🚀 go-pugleaf

Hi Everyone,

Thanks SO much for your help. I'm still struggling with this whole
thing. Can you have a look at this code? I've stripped out everything I
can think of and reduced it to a single application thread by using the
WM_TIMER event. I must be missing something obvious...

Many thanks,

Rob

_________________________________________________________________________


#include <vcl.h> 							#include "PixelSaverShell.h"   				
#pragma hdrstop                     		
#pragma package(smart_init)            	
#pragma resource "*.dfm"

typedef struct
{
   BITMAPINFOHEADER bmiHeader;    	
   RGBQUAD          bmiColors[256];
}
BITMAPINFOSTRUCT;

// global variables
TShellForm       *ShellForm;  				
HDC		 hDC;						
BITMAPINFOSTRUCT  bmInfo;					
BITMAP 		  bmBitmap;

__fastcall TShellForm::TShellForm(TComponent* Owner) : TForm(Owner)
{
}
//---------------------------------------------------------------------------

void __fastcall TShellForm::FormCreate(TObject *Sender)
{
	Left = 0;
	Top  = 0;
	ClientWidth  = Screen->Width;
	ClientHeight = Screen->Height;

	bmBitmap.bmType       = 0;
	bmBitmap.bmPlanes     = 1;
	bmBitmap.bmWidth      = ClientWidth;
	bmBitmap.bmHeight     = ClientHeight;
	bmBitmap.bmBitsPixel  = 8;
	bmBitmap.bmWidthBytes = ClientWidth;

	// pad rows
	short RowPad = bmBitmap.bmWidthBytes % 4;
	if (RowPad != 0)
		bmBitmap.bmWidthBytes += 4 - RowPad;

	bmBitmap.bmBits = (unsigned char *)malloc(bmBitmap.bmWidthBytes *
bmBitmap.bmHeight);

	bmInfo.bmiHeader.biSize	         = sizeof(BITMAPINFOHEADER);
	bmInfo.bmiHeader.biWidth	 = bmBitmap.bmWidth;
	bmInfo.bmiHeader.biHeight	 = bmBitmap.bmHeight;
	bmInfo.bmiHeader.biPlanes	 = bmBitmap.bmPlanes;
	bmInfo.bmiHeader.biBitCount	 = bmBitmap.bmBitsPixel;
	bmInfo.bmiHeader.biCompression	 = BI_RGB;
	bmInfo.bmiHeader.biSizeImage	 = bmBitmap.bmWidthBytes * bmBitmap.bmHeight;
	bmInfo.bmiHeader.biXPelsPerMeter = 0;
	bmInfo.bmiHeader.biYPelsPerMeter = 0;
	bmInfo.bmiHeader.biClrUsed	 = (bmBitmap.bmBitsPixel == 8) ? 256 : 0;
	bmInfo.bmiHeader.biClrImportant  = 0;

	// initialize color table - monochrome greyscale image
	for (DWORD i = 0; i < 256; i++)
	{
		bmInfo.bmiColors[i].rgbRed      = i;
		bmInfo.bmiColors[i].rgbGreen    = i;
		bmInfo.bmiColors[i].rgbBlue     = i;
		bmInfo.bmiColors[i].rgbReserved = 0;
	}

	hDC = GetDC(Handle);
}
//---------------------------------------------------------------------------

void __fastcall TShellForm::FormShow(TObject *Sender)
{
	DisplayTimer->Enabled = true;
}
//---------------------------------------------------------------------------

// draw video frame
void __fastcall TShellForm::DisplayTimerTimer(TObject *Sender)
{
    static unsigned char ThisShade = 127;

    memset(bmBitmap.bmBits,
           ThisShade++,
           bmBitmap.bmWidthBytes * bmBitmap.bmHeight);

    StretchDIBits(hDC,
		  0,
		  0,
		  ClientWidth,
		  ClientHeight,
		  0,
		  0,
		  bmInfo.bmiHeader.biWidth,
		  bmInfo.bmiHeader.biHeight,
		  bmBitmap.bmBits,
		  (BITMAPINFO *)&bmInfo,
		  DIB_RGB_COLORS,
		  SRCCOPY);
}
//---------------------------------------------------------------------------

void __fastcall TShellForm::FormDestroy(TObject *Sender)
{
	ReleaseDC(Handle, hDC);

	free(bmBitmap.bmBits);
}
//---------------------------------------------------------------------------