[Lazarus] How can I improve my bitmap font drawing unit (attached) ?

[Pavel Řezníček]

Peter Williams wrote:
>
> Hi All,
>
> I'd like some advice about the attached unit, named 
> "uFixedWidthFonts.pas". It is designed to read 2-colour bitmaps of 
> font character sets of different sizes, from files which are Windowz 
> BMP format. For example, "Chars_Lower_8x8.bmp" -- this is a 320 x 56 
> pixels, 1 layer BMP file, file size 2.25 KB. E.g. the BMP file is a 2 
> colour image of a 256 character bitmap, where each character in the 
> BMP file (in this case) is 8x8 pixels.
>
> There are 8 BMP files:
>
> Chars_Lower_8x8.bmp
> Chars_Lower_16x16.bmp
> Chars_Lower_24x24.bmp
> Chars_Lower_32x32.bmp
> Chars_Upper_8x8.bmp
> Chars_Upper_16x16.bmp
> Chars_Upper_24x24.bmp
> Chars_Upper_32x32.bmp
>
> The *Lower* files define the Commodore PET 4032 upper/lower case 
> character set & the *Upper* files define the Graphics/Uppercase 
> character set.
>
> My main question is: would I be better off using a TImageList?!? Can 
> someone please post sample code. Note: I tried to run the TImageList 
> example program for Lazarus... it compiles okay... but when run it 
> does not find some of its files (BMPs) in the Image sub-folder of the 
> example program. e.g. it gets a runtime error.
>
> Note that this unit is based strongly on a unit from the Jedi SDL 
> component, sample unit for drawing bitmap fonts onto a graphic canvas.
>
> At the moment I use statements like this to define the bitmap font 
> (some of the code is pasted below):
>
> Best Regards & Happy Programming ;-)))
> PEW
> ...

G'day Peter,

what are you currently coding reminds me on my effort to rewrite an 
Atari ST game. I had many single bitmaps for that reason but it was in 
the times when I knew only Visual Basic and nothing more and was a 
beginner. As I got experience, I created three regular MS Windows bitmap 
fonts:

The 1st to simulate the real ST character set,
the 2nd to display the lowest character codes from 0 to 31 - I shifted 
them by 32 in codes
the 3rd to resemble the Atari font style but displaying the Windows code 
page (actually, it was in Eastern European CP1250).

I then managed to create a half-way text/binary editor that used the 
RichTextBox to edit binary files from Atari in their original look.

I used a font creation program called Softy to achieve this and also the 
resource editor shipped with Delphi 5.

In Visual Basic, there was a control called PictureClip. It would serve 
well for your purpose (if you wrote it in VB, of course). I think it was 
actually an OCX (ActiveX) control from Windows that you could employ but 
if you are going to be multi-platform friendly, you cannot rely on a 
Windows-only technology.

Picture clip's principle is that you can define rows and columns over a 
loaded image and then easily get parts of it by accessing the cells or 
get the part by directly specifying the coordinates and size of the 
wanted region.

Does somebody know if there's such a control for Lazarus too?

BTW, you did this yourself. Every needed function is already contained 
in the graphic controls containing TCanvas ;-)

I now try to start a Motorola 68000 code disassembler and perhaps a 
partial Atari ST emulator.

However I have no special advise for you that you requested how to speed 
the drawing up. I suppose you won't go the way of real system fonts 
because your approach is more dynamic. It's easier to draw a bitmap of 
the whole font than to use special software and install the font to the 
system. Not mentioning that I found no direct way to convert those 
system fonts to Linux.

Pavel