Creating a Bitmap image

[JoeC]

I have created some monochrome bitmaps and and drawing program. I am
trying to create a bitmap from scratch. I am trying to write my own
pixel and color data. Then I need to create the bitmap and then use
the select the bitmap with hbitmap then bit it over to the graphics
space. What am I doing wrong or what step am I missing or have wrong.

I have the following that creates a blank bitmap.

struct BITMAP_INFO{
BITMAPFILEHEADER bmHead;
RGBQUAD bmColor[16];
};

BITMAP_INFO bfo;
HBITMAP hbitmap;

RGBQUAD palet[16];

BYTE cdata[] = {0xff, 0xff, 0xff, //...
// Palette data

int num = 16;
BYTE * pdata = &cdata[0];

int datasz = 3*num;
int count = 0;

RGBQUAD palette[16];
ZeroMemory(bfo.bmColor, sizeof(palette));
while(count < datasz/num ){

bfo.bmColor[count].rgbRed = *pdata++;
bfo.bmColor[count].rgbBlue = *pdata++;
bfo.bmColor[count].rgbGreen = *pdata++;
bfo.bmColor[count].rgbReserved = 0;
count++;
}

BYTE data[] = {0xff,0xff,0x80,0x01,1,1,1,1,1,1,1,1,1,1,1,1, //...
//Bit data for the bitmap

PBYTE BitmapImage = (BYTE*)LockResource;

BITMAPINFO * BitmapInfo = (BITMAPINFO*)(new BITMAP_INFO);
if (BitmapInfo == NULL){
MessageBox(NULL, "Bitmap Error", "Info", MB_OK);
return;

hbitmap= CreateDIBSection( hdc, BitmapInfo,
DIB_RGB_COLORS, &pbits, NULL, 0 );

HDC hMem = CreateCompatibleDC(hdc);

UINT cColors = GetDIBColorTable(hMem, 0, 16, bfo.bmColor);
SetDIBColorTable(hMem, 0, cColors, bfo.bmColor);

HBITMAP hOldBitmap = (HBITMAP)SelectObject(hMem, hbitmap);
SelectObject(hMem, hOldBitmap);

BitBlt(hdc, 100, 150, 16, 16 , hMem, 0, 0, SRCCOPY);

DeleteDC(hMem);

ReleaseDC(hwnd, hMem);

[JoeC]

I did some more research and changes. The bitmap seems have been
created now but it is just a blank white box. I am trying to put some
data into the bitmap so I can start to understand how it creates
pictures. What can I do to make this work correctly?

void paint(HDC hdc, HWND hwnd){

BITMAP_INFO bfo;
HBITMAP hbitmap;

int dwn, acc = 16;
int accLoc, dnLoc = 100;

HDC hDc = CreateCompatibleDC(hdc);

memset(&bfo, 0, sizeof(bfo));

RGBQUAD palet[16];

BYTE cdata[] = {0xff, 0xff, 0xff,

0,0,0,
0xff,0,0,
0,0xff,0,
0,0,0xff,
0xf0,0xf0,0xf0,
0xf0,0xf0,0,
0xf0,0,0xf0,
0,0xf0,0xf0,
0xff,0,0xff,
0x3c,0x3c,0,
0x3c,0,0x3c,
0,0x3c,0x3c,
0xf0,0xf0,0,
0xf0,0,0xf0,
0,0xf0,0xf0};

int num = 16;
BYTE * pdata = &cdata[0];

int datasz = 3*num;
int count = 0;

RGBQUAD palette[16];
ZeroMemory(bfo.bmColor, sizeof(palette));
while(count < datasz/num ){

bfo.bmColor[count].rgbRed = *pdata++;
bfo.bmColor[count].rgbBlue = *pdata++;
bfo.bmColor[count].rgbGreen = *pdata++;
bfo.bmColor[count].rgbReserved = 0;
count++;
}

BYTE data[] = {1,1,0,1,1,1,1,1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
1,1,2,2,2,2,2,2,2,2,2,2,2,2,1,1,
1,1,2,2,2,2,2,2,2,2,2,2,2,2,1,1,
1,1,2,2,3,3,3,2,2,3,3,3,2,2,1,1,
1,1,2,2,3,3,3,4,4,3,3,3,2,2,1,1,
1,1,2,2,3,3,3,4,4,3,3,3,2,2,1,1,
1,1,2,2,0,0,0,0,0,0,0,0,2,2,1,1,
1,1,2,2,0,0,0,0,0,0,0,0,2,2,1,1,
1,1,2,2,2,2,2,2,2,2,2,2,2,2,1,1,
1,1,2,2,0,0,0,0,0,0,0,0,2,2,1,1,
1,1,2,2,2,2,2,2,2,2,2,2,2,2,1,1,
1,1,2,2,3,3,3,2,2,3,3,3,2,2,1,1,
1,1,2,2,3,3,3,4,4,3,3,3,2,2,1,1,
1,1,2,2,3,3,3,4,4,3,3,3,2,2,1,1,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1};

BITMAPINFO * BitmapInfo = (BITMAPINFO*)(new BITMAP_INFO);
if (BitmapInfo == NULL){
MessageBox(NULL, "Bitmap Error", "Info", MB_OK);
return;
}

for(int lp = 0 ; lp != 16; lp++){

BitmapInfo->bmiColors[lp].rgbBlue = bfo.bmColor[lp].rgbBlue;
BitmapInfo->bmiColors[lp].rgbGreen= bfo.bmColor[lp].rgbGreen;
BitmapInfo->bmiColors[lp].rgbRed = bfo.bmColor[lp].rgbRed;
BitmapInfo->bmiColors[lp].rgbReserved = 0;
}

BitmapInfo->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
BitmapInfo->bmiHeader.biBitCount = 4;
BitmapInfo->bmiHeader.biHeight = 16;
BitmapInfo->bmiHeader.biWidth = 16;
BitmapInfo->bmiHeader.biCompression = BI_RGB;
BitmapInfo->bmiHeader.biPlanes = 1;

hbitmap = CreateDIBSection(hDc, BitmapInfo, DIB_RGB_COLORS,
(PVOID*)&data, NULL, 0);

SelectObject(hDc, hbitmap);
GdiFlush();
StretchBlt(hdc, 250,250,16*5,16*5,hDc,0,0,16,16,MERGECOPY);

DeleteDC(hDc);
ReleaseDC(hwnd, hDc);
}

[Christian ASTOR]

On 21 déc, 22:58, JoeC <enki...@yahoo.com> wrote:
> I did some more research and changes. The bitmap seems have been
> created now but it is just a blank white box.  I am trying to put some
> data into the bitmap so I can start to understand how it creates
> pictures.  What can I do to make this work correctly?

You must play with RGB values...
Just for an example, to create a red grid with CreateDIBSection()=>

HBITMAP hBitmapOld;
HDC hDC = GetDC(NULL);
HDC hDCMem = CreateCompatibleDC(hDC);

int nX = 800, nY = 600;
BITMAPINFO bi = {0};
bi.bmiHeader.biSize = sizeof(bi.bmiHeader);
bi.bmiHeader.biWidth = nX;
bi.bmiHeader.biHeight = nY;
bi.bmiHeader.biPlanes = 1;
bi.bmiHeader.biBitCount = 32;
bi.bmiHeader.biCompression = BI_RGB;
BYTE *pbBitmap;
HBITMAP hBitmap = CreateDIBSection(hDCMem, &bi, DIB_RGB_COLORS,
(void**)&pbBitmap, NULL, 0);
if (hBitmap)
{
hBitmapOld = (HBITMAP)SelectObject(hDCMem, hBitmap);
RGBQUAD *pRGB;
LONG nPixels;
for (pRGB = (RGBQUAD *)pbBitmap, nPixels = nX * nY; nPixels >= 0; +
+pRGB, --nPixels)
{
if ( nPixels%10 == 0 || (nPixels/800) %10 == 0)
pRGB->rgbRed = 255;
}
BitBlt(hDC, 0, 0, nX, nY, hDCMem, 0, 0, SRCCOPY);
SelectObject(hDCMem, hBitmapOld);
DeleteObject(hBitmap);
}
DeleteDC(hDCMem);
ReleaseDC(NULL, hDC);

[Friedel Jantzen]

>
> hbitmap = CreateDIBSection(hDc, BitmapInfo, DIB_RGB_COLORS,
> (PVOID*)&data, NULL, 0);

http://msdn.microsoft.com/en-us/library/dd183494(VS.85).aspx
ppvBits [out]
A pointer to a variable that receives a pointer to the location of the
DIB bit values.

void *ppvBits;

hbitmap = CreateDIBSection(hDc, BitmapInfo, DIB_RGB_COLORS,

&ppvBits, NULL, 0);
CopyMemory(ppvBits, data, dataSize);

hth,
Friedel

[JoeC]

Thanks, I did some research to get that far and it seems those few
changes have made the bitmap work. I just I have to manipulate the
data to see what I can do.