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Code archives/Graphics/Bitmap font routine.

This code has been declared by its author to be Public Domain code.

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Bitmap font routine. by VP2005
This is a working, but early, version of my bitmap font routine.

Requirements are minimal.

To get up and running, you need to supply a valid Blitz image which contains the characters of your font as one character per frame of animation. Font graphic should be 2 colour black and white with black being the background colour. This Will Be Done or specifying a colour when you call the function will not work as expected.

Example code to generate such an image:
temp=LoadImage("resources/graphics/font.png")
SetBuffer ImageBuffer(temp)
imgFont = CreateImage(32,32,44)
MaskImage imgFont,$FF,$FF,$FF
For i% = 0 To 43
    GrabImage imgFont,i%*32,0,i%
Next
FreeImage temp

Example usage:
bfText(imgFont,"Hello World",$FFAA55,BF_JUSTIFY_CENTRE Or BF_JUSTIFY_MIDDLE Or BF_CHARSET_RESTRICTED_UPPERCASE)
; Bitmap font routines.
;
; Version 0.21 FREELY DISTRIBUTABLE
; Conception 10th December 2005 14:20 GMT.

; Copyright © 2005 Stefan Holmes.
; Whilst I retain copyright, I give permission for the free distribution and use of this sourcecode.

; HISTORY
;
; Version 0.01, 10th December 2005.
; Non-working alpha.
; --
; Version 0.10, 10th December 2005.
; Working beta.
; Text justification not implemented.
; --
; Version 0.20, 10th December 2005.
; Working release.
; Multi-line output is missing.
; --
; Version 0.21, 10th December 2005.
; Working release.
; Multi-line output is missing.
; Implemented colour. Requires change to how the font image is grabbed.

Const BF_JUSTIFY_LEFT                   = %0000000000000001 ; $0001
Const BF_JUSTIFY_RIGHT                  = %0000000000000010 ; $0002
Const BF_JUSTIFY_CENTRE                 = %0000000000000011 ; $0003
Const BF_JUSTIFY_TOP                    = %0000000000000100 ; $0004
Const BF_JUSTIFY_BOTTOM                 = %0000000000001000 ; $0008
Const BF_JUSTIFY_MIDDLE                 = %0000000000001100 ; $000C

Const BF_CHARSET_RESTRICTED_UPPERCASE   = %0000000000010000 ; $0010
Const BF_CHARSET_RESTRICTED_BOTHCASES   = %0000000000100000 ; $0020
Const BF_CHARSET_FULL_UPPERCASE         = %0000000000110000 ; $0030
Const BF_CHARSET_FULL_BOTHCASES         = %0000000001000000 ; $0040
Const BF_CHARSET_FULL_INTERNATIONAL     = %0000000001010000 ; $0050
Const BF_CHARSET_RESERVED1              = %0000000001100000 ; $0060
Const BF_CHARSET_RESERVED2              = %0000000001110000 ; $0070


Function bfText(font,word$,bfColor%=$FFFFFF,flags%=0,x%=0,y%=0,w%=0,h%=0)
; ARGUMENTS:
;
; font  = Valid Blitz image with anim frames containing characters. Sequence
;         depends on the BF_CHARSET_... bitmask.
;
;       BF_CHARSET_RESTRICTED_UPPERCASE =
;       ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789.,!?@#-©®
;       45 characters.
;
;       BF_CHARSET_RESTRICTED_BOTHCASES =
;       ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789.,!?@#-©®
;       71 characters.
;
;       BF_CHARSET_FULL_UPPERCASE =
;       ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789,.!?@#-'"£$%^&*()=+_:;<>/\[]{}~©®
;       69 characters.
;
;       BF_CHARSET_FULL_BOTHCASES =
;       ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789,.!?@#-'"£$%^&*()=+_:;<>/\[]{}~©®
;       95 characters.
;
;       BF_CHARSET_FULL_INTERNATIONAL is not defined in this version.
;
;       BF_CHARSET_RESERVED1 and BF_CHARSET_RESERVED2 are undefined in this version.
;
; word$ = Text to be displayed.
;
; bfColor%  = $RRGGBB hex value.
;           N.B. There is a gotcha here. Because of the way the images are masked, pure black text
;           is not possible. Pure black is converted to darkest blue $000001.
;
; flags%    = Bit flags denoting how the text is rendered.
;
;           Bits 1-2 control horizontal justification.
;           Bits 3-4 control vertical justification.
;           Bits 5-7 denote which charset to use (CAUTION: incorrect setting can cause program to exit).
;           All other bits are undefined in this version.
;
; x% and y% = Nominal pixel coordinates where text is to be displayed.
;
; w% and h% = If non-zero denotes a virtual display width and height.
;             If zero, current screen width and height are used.


If font = 0
    DebugLog "bfText: font image not available" : End
EndIf

If bfColor%=0 Then bfColor%=$000001
b% = bfColor% And %00000000000000000000000011111111
g% = (bfColor% And %00000000000000001111111100000000) Shr 8
r% = (bfColor% And %00000000111111110000000000000000) Shr 16

charwidth%  = ImageWidth(font)
charheight% = ImageHeight(font)

If w% = 0 Then w% = GraphicsWidth()
If h% = 0 Then h% = GraphicsHeight()

horizjustify%   = (flags% And %0000000000000011)
vertjustify%    = (flags% And %0000000000001100) Shr 2
charset%        = (flags% And %0000000001110000) Shr 4

Select horizjustify%
    Case 1
        ; BF_JUSTIFY_LEFT
        offsetx% = x%
    Case 2
        ; BF_JUSTIFY_RIGHT
        offsetx% = w% - (charwidth% * Len(word$)) + x%
    Case 3
        ; BF_JUSTIFY_CENTRE
        offsetx% = (w% / 2) - ((charwidth% * Len(word$)) / 2) + x%
End Select

Select vertjustify%
    Case 1
        offsety% = y%
    Case 2
        offsety% = h% - charheight% + y%
    Case 3
        offsety% = (h% / 2) - (charheight% / 2) + y%
End Select 

Select charset%
    Case 0
        DebugLog "bfText: No charset defined" : End
    Case 1
        ; BF_CHARSET_RESTRICTED_UPPERCASE
        source$="ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789.,!?@#-©®"
        word$ = Upper(word$)
    Case 2
        ; BF_CHARSET_RESTRICTED_BOTHCASES
        source$="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789.,!?@#-©®"
    Case 3
        ; BF_CHARSET_FULL_UPPERCASE
        source$="ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789,.!?@#-'"+Chr$(34)+"£$%^&*()=+_:;<>/\[]{}~©®"
        word$ = Upper(word$)
    Case 4
        ; BF_CHARSET_FULL_BOTHCASES
        source$="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789,.!?@#-'"+Chr$(34)+"£$%^&*()=+_:;<>/\[]{}~©®"
    Case 5
        ; BF_CHARSET_FULL_INTERNATIONAL
        DebugLog "bfText: BF_CHARSET_FULL_INTERNATIONAL not implemented" : End
    Case 6
        ; BF_CHARSET_RESERVED1
        DebugLog "bfText: Illegal flag BF_CHARSET_RESERVED1" : End
    Case 7
        ; BF_CHARSET_RESERVED2
        DebugLog "bfText: Illegal flag BF_CHARSET_RESERVED2" : End
End Select

originalbuffer = GraphicsBuffer()
imgTemp = CreateImage(Len(word$)*charwidth,charheight%)

SetBuffer ImageBuffer(imgTemp)
ClsColor r%,g%,b% : Color 0,0,0 : Cls ; This sets the colour of the text.

For i% = 1 To Len(word$)
    char% = Instr(source$,Mid$(word$,i%,1))
    If char%>0
        DrawImage font,(i%-1)*charwidth%,0,char%-1
    Else
        Rect (i%-1)*charwidth%,0,charwidth%,charheight%,True ; Draw a negative space!
    EndIf 
Next 

SetBuffer originalbuffer
DrawImage imgTemp,offsetx%,offsety%

End Function

; EOF

Comments

Pinete2005
Very good stuff!,

Taking a look at the code I've seen you have in mind to support unicode posibilities at future... great!

I upload some time ago a library to draw 2D fonts with antialiasing... It was very fast and it was very similar
to your lib, except my lib supported antialiasing.

If you make your character at double size and before grab it, you scale the image and masked it later, the result is very impressive.

If you want, take a look at it, you can find it at graphics code archives and maybe you can obtain or extract some idea to improve your fantastic lib.

regards!


VP2005
Yes, I recall looking at your code some weeks ago. It wasn't quite suitable for what I wanted (needed a bitmap font solution) but it was interesting how you managed to get the text anti-aliased with such a small amount of effort.

If I get time, I will see if I can implement your anti-aliasing, though I will need to measure its speed impact on slow (350MHz) PC's.

If I can display anti-aliased text updating at 60-85Hz on an animated (scrolling) background, it will be perfect for my project :)


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