src/gb/gbPrinter.c

   1 // VisualBoyAdvance - Nintendo Gameboy/GameboyAdvance (TM) emulator.
   2 // Copyright (C) 1999-2003 Forgotten
   3 // Copyright (C) 2004 Forgotten and the VBA development team
   4
   5 // This program is free software; you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation; either version 2, or(at your option)
   8 // any later version.
   9 //
  10 // This program is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with this program; if not, write to the Free Software Foundation,
  17 // Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18
  19 #include <stdio.h>
  20 #include <memory.h>
  21 #include "../GBA.h"
  22
  23 u8 gbPrinterStatus = 0;
  24 int gbPrinterState = 0;
  25 u8 gbPrinterData[0x280*9];
  26 u8 gbPrinterPacket[0x400];
  27 int gbPrinterCount = 0;
  28 int gbPrinterDataCount = 0;
  29 int gbPrinterDataSize = 0;
  30 int gbPrinterResult = 0;
  31
  32 bool gbPrinterCheckCRC()
  33 {
  34   u16 crc = 0;
  35
  36   for(int i = 2; i < (6+gbPrinterDataSize); i++) {
  37     crc += gbPrinterPacket[i];
  38   }
  39
  40   int msgCrc = gbPrinterPacket[6+gbPrinterDataSize] +
  41     (gbPrinterPacket[7+gbPrinterDataSize]<<8);
  42
  43   return msgCrc == crc;
  44 }
  45
  46 void gbPrinterReset()
  47 {
  48   gbPrinterState = 0;
  49   gbPrinterDataSize = 0;
  50   gbPrinterDataCount = 0;
  51   gbPrinterCount = 0;
  52   gbPrinterStatus = 0;
  53   gbPrinterResult = 0;
  54 }
  55
  56 void gbPrinterShowData()
  57 {
  58   systemGbPrint(gbPrinterData,
  59                 gbPrinterPacket[6],
  60                 gbPrinterPacket[7],
  61                 gbPrinterPacket[8],
  62                 gbPrinterPacket[9]);
  63   /*
  64   allegro_init();
  65   install_keyboard();
  66   set_gfx_mode(GFX_AUTODETECT, 160, 144, 0, 0);
  67   PALETTE pal;
  68   pal[0].r = 255;
  69   pal[0].g = 255;
  70   pal[0].b = 255;
  71   pal[1].r = 168;
  72   pal[1].g = 168;
  73   pal[1].b = 168;
  74   pal[2].r = 96;
  75   pal[2].g = 96;
  76   pal[2].b = 96;
  77   pal[3].r = 0;
  78   pal[3].g = 0;
  79   pal[3].b = 0;
  80   set_palette(pal);
  81   acquire_screen();
  82   u8 *data = gbPrinterData;
  83   for(int y = 0; y < 0x12; y++) {
  84     for(int x = 0; x < 0x14; x++) {
  85       for(int k = 0; k < 8; k++) {
  86         int a = *data++;
  87         int b = *data++;
  88         for(int j = 0; j < 8; j++) {
  89           int mask = 1 << (7-j);
  90           int c = 0;
  91           if(a & mask)
  92             c++;
  93           if(b & mask)
  94             c+=2;
  95           putpixel(screen, x*8+j, y*8+k, c);
  96         }
  97       }
  98     }
  99   }
 100   release_screen();
 101   while(!keypressed()) {
 102   }
 103   */
 104 }
 105
 106 void gbPrinterReceiveData()
 107 {
 108   if(gbPrinterPacket[3]) { // compressed
 109     u8 *data = &gbPrinterPacket[6];
 110     u8 *dest = &gbPrinterData[gbPrinterDataCount];
 111     int len = 0;
 112     while(len < gbPrinterDataSize) {
 113       u8 control = *data++;
 114       if(control & 0x80) { // repeated data
 115         control &= 0x7f;
 116         control += 2;
 117         memset(dest, *data++, control);
 118         len += control;
 119         dest += control;
 120       } else { // raw data
 121         control++;
 122         memcpy(dest, data, control);
 123         dest += control;
 124         data += control;
 125         len += control;
 126       }
 127     }
 128   } else {
 129     memcpy(&gbPrinterData[gbPrinterDataCount],
 130            &gbPrinterPacket[6],
 131            gbPrinterDataSize);
 132     gbPrinterDataCount += gbPrinterDataSize;
 133   }
 134 }
 135
 136 void gbPrinterCommand()
 137 {
 138   switch(gbPrinterPacket[2]) {
 139   case 0x01:
 140     // reset/initialize packet
 141     gbPrinterDataCount = 0;
 142     gbPrinterStatus = 0;
 143     break;
 144   case 0x02:
 145     // print packet
 146     gbPrinterShowData();
 147     break;
 148   case 0x04:
 149     // data packet
 150     gbPrinterReceiveData();
 151     break;
 152   case 0x0f:
 153     // NUL packet
 154     break;
 155   }
 156 }
 157
 158 u8 gbPrinterSend(u8 b)
 159 {
 160   switch(gbPrinterState) {
 161   case 0:
 162     gbPrinterCount = 0;
 163     // receiving preamble
 164     if(b == 0x88) {
 165       gbPrinterPacket[gbPrinterCount++] = b;
 166       gbPrinterState++;
 167     } else {
 168       // todo: handle failure
 169       gbPrinterReset();
 170     }
 171     break;
 172   case 1:
 173     // receiving preamble
 174     if(b == 0x33) {
 175       gbPrinterPacket[gbPrinterCount++] = b;
 176       gbPrinterState++;
 177     } else {
 178       // todo: handle failure
 179       gbPrinterReset();
 180     }
 181     break;
 182   case 2:
 183     // receiving header
 184     gbPrinterPacket[gbPrinterCount++] = b;
 185     if(gbPrinterCount == 6) {
 186       gbPrinterState++;
 187       gbPrinterDataSize = gbPrinterPacket[4] + (gbPrinterPacket[5]<<8);
 188     }
 189     break;
 190   case 3:
 191     // receiving data
 192     if(gbPrinterDataSize) {
 193       gbPrinterPacket[gbPrinterCount++] = b;
 194       if(gbPrinterCount == (6+gbPrinterDataSize)) {
 195         gbPrinterState++;
 196       }
 197       break;
 198     }
 199     gbPrinterState++;
 200     // intentionally move to next if no data to receive
 201   case 4:
 202     // receiving CRC
 203     gbPrinterPacket[gbPrinterCount++] = b;
 204     gbPrinterState++;
 205     break;
 206   case 5:
 207     // receiving CRC-2
 208     gbPrinterPacket[gbPrinterCount++] = b;
 209     if(gbPrinterCheckCRC()) {
 210       gbPrinterCommand();
 211     }
 212     gbPrinterState++;
 213     break;
 214   case 6:
 215     // receiving dummy 1
 216     gbPrinterPacket[gbPrinterCount++] = b;
 217     gbPrinterResult = 0x81;
 218     gbPrinterState++;
 219     break;
 220   case 7:
 221     // receiving dummy 2
 222     gbPrinterPacket[gbPrinterCount++] = b;
 223     gbPrinterResult = gbPrinterStatus;
 224     gbPrinterState = 0;
 225     gbPrinterCount = 0;
 226     break;
 227   }
 228   return gbPrinterResult;
 229 }