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

   1 ;
   2 ; bbox.s
   3 ;
   4 ; Bounding box calculations for Sculptrix borders
   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 ;----- External dependencies ------------------------------------------------
  35
  36                 GET     sh.vString
  37                 GET     sh.wSpace
  38
  39 ;----- Main code ------------------------------------------------------------
  40
  41                 AREA    |Module$$Code|,CODE,READONLY
  42
  43 ; --- bbox_calc ---
  44 ;
  45 ; On entry:     R1 == pointer to icon block
  46 ;
  47 ; On exit:      R0 == 0 if there was no border, or nonzero otherwise
  48 ;
  49 ; Use:          Updates the block to represent the size of the border.
  50
  51                 EXPORT  bbox_calc
  52 bbox_calc       ROUT
  53
  54                 STMFD   R13!,{R1-R4,R14}        ;Save some registers
  55                 BL      vString_read            ;Read the validation string
  56                 BCC     %85bbox_calc            ;If no border, return
  57
  58                 ; --- Work out where to go ---
  59
  60                 AND     R14,R0,#&0000FF00       ;Extract the general code
  61                 CMP     R14,#(%10-%00)<<6       ;Check it's in range
  62                 ADDCC   PC,PC,R14,LSR #6        ;Yes -- dispatch it then
  63                 B       %85bbox_calc            ;Otherwise ignore it
  64
  65 00              B       %10bbox_calc            ;A simple border type
  66                 B       %20bbox_calc            ;A group box
  67                 B       %85bbox_calc            ;A text+sprite icon
  68
  69                 ; --- A normal icon ---
  70
  71 10bbox_calc     AND     R0,R0,#&FF              ;Leave only the subtype
  72                 ADR     R14,bbox__table         ;Point to a smart table
  73                 LDRB    R0,[R14,R0]             ;Load the sizes out
  74
  75                 LDMIA   R1,{R2-R4,R14}          ;Load the bounding box
  76                 SUB     R2,R2,R0                ;Modify the bounding box
  77                 SUB     R3,R3,R0
  78                 ADD     R4,R4,R0
  79                 ADD     R14,R14,R0
  80                 STMIA   R1,{R2-R4,R14}          ;Save modified box back
  81                 MOV     R0,#-1                  ;Return a mystic value
  82                 B       %90bbox_calc            ;And return to caller
  83
  84                 ; --- A group box ---
  85
  86 20bbox_calc     LDMIA   R1,{R2-R4,R14}          ;Load the bounding box
  87                 SUB     R2,R2,#8                ;Modify the bounding box
  88                 SUB     R3,R3,#8
  89                 ADD     R4,R4,#8
  90                 ADD     R14,R14,#32
  91                 STMIA   R1,{R2-R4,R14}          ;Save modified box back
  92                 MOV     R0,#-1                  ;Return a mystic value
  93                 B       %90bbox_calc            ;And return to caller
  94
  95                 ; --- Return then ---
  96
  97 85bbox_calc     MOV     R0,#0                   ;Nothing happened here
  98 90bbox_calc     LDMFD   R13!,{R1-R4,PC}^        ;Return to caller
  99
 100 bbox__table     DCB     4,12,8,12,8
 101
 102                 LTORG
 103
 104 ;----- That's all, folks ----------------------------------------------------
 105
 106                 END