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   1 ;
   2 ; rules.s
   3 ;
   4 ; Draws horizontal and vertical rules 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 ;----- The main idea --------------------------------------------------------
  35 ;
  36 ; In the new version of Sculptrix, we define border types in terms of
  37 ; a collection of rules, which may be horizontal and vertical.  The positions
  38 ; of these rules relative to the icon, and their colours, are determined
  39 ; by a `border definition', which is parsed elsewhere.  This calls the
  40 ; rule drawing routines through a standardised interface.
  41 ;
  42 ; On entry to a rule routine, the colour has already been set up, through
  43 ; a call to Wimp_SetColour, or similar.  Coordinates for the rule to plot
  44 ; are passed in R3-R6, although all the registers may not have sensible
  45 ; values.  Values of dx, dy, and `start' are passed in R7, R8, and R9
  46 ; respectively.
  47
  48 ;----- Main code ------------------------------------------------------------
  49
  50                 AREA    |Module$$Code|,CODE,READONLY
  51
  52 ; --- rule_left ---
  53 ;
  54 ; On entry:     R3 == left hand side of the icon
  55 ;               R4 == bottom y position
  56 ;               R5 == unused
  57 ;               R6 == top y position
  58 ;               R7 == pixel width
  59 ;               R8 == pixel height
  60 ;               R9 == start position for mitring
  61 ;
  62 ; On exit:      R0-R6 corrupted
  63 ;
  64 ; Use:          Plots a vertical rule in the current colour.
  65
  66                 EXPORT  rule_left
  67 rule_left       ROUT
  68
  69                 STMFD   R13!,{R14}              ;Save some registers
  70
  71                 MOV     R0,#move+abs            ;Move cursor absolute
  72                 SUB     R1,R3,#4                ;Get the x position sorted
  73                 SUB     R2,R4,#4                ;And the y position
  74                 SWI     XOS_Plot                ;Move the graphics cursor
  75
  76                 MOV     R0,#rectfill+abs+fore   ;Now do the rectangle fill
  77                 SUB     R1,R3,R7                ;Find the x limit
  78                 SUB     R2,R6,R8                ;And the y limit
  79                 ADD     R2,R2,#4                ;Provide some overlap
  80                 SWI     XOS_Plot                ;Do that, please
  81
  82                 LDMFD   R13!,{PC}^              ;And return to caller
  83
  84                 LTORG
  85
  86 ; --- rule_right ---
  87 ;
  88 ; On entry:     R3 == unused
  89 ;               R4 == bottom y position
  90 ;               R5 == right hand side of the icon
  91 ;               R6 == top y position
  92 ;               R7 == pixel width
  93 ;               R8 == pixel height
  94 ;               R9 == start position for mitring
  95 ;
  96 ; On exit:      R0-R6 corrupted
  97 ;
  98 ; Use:          Plots a vertical rule in the current colour.
  99
 100                 EXPORT  rule_right
 101 rule_right      ROUT
 102
 103                 STMFD   R13!,{R14}              ;Save some registers
 104
 105                 MOV     R0,#move+abs            ;Move cursor absolute
 106                 MOV     R1,R5                   ;Get the x position sorted
 107                 SUB     R2,R4,#4                ;And the y position
 108                 SWI     XOS_Plot                ;Move the graphics cursor
 109
 110                 MOV     R0,#rectfill+abs+fore   ;Now do the rectangle fill
 111                 SUB     R1,R5,R7                ;Find the x limit
 112                 ADD     R1,R1,#4                ;Move over, for niceness
 113                 SUB     R2,R6,R8                ;And the y limit
 114                 ADD     R2,R2,#4                ;Provide some overlap
 115                 SWI     XOS_Plot                ;Do that, please
 116
 117                 LDMFD   R13!,{PC}^              ;And return to caller
 118
 119                 LTORG
 120
 121 ; --- rule_top ---
 122 ;
 123 ; On entry:     R3 == left hand side of the icon
 124 ;               R4 == unused
 125 ;               R5 == right hand side of the icon
 126 ;               R6 == top y position
 127 ;               R7 == pixel width
 128 ;               R8 == pixel height
 129 ;               R9 == start position for mitring
 130 ;
 131 ; On exit:      R0-R6 corrupted
 132 ;
 133 ; Use:          Plots a horizontal rule in the current colour.
 134
 135                 EXPORT  rule_top
 136 rule_top        ROUT
 137
 138                 STMFD   R13!,{R14}              ;Save return address
 139
 140                 ; --- Set up for the loop ---
 141
 142                 ADD     R4,R6,#4                ;A limit for the loop
 143                 SUB     R5,R5,R7                ;Step back a pixel
 144                 ADD     R5,R5,R9                ;And move on one too
 145
 146                 ; --- Now do the plotting ---
 147
 148 00              MOV     R0,#move+abs            ;Move cursor absolute
 149                 SUB     R1,R3,#4                ;Get the x position
 150                 MOV     R2,R6                   ;And the y position
 151                 SWI     XOS_Plot                ;Go and do that then
 152                 MOV     R0,#line+abs+fore       ;Draw line absolute
 153                 MOV     R1,R5                   ;Get the x limit value
 154                 MOV     R2,R6                   ;And the old y position
 155                 SWI     XOS_Plot                ;Go and do that, please
 156
 157                 ADD     R5,R5,R8                ;Extend the mitring
 158                 ADD     R6,R6,R8                ;Move up by a pixel
 159                 CMP     R6,R4                   ;Have we reached the end?
 160                 BLT     %b00                    ;No -- look back then
 161
 162                 LDMFD   R13!,{PC}^              ;And return to caller
 163
 164                 LTORG
 165
 166 ; --- rule_bottom ---
 167 ;
 168 ; On entry:     R3 == left hand side of the icon
 169 ;               R4 == unused
 170 ;               R5 == right hand side of the icon
 171 ;               R6 == top y position
 172 ;               R7 == pixel width
 173 ;               R8 == pixel height
 174 ;               R9 == start position for mitring
 175 ;
 176 ; On exit:      R0-R6 corrupted
 177 ;
 178 ; Use:          Plots a horizontal rule in the current colour.
 179
 180                 EXPORT  rule_bottom
 181 rule_bottom     ROUT
 182
 183                 STMFD   R13!,{R14}              ;Save return address
 184
 185                 ; --- Set up for the loop ---
 186
 187                 SUB     R6,R4,R8                ;Drop down a pixel to start
 188                 SUB     R4,R4,#4                ;A limit for the loop
 189                 SUB     R3,R3,R9                ;And move on one too
 190                 SUBS    R14,R7,R8               ;Which pixel size is bigger?
 191                 ADDPL   R3,R3,R14               ;Bodge for flattened modes
 192                 SUB     R5,R5,R7                ;Sort out right hand side
 193
 194                 ; --- Now do the plotting ---
 195
 196 00              MOV     R0,#move+abs            ;Move cursor absolute
 197                 MOV     R1,R3                   ;Get the x position
 198                 MOV     R2,R6                   ;And the y position
 199                 SWI     XOS_Plot                ;Go and do that then
 200                 MOV     R0,#line+abs+fore       ;Draw line absolute
 201                 ADD     R1,R5,#4                ;Get the x limit value
 202                 MOV     R2,R6                   ;And the old y position
 203                 SWI     XOS_Plot                ;Go and do that, please
 204
 205                 SUB     R3,R3,R8                ;Extend the mitring
 206                 SUB     R6,R6,R8                ;Move up by a pixel
 207                 CMP     R6,R4                   ;Have we reached the end?
 208                 BGE     %b00                    ;No -- look back then
 209
 210                 LDMFD   R13!,{PC}^              ;And return to caller
 211
 212                 LTORG
 213
 214 ; --- rule_pTop ---
 215 ;
 216 ; On entry:     R3 == left hand side of the icon
 217 ;               R4 == unused
 218 ;               R5 == right hand side of the icon
 219 ;               R6 == top y position
 220 ;               R7 == pixel width
 221 ;               R8 == pixel height
 222 ;               R9 == start position for mitring
 223 ;
 224 ; On exit:      R0-R6 corrupted
 225 ;
 226 ; Use:          Plots a horizontal rule in the current colour, without
 227 ;               mitring.
 228
 229                 EXPORT  rule_pTop
 230 rule_pTop       ROUT
 231
 232                 STMFD   R13!,{R14}              ;Save return address
 233
 234                 MOV     R0,#move+abs            ;Move cursor absolute
 235                 SUB     R1,R3,#4                ;Sort out left hand side
 236                 MOV     R2,R6                   ;And the y position
 237                 SWI     XOS_Plot                ;Move the cursor
 238
 239                 MOV     R0,#rectfill+abs+fore   ;Plot the rectangle
 240                 SUB     R1,R5,R7                ;Sort out the overhang
 241                 ADD     R1,R1,#4                ;And add some overlap
 242                 SUB     R2,R6,R8                ;Set the y position
 243                 ADD     R2,R2,#4                ;Move up a little
 244                 SWI     XOS_Plot                ;And plot the rectangle
 245
 246                 LDMFD   R13!,{PC}^              ;And return to caller
 247
 248                 LTORG
 249
 250 ; --- rule_pBottom ---
 251 ;
 252 ; On entry:     R3 == left hand side of the icon
 253 ;               R4 == unused
 254 ;               R5 == right hand side of the icon
 255 ;               R6 == top y position
 256 ;               R7 == pixel width
 257 ;               R8 == pixel height
 258 ;               R9 == start position for mitring
 259 ;
 260 ; On exit:      R0-R6 corrupted
 261 ;
 262 ; Use:          Plots a horizontal rule in the current colour, without
 263 ;               mitring.
 264
 265                 EXPORT  rule_pBottom
 266 rule_pBottom    ROUT
 267
 268                 STMFD   R13!,{R14}              ;Save return address
 269
 270                 MOV     R0,#move+abs            ;Move cursor absolute
 271                 SUB     R1,R3,#4                ;Sort out left hand side
 272                 SUB     R2,R4,#4                ;And the y position
 273                 SWI     XOS_Plot                ;Move the cursor
 274
 275                 MOV     R0,#rectfill+abs+fore   ;Plot the rectangle
 276                 SUB     R1,R5,R7                ;Sort out the overhang
 277                 ADD     R1,R1,#4                ;And add some overlap
 278                 SUB     R2,R4,R8                ;Set the y position
 279                 SWI     XOS_Plot                ;And plot the rectangle
 280
 281                 LDMFD   R13!,{PC}^              ;And return to caller
 282
 283                 LTORG
 284
 285 ; --- rule_border ---
 286 ;
 287 ; On entry:     R3 == left hand side of the icon
 288 ;               R4 == bottom edge of icon
 289 ;               R5 == right hand side of the icon
 290 ;               R6 == top y position
 291 ;               R7 == pixel width
 292 ;               R8 == pixel height
 293 ;               R9 == start position for mitring
 294 ;
 295 ; On exit:      R0-R6 corrupted
 296 ;
 297 ; Use:          Fills the icon in, and plots a border around it, using the
 298 ;               current foreground and background colours.
 299
 300                 EXPORT  rule_border
 301 rule_border     ROUT
 302
 303                 STMFD   R13!,{R14}              ;Save return address
 304
 305                 ; --- Fill in the background ---
 306                 ;
 307                 ; We plot /within/ the border, to ensure that there's no
 308                 ; flicker.
 309
 310                 MOV     R0,#move+abs            ;Move cursor absolute
 311                 ADD     R1,R3,R7                ;Move slightly inwards
 312                 ADD     R2,R4,R8                ;Move slightly upwards
 313                 SWI     XOS_Plot                ;Do the plotting
 314
 315                 MOV     R0,#rectfill+abs+back   ;Plot rectangle in background
 316                 SUB     R1,R5,R7,LSL #1         ;Move inwards from right
 317                 SUB     R2,R6,R8,LSL #1         ;And downwards from top
 318                 SWI     XOS_Plot                ;Do the rectangle now
 319
 320                 ; --- Plot the border around the edge ---
 321
 322                 MOV     R0,#move+abs            ;Move cursor absolute
 323                 MOV     R1,R3                   ;Start on the left
 324                 MOV     R2,R4                   ;And at the bottom
 325                 SWI     XOS_Plot                ;Move the cursor
 326
 327                 MOV     R0,#line+abs+fore       ;Draw line absolute
 328                 MOV     R1,R3                   ;Stay on the left
 329                 SUB     R2,R6,R8                ;Move to the top
 330                 SWI     XOS_Plot                ;Draw the line
 331
 332                 MOV     R0,#line+abs+fore       ;Draw line absolute
 333                 SUB     R1,R5,R7                ;Move to the right
 334                 SUB     R2,R6,R8                ;Stay at the top
 335                 SWI     XOS_Plot                ;Draw the line
 336
 337                 MOV     R0,#line+abs+fore       ;Draw line absolute
 338                 SUB     R1,R5,R7                ;Stay on the right
 339                 MOV     R2,R4                   ;Move to the bottom
 340                 SWI     XOS_Plot                ;Draw the line
 341
 342                 MOV     R0,#line+abs+fore       ;Draw line absolute
 343                 MOV     R1,R3                   ;Move to the left
 344                 MOV     R2,R4                   ;Stay at the bottom
 345                 SWI     XOS_Plot                ;Draw the line
 346
 347                 LDMFD   R13!,{PC}^              ;Return when done
 348
 349                 LTORG
 350
 351 ;----- Plot codes -----------------------------------------------------------
 352
 353 rel             EQU     0
 354 abs             EQU     4
 355
 356 move            EQU     0
 357 line            EQU     0
 358 rectfill        EQU     96
 359
 360 fore            EQU     1
 361 back            EQU     3
 362
 363 ;----- That's all, folks ----------------------------------------------------
 364
 365                 END