Using 'brush' to render text with DrawText into DIBsection 1bpp bitmap

Question

I'm wondering if there is a way to set a 'brush' or pixel map for the DrawText() call to use so that the elements of the text are not solid lines. I would like the rendered text to use alternating pixels.

I can't find any examples of anything like this.

Regards,
Greg

Answer 1

If you decide to use C++/CLI to simplify some tasks, then consider an example:

#include <msclr/auto_handle.h>  
  
. . .  
  
using namespace System::Drawing;  
using namespace System::Drawing::Imaging;  
using namespace System::Drawing::Drawing2D;  
using namespace msclr;  
  
auto_handle<Bitmap> bmp( gcnew Bitmap( 200, 100, PixelFormat::Format24bppRgb ));  
auto_handle<Graphics> g( Graphics::FromImage( bmp.get() ));  
  
g->Clear( Color::White );  
  
HatchBrush brush( HatchStyle::DottedDiamond, Color::White, Color::Black );  
System::Drawing::Font font( "Arial", 50 );  
  
g->DrawString( "Hello", %font, %brush, 10, 10, StringFormat::GenericDefault );  
  
bmp->Save( "test1.bmp", ImageFormat::Bmp );  
  
auto_handle<Image> bmp2( bmp->Clone( Rectangle( 0, 0, bmp->Width, bmp->Height ), PixelFormat::Format1bppIndexed ));  
bmp2->Save( "test2.bmp", ImageFormat::Bmp );  

The generated "test2.bmp" file will be a 1-bit-per-pixel one.

You can use different styles of HatchBrush, or build a TextureBrush, or use other kinds of brushes.

Answer 2

You can use the method from Feng Yuan book "Windows Graphics Programming Win32 GDI and DirectDraw" :

int nWidth = 256, nHeight = 256;  
COLORREF clrBackground = RGB(0, 0, 255);  
COLORREF clrForeground = RGB(255, 255, 0);  
HBITMAP hBitmap = CreateMonochromeBitmap(nWidth, nHeight, clrBackground, clrForeground);  
HDC hDC = GetDC(NULL);  
HDC hDCMem = CreateCompatibleDC(hDC);  
HBITMAP hBitmapOld = (HBITMAP)SelectObject(hDCMem, hBitmap);  
  
HBRUSH hBrush = CreateHatchBrush(HS_DIAGCROSS, clrForeground);  
SetBkColor(hDCMem, clrBackground);  
WCHAR wsText[] = L"This is a test";  
  
int nFontSize = -MulDiv(31, GetDeviceCaps(hDC, LOGPIXELSY), 72);  
HFONT hFont = CreateFont(nFontSize, 0, 0, 0, FW_DONTCARE, FALSE, FALSE, FALSE, ANSI_CHARSET, OUT_RASTER_PRECIS, CLIP_DEFAULT_PRECIS,  
    NONANTIALIASED_QUALITY, VARIABLE_PITCH | FF_DONTCARE, L"Arial");  
HFONT hFontOld = (HFONT)SelectObject(hDCMem, hFont);  
ColorText(hDCMem, 10, 10, wsText, lstrlen(wsText), hBrush);  
SelectObject(hDCMem, hFontOld);  
DeleteObject(hFont);  
DeleteObject(hBrush);  
// Test copy bitmap on screen  
BitBlt(hDC, 0, 0, nWidth, nHeight, hDCMem, 0, 0, SRCCOPY);  

SelectObject(hDCMem, hBitmapOld);  
DeleteDC(hDCMem);  
DeleteObject(hBitmap);  
ReleaseDC(NULL, hDC);  

HBITMAP CreateMonochromeBitmap(int cx, int cy, COLORREF clrBackground, COLORREF clrForeground)  
{  
    struct  
    {  
        BITMAPINFOHEADER bi;  
        RGBQUAD bmiColors[2];  
    } dib = { 0 };  
    dib.bi.biSize = sizeof(dib.bi);  
    dib.bi.biWidth = cx;  
    dib.bi.biHeight = cy;  
    dib.bi.biPlanes = 1;  
    dib.bi.biBitCount = 1;  
    dib.bi.biCompression = BI_RGB;   
    dib.bmiColors[0].rgbBlue = GetBValue(clrBackground);  
    dib.bmiColors[0].rgbGreen = GetGValue(clrBackground);  
    dib.bmiColors[0].rgbRed = GetRValue(clrBackground);  
    dib.bmiColors[1].rgbBlue = GetBValue(clrForeground);  
    dib.bmiColors[1].rgbGreen = GetGValue(clrForeground);  
    dib.bmiColors[1].rgbRed = GetRValue(clrForeground);  
     
    HBITMAP hBitmap = NULL;  
    HDC hDC = CreateCompatibleDC(NULL);  
    if (hDC)  
    {  
        hBitmap = CreateDIBSection(hDC, (BITMAPINFO*)&dib, DIB_RGB_COLORS, NULL, NULL, 0);  
        DeleteDC(hDC);  
    }  
    return hBitmap;  
}      
   
   
// From book "Windows Graphics Programming Win32 GDI and DirectDraw""  
  
// ABC extent of a text string  
// ( A0, B0, C0 ) + ( A1, B1, C1 ) = ( A0, B0+C0+A1+B1, C1 }  
BOOL GetTextABCExtent(HDC hDC, LPCTSTR lpString, int cbString, long* pHeight, ABC* pABC)  
{  
    SIZE size;  
  
    if (!GetTextExtentPoint32(hDC, lpString, cbString, &size))  
        return FALSE;  
  
    *pHeight = size.cy;  
    pABC->abcB = size.cx;  
  
    ABC abc;  
    GetCharABCWidths(hDC, lpString[0], lpString[0], &abc); // first  
    pABC->abcB -= abc.abcA;  
    pABC->abcA = abc.abcA;  
  
    GetCharABCWidths(hDC, lpString[cbString - 1], lpString[cbString - 1], &abc); // last  
    pABC->abcB -= abc.abcC;  
    pABC->abcC = abc.abcC;  
  
    return TRUE;  
}  
  
BOOL GetOpaqueBox(HDC hDC, LPCTSTR lpString, int cbString, RECT* pRect, int x, int y)  
{  
    long height;  
    ABC  abc;  
  
    if (!GetTextABCExtent(hDC, lpString, cbString, &height, &abc))  
        return FALSE;  
  
    switch (GetTextAlign(hDC) & (TA_LEFT | TA_RIGHT | TA_CENTER))  
    {  
    case TA_LEFT: break;  
    case TA_RIGHT: x -= abc.abcB; break;  
    case TA_CENTER: x -= abc.abcB / 2; break;  
    default:   assert(false);  
    }  
  
    switch (GetTextAlign(hDC) & (TA_TOP | TA_BASELINE | TA_BOTTOM))  
    {  
    case TA_TOP: break;  
    case TA_BOTTOM: y = -height; break;  
    case TA_BASELINE:  
    {  
        TEXTMETRIC tm;  
        GetTextMetrics(hDC, &tm);  
        y = -tm.tmAscent;  
    }  
    break;  
    default:   assert(false);  
    }  
  
    pRect->left = x + min(abc.abcA, 0);  
    pRect->right = x + abc.abcA + abc.abcB + max(abc.abcC, 0);  
    pRect->top = y;  
    pRect->bottom = y + height;  
  
    return TRUE;  
}  
  
BOOL ColorText(HDC hDC, int x, int y, LPCTSTR pString, int nCount, HBRUSH hFore)  
{  
    HGDIOBJ hOld = SelectObject(hDC, hFore);  
  
    RECT rect;  
    GetOpaqueBox(hDC, pString, nCount, &rect, x, y);  
    PatBlt(hDC, rect.left, rect.top,  
        rect.right - rect.left, rect.bottom - rect.top, PATINVERT);  
  
    int      oldBk = SetBkMode(hDC, TRANSPARENT);  
    COLORREF oldColor = SetTextColor(hDC, RGB(0, 0, 0));  
  
    TextOut(hDC, x, y, pString, nCount);  
    SetBkMode(hDC, oldBk);  
    SetTextColor(hDC, oldColor);  
  
    BOOL rslt = PatBlt(hDC, rect.left, rect.top,  
        rect.right - rect.left, rect.bottom - rect.top, PATINVERT);  
  
    SelectObject(hDC, hOld);  
  
    return rslt;  
}