PCem: d0d530adce12 src/vid

PCem

view src/vid_cga.c @ 154:d0d530adce12

Initial port to Linux (using Allegro). 64-bit fixes. Some changes to aid portability. A few other tweaks.

author	TomW
date	Thu Sep 04 21:07:24 2014 +0100
parents	b53e148867e5
children

line source

1 /*CGA emulation*/

2 #include <stdlib.h>

3 #include <math.h>

4 #include "ibm.h"

5 #include "device.h"

6 #include "io.h"

7 #include "mem.h"

8 #include "timer.h"

9 #include "video.h"

10 #include "vid_cga.h"

12 static int i_filt[8],q_filt[8];

14 static uint8_t crtcmask[32] =

15 {

16 0xff, 0xff, 0xff, 0xff, 0x7f, 0x1f, 0x7f, 0x7f, 0xf3, 0x1f, 0x7f, 0x1f, 0x3f, 0xff, 0x3f, 0xff,

17 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00

18 };

20 void cga_recalctimings(cga_t *cga);

22 void cga_out(uint16_t addr, uint8_t val, void *p)

23 {

24 cga_t *cga = (cga_t *)p;

25 uint8_t old;

26 // pclog("CGA_OUT %04X %02X\n", addr, val);

27 switch (addr)

28 {

29 case 0x3D4:

30 cga->crtcreg = val & 31;

31 return;

32 case 0x3D5:

33 old = cga->crtc[cga->crtcreg];

34 cga->crtc[cga->crtcreg] = val & crtcmask[cga->crtcreg];

35 if (old != val)

36 {

37 if (cga->crtcreg < 0xe || cga->crtcreg > 0x10)

38 {

39 fullchange = changeframecount;

40 cga_recalctimings(cga);

41 }

42 }

43 return;

44 case 0x3D8:

45 cga->cgamode = val;

46 return;

47 case 0x3D9:

48 cga->cgacol = val;

49 return;

50 }

51 }

53 uint8_t cga_in(uint16_t addr, void *p)

54 {

55 cga_t *cga = (cga_t *)p;

56 // pclog("CGA_IN %04X\n", addr);

57 switch (addr)

58 {

59 case 0x3D4:

60 return cga->crtcreg;

61 case 0x3D5:

62 return cga->crtc[cga->crtcreg];

63 case 0x3DA:

64 return cga->cgastat;

65 }

66 return 0xFF;

67 }

69 void cga_write(uint32_t addr, uint8_t val, void *p)

70 {

71 cga_t *cga = (cga_t *)p;

72 // pclog("CGA_WRITE %04X %02X\n", addr, val);

73 cga->vram[addr & 0x3fff] = val;

74 cga->charbuffer[ ((int)(((cga->dispontime - cga->vidtime) * 2) / CGACONST)) & 0xfc] = val;

75 cga->charbuffer[(((int)(((cga->dispontime - cga->vidtime) * 2) / CGACONST)) & 0xfc) | 1] = val;

76 egawrites++;

77 cycles -= 4;

78 }

80 uint8_t cga_read(uint32_t addr, void *p)

81 {

82 cga_t *cga = (cga_t *)p;

83 cycles -= 4;

84 cga->charbuffer[ ((int)(((cga->dispontime - cga->vidtime) * 2) / CGACONST)) & 0xfc] = cga->vram[addr & 0x3fff];

85 cga->charbuffer[(((int)(((cga->dispontime - cga->vidtime) * 2) / CGACONST)) & 0xfc) | 1] = cga->vram[addr & 0x3fff];

86 egareads++;

87 // pclog("CGA_READ %04X\n", addr);

88 return cga->vram[addr & 0x3fff];

89 }

91 void cga_recalctimings(cga_t *cga)

92 {

93 double disptime;

94 double _dispontime, _dispofftime;

95 pclog("Recalc - %i %i %i\n", cga->crtc[0], cga->crtc[1], cga->cgamode & 1);

96 if (cga->cgamode & 1)

97 {

98 disptime = cga->crtc[0] + 1;

99 _dispontime = cga->crtc[1];

100 }

101 else

102 {

103 disptime = (cga->crtc[0] + 1) << 1;

104 _dispontime = cga->crtc[1] << 1;

105 }

106 _dispofftime = disptime - _dispontime;

107 // printf("%i %f %f %f %i %i\n",cgamode&1,disptime,dispontime,dispofftime,crtc[0],crtc[1]);

108 _dispontime *= CGACONST;

109 _dispofftime *= CGACONST;

110 // printf("Timings - on %f off %f frame %f second %f\n",dispontime,dispofftime,(dispontime+dispofftime)*262.0,(dispontime+dispofftime)*262.0*59.92);

111 cga->dispontime = (int)(_dispontime * (1 << TIMER_SHIFT));

112 cga->dispofftime = (int)(_dispofftime * (1 << TIMER_SHIFT));

113 }

114

115 static int ntsc_col[8][8]=

116 {

117 {0,0,0,0,0,0,0,0}, /*Black*/

118 {0,0,1,1,1,1,0,0}, /*Blue*/

119 {1,0,0,0,0,1,1,1}, /*Green*/

120 {0,0,0,0,1,1,1,1}, /*Cyan*/

121 {1,1,1,1,0,0,0,0}, /*Red*/

122 {0,1,1,1,1,0,0,0}, /*Magenta*/

123 {1,1,0,0,0,0,1,1}, /*Yellow*/

124 {1,1,1,1,1,1,1,1} /*White*/

125 };

126

127 void cga_poll(void *p)

128 {

129 cga_t *cga = (cga_t *)p;

130 uint16_t ca = (cga->crtc[15] | (cga->crtc[14] << 8)) & 0x3fff;

131 int drawcursor;

132 int x, c;

133 int oldvc;

134 uint8_t chr, attr;

135 uint16_t dat;

136 int cols[4];

137 int col;

138 int oldsc;

139 int y_buf[8] = {0, 0, 0, 0, 0, 0, 0, 0}, y_val, y_tot;

140 int i_buf[8] = {0, 0, 0, 0, 0, 0, 0, 0}, i_val, i_tot;

141 int q_buf[8] = {0, 0, 0, 0, 0, 0, 0, 0}, q_val, q_tot;

142 int r, g, b;

143 if (!cga->linepos)

144 {

145 cga->vidtime += cga->dispofftime;

146 cga->cgastat |= 1;

147 cga->linepos = 1;

148 oldsc = cga->sc;

149 if ((cga->crtc[8] & 3) == 3)

150 cga->sc = ((cga->sc << 1) + cga->oddeven) & 7;

151 if (cga->cgadispon)

152 {

153 if (cga->displine < cga->firstline)

154 {

155 cga->firstline = cga->displine;

156 // printf("Firstline %i\n",firstline);

157 }

158 cga->lastline = cga->displine;

159 for (c = 0; c < 8; c++)

160 {

161 if ((cga->cgamode & 0x12) == 0x12)

162 {

163 buffer->line[cga->displine][c] = 0;

164 if (cga->cgamode & 1) buffer->line[cga->displine][c + (cga->crtc[1] << 3) + 8] = 0;

165 else buffer->line[cga->displine][c + (cga->crtc[1] << 4) + 8] = 0;

166 }

167 else

168 {

169 buffer->line[cga->displine][c] = (cga->cgacol & 15) + 16;

170 if (cga->cgamode & 1) buffer->line[cga->displine][c + (cga->crtc[1] << 3) + 8] = (cga->cgacol & 15) + 16;

171 else buffer->line[cga->displine][c + (cga->crtc[1] << 4) + 8] = (cga->cgacol & 15) + 16;

172 }

173 }

174 if (cga->cgamode & 1)

175 {

176 for (x = 0; x < cga->crtc[1]; x++)

177 {

178 chr = cga->charbuffer[x << 1];

179 attr = cga->charbuffer[(x << 1) + 1];

180 drawcursor = ((cga->ma == ca) && cga->con && cga->cursoron);

181 if (cga->cgamode & 0x20)

182 {

183 cols[1] = (attr & 15) + 16;

184 cols[0] = ((attr >> 4) & 7) + 16;

185 if ((cga->cgablink & 8) && (attr & 0x80) && !cga->drawcursor)

186 cols[1] = cols[0];

187 }

188 else

189 {

190 cols[1] = (attr & 15) + 16;

191 cols[0] = (attr >> 4) + 16;

192 }

193 if (drawcursor)

194 {

195 for (c = 0; c < 8; c++)

196 buffer->line[cga->displine][(x << 3) + c + 8] = cols[(fontdat[chr][cga->sc & 7] & (1 << (c ^ 7))) ? 1 : 0] ^ 15;

197 }

198 else

199 {

200 for (c = 0; c < 8; c++)

201 buffer->line[cga->displine][(x << 3) + c + 8] = cols[(fontdat[chr][cga->sc & 7] & (1 << (c ^ 7))) ? 1 : 0];

202 }

203 cga->ma++;

204 }

205 }

206 else if (!(cga->cgamode & 2))

207 {

208 for (x = 0; x < cga->crtc[1]; x++)

209 {

210 chr = cga->vram[((cga->ma << 1) & 0x3fff)];

211 attr = cga->vram[(((cga->ma << 1) + 1) & 0x3fff)];

212 drawcursor = ((cga->ma == ca) && cga->con && cga->cursoron);

213 if (cga->cgamode & 0x20)

214 {

215 cols[1] = (attr & 15) + 16;

216 cols[0] = ((attr >> 4) & 7) + 16;

217 if ((cga->cgablink & 8) && (attr & 0x80)) cols[1] = cols[0];

218 }

219 else

220 {

221 cols[1] = (attr & 15) + 16;

222 cols[0] = (attr >> 4) + 16;

223 }

224 cga->ma++;

225 if (drawcursor)

226 {

227 for (c = 0; c < 8; c++)

228 buffer->line[cga->displine][(x << 4)+(c << 1) + 8] = buffer->line[cga->displine][(x << 4) + (c << 1) + 1 + 8] = cols[(fontdat[chr][cga->sc & 7] & (1 << (c ^ 7))) ? 1 : 0] ^ 15;

229 }

230 else

231 {

232 for (c = 0; c < 8; c++)

233 buffer->line[cga->displine][(x << 4) + (c << 1) + 8] = buffer->line[cga->displine][(x << 4) + (c << 1) + 1 + 8] = cols[(fontdat[chr][cga->sc & 7] & (1 << (c ^ 7))) ? 1 : 0];

234 }

235 }

236 }

237 else if (!(cga->cgamode & 16))

238 {

239 cols[0] = (cga->cgacol & 15) | 16;

240 col = (cga->cgacol & 16) ? 24 : 16;

241 if (cga->cgamode & 4)

242 {

243 cols[1] = col | 3;

244 cols[2] = col | 4;

245 cols[3] = col | 7;

246 }

247 else if (cga->cgacol & 32)

248 {

249 cols[1] = col | 3;

250 cols[2] = col | 5;

251 cols[3] = col | 7;

252 }

253 else

254 {

255 cols[1] = col | 2;

256 cols[2] = col | 4;

257 cols[3] = col | 6;

258 }

259 for (x = 0; x < cga->crtc[1]; x++)

260 {

261 dat = (cga->vram[((cga->ma << 1) & 0x1fff) + ((cga->sc & 1) * 0x2000)] << 8) | cga->vram[((cga->ma << 1) & 0x1fff) + ((cga->sc & 1) * 0x2000) + 1];

262 cga->ma++;

263 for (c = 0; c < 8; c++)

264 {

265 buffer->line[cga->displine][(x << 4) + (c << 1) + 8] =

266 buffer->line[cga->displine][(x << 4) + (c << 1) + 1 + 8] = cols[dat >> 14];

267 dat <<= 2;

268 }

269 }

270 }

271 else

272 {

273 cols[0] = 0; cols[1] = (cga->cgacol & 15) + 16;

274 for (x = 0; x < cga->crtc[1]; x++)

275 {

276 dat = (cga->vram[((cga->ma << 1) & 0x1fff) + ((cga->sc & 1) * 0x2000)] << 8) | cga->vram[((cga->ma << 1) & 0x1fff) + ((cga->sc & 1) * 0x2000) + 1];

277 cga->ma++;

278 for (c = 0; c < 16; c++)

279 {

280 buffer->line[cga->displine][(x << 4) + c + 8] = cols[dat >> 15];

281 dat <<= 1;

282 }

283 }

284 }

285 }

286 else

287 {

288 cols[0] = ((cga->cgamode & 0x12) == 0x12) ? 0 : (cga->cgacol & 15) + 16;

289 if (cga->cgamode & 1) hline(buffer, 0, cga->displine, (cga->crtc[1] << 3) + 16, cols[0]);

290 else hline(buffer, 0, cga->displine, (cga->crtc[1] << 4) + 16, cols[0]);

291 }

292

293 if (cga->cgamode & 1) x = (cga->crtc[1] << 3) + 16;

294 else x = (cga->crtc[1] << 4) + 16;

295 if (cga_comp)

296 {

297 for (c = 0; c < x; c++)

298 {

299 y_buf[(c << 1) & 6] = ntsc_col[buffer->line[cga->displine][c] & 7][(c << 1) & 6] ? 0x6000 : 0;

300 y_buf[(c << 1) & 6] += (buffer->line[cga->displine][c] & 8) ? 0x3000 : 0;

301 i_buf[(c << 1) & 6] = y_buf[(c << 1) & 6] * i_filt[(c << 1) & 6];

302 q_buf[(c << 1) & 6] = y_buf[(c << 1) & 6] * q_filt[(c << 1) & 6];

303 y_tot = y_buf[0] + y_buf[1] + y_buf[2] + y_buf[3] + y_buf[4] + y_buf[5] + y_buf[6] + y_buf[7];

304 i_tot = i_buf[0] + i_buf[1] + i_buf[2] + i_buf[3] + i_buf[4] + i_buf[5] + i_buf[6] + i_buf[7];

305 q_tot = q_buf[0] + q_buf[1] + q_buf[2] + q_buf[3] + q_buf[4] + q_buf[5] + q_buf[6] + q_buf[7];

306

307 y_val = y_tot >> 10;

308 if (y_val > 255) y_val = 255;

309 y_val <<= 16;

310 i_val = i_tot >> 12;

311 if (i_val > 39041) i_val = 39041;

312 if (i_val < -39041) i_val = -39041;

313 q_val = q_tot >> 12;

314 if (q_val > 34249) q_val = 34249;

315 if (q_val < -34249) q_val = -34249;

316

317 r = (y_val + 249*i_val + 159*q_val) >> 16;

318 g = (y_val - 70*i_val - 166*q_val) >> 16;

319 b = (y_val - 283*i_val + 436*q_val) >> 16;

320

321 y_buf[((c << 1) & 6) + 1] = ntsc_col[buffer->line[cga->displine][c] & 7][((c << 1) & 6) + 1] ? 0x6000 : 0;

322 y_buf[((c << 1) & 6) + 1] += (buffer->line[cga->displine][c] & 8) ? 0x3000 : 0;

323 i_buf[((c << 1) & 6) + 1] = y_buf[((c << 1) & 6) + 1] * i_filt[((c << 1) & 6) + 1];

324 q_buf[((c << 1) & 6) + 1] = y_buf[((c << 1) & 6) + 1] * q_filt[((c << 1) & 6) + 1];

325 y_tot = y_buf[0] + y_buf[1] + y_buf[2] + y_buf[3] + y_buf[4] + y_buf[5] + y_buf[6] + y_buf[7];

326 i_tot = i_buf[0] + i_buf[1] + i_buf[2] + i_buf[3] + i_buf[4] + i_buf[5] + i_buf[6] + i_buf[7];

327 q_tot = q_buf[0] + q_buf[1] + q_buf[2] + q_buf[3] + q_buf[4] + q_buf[5] + q_buf[6] + q_buf[7];

328

329 y_val = y_tot >> 10;

330 if (y_val > 255) y_val = 255;

331 y_val <<= 16;

332 i_val = i_tot >> 12;

333 if (i_val > 39041) i_val = 39041;

334 if (i_val < -39041) i_val = -39041;

335 q_val = q_tot >> 12;

336 if (q_val > 34249) q_val = 34249;

337 if (q_val < -34249) q_val = -34249;

338

339 r = (y_val + 249*i_val + 159*q_val) >> 16;

340 g = (y_val - 70*i_val - 166*q_val) >> 16;

341 b = (y_val - 283*i_val + 436*q_val) >> 16;

342 if (r > 511) r = 511;

343 if (g > 511) g = 511;

344 if (b > 511) b = 511;

345

346 ((uint32_t *)buffer32->line[cga->displine])[c] = makecol32(r / 2, g / 2, b / 2);

347 }

348 }

349

350 cga->sc = oldsc;

351 if (cga->vc == cga->crtc[7] && !cga->sc)

352 cga->cgastat |= 8;

353 cga->displine++;

354 if (cga->displine >= 360)

355 cga->displine = 0;

356 }

357 else

358 {

359 cga->vidtime += cga->dispontime;

360 if (cga->cgadispon) cga->cgastat &= ~1;

361 cga->linepos = 0;

362 if (cga->vsynctime)

363 {

364 cga->vsynctime--;

365 if (!cga->vsynctime)

366 cga->cgastat &= ~8;

367 }

368 if (cga->sc == (cga->crtc[11] & 31) || ((cga->crtc[8] & 3) == 3 && cga->sc == ((cga->crtc[11] & 31) >> 1)))

369 {

370 cga->con = 0;

371 cga->coff = 1;

372 }

373 if ((cga->crtc[8] & 3) == 3 && cga->sc == (cga->crtc[9] >> 1))

374 cga->maback = cga->ma;

375 if (cga->vadj)

376 {

377 cga->sc++;

378 cga->sc &= 31;

379 cga->ma = cga->maback;

380 cga->vadj--;

381 if (!cga->vadj)

382 {

383 cga->cgadispon = 1;

384 cga->ma = cga->maback = (cga->crtc[13] | (cga->crtc[12] << 8)) & 0x3fff;

385 cga->sc = 0;

386 }

387 }

388 else if (cga->sc == cga->crtc[9])

389 {

390 cga->maback = cga->ma;

391 cga->sc = 0;

392 oldvc = cga->vc;

393 cga->vc++;

394 cga->vc &= 127;

395

396 if (cga->vc == cga->crtc[6])

397 cga->cgadispon = 0;

398

399 if (oldvc == cga->crtc[4])

400 {

401 cga->vc = 0;

402 cga->vadj = cga->crtc[5];

403 if (!cga->vadj) cga->cgadispon = 1;

404 if (!cga->vadj) cga->ma = cga->maback = (cga->crtc[13] | (cga->crtc[12] << 8)) & 0x3fff;

405 if ((cga->crtc[10] & 0x60) == 0x20) cga->cursoron = 0;

406 else cga->cursoron = cga->cgablink & 8;

407 }

408

409 if (cga->vc == cga->crtc[7])

410 {

411 cga->cgadispon = 0;

412 cga->displine = 0;

413 cga->vsynctime = (cga->crtc[3] >> 4) + 1;

414 if (cga->crtc[7])

415 {

416 if (cga->cgamode & 1) x = (cga->crtc[1] << 3) + 16;

417 else x = (cga->crtc[1] << 4) + 16;

418 cga->lastline++;

419 if (x != xsize || (cga->lastline - cga->firstline) != ysize)

420 {

421 xsize = x;

422 ysize = cga->lastline - cga->firstline;

423 if (xsize < 64) xsize = 656;

424 if (ysize < 32) ysize = 200;

425 updatewindowsize(xsize, (ysize << 1) + 16);

426 }

427

428 startblit();

429 if (cga_comp)

430 video_blit_memtoscreen(0, cga->firstline - 4, 0, (cga->lastline - cga->firstline) + 8, xsize, (cga->lastline - cga->firstline) + 8);

431 else

432 video_blit_memtoscreen_8(0, cga->firstline - 4, xsize, (cga->lastline - cga->firstline) + 8);

433 frames++;

434 endblit();

435 video_res_x = xsize - 16;

436 video_res_y = ysize;

437 if (cga->cgamode & 1)

438 {

439 video_res_x /= 8;

440 video_res_y /= cga->crtc[9] + 1;

441 video_bpp = 0;

442 }

443 else if (!(cga->cgamode & 2))

444 {

445 video_res_x /= 16;

446 video_res_y /= cga->crtc[9] + 1;

447 video_bpp = 0;

448 }

449 else if (!(cga->cgamode & 16))

450 {

451 video_res_x /= 2;

452 video_bpp = 2;

453 }

454 else

455 {

456 video_bpp = 1;

457 }

458 }

459 cga->firstline = 1000;

460 cga->lastline = 0;

461 cga->cgablink++;

462 cga->oddeven ^= 1;

463 }

464 }

465 else

466 {

467 cga->sc++;

468 cga->sc &= 31;

469 cga->ma = cga->maback;

470 }

471 if ((cga->sc == (cga->crtc[10] & 31) || ((cga->crtc[8] & 3) == 3 && cga->sc == ((cga->crtc[10] & 31) >> 1))))

472 cga->con = 1;

473 if (cga->cgadispon && (cga->cgamode & 1))

474 {

475 for (x = 0; x < (cga->crtc[1] << 1); x++)

476 cga->charbuffer[x] = cga->vram[(((cga->ma << 1) + x) & 0x3fff)];

477 }

478 }

479 }

480

481 void cga_init(cga_t *cga)

482 {

483 }

484

485 void *cga_standalone_init()

486 {

487 int c;

488 int cga_tint = -2;

489 cga_t *cga = malloc(sizeof(cga_t));

490 memset(cga, 0, sizeof(cga_t));

491

492 cga->vram = malloc(0x4000);

493

494 for (c = 0; c < 8; c++)

495 {

496 i_filt[c] = 512.0 * cos((3.14 * (cga_tint + c * 4) / 16.0) - 33.0 / 180.0);

497 q_filt[c] = 512.0 * sin((3.14 * (cga_tint + c * 4) / 16.0) - 33.0 / 180.0);

498 }

499 timer_add(cga_poll, &cga->vidtime, TIMER_ALWAYS_ENABLED, cga);

500 mem_mapping_add(&cga->mapping, 0xb8000, 0x08000, cga_read, NULL, NULL, cga_write, NULL, NULL, NULL, 0, cga);

501 io_sethandler(0x03d0, 0x0010, cga_in, NULL, NULL, cga_out, NULL, NULL, cga);

502 return cga;

503 }

504

505 void cga_close(void *p)

506 {

507 cga_t *cga = (cga_t *)p;

508

509 free(cga->vram);

510 free(cga);

511 }

512

513 void cga_speed_changed(void *p)

514 {

515 cga_t *cga = (cga_t *)p;

516

517 cga_recalctimings(cga);

518 }

519

520 device_t cga_device =

521 {

522 "CGA",

523 0,

524 cga_standalone_init,

525 cga_close,

526 NULL,

527 cga_speed_changed,

528 NULL,

529 NULL

530 };