName(). But when multiple files are selected the folder path is returned. How do I get the path of all the files that are selected.

Re: CFileDialog question

David Crow6-Oct-06 3:55

David Crow

6-Oct-06 3:55

Did you not read the documentation? It plainly states that:

If m_ofn.Flags has the OFN_ALLOWMULTISELECT flag set, you should call GetStartPosition() and GetNextPathName() to retrieve a file pathname.

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

Re: CFileDialog question

<color>Aljechin 6-Oct-06 4:55

<color>Aljechin

6-Oct-06 4:55

I asked a doubt and I give 5 when I am helped. I dont know who is the fool that is giving a low rating to a person who replied to *me*. 5/5 for both of you.

Re: CFileDialog question

David Crow6-Oct-06 5:04

David Crow

6-Oct-06 5:04

Just ignore the voting system. It's so easily abused, the numbers mean nothing.

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

Re: CFileDialog question [modified]

prasad_som6-Oct-06 3:58

prasad_som

6-Oct-06 3:58

Use this loop ,

POSITION pos = dlg.GetStartPosition();
while (pos != NULL)
{
   CString sFileName = dlg.GetNextPathName(pos);
}

-- modified at 10:05 Friday 6th October, 2006

Prasad
Notifier using ATL | Operator new[],delete[][^]

Re: CFileDialog question

<color>Aljechin 6-Oct-06 4:05

<color>Aljechin

6-Oct-06 4:05

Thank you very much.

Re: CFileDialog question

<color>Aljechin 6-Oct-06 4:56

<color>Aljechin

6-Oct-06 4:56

I asked a doubt and I give 5 when I am helped. I dont know who is the fool that is giving a low rating to a person who replied to *me*. 5/5 for both of you.

Re: CFileDialog question

prasad_som6-Oct-06 5:15

prasad_som

6-Oct-06 5:15

As said by David , just ignore it. Smile | :)

Prasad
Notifier using ATL | Operator new[],delete[][^]

Page Rank

Mahesh Kulkarni6-Oct-06 2:16

Mahesh Kulkarni

6-Oct-06 2:16

Hi All,
Does anyone have idea how to get the Google PageRank using VC++?
Thanks In Advance.

The secret of life is not enjoyment
but education through experience.
- Swami Vivekananda.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.