mdw@git.distorted.org.uk Git - ssr/blob - StraySrc/Glass/!Glass/c/wGraph

   1 /*
   2  * wGraph.c
   3  *
   4  * Low-level graphics handling
   5  *
   6  * © 1994-1998 Straylight
   7  */
   8
   9 /*----- Licensing note ----------------------------------------------------*
  10  *
  11  * This file is part of Straylight's Glass.
  12  *
  13  * Glass 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  * Glass 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 Glass.  If not, write to the Free Software Foundation,
  25  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  26  */
  27
  28 /*----- Header files ------------------------------------------------------*/
  29
  30 /*
  31  * ANSI standard headers
  32  */
  33
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37
  38 /*
  39  * Steel headers
  40  */
  41
  42 #define _STDAPP
  43 #define _LOWLVL
  44 #include "steel/Steel.h"
  45
  46 #include "steel/bbc.h"
  47 #include "steel/colourtran.h"
  48
  49 /*
  50  * Glass headers
  51  */
  52
  53 #include "gStruct.h"
  54 #include "gMenus.h"
  55 #include "gIcons.h"
  56
  57 #include "glass.h"
  58 #include "gPrefs.h"
  59 #include "window.h"
  60 #include "_window.h"
  61
  62 /*----- Private variables -------------------------------------------------*/
  63
  64 static int window__dashPos;      /* Current rotating dash position         */
  65
  66 /*----- Main code ---------------------------------------------------------*/
  67
  68 /*
  69  * void window__colourChange(int col1,int col2)
  70  *
  71  * Use
  72  *  Sets up the current foreground colour so that when plotted over colour
  73  *  col1 it looks like col2 and vice-versa.  The effects of plotting over
  74  *  other colours is defined to be psychedelically interesting, but not
  75  *  pretty.
  76  *
  77  *  Basically, all it does is suss out what the colours really mean and XOR
  78  *  them together.
  79  *
  80  * Parameters
  81  *  int col1,int col2 == the Wimp colour numbers to swap between
  82  */
  83
  84 void window__colourChange(int col1,int col2)
  85 {
  86   wimp_palettestr pal;
  87   int x,y;
  88   wimpt_noerr(wimp_readpalette(&pal));
  89   wimpt_noerr(colourtran_return_colournumber(pal.c[col1],&x));
  90   wimpt_noerr(colourtran_return_colournumber(pal.c[col2],&y));
  91   if (os_swiv(XOS_SetColour,3,x^y))
  92   {
  93     if (wimpt_bpp()==8)
  94     {
  95       wimpt_noerr(colourtran_colournumbertoGCOL(x^y,&x));
  96       bbc_vduq(18,3,x>>2);
  97       bbc_vduq(23,17,2,(x & 3)<<6,0,0,0,0,0,0);
  98     }
  99     else
 100       bbc_vduq(18,3,x^y);
 101   }
 102 }
 103
 104 /*
 105  * void window__setXORColour(glass_windPointer *w,int col)
 106  *
 107  * Use
 108  *  Sets up the current foreground colour so that it appears to be WIMP
 109  *  colour col on the specified window background.  Lots of tedious
 110  *  ColourTransing to do on this, with no real reward, but at least it will
 111  *  look vaguely right in 256 colour modes.
 112  *
 113  * Parameters
 114  *  glass_windPointer *w == the window in which to set the colour
 115  *  int col == the colour to set
 116  */
 117
 118 void window__setXORColour(glass_windPointer *w,int col)
 119 {
 120   int old=w->def->desc.w.colours[3];
 121
 122   /* --- Make sure the background isn't transparent --- */
 123
 124   if (old==255)
 125     old=1;
 126
 127   window__colourChange(old,col);
 128 }
 129
 130 /*
 131  * void window__makeDashPattern(int ptn)
 132  *
 133  * Use
 134  *  Sets the OS dash pattern to the given pattern (only the lowest byte
 135  *  is considered).
 136  *
 137  * Parameters
 138  *  int ptn == the LSB of this word contains the dash pattern as a bit
 139  *   pattern
 140  */
 141
 142 void window__makeDashPattern(int ptn)
 143 {
 144   int byte1,byte2;
 145   byte1=242;
 146   byte2=8;
 147   wimpt_noerr(os_byte(163,&byte1,&byte2)); /* Dot-dash length              */
 148   bbc_vduq(23,6,ptn,ptn,ptn,ptn,ptn,ptn,ptn,ptn);
 149 }
 150
 151 /*
 152  * void window__setDash(void)
 153  *
 154  * Use
 155  *  Sets the dashed pattern so that it looks as if a 'rotating' box is being
 156  *  dragged, like the WIMP's, only better...  The box is set up so that a
 157  *  SINGLE exclusive-or plot will move the dash round.
 158  */
 159
 160 #define SECTION(x,i) ((((x)<<(i)) & 0xff00) >> 8)
 161
 162 void window__setDash(void)
 163 {
 164   int dash=SECTION(0xFCFCFC,window__dashPos);
 165   int newDash;
 166   window__dashPos+=2;
 167   if (window__dashPos>7)
 168     window__dashPos=0;
 169   newDash=SECTION(0xFCFCFC,window__dashPos);
 170   dash^=newDash;
 171   window__makeDashPattern(dash);
 172   window__setXORColour(window__dragWind(),window__DRAGCOL);
 173 }
 174
 175 /*
 176  * void window__rotate(int by)
 177  *
 178  * Use
 179  *  Rotates the current rotating-dash pattern by a given amount.  This is
 180  *  used to rotate the dash box while the box is moving.
 181  *
 182  * Parameters
 183  *  int by == the number of steps to rotate the dash pattern.
 184  */
 185
 186 void window__rotate(int by)
 187 {
 188   window__dashPos+=by;
 189   if (window__dashPos<0)
 190     window__dashPos=6;
 191   else if (window__dashPos>7)
 192     window__dashPos=0;
 193   window__makeDashPattern(SECTION(0xFCFCFC,window__dashPos));
 194   window__setXORColour(window__dragWind(),window__DRAGCOL);
 195 }
 196
 197 /*
 198  * void window__rectangle(int x,int y,int w,int h)
 199  *
 200  * Use
 201  *  Draws a rectangle, using the current dotted line pattern
 202  *
 203  * Parameters
 204  *  int x == the left side of the rectangle
 205  *  int y == the right side of the rectangle
 206  *  int w == the width of the rectangle (may be <0)
 207  *  int h == the height of the rectangle (may be <0)
 208  */
 209
 210 void window__rectangle(int x,int y,int w,int h)
 211 {
 212   bbc_plot(bbc_DottedBoth+bbc_MoveCursorAbs,x,y);
 213   bbc_plot(bbc_DottedBoth+bbc_DrawRelFore,0,h);
 214   bbc_plot(bbc_DottedExInit+bbc_DrawRelFore,w,0);
 215   bbc_plot(bbc_DottedExInit+bbc_DrawRelFore,0,-h);
 216   bbc_plot(bbc_DottedExBoth+bbc_DrawRelFore,-w,0);
 217 }