Screen Capture Program

Question

kashmir323 21 Light Poster

14 Years Ago

I am creating this simple program that will capture screen shots. I want to make it so the name of the image that is saved is what the user enters into a text field before the picture is taken. and if at all possible is there a way to make this window pop up above the game screen when a key combination is pressed?

thanks! this is the code i have so far btw.

#include<iostream>
#include<windows.h>
using namespace std;

inline int GetFilePointer(HANDLE FileHandle){
	return SetFilePointer(FileHandle, 0, 0, FILE_CURRENT);
}

bool SaveBMPFile(char *filename, HBITMAP bitmap, HDC bitmapDC, int width, int height){
	bool Success=0;
	HDC SurfDC=NULL;
	HBITMAP OffscrBmp=NULL;
	HDC OffscrDC=NULL;
	LPBITMAPINFO lpbi=NULL;
	LPVOID lpvBits=NULL;
	HANDLE BmpFile=INVALID_HANDLE_VALUE;
	BITMAPFILEHEADER bmfh;
	if ((OffscrBmp = CreateCompatibleBitmap(bitmapDC, width, height)) == NULL)
		return 0;
	if ((OffscrDC = CreateCompatibleDC(bitmapDC)) == NULL)
		return 0;
	HBITMAP OldBmp = (HBITMAP)SelectObject(OffscrDC, OffscrBmp);
	BitBlt(OffscrDC, 0, 0, width, height, bitmapDC, 0, 0, SRCCOPY);
	if ((lpbi = (LPBITMAPINFO)(new char[sizeof(BITMAPINFOHEADER) + 256 * sizeof(RGBQUAD)])) == NULL)
		return 0;
	ZeroMemory(&lpbi->bmiHeader, sizeof(BITMAPINFOHEADER));
	lpbi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
	SelectObject(OffscrDC, OldBmp);
	if (!GetDIBits(OffscrDC, OffscrBmp, 0, height, NULL, lpbi, DIB_RGB_COLORS))
		return 0;
	if ((lpvBits = new char[lpbi->bmiHeader.biSizeImage]) == NULL)
		return 0;
	if (!GetDIBits(OffscrDC, OffscrBmp, 0, height, lpvBits, lpbi, DIB_RGB_COLORS))
		return 0;
	if ((BmpFile = CreateFile(filename,
						GENERIC_WRITE,
						0, NULL,
						CREATE_ALWAYS,
						FILE_ATTRIBUTE_NORMAL,
						NULL)) == INVALID_HANDLE_VALUE)
		return 0;
	DWORD Written;
	bmfh.bfType = 19778;
	bmfh.bfReserved1 = bmfh.bfReserved2 = 0;
	if (!WriteFile(BmpFile, &bmfh, sizeof(bmfh), &Written, NULL))
		return 0;
	if (Written < sizeof(bmfh))
		return 0;
	if (!WriteFile(BmpFile, &lpbi->bmiHeader, sizeof(BITMAPINFOHEADER), &Written, NULL))
		return 0;
	if (Written < sizeof(BITMAPINFOHEADER))
		return 0;
	int PalEntries;
	if (lpbi->bmiHeader.biCompression == BI_BITFIELDS)
		PalEntries = 3;
	else PalEntries = (lpbi->bmiHeader.biBitCount <= 8) ?
					  (int)(1 << lpbi->bmiHeader.biBitCount) : 0;
	if(lpbi->bmiHeader.biClrUsed)
	PalEntries = lpbi->bmiHeader.biClrUsed;
	if(PalEntries){
	if (!WriteFile(BmpFile, &lpbi->bmiColors, PalEntries * sizeof(RGBQUAD), &Written, NULL))
		return 0;
		if (Written < PalEntries * sizeof(RGBQUAD))
			return 0;
	}
	bmfh.bfOffBits = GetFilePointer(BmpFile);
	if (!WriteFile(BmpFile, lpvBits, lpbi->bmiHeader.biSizeImage, &Written, NULL))
		return 0;
	if (Written < lpbi->bmiHeader.biSizeImage)
		return 0;
	bmfh.bfSize = GetFilePointer(BmpFile);
	SetFilePointer(BmpFile, 0, 0, FILE_BEGIN);
	if (!WriteFile(BmpFile, &bmfh, sizeof(bmfh), &Written, NULL))
		return 0;
	if (Written < sizeof(bmfh))
		return 0;
	return 1;
}
bool ScreenCapture(int x, int y, int width, int height, char *filename){
	HDC hDc = CreateCompatibleDC(0);
	HBITMAP hBmp = CreateCompatibleBitmap(GetDC(0), width, height);
	SelectObject(hDc, hBmp);
	BitBlt(hDc, 0, 0, width, height, GetDC(0), x, y, SRCCOPY);
	bool ret = SaveBMPFile(filename, hBmp, hDc, width, height);
	DeleteObject(hBmp);
	return ret;
}

int main() {
	int x1 = 0;
	int y1 = 0;
	int x2 = GetSystemMetrics(SM_CXSCREEN);
	int y2 = GetSystemMetrics(SM_CYSCREEN);
	ScreenCapture(x1, y1, x2 - x1, y2 - y1, "rename_me_before_upload.bmp");
	cin.ignore();
	return 0;
}

c++

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Latest Post 14 Years Ago Latest Post by thefly

All 7 Replies

William Hemsworth 1,339 Posting Virtuoso

14 Years Ago

If all you want to do is let allow the user to input the bitmap name, use std::cin to get the name, and strcat ".bmp" on the end. Change your main code like this:

int main() {
  int x1 = 0;
  int y1 = 0;
  int x2 = GetSystemMetrics(SM_CXSCREEN);
  int y2 = GetSystemMetrics(SM_CYSCREEN);

  char bmp_name[100];
  cin.getline( bmp_name, 96 );
  strcat( bmp_name, ".bmp" );


  ScreenCapture(x1, y1, x2 - x1, y2 - y1, bmp_name);

  cin.ignore();
  return 0;
}

>if at all possible is there a way to make this window pop up above the game screen when a key combination is pressed?
Not quite sure what you mean by this.

William Hemsworth 1,339 Posting Virtuoso

14 Years Ago

Okay, that's tricky but possible. In this small example, I check to see if those keys are down. If they are down, it will toggle the windows visibility. I tried using windows hooks to give this example, but I couldn't set the hook without having a hInstance, so I tried this alternative method which works on console windows.

#define _WIN32_WINNT 0x0500
#include <windows.h>
#include <iostream>
using namespace std;

int main() {
  bool visible = false;
  ShowWindow( GetConsoleWindow(), SW_HIDE );

  for ( ; ; ) {

    if ( GetAsyncKeyState( VK_SHIFT ) &&
         GetAsyncKeyState( VK_MENU ) &&
         GetAsyncKeyState( VkKeyScanA('s') ) )
    {
      if ( visible )
        ShowWindow( GetConsoleWindow(), SW_HIDE );
      else
        ShowWindow( GetConsoleWindow(), SW_SHOW );

      visible = !visible;
      Sleep( 500 );
    }

    Sleep( 100 );
  }

  cin.ignore();
}

Whether or not ShowWindow will be enough to bring the console window in front of the game, I don't know, but that would be the next stage if the above doesn't work.

Hope this helps.

Code tags don't seem to work correctly, and can't get the C++ syntax, not sure why.

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kashmir323 21 Light Poster · Answer 1 · 2009-05-02T04:31:49+00:00

Since this program is a anti-cheat parameter for the league, the picture wont be needed till once the player is in game. so once in game i would like the players to push lets say Shift+Alt+S to bring up the console app over top the game. Then once the picture is taken and saved then push Shift+Alt+S to minimize the console behind the top screen again.

kashmir323 21 Light Poster · Answer 2 · 2009-05-02T06:46:43+00:00

Alright. So i havent compiled any programs for a while and im compiling this using the Microsoft Visual C++ Toolkit 2003. When i click build it gives me an error saying:

"LRSscreenshooter - Release" uses an invalid compiler. Skipping...
Nothing to be done.

Any idea what is wrong? And im building this in CodeBlocks 8.02.

thefly 0 Newbie Poster · Answer 3 · 2009-10-28T14:06:33+00:00

Hello,

I'm trying to use the code in the first post to capture a smaller area than the whole screen. I have a point that is at the center of the area I need to capture. In my main() function I call ScreenCapture(xPos - 25, yPos - 25, 50, 50, "image.bmp"), where xPos is the x-position of the center and yPos is the y-position of the center point.

Everything is running OK, but the saved image is black. It has the right size, but it's black. What am I doing wrong?

Thanx!

ithelp 757 Posting Virtuoso Banned · Answer 4 · 2009-10-28T14:08:54+00:00

Hello,
I'm trying to use the code in the first post to capture a smaller area than the whole screen. I have a point that is at the center of the area I need to capture. In my main() function I call ScreenCapture(xPos - 25, yPos - 25, 50, 50, "image.bmp"), where xPos is the x-position of the center and yPos is the y-position of the center point.
Everything is running OK, but the saved image is black. It has the right size, but it's black. What am I doing wrong?
Thanx!

What OS are you using ?

thefly 0 Newbie Poster · Answer 5 · 2009-10-28T14:16:40+00:00

What OS are you using ?

Windows Vista 32bit. Capturing the whole screen works well. I get normal screen shot.

Screen Capture Program

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