Devices now have a couple of new font options. One option is to have the system download its own fonts to the device driver. The other option is to let the system manage text queries and strings while letting the device actually render the images.
Download Fonts
Two things must be done to tell the graphics subsystem that your device driver wants to be font-download enabled:
Once this has been done, the graphics subsystem sends all text output to the device driver via pfnTextBlt.
APIRET APIENTRY pfnTextBlt(PTEXTBLTINFO ptbi, ULONG hddc); TEXTBLTINFO ULONG ulLength sizeof(TEXTBLTINFO) ULONG flOptions 00 ULONG lGlyphCnt Count of Glyphs to render PLONG pGlyphIndices pointer to glyph indicies ULONG ulFGMix Foreground mix mode ULONG ulBGMix Background mix mode ULONG ulFGColor Foreground text color ULONG ulBGColor Background text color PBMAPINFO pDstBmapInfo Destination bitmap information PDEVFONTINFO pDevFntInfo Device font information ULONG ulClpCnt Non-Clipping Drivers Ignore PBLTRECT abrClipRects Non-Clipping Drivers Ignore PPOINTL aptlSrcOrg Clipping Drivers Ignore PBLTRECT abrDst Clipping Drivers Ignore .ulXExt & ulYExt DEVFONTINFO ULONG ulFntCnt Maximum glyphs contained in this font ULONG fFontInfo Flags ULONG ulEngTag Renderer Tag - i.e. 'GRE' ULONG ulUniqueFntID Unique font ID ULONG ulMaxHeight Font maximum height ULONG ulMaxWidth Font maximum width PGHBTBL pghbTbl Pointer to glyph high-byte table see below ULONG ulHalfWidth N/A CHAR szGlyphlist[16] Glyph list name (ie. PM383) ULONG ulReserved1 N/A ULONG ulReserved2 N/A DFI_FIXED_FONT Font is a fixed-width font DFI_DBCS_FONT Font is a DBCS font GRETAG "GRE_" Font is a PM system style font WINTAG "WIN_" Font is a WIN system style font
The Glyph Table is designed to be a dynamic 2-byte font table. As an example, lets take a PM383 font with three cached entries, index 34, 36 and 301:
GHBTBL ┌────────────┐ ┌────────────┐ 0 │ pglbtbl1 │─────┐ ┌───>│ A Space │ ├────────────┤ │ │ ├────────────┤ 1 │ pglbtbl2 │──┐ │ │ │ B Space │ ├────────────┤ │ │ │ ├────────────┤ 2 │ │ │ │ │ │ C Space │ ├────────────┤ │ │ │ ├────────────┤ n │ │ │ │ │ │ Pad │ └────────────┘ │ │ │ ├────────────┤ │ │ │ │ Bitmapinfo │ │ │ GLBTBL │ └────────────┘ │ │ ┌────────────┐ │ │ ├───>34 │ pGlyphInfo │───┘ ┌────────────┐ │ │ ├────────────┤ ┌────>│ A Space │ │ │ 35 │ │ │ ├────────────┤ │ │ ├────────────┤ │ │ B Space │ │ └───>36 │ pGlyphInfo │───────┘ ├────────────┤ │ ├────────────┤ │ C Space │ │ 37 │ │ ├────────────┤ │ └────────────┘ │ Pad │ │ ├────────────┤ │ GLBTBL │ Bitmapinfo │ │ ┌────────────┐ └────────────┘ │ 44 │ │ │ ├────────────┤ ┌────────────┐ └──────>45 │ pGlyphInfo │─────────────────>│ A Space │ ├────────────┤ ├────────────┤ 46 │ │ │ B Space │ ├────────────┤ ├────────────┤ 47 │ │ │ C Space │ └────────────┘ ├────────────┤ │ Pad │ ├────────────┤ │ Bitmapinfo │ └────────────┘
GHBTBL PGLBTBL pglbTbl[1] Up to 256 entries per table GLBTBL PGLYPHINFO pGlyphInfo[1] Up to 256 entries per table GLYPHINFO char bAspace char bBspace char bCspace char bPad BMAPINFO bmapinfo
Device Fonts Handled By The System
Here again, the DS_DEVICE_FONTS flag needs to be set and the pfnTextBlt function must be hooked out and handled by the device driver. In order for the system to handle font queries and text positioning of the device font, the system will query the fonts and font attributes for all the supported device fonts.
The system will need to know what fonts the driver wants supported. The system will query the driver the first time a device font request is initiated via the following new dispatch entry:
APIRET APIENTRY QueryDeviceFontMetrics(HDC hdc, PDEVFONTMETRICS abDFM, ULONG lDFMFlags, ULONG hddc, ULONG ulFunN) return: Count of device fonts DEVFONTMETRICS ULONG flOptions Device font metrics options PFOCAFONT pFoca pointer to focafont information PVOID pUniPanhose pointer to panhose info for uni fonts char achFileName[260] if pFoca is null then font file name to use PSZ pszFullFamilyName pointer family name null if pFoca null PSZ pszFullFaceName pointer to face name null if pFoca null char achGlyphListName[16] glyph list name PFN pfnDevQueryCodePage pointer to code page functionality (defaulted to PM383 ) LONG lDevMatch Devices lmatch number (negative) Options for flOptions of DEVFONTMETRICS DEVFONT_DEFAULT selects which font in the array of DEVFONTMETRICS is the device's default font.