C / C++ / MFC

How to draw a Gradient(as fog) background

14-Jun-07 17:47

If you install a hook, your applications hook will be called first. If another application installs a hook after some time, then that applications hook willl be called first and then that application calls your hook using the CallNextHookEx (). So you dont have to mind the hook installed after your application has started.

So in your hook funtion, call the CallNextHookEx() first( this will call all the preinstalled hooks ) then only do the processing you want. Thus your hook will become the last one.

nave

[OpenedFileFinder]

Re: Hook chain order

codeprojecter_15-Jun-07 4:17

codeprojecter_

15-Jun-07 4:17

Thanks Naveen Smile | :)

HOW WHAT14-Jun-07 14:39

14-Jun-07 14:39

Hi, i need draw a fog background, i search Internet find a source, but it run slow, how to optimize these code let it run fast( i nill malloc memory in twice, i want to unite DrawGradient function and ApplyTransformation function). or tell me other draw example.

Thanks.

// GradientRender.h: interface for the CGradientRender class.<br />
//<br />
//////////////////////////////////////////////////////////////////////<br />
<br />
#if !defined(AFX_GRADIENTRENDER_H__9B3090DB_F7D0_4D23_8BDA_9CFAC9A64ABE__INCLUDED_)<br />
#define AFX_GRADIENTRENDER_H__9B3090DB_F7D0_4D23_8BDA_9CFAC9A64ABE__INCLUDED_<br />
<br />
#if _MSC_VER > 1000<br />
#pragma once<br />
#endif // _MSC_VER > 1000<br />
<br />
class CGradientRender  <br />
{<br />
private:<br />
	unsigned char* m_Data;<br />
	void ApplyTransformation(int width, int height);<br />
<br />
public:<br />
	void DrawGradient( HDC hDC, RECT& rect, COLORREF startColor, COLORREF endColor);<br />
<br />
	CGradientRender();<br />
	virtual ~CGradientRender();<br />
<br />
};<br />
<br />
#endif // !defined(AFX_GRADIENTRENDER_H__9B3090DB_F7D0_4D23_8BDA_9CFAC9A64ABE__INCLUDED_)

// GradientRender.cpp: implementation of the CGradientRender class.<br />
//<br />
//////////////////////////////////////////////////////////////////////<br />
<br />
#include "stdafx.h"<br />
#include "GradientRender.h"<br />
#include "math.h"<br />
<br />
#ifdef _DEBUG<br />
#undef THIS_FILE<br />
static char THIS_FILE[]=__FILE__;<br />
#define new DEBUG_NEW<br />
#endif<br />
<br />
//////////////////////////////////////////////////////////////////////<br />
// Construction/Destruction<br />
//////////////////////////////////////////////////////////////////////<br />
<br />
CGradientRender::CGradientRender()<br />
{<br />
	m_Data = NULL;<br />
}<br />
<br />
CGradientRender::~CGradientRender()<br />
{<br />
	if ( m_Data != NULL )<br />
		delete m_Data;<br />
}<br />
<br />
void CGradientRender::DrawGradient( HDC hDC, RECT& rect, COLORREF startColor, COLORREF endColor)<br />
{<br />
	int i, j;<br />
	double r;<br />
	int X, Y;<br />
	double fi;<br />
	// Calculate image size<br />
	int width = rect.right - rect.left;<br />
	int height = rect.bottom - rect.top;<br />
	int size = height*width*4;<br />
	double radius = sqrt( pow(height/2,2) + pow(width/2,2) );<br />
	double R = sqrt( pow(width/4,2) + pow(height/4,2) );<br />
<br />
	// Create data buffer<br />
	m_Data = new unsigned char[size];<br />
	<br />
	// Create gradient<br />
	for ( i=0; i<height; i++ )<br />
	{<br />
		for ( j=0; j<width; j++ )<br />
		{<br />
			r = sqrt( pow(double(i-height/2)/radius,2) + pow(double(j-width/2)/radius,2) );<br />
			if ( r <= 1.0 )<br />
			{<br />
				m_Data[i*width*4 + j*4] = (unsigned char)(r*GetBValue(endColor) + (1-r)*GetBValue(startColor));<br />
				m_Data[i*width*4 + j*4+1] = (unsigned char)(r*GetGValue(endColor) + (1-r)*GetGValue(startColor));<br />
				m_Data[i*width*4 + j*4+2] = (unsigned char)(r*GetRValue(endColor) + (1-r)*GetRValue(startColor));<br />
			}<br />
			else<br />
			{<br />
				m_Data[i*width*4 + j*4] = GetBValue(endColor);<br />
				m_Data[i*width*4 + j*4+1] = GetGValue(endColor);<br />
				m_Data[i*width*4 + j*4+2] = GetRValue(endColor);<br />
			}<br />
<br />
		}<br />
	}<br />
<br />
<br />
	ApplyTransformation( width, height );<br />
<br />
	// Create temporary bitmap<br />
	HBITMAP hBitmap = (HBITMAP)CreateBitmap( width, height, 1, 32, m_Data );<br />
	<br />
	// Create temporary device context<br />
	HDC hMemDC = CreateCompatibleDC(hDC);<br />
	HBITMAP hOldBitmap = (HBITMAP)SelectObject( hMemDC, hBitmap );<br />
	<br />
	// Blit gradient bitmap<br />
	BitBlt( hDC, rect.left, rect.top, width, height, hMemDC, 0, 0, SRCCOPY );<br />
	<br />
	// Free memory<br />
	SelectObject( hMemDC, hOldBitmap );<br />
	DeleteDC(hMemDC);<br />
	DeleteObject(hBitmap);<br />
	delete m_Data;<br />
	m_Data = NULL;<br />
}<br />
<br />
void CGradientRender::ApplyTransformation(int width, int height)<br />
{<br />
	int X, Y;<br />
	double r, fi;<br />
	double R = sqrt( pow(width/4,2) + pow(height/4,2) );<br />
	<br />
	int size = height*width*4;<br />
	unsigned char* newBuffer = new unsigned char[size];<br />
	memcpy( newBuffer, m_Data, size );<br />
	<br />
	for ( int i=0; i<height; i++ )<br />
	{<br />
		for ( int j=0; j<width; j++ )<br />
		{<br />
			fi = atan(double(i-height/2)/double(j-width/2));<br />
			r = sqrt( pow((i-height/2),2) + pow((j-width/2),2) );<br />
			X = int((pow(r,2)/R)*cos(fi));<br />
			Y = int(fabs((pow(r,2)/R)*sin(fi))) % height;<br />
			newBuffer[i*width*4 + j*4] = m_Data[Y*width*4 + X*4];<br />
			newBuffer[i*width*4 + j*4+1] = m_Data[Y*width*4 + X*4+1];<br />
			newBuffer[i*width*4 + j*4+2] = m_Data[Y*width*4 + X*4+2];<br />
		}<br />
	}<br />
<br />
	memcpy( m_Data, newBuffer, size );<br />
	delete newBuffer;<br />
}

Naveen14-Jun-07 14:56

14-Jun-07 14:56

How about the GDI+. check the Graphics classs and LinerGradientBrush in the GDI+.

nave

[OpenedFileFinder]

HOW WHAT14-Jun-07 16:12

14-Jun-07 16:12

Oh, thanks. But i don't want use GDI+.

Hamid_RT14-Jun-07 19:31

Hamid_RT

14-Jun-07 19:31

See http://www.codeproject.com/bitmap/CGradientRender.asp[^]

WhiteSky

HOW WHAT14-Jun-07 20:57

14-Jun-07 20:57

Those Question source code, copy from CGradientRender.

Nibu babu thomas14-Jun-07 17:13

Nibu babu thomas

14-Jun-07 17:13

HOW WHAT wrote:
but it run slow, how to optimize these code let it run fast( i nill malloc memory in twice, i want to unite DrawGradient function and ApplyTransformation function). or tell me other draw example.

Use GradientFill.

Nibu thomas
A Developer

Code must be written to be read, not by the compiler, but by another human being.

http:\\nibuthomas.wordpress.com

HOW WHAT14-Jun-07 20:53

Questions about HW Information

14-Jun-07 20:53

But how to use GradientFill draw fog background...

LAN Bandwidth setting

Akin Ocal14-Jun-07 14:25

Akin Ocal

14-Jun-07 14:25

How can i set my LAN network bandwidth to a specific value ?

BEST REGARDS

Akin Ocal14-Jun-07 14:24

Akin Ocal

14-Jun-07 14:24

I dont want to use WMI. How can i get datas of :

1. RAM
2. Ethernet
3. Harddisk and other optical disks on my system
4. PCI Devices
5. USB Devices

Thank you very much.

Re: Questions about HW Information

Hamid_RT14-Jun-07 19:43

Hamid_RT

14-Jun-07 19:43

See http://www.codeproject.com/useritems/DriveInfoEx.asp?df=100&forumid=371167&exp=0&select=1833711[^] for harddisk but can you say why you want without WMI ?

WhiteSky

how to query data from CRecordset

paulosuckow14-Jun-07 12:06

paulosuckow

14-Jun-07 12:06

Hi
Please help me do a query based on date.

I have m_pSet (a pointer to CRecordset) and a filter m_strFilter

my date is a ColeDateTime in the form of "mm/dd/yyyy"

I need to set: m-pSet->m_strFilter to select records with birthday >= 1/1/1970

Any idea.

Thanks
Dan

Bitmap in parent overlaps child dialog.

aquawicket14-Jun-07 11:49

14-Jun-07 11:49

I've got a parent dialog with a picture control linked to a .bmp file. Then I've got a child dialog that opens in the parent. When I open the child dialog the bitmap of the parent overlaps the child window. Any ideas?

Mark Salsbery14-Jun-07 12:02

14-Jun-07 12:02

What are the style and extended style flags used when creating the child dialog?

Mark

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

aquawicket14-Jun-07 12:10

14-Jun-07 12:10

childDlg = new cChildDlg;
childDlg->Create(cChildDlg::IDD, this);
childDlg->SetWindowPos(NULL, a, b, c, d, SWP_SHOWWINDOW);

Mark Salsbery14-Jun-07 12:17

14-Jun-07 12:17

I meant the window styles Smile | :)

Try using wndTop as the first parameter to childDlg->SetWindowPos().

You may also want to try editing the child dialog resource and set the clip siblings property to
true.

Mark

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

Naveen14-Jun-07 14:32

14-Jun-07 14:32

aquawicket wrote:
childDlg->SetWindowPos(NULL, a, b, c, d, SWP_SHOWWINDOW);

if you specify the first parameter as NULL, you must specify the SWP_NOZORDER flag also.

nave

[OpenedFileFinder]

Naveen14-Jun-07 14:37

14-Jun-07 14:37

Also call

childDlg->BringWindowToTop()

nave

[OpenedFileFinder]

aquawicket15-Jun-07 5:49

15-Jun-07 5:49

Hmmm... So far I've tried all of the above, nothing does it yet...
In the resource editor, the dialog type is set to child. All of my other modal and modeless dialogs overlap the bitmap on the parent ok. It's just these child dialogs.

Mark Salsbery15-Jun-07 7:12

15-Jun-07 7:12

You stated "Then I've got a child dialog that opens in the parent."

How is this dialog created? Modal? Modeless?

Try using MoveWindow() instead of SetWindowPos(). MoveWindow doesn't mess with Z-order and your
most recent created child should be at the top of the z-order unless you've made another child
alwaysontop.

Mark

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

aquawicket15-Jun-07 9:57

IMPLEMENT_DYNCREATE - passing parameters to constructor

15-Jun-07 9:57

Good man mark... It was definetly a Z-order issue.. MoveWindow() works it out.. Smile | :)

Thank you very very much..

Vaclav_14-Jun-07 11:46

Vaclav_

14-Jun-07 11:46

This IMPLEMENT_DYNCREATE / DECLARE_DYNCREATE pair uses only default, protected and without parameters constructor. The macro uses class name as a paramater.
Is there any way to get around this?
Thanks for reading
Vaclav

Re: IMPLEMENT_DYNCREATE - passing parameters to constructor

Mark Salsbery14-Jun-07 12:10