mdw@git.distorted.org.uk Git - ssr/blob - StraySrc/Sculptrix/sculptrix/s/utils

   1 ;
   2 ; utils
   3 ;
   4 ; Various useful routines
   5 ;
   6 ; © 1995-1998 Straylight
   7 ;
   8
   9 ;----- Licensing note -------------------------------------------------------
  10 ;
  11 ; This file is part of Straylight's Sculptrix.
  12 ;
  13 ; Sculptrix is free software; you can redistribute it and/or modify
  14 ; it under the terms of the GNU General Public License as published by
  15 ; the Free Software Foundation; either version 2, or (at your option)
  16 ; any later version.
  17 ;
  18 ; Sculptrix is distributed in the hope that it will be useful,
  19 ; but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 ; GNU General Public License for more details.
  22 ;
  23 ; You should have received a copy of the GNU General Public License
  24 ; along with Sculptrix.  If not, write to the Free Software Foundation,
  25 ; 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  26
  27 ;----- Standard header ------------------------------------------------------
  28
  29                 GET     libs:header
  30                 GET     libs:swis
  31
  32                 GET     libs:stream
  33
  34 ;----- Main code ------------------------------------------------------------
  35
  36                 AREA    |Module$$Code|,CODE,READONLY
  37
  38 ; --- utils_strWidth ---
  39 ;
  40 ; On entry:     R0 == pointer to a string
  41 ;
  42 ; On exit:      R0 == width of the string in OS units
  43 ;
  44 ; Use:          Returns the width of a string, as it would be displayed in
  45 ;               an icon (i.e. taking into account things like the current
  46 ;               desktop font etc.)  The width is exact, so if you want to
  47 ;               e.g. draw a box round it, you'll have to add on a little
  48 ;               clearance at each end.  8 OS units seems to be a good size
  49 ;               for the clearance (so the total width you'd use is given by
  50 ;               utils_strWidth(string)+16, because it has two ends).
  51 ;
  52 ;               [Stolen and bodged from sapphire/wimp.s by mdw]
  53
  54                 EXPORT  utils_strWidth
  55 utils_strWidth  ROUT
  56
  57                 ; --- We need to find the string length anyway ---
  58                 ;
  59                 ; This length calculation is done inline to avoid a
  60                 ; dependency on string.  It's not very long, anyway, and
  61                 ; it *does* save a MOV R5,R0 :-)
  62
  63                 STMFD   R13!,{R1-R6,R14}        ;Save a bunch of registers
  64                 MOV     R5,#0                   ;Length counter starts at 0
  65                 MOV     R6,R0                   ;Keep string pointer
  66
  67 00              LDRB    R14,[R0,R5]             ;Get a byte from the string
  68                 CMP     R14,#' '                ;Is it a control char?
  69                 ADDCS   R5,R5,#1                ;Bump on *anyway* (see above)
  70                 BCS     %b00                    ;If more to go, loop back
  71
  72                 ; --- Now try to find the current font handle ---
  73
  74                 MOV     R0,#8                   ;Read Wimp font handle
  75                 SWI     XWimp_ReadSysInfo       ;Find out from WindowMangler
  76                 MOVVS   R0,#0                   ;If nothing, assume no font
  77                 CMP     R0,#0                   ;Is there there a real font?
  78                 BEQ     %10utils_strWidth       ;No -- skip ahead too
  79
  80                 ; --- Now suss out the width of the string ---
  81
  82                 SWI     Font_SetFont            ;Set up the desktop font
  83                 MOV     R1,#1000                ;A nice big round number
  84                 MOV     R2,R1                   ;And another nice big number
  85                 SWI     Font_Converttopoints    ;Font_StringWidth is weird
  86                 MOV     R3,R2                   ;Move coords to right regs
  87                 MOV     R2,R1                   ;That means both of them
  88                 MOV     R1,R6                   ;Retreive string pointer
  89                 MOV     R4,#-1                  ;Don't split the string
  90                 ADD     R5,R5,#1                ;Move this counter on one
  91                 SWI     Font_StringWidth        ;Find the width of the string
  92                 MOV     R1,R2                   ;Move coordinates back again
  93                 MOV     R2,R3                   ;Again, that means both
  94                 SWI     Font_ConverttoOS        ;Convert to OS units now
  95                 MOV     R0,R1                   ;Put the width in R0
  96                 LDMFD   R13!,{R1-R6,PC}^        ;Return to caller, then
  97
  98                 ; --- Just normal system font ---
  99
 100 10              MOV     R0,R5,LSL #4            ;Multiply by character width
 101                 LDMFD   R13!,{R1-R6,PC}^        ;Return to caller
 102
 103                 LTORG
 104
 105 ;----- That's all, folks ----------------------------------------------------
 106
 107                 END