Plasma.js

   1 var SCREEN_WIDTH = 320;\r
   2 var SCREEN_HEIGHT = 400;\r
   3 var FRAME_BUFFER_WIDTH = 384;\r
   4 var FRAME_BUFFER_HEIGHT = 400;\r
   5 var PLANE_COUNT = 4;\r
   6 var COLOURS_PER_ENTRY = 3;\r
   7 var DPII = (3.1415926535*2.0);\r
   8 var MAXY = 280;\r
   9 \r
  10 var g_au8FrameBuffer = new Uint8Array(FRAME_BUFFER_WIDTH * FRAME_BUFFER_HEIGHT);\r
  11 var s_abSelectedPlanes = [ false, false, false, false ];\r
  12 var s_nLineCompareY = 0;\r
  13 var s_nHorizontalScrollOffset = 0;\r
  14 var s_au8Palette = new Uint8Array(256 * COLOURS_PER_ENTRY);\r
  15 var frame_count = 0;\r
  16 var cop_drop = 0;\r
  17 var do_pal = 0;\r
  18 var cop_start = 0;\r
  19 var cop_scrl = 0;\r
  20 var cop_plz = 1;\r
  21 var pompi = 0;\r
  22 var dtau = new Array();\r
  23 var fadepal = new Uint8Array(768 * 2);\r
  24 var cop_fadepal_SelectedPaletteIndex = 0;\r
  25 var anSelfModifyOffsets = new Uint16Array(5 * 84);\r
  26 \r
  27 // [NK 8/1/2014] The assembly code assumes the tables are sequential in memory,\r
  28 // [NK 8/1/2014] so merge them into one array to be safe.\r
  29 var psini = new Uint8Array(16384 + (8192 * 2) + (8192 * 2));\r
  30 var psini_DataView = new DataView(psini.buffer);\r
  31 var ptau = new Uint8Array(256);\r
  32 var pals = new Uint16Array(6 * 768);\r
  33 var pals_DataView = new DataView(pals.buffer);\r
  34 \r
  35 var curpal=0;\r
  36 var timetable=[64*6*2-45,64*6*4-45,64*6*5-45,64*6*6-45,64*6*7+90,0];\r
  37 var ttptr=0;\r
  38 \r
  39 var     l1=1000, l2=2000, l3=3000, l4=4000;\r
  40 var     k1=3500, k2=2300, k3=3900, k4=3670;\r
  41 \r
  42 var     il1=1000, il2=2000, il3=3000, il4=4000;\r
  43 var     ik1=3500, ik2=2300, ik3=3900, ik4=3670;\r
  44 \r
  45 var inittable = new Array();\r
  46 var IsComplete = false;\r
  47 \r
  48 //--------------------------------------------------------------------------------------\r
  49 // Variable wrappers\r
  50 \r
  51 function Palette_WriteByte(nOffset, u8Byte)\r
  52 {\r
  53         s_au8Palette[nOffset] = u8Byte;\r
  54 }\r
  55 \r
  56 function Palette_ReadByte(nOffset)\r
  57 {\r
  58         return s_au8Palette[nOffset];\r
  59 }\r
  60 \r
  61 function FrameBuffer_WriteByte(nOffset, u8Byte)\r
  62 {\r
  63         g_au8FrameBuffer[nOffset] = u8Byte;\r
  64 }\r
  65 \r
  66 function FrameBuffer_ReadByte(nOffset)\r
  67 {\r
  68         return g_au8FrameBuffer[nOffset];\r
  69 }\r
  70 \r
  71 function lsini16_GetOffset()\r
  72 {\r
  73         return 16384 + (8192 * 2);\r
  74 }\r
  75 \r
  76 function lsini4_GetOffset()\r
  77 {\r
  78         return 16384;\r
  79 }\r
  80 \r
  81 function cop_fadepal_SetSelectedPaletteIndex(nIndex)\r
  82 {\r
  83         cop_fadepal_SelectedPaletteIndex = nIndex;\r
  84 }\r
  85 \r
  86 function cop_fadepal_ReadWord(nByteOffset)\r
  87 {\r
  88         // Advance to the currently selected palette.\r
  89         nByteOffset += (cop_fadepal_SelectedPaletteIndex * 768 * 2);\r
  90 \r
  91         return pals_DataView.getUint16(nByteOffset);\r
  92 }\r
  93 \r
  94 function fadepal_ReadByte(nByteOffset)\r
  95 {\r
  96         return fadepal[nByteOffset];\r
  97 }\r
  98 \r
  99 function fadepal_WriteByte(nByteOffset, nValue)\r
 100 {\r
 101         fadepal[nByteOffset] = nValue;\r
 102 }\r
 103 \r
 104 function lsini4_WriteWord(nIndex, nValue)\r
 105 {\r
 106         var nByteOffset = lsini4_GetOffset() + (nIndex * 2);\r
 107         psini_WriteWord(nByteOffset, nValue);\r
 108 }\r
 109 \r
 110 function lsini16_WriteWord(nIndex, nValue)\r
 111 {\r
 112         var nByteOffset = lsini16_GetOffset() + (nIndex * 2);\r
 113         psini_WriteWord(nByteOffset, nValue);\r
 114 }\r
 115 \r
 116 function psini_WriteByte(nIndex, nValue)\r
 117 {\r
 118         psini[nIndex] = nValue;\r
 119 }\r
 120 \r
 121 function psini_ReadByte(nIndex, nValue)\r
 122 {\r
 123         return psini[nIndex];\r
 124 }\r
 125 \r
 126 function psini_WriteWord(nByteOffset, nValue) {\r
 127         psini_DataView.setUint16(nByteOffset, nValue);\r
 128 }\r
 129 \r
 130 function psini_ReadWord(nByteOffset, nValue) {\r
 131         return psini_DataView.getUint16(nByteOffset);\r
 132 }\r
 133 \r
 134 function ptau_WriteByte(nIndex, nValue)\r
 135 {\r
 136         ptau[nIndex] = nValue;\r
 137 }\r
 138 \r
 139 function ptau_ReadByte(nIndex)\r
 140 {\r
 141         return ptau[nIndex];\r
 142 }\r
 143 \r
 144 function pal_WriteWord(nByteOffset, nWord)\r
 145 {\r
 146         pals_DataView.setUint16(nByteOffset, nWord);\r
 147 }\r
 148 \r
 149 function pal_ReadWord(nByteOffset)\r
 150 {\r
 151         return pals_DataView.getUint16(nByteOffset);\r
 152 }\r
 153 \r
 154 function fadepal_Clear()\r
 155 {\r
 156         for (var i = 0; i < 768; i++)\r
 157         {\r
 158                 fadepal[i] = 0;\r
 159         }\r
 160 }\r
 161 \r
 162 function fadepal_ClearToWhite() {\r
 163         for (var i = 0; i < 768; i++) {\r
 164                 fadepal[i] = 63;\r
 165         }\r
 166 }\r
 167 \r
 168 function anSelfModifyOffsets_ReadWord(nOffset)\r
 169 {\r
 170         return anSelfModifyOffsets[nOffset];\r
 171 }\r
 172 \r
 173 function anSelfModifyOffsets_WriteWord(nOffset, nValue)\r
 174 {\r
 175         anSelfModifyOffsets[nOffset] = nValue;\r
 176 }\r
 177 \r
 178 //--------------------------------------------------------------------------------------\r
 179 // SDL\r
 180 \r
 181 function SDL_SetPixel(x, y, color)\r
 182 {\r
 183         var pixels = image.data;\r
 184         var nOffset = (((y * 320) + x) * 4);\r
 185         pixels[nOffset] = (color >> 0) & 0xFF;\r
 186         nOffset++;\r
 187         pixels[nOffset] = (color >> 8) & 0xFF;\r
 188         nOffset++;\r
 189         pixels[nOffset] = (color >> 16) & 0xFF;\r
 190         nOffset++;\r
 191         pixels[nOffset] = 0xFF;\r
 192         nOffset++;\r
 193 }\r
 194 \r
 195 function SDL_SetPixelColours(x, y, nRed, nGreen, nBlue)\r
 196 {\r
 197         var pixels = image.data;\r
 198         var nOffset = (((y * 320) + x) * 4);\r
 199         pixels[nOffset] = (nRed) & 0xFF;\r
 200         nOffset++;\r
 201         pixels[nOffset] = (nGreen) & 0xFF;\r
 202         nOffset++;\r
 203         pixels[nOffset] = (nBlue) & 0xFF;\r
 204         nOffset++;\r
 205         pixels[nOffset] = 0xFF;\r
 206         nOffset++;\r
 207 }\r
 208 \r
 209 //--------------------------------------------------------------------------------------\r
 210 // VGA\r
 211 \r
 212 function VGA_SelectBitPlanes02()\r
 213 {\r
 214         s_abSelectedPlanes[0] = true;\r
 215         s_abSelectedPlanes[1] = false;\r
 216         s_abSelectedPlanes[2] = true;\r
 217         s_abSelectedPlanes[3] = false;\r
 218 }\r
 219 \r
 220 function VGA_SelectBitPlanes13()\r
 221 {\r
 222         s_abSelectedPlanes[0] = false;\r
 223         s_abSelectedPlanes[1] = true;\r
 224         s_abSelectedPlanes[2] = false;\r
 225         s_abSelectedPlanes[3] = true;\r
 226 }\r
 227 \r
 228 function VGA_SelectBitPlanes0123()\r
 229 {\r
 230         s_abSelectedPlanes[0] = true;\r
 231         s_abSelectedPlanes[1] = true;\r
 232         s_abSelectedPlanes[2] = true;\r
 233         s_abSelectedPlanes[3] = true;\r
 234 }\r
 235 \r
 236 function VGA_WriteDword(nOffset, uValue)\r
 237 {\r
 238         // For each selected plane, calculate 4 pixel offsets and write 4 bytes.\r
 239         // nOffset = 0, 4, 8, etc\r
 240 \r
 241         for (var nPlaneIndex = 0; nPlaneIndex < PLANE_COUNT; nPlaneIndex++)\r
 242         {\r
 243                 if (s_abSelectedPlanes[nPlaneIndex])\r
 244                 {\r
 245                         for (var nPixelIndex = 0; nPixelIndex < 4; nPixelIndex++)\r
 246                         {\r
 247                                 // Get byte to write.\r
 248                                 var u8Byte = (uValue >> (nPixelIndex * 8)) & 0xFF;\r
 249 \r
 250                                 // Calculate offset.\r
 251                                 var nFrameBufferOffset = nPlaneIndex + (nOffset * 4) + (nPixelIndex * 4);\r
 252 \r
 253                                 // Write pixel.\r
 254                                 FrameBuffer_WriteByte(nFrameBufferOffset, u8Byte);\r
 255                         }\r
 256                 }\r
 257         }\r
 258 }\r
 259 \r
 260 function VGA_SetLineCompare(nY)\r
 261 {\r
 262         s_nLineCompareY = nY;\r
 263 }\r
 264 \r
 265 function VGA_SetPaletteEntry(nIndex, u8Red, u8Green, u8Blue)\r
 266 {\r
 267         var nOffset = 0;\r
 268 \r
 269         nOffset = (nIndex * 3) + 0;\r
 270         Palette_WriteByte(nOffset, u8Red);\r
 271 \r
 272         nOffset = (nIndex * 3) + 1;\r
 273         Palette_WriteByte(nOffset, u8Green);\r
 274 \r
 275         nOffset = (nIndex * 3) + 2;\r
 276         Palette_WriteByte(nOffset, u8Blue);\r
 277 }\r
 278 \r
 279 function VGA_ShowFrameBuffer()\r
 280 {\r
 281         copper1();\r
 282         copper2();\r
 283 \r
 284         var nFirstLineIndex = (s_nLineCompareY + 1);\r
 285 \r
 286         // Plot the palettised frame buffer.\r
 287         var nFrameBufferOffset = 0;\r
 288 \r
 289         for (var nY = nFirstLineIndex; nY < SCREEN_HEIGHT; nY++)\r
 290         {\r
 291                 for (var nX = 0; nX < SCREEN_WIDTH; nX++)\r
 292                 {\r
 293                         //ASSERT(nX + s_nHorizontalScrollOffset < FRAME_BUFFER_WIDTH);\r
 294                         var nPaletteIndex = FrameBuffer_ReadByte(nFrameBufferOffset + nX + s_nHorizontalScrollOffset);\r
 295 \r
 296                         var nPaletteOffset = 0;\r
 297                         nPaletteOffset = (nPaletteIndex * 3) + 0;\r
 298                         var nRed = Palette_ReadByte(nPaletteOffset);\r
 299                         nPaletteOffset = (nPaletteIndex * 3) + 1;\r
 300                         var nGreen = Palette_ReadByte(nPaletteOffset);\r
 301                         nPaletteOffset = (nPaletteIndex * 3) + 2;\r
 302                         var nBlue = Palette_ReadByte(nPaletteOffset);\r
 303 \r
 304                         // [NK 12/1/2014] VGA colours range from 0 - 63 inclusive, but\r
 305                         // [NK 12/1/2014] SDL colours range from 0 - 255 inclusive, so\r
 306                         // [NK 12/1/2014] account for this here.\r
 307                         nRed &= 63;\r
 308                         nGreen &= 63;\r
 309                         nBlue &= 63;\r
 310 \r
 311                         nRed *= 255;\r
 312                         nRed /= 63;\r
 313                         nGreen *= 255;\r
 314                         nGreen /= 63;\r
 315                         nBlue *= 255;\r
 316                         nBlue /= 63;\r
 317 \r
 318                         SDL_SetPixelColours(nX, nY, nRed, nGreen, nBlue);\r
 319                 }\r
 320 \r
 321                 nFrameBufferOffset += FRAME_BUFFER_WIDTH;\r
 322         }\r
 323 }\r
 324 \r
 325 function VGA_SetHorizontalScrollOffset(nOffset)\r
 326 {\r
 327         s_nHorizontalScrollOffset = nOffset;\r
 328 }\r
 329 \r
 330 function VGA_UploadPalette(Palette)\r
 331 {\r
 332         var Source = new Uint8Array(Palette.buffer, 0, 768);\r
 333         var Destination = s_au8Palette;\r
 334         Destination.set(Source);\r
 335 }\r
 336 \r
 337 //--------------------------------------------------------------------------------------\r
 338 // Tweak\r
 339 \r
 340 function tw_setrgbpalette(pal, r, g, b)\r
 341 {\r
 342         VGA_SetPaletteEntry(pal, r, g, b);\r
 343 }\r
 344 \r
 345 //--------------------------------------------------------------------------------------\r
 346 // Asmyt\r
 347 \r
 348 function plzline(y, vseg)\r
 349 {\r
 350         // vseg represented a segment, so multiply by sixteen (shift left by 4)\r
 351         // to convert into an offset.\r
 352         var nVgaYOffset = vseg * 16;\r
 353 \r
 354         var cccTable =\r
 355         [\r
 356                 3,2,1,0,7,6,5,4,11,10,9,8,15,14,13,12,19,18,17,16,23,22,21,20,27,26,25,24,31,30,29,28,35,34,33,32,39,38,37,36,43,42,41,40,47,46,45,44,51,50,49,48,55,54,53,52,59,58,57,56,63,62,61,60,67,66,65,64,71,70,69,68,75,74,73,72,79,78,77,76,83,82,81,80\r
 357         ];\r
 358         var nCount = 84;\r
 359 \r
 360         var ah = 0;\r
 361         var al = 0;\r
 362         var eax = 0;\r
 363 \r
 364         for (var nIndex = 0; nIndex < nCount; nIndex++)\r
 365         {\r
 366                 var ccc = cccTable[nIndex];\r
 367 \r
 368                 if ((ccc & 1) == 1)\r
 369                 {\r
 370                         var nByteOffset = 0;\r
 371                         var bx = 0;\r
 372 \r
 373                         nByteOffset = (y * 2) + anSelfModifyOffsets_ReadWord((2 * 84) + ccc);\r
 374                         nByteOffset &= 0xFFFF;\r
 375                         bx = psini_ReadWord(nByteOffset);\r
 376 \r
 377                         nByteOffset = bx + anSelfModifyOffsets_ReadWord((1 * 84) + ccc);\r
 378                         nByteOffset &= 0xFFFF;\r
 379                         ah = psini_ReadByte(nByteOffset);\r
 380 \r
 381                         nByteOffset = (y * 2) + anSelfModifyOffsets_ReadWord((4 * 84) + ccc);\r
 382                         nByteOffset &= 0xFFFF;\r
 383                         bx = psini_ReadWord(nByteOffset);\r
 384 \r
 385                         nByteOffset = bx + (y * 2) + anSelfModifyOffsets_ReadWord((3 * 84) + ccc);\r
 386                         nByteOffset &= 0xFFFF;\r
 387                         ah += psini_ReadByte(nByteOffset);\r
 388                         ah &= 0xFF;\r
 389                 }\r
 390                 else\r
 391                 {\r
 392                         var nByteOffset = 0;\r
 393                         var bx = 0;\r
 394 \r
 395                         nByteOffset = (y * 2) + anSelfModifyOffsets_ReadWord((2 * 84) + ccc);\r
 396                         nByteOffset &= 0xFFFF;\r
 397                         bx = psini_ReadWord(nByteOffset);\r
 398 \r
 399                         nByteOffset = bx + anSelfModifyOffsets_ReadWord((1 * 84) + ccc);\r
 400                         nByteOffset &= 0xFFFF;\r
 401                         al = psini_ReadByte(nByteOffset);\r
 402 \r
 403                         nByteOffset = (y * 2) + anSelfModifyOffsets_ReadWord((4 * 84) + ccc);\r
 404                         nByteOffset &= 0xFFFF;\r
 405                         bx = psini_ReadWord(nByteOffset);\r
 406 \r
 407                         nByteOffset = bx + (y * 2) + anSelfModifyOffsets_ReadWord((3 * 84) + ccc);\r
 408                         nByteOffset &= 0xFFFF;\r
 409                         al += psini_ReadByte(nByteOffset);\r
 410                         al &= 0xFF;\r
 411                 }\r
 412 \r
 413                 if ((ccc & 3) == 2)\r
 414                 {\r
 415                         eax = (ah << 8) | (al << 0);\r
 416                         eax <<= 16;\r
 417                 }\r
 418 \r
 419                 if ((ccc & 3) == 0)\r
 420                 {\r
 421                         eax |= (ah << 8) | (al << 0);\r
 422 \r
 423                         VGA_WriteDword(nVgaYOffset + ccc, eax);\r
 424                 }\r
 425         }\r
 426 \r
 427         return 0;\r
 428 }\r
 429 \r
 430 function setplzparas(c1, c2, c3, c4)\r
 431 {\r
 432         var psiniOffset = 0;\r
 433         var lsini16Offset = lsini16_GetOffset();\r
 434         var lsini4Offset = lsini4_GetOffset();\r
 435 \r
 436         for (var ccc = 0; ccc < 84; ccc++)\r
 437         {\r
 438                 var lc1 = c1 + psiniOffset + (ccc * 8);\r
 439                 lc1 &= 0xFFFF;\r
 440                 anSelfModifyOffsets_WriteWord((1 * 84) + ccc, lc1);\r
 441 \r
 442                 var lc2 = (c2 * 2) + lsini16Offset - (ccc * 8) + (80 * 8); \r
 443                 lc2 &= 0xFFFF;\r
 444                 anSelfModifyOffsets_WriteWord((2 * 84) + ccc, lc2);\r
 445 \r
 446                 var lc3 = c3 + psiniOffset - (ccc * 4) + (80 * 4);\r
 447                 lc3 &= 0xFFFF;\r
 448                 anSelfModifyOffsets_WriteWord((3 * 84) + ccc, lc3);\r
 449 \r
 450                 var lc4 = (c4 * 2) + lsini4Offset + (ccc * 32);\r
 451                 lc4 &= 0xFFFF;\r
 452                 anSelfModifyOffsets_WriteWord((4 * 84) + ccc, lc4);\r
 453         }       \r
 454 \r
 455         return 0;\r
 456 }\r
 457 \r
 458 function set_plzstart(start)\r
 459 {\r
 460         VGA_SetLineCompare(start);\r
 461 \r
 462         return 0;\r
 463 }\r
 464 \r
 465 \r
 466 //--------------------------------------------------------------------------------------\r
 467 // Copper\r
 468 \r
 469 function init_copper()\r
 470 {\r
 471         for (var ccc = 0; ccc < 65; ccc++)\r
 472         {\r
 473                 dtau[ccc] = Math.floor(ccc * ccc / 4 * 43 / 128 + 60);\r
 474         }\r
 475 \r
 476         return 0;\r
 477 }\r
 478 \r
 479 function close_copper()\r
 480 {\r
 481         return 0;\r
 482 }\r
 483 \r
 484 function pompota() {\r
 485 \r
 486         // [NK 18/1/2014] Disable this for now, as it looks a bit jittery.\r
 487         return;\r
 488 \r
 489         // [nk] This function toggles the horizontal split point every frame\r
 490         // [nk] between line 60 and 61, along with the horizontal offset.\r
 491         // [nk] (since set_plzstart == 60, it's splitting at the top of the plasma)\r
 492         VGA_SetLineCompare(60);\r
 493         cop_scrl = 4;\r
 494 \r
 495         pompi++;\r
 496 \r
 497         if ((pompi & 1) != 0)\r
 498         {\r
 499                 // [NK 12/1/2014] Moving the starting line up and down each alternate frame\r
 500                 // [NK 12/1/2014] doesn't look good in windowed mode.\r
 501                 // [NK 13/1/2014] Seems to work okay in fullscreen mode though.\r
 502                 //VGA_SetLineCompare(61);\r
 503                 cop_scrl = 0;\r
 504         }\r
 505 }\r
 506 \r
 507 function moveplz()\r
 508 {\r
 509         k1 += -3;\r
 510         k1 &= 4095;\r
 511         k2 += -2;\r
 512         k2 &= 4095;\r
 513         k3 += 1;\r
 514         k3 &= 4095;\r
 515         k4 += 2;\r
 516         k4 &= 4095;\r
 517         l1 += -1;\r
 518         l1 &= 4095;\r
 519         l2 += -2;\r
 520         l2 &= 4095;\r
 521         l3 += 2;\r
 522         l3 &= 4095;\r
 523         l4 += 3;\r
 524         l4 &= 4095;\r
 525 }\r
 526 \r
 527 function initpparas()\r
 528 {\r
 529         l1 = il1;\r
 530         l2 = il2;\r
 531         l3 = il3;\r
 532         l4 = il4;\r
 533 \r
 534         k1 = ik1;\r
 535         k2 = ik2;\r
 536         k3 = ik3;\r
 537         k4 = ik4;\r
 538 }\r
 539 \r
 540 function do_drop()\r
 541 {\r
 542         cop_drop++;\r
 543 \r
 544         if (cop_drop <= 64)\r
 545         {\r
 546                 VGA_SetLineCompare(dtau[cop_drop]);\r
 547         }\r
 548         else\r
 549         {\r
 550                 var bShouldFade = false;\r
 551 \r
 552                 // [NK 18/1/2014] Hack for looping back to the first plasma.\r
 553                 if ((cop_drop == 65) && (ttptr == 0)) {\r
 554                         cop_drop = 128;\r
 555                 }\r
 556 \r
 557                 if (cop_drop >= 256)\r
 558                 {\r
 559                 }\r
 560                 else if (cop_drop >= 128)\r
 561                 {\r
 562                         bShouldFade = true;\r
 563                 }\r
 564                 else if (cop_drop > 96)\r
 565                 {\r
 566                 }\r
 567                 else //if (cop_drop > 64)\r
 568                 {\r
 569                         bShouldFade = true;\r
 570                 }\r
 571 \r
 572                 if (bShouldFade)\r
 573                 {\r
 574                         // [NK 15/1/2014] cop_pal always points to fadepal, so just upload fadepal.\r
 575                         //cop_pal = fadepal;\r
 576                         do_pal = 1;\r
 577 \r
 578                         if (cop_drop == 65)\r
 579                         {\r
 580                                 VGA_SetLineCompare(400);\r
 581                                 initpparas();\r
 582                         }\r
 583                         else\r
 584                         {\r
 585                                 VGA_SetLineCompare(60);\r
 586 \r
 587                                 // [NK 9/1/2014] I think it's using 8.8 fixed point numbers to fade the palette.\r
 588                                 var cop_fadepalIndex = 0;\r
 589                                 var pfadepalIndex = 0;\r
 590 \r
 591                                 for (var nIndex = 0; nIndex < (768 / 16); nIndex++)\r
 592                                 {\r
 593                                         for (var ccc = 0; ccc < 16; ccc++)\r
 594                                         {\r
 595                                                 // var al = cop_fadepal_ReadByte(cop_fadepalIndex + (ccc * 2));\r
 596                                                 // al &= 0xFF;\r
 597                                                 // var ah = cop_fadepal_ReadByte(cop_fadepalIndex + (ccc * 2) + 1);\r
 598                                                 // ah &= 0xFF;\r
 599                                                 // [NK 17/1/2014] Read cop_fadepal as words, rather than bytes,\r
 600                                                 // [NK 17/1/2014] to avoid endian issues.\r
 601                                                 var ax = cop_fadepal_ReadWord(cop_fadepalIndex + (ccc * 2));\r
 602                                                 var al = ax & 0xFF;\r
 603                                                 var ah = (ax >> 8) & 0xFF;\r
 604 \r
 605                                                 var nOldValue = fadepal_ReadByte(pfadepalIndex + ccc + 768);\r
 606                                                 nOldValue &= 0xFF;\r
 607 \r
 608                                                 var t = fadepal_ReadByte(pfadepalIndex + ccc + 768);\r
 609                                                 t &= 0xFF;\r
 610                                                 t += al;\r
 611                                                 t &= 0xFF;\r
 612                                                 fadepal_WriteByte(pfadepalIndex + ccc + 768, t);\r
 613 \r
 614                                                 var nNewValue = fadepal_ReadByte(pfadepalIndex + ccc + 768);\r
 615                                                 nNewValue &= 0xFF;\r
 616 \r
 617                                                 var nCarry = 0;\r
 618 \r
 619                                                 if (nNewValue < nOldValue)\r
 620                                                 {\r
 621                                                         nCarry = 1;\r
 622                                                 }\r
 623 \r
 624                                                 t = fadepal_ReadByte(pfadepalIndex + ccc);\r
 625                                                 t &= 0xFF;\r
 626                                                 t += ah + nCarry;\r
 627                                                 t &= 0xFF;\r
 628                                                 fadepal_WriteByte(pfadepalIndex + ccc, t);\r
 629                                         }\r
 630 \r
 631                                         cop_fadepalIndex += 32;\r
 632                                         pfadepalIndex += 16;\r
 633                                 }\r
 634                         }\r
 635                 }\r
 636                 else\r
 637                 {\r
 638                         cop_drop = 0;\r
 639                 }\r
 640         }\r
 641 }\r
 642 \r
 643 // [nk] just before retrace\r
 644 function copper1()\r
 645 {\r
 646         // There is also assembly code to set the first pixel of\r
 647         // display memory here, but it may not be necessary.\r
 648 \r
 649         VGA_SetHorizontalScrollOffset(cop_scrl);\r
 650 }\r
 651 \r
 652 // [nk] in retrace\r
 653 function copper2()\r
 654 {\r
 655         // [nk] Don't think this is used.\r
 656         frame_count++;\r
 657 \r
 658         if (do_pal != 0)\r
 659         {\r
 660                 do_pal = 0;\r
 661                 // [NK 15/1/2014] cop_pal always points to fadepal, so just upload fadepal.\r
 662                 //VGA_UploadPalette(cop_pal);\r
 663                 VGA_UploadPalette(fadepal);\r
 664         }\r
 665 \r
 666         pompota();\r
 667         moveplz();\r
 668 \r
 669         if (cop_drop != 0)\r
 670         {\r
 671                 do_drop();\r
 672         }\r
 673 }\r
 674 \r
 675 \r
 676 //--------------------------------------------------------------------------------------\r
 677 // Plz\r
 678 \r
 679 function dis_exit()\r
 680 {\r
 681         return false;\r
 682 }\r
 683 \r
 684 var s_nFrameCount = 0;\r
 685 function dis_getmframe()\r
 686 {\r
 687         s_nFrameCount++;\r
 688         return s_nFrameCount;\r
 689 }\r
 690 \r
 691 function init_plz()\r
 692 {\r
 693         var a;\r
 694 \r
 695         // [NK 8/1/2014] Instead of writing the tables as assembly files,\r
 696         // [NK 8/1/2014] just use them directly in C++.\r
 697         {\r
 698                 for(var a=0;a<1024*16;a++)\r
 699                 {\r
 700                         if(a<1024*8)\r
 701                         {\r
 702                                 lsini4_WriteWord(a, (Math.sin(a * DPII / 4096) * 55 + Math.sin(a * DPII / 4096 * 5) * 8 + Math.sin(a * DPII / 4096 * 15) * 2 + 64) * 8);\r
 703                                 lsini16_WriteWord(a, (Math.sin(a * DPII / 4096) * 55 + Math.sin(a * DPII / 4096 * 4) * 5 + Math.sin(a * DPII / 4096 * 17) * 3 + 64) * 16);\r
 704                         }\r
 705                         psini_WriteByte(a, Math.sin(a * DPII / 4096) * 55 + Math.sin(a * DPII / 4096 * 6) * 5 + Math.sin(a * DPII / 4096 * 21) * 4 + 64);\r
 706                 }\r
 707 \r
 708                 for(var a=1;a<=128;a++)\r
 709                 {\r
 710                         ptau_WriteByte(a, Math.cos(a * DPII / 128 + 3.1415926535) * 31 + 32);\r
 711                 }\r
 712         }\r
 713 \r
 714         cop_start=96*(682-400);\r
 715         set_plzstart(60);\r
 716         init_copper();\r
 717         for(var a=0;a<256;a++) tw_setrgbpalette(a,63,63,63);\r
 718 \r
 719 //      RGB\r
 720         var nPalOffset = ((0 * 768) + 3) * 2;\r
 721         for(a=1;a<64;a++)\r
 722         {\r
 723                 pal_WriteWord(nPalOffset, ptau_ReadByte(a)); nPalOffset += 2;\r
 724                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)); nPalOffset += 2;\r
 725                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)); nPalOffset += 2;\r
 726         }\r
 727         for(a=0;a<64;a++)\r
 728         {\r
 729                 pal_WriteWord(nPalOffset, ptau_ReadByte(63 - a)); nPalOffset += 2;\r
 730                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)); nPalOffset += 2;\r
 731                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)); nPalOffset += 2;\r
 732         }\r
 733         for(a=0;a<64;a++)\r
 734         {\r
 735                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)); nPalOffset += 2;\r
 736                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)); nPalOffset += 2;\r
 737                 pal_WriteWord(nPalOffset, ptau_ReadByte(a)); nPalOffset += 2;\r
 738         }\r
 739         for(a=0;a<64;a++)\r
 740         {\r
 741                 pal_WriteWord(nPalOffset, ptau_ReadByte(a)); nPalOffset += 2;\r
 742                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)); nPalOffset += 2;\r
 743                 pal_WriteWord(nPalOffset, ptau_ReadByte(63 - a)); nPalOffset += 2;\r
 744         }\r
 745 \r
 746 //      RB-black\r
 747         nPalOffset = ((1 * 768) + 3) * 2;\r
 748         for(a=1;a<64;a++)\r
 749         {\r
 750                 pal_WriteWord(nPalOffset, ptau_ReadByte(a)); nPalOffset += 2;\r
 751                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)); nPalOffset += 2;\r
 752                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)); nPalOffset += 2;\r
 753         }\r
 754         for(a=0;a<64;a++)\r
 755         {\r
 756                 pal_WriteWord(nPalOffset, ptau_ReadByte(63 - a)); nPalOffset += 2;\r
 757                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)); nPalOffset += 2;\r
 758                 pal_WriteWord(nPalOffset, ptau_ReadByte(a)); nPalOffset += 2;\r
 759         }\r
 760         for(a=0;a<64;a++)\r
 761         {\r
 762                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)); nPalOffset += 2;\r
 763                 pal_WriteWord(nPalOffset, ptau_ReadByte(a)); nPalOffset += 2;\r
 764                 pal_WriteWord(nPalOffset, ptau_ReadByte(63 - a)); nPalOffset += 2;\r
 765         }\r
 766         for(a=0;a<64;a++)\r
 767         {\r
 768                 pal_WriteWord(nPalOffset, ptau_ReadByte(a)); nPalOffset += 2;\r
 769                 pal_WriteWord(nPalOffset, ptau_ReadByte(63)); nPalOffset += 2;\r
 770                 pal_WriteWord(nPalOffset, ptau_ReadByte(a)); nPalOffset += 2;\r
 771         }\r
 772 \r
 773 //      RB-white\r
 774         nPalOffset = ((3 * 768) + 3) * 2;\r
 775         for(a=1;a<64;a++)\r
 776         {\r
 777                 pal_WriteWord(nPalOffset, ptau_ReadByte(a)); nPalOffset += 2;\r
 778                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)); nPalOffset += 2;\r
 779                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)); nPalOffset += 2;\r
 780         }\r
 781         for(a=0;a<64;a++)\r
 782         {\r
 783                 pal_WriteWord(nPalOffset, ptau_ReadByte(63)); nPalOffset += 2;\r
 784                 pal_WriteWord(nPalOffset, ptau_ReadByte(a)); nPalOffset += 2;\r
 785                 pal_WriteWord(nPalOffset, ptau_ReadByte(a)); nPalOffset += 2;\r
 786         }\r
 787         for(a=0;a<64;a++)\r
 788         {\r
 789                 pal_WriteWord(nPalOffset, ptau_ReadByte(63-a)); nPalOffset += 2;\r
 790                 pal_WriteWord(nPalOffset, ptau_ReadByte(63-a)); nPalOffset += 2;\r
 791                 pal_WriteWord(nPalOffset, ptau_ReadByte(63)); nPalOffset += 2;\r
 792         }\r
 793         for(a=0;a<64;a++)\r
 794         {\r
 795                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)); nPalOffset += 2;\r
 796                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)); nPalOffset += 2;\r
 797                 pal_WriteWord(nPalOffset, ptau_ReadByte(63)); nPalOffset += 2;\r
 798         }\r
 799 \r
 800 //      white\r
 801         nPalOffset = ((2 * 768) + 3) * 2;\r
 802         for(a=1;a<64;a++)\r
 803         {\r
 804                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)/2); nPalOffset += 2;\r
 805                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)/2); nPalOffset += 2;\r
 806                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)/2); nPalOffset += 2;\r
 807         }\r
 808         for(a=0;a<64;a++)\r
 809         {\r
 810                 pal_WriteWord(nPalOffset, ptau_ReadByte(a)/2); nPalOffset += 2;\r
 811                 pal_WriteWord(nPalOffset, ptau_ReadByte(a)/2); nPalOffset += 2;\r
 812                 pal_WriteWord(nPalOffset, ptau_ReadByte(a)/2); nPalOffset += 2;\r
 813         }\r
 814         for(a=0;a<64;a++)\r
 815         {\r
 816                 pal_WriteWord(nPalOffset, ptau_ReadByte(63-a)/2); nPalOffset += 2;\r
 817                 pal_WriteWord(nPalOffset, ptau_ReadByte(63-a)/2); nPalOffset += 2;\r
 818                 pal_WriteWord(nPalOffset, ptau_ReadByte(63-a)/2); nPalOffset += 2;\r
 819         }\r
 820         for(a=0;a<64;a++)\r
 821         {\r
 822                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)/2); nPalOffset += 2;\r
 823                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)/2); nPalOffset += 2;\r
 824                 pal_WriteWord(nPalOffset, ptau_ReadByte(0)/2); nPalOffset += 2;\r
 825         }\r
 826 \r
 827 \r
 828 //      white II\r
 829         nPalOffset = ((4 * 768) + 3) * 2;\r
 830         for(a=1;a<75;a++)\r
 831         {\r
 832                 pal_WriteWord(nPalOffset, ptau_ReadByte(63-a*64/75)); nPalOffset += 2;\r
 833                 pal_WriteWord(nPalOffset, ptau_ReadByte(63-a*64/75)); nPalOffset += 2;\r
 834                 pal_WriteWord(nPalOffset, ptau_ReadByte(63-a*64/75)); nPalOffset += 2;\r
 835         }\r
 836         for(a=0;a<106;a++)\r
 837         {\r
 838                 pal_WriteWord(nPalOffset, 0); nPalOffset += 2;\r
 839                 pal_WriteWord(nPalOffset, 0); nPalOffset += 2;\r
 840                 pal_WriteWord(nPalOffset, 0); nPalOffset += 2;\r
 841         }\r
 842         for(a=0;a<75;a++)\r
 843         {\r
 844                 pal_WriteWord(nPalOffset, ptau_ReadByte(a*64/75)*8/10); nPalOffset += 2;\r
 845                 pal_WriteWord(nPalOffset, ptau_ReadByte(a*64/75)*9/10); nPalOffset += 2;\r
 846                 pal_WriteWord(nPalOffset, ptau_ReadByte(a*64/75)); nPalOffset += 2;\r
 847         }\r
 848 \r
 849         nPalOffset = 0;\r
 850         for(var a=0;a<768;a++)\r
 851         {\r
 852                 var n = pal_ReadWord(nPalOffset);\r
 853                 n -= 63;\r
 854                 n *= 2;\r
 855                 n &= 0xFFFF;\r
 856                 pal_WriteWord(nPalOffset, n);\r
 857                 nPalOffset += 2;\r
 858         }\r
 859 \r
 860         for(var a=768;a<768*5;a++)\r
 861         {\r
 862                 var n = pal_ReadWord(nPalOffset);\r
 863                 n *= 8;\r
 864                 n &= 0xFFFF;\r
 865                 pal_WriteWord(nPalOffset, n);\r
 866                 nPalOffset += 2;\r
 867         }\r
 868 }\r
 869 \r
 870 function plz()\r
 871 {\r
 872         var y;\r
 873 \r
 874         if(dis_getmframe()>timetable[ttptr])\r
 875         {\r
 876                 fadepal_Clear();\r
 877                 cop_drop=1;\r
 878                 ttptr++;\r
 879 \r
 880                 if (ttptr == 4) {\r
 881                         // [NK 18/1/2014] Loop back to the first plasma again.\r
 882                         ttptr = 0;\r
 883                         curpal = 0;\r
 884                         s_nFrameCount = 0;\r
 885                         fadepal_ClearToWhite();\r
 886                         cop_drop = 1;\r
 887                 }\r
 888 \r
 889                 cop_fadepal_SetSelectedPaletteIndex(curpal++);\r
 890 \r
 891                 il1=inittable[ttptr][0];\r
 892                 il2=inittable[ttptr][1];\r
 893                 il3=inittable[ttptr][2];\r
 894                 il4=inittable[ttptr][3];\r
 895                 ik1=inittable[ttptr][4];\r
 896                 ik2=inittable[ttptr][5];\r
 897                 ik3=inittable[ttptr][6];\r
 898                 ik4=inittable[ttptr][7];\r
 899         }\r
 900 //      if (curpal == 5 && cop_drop > 64) {\r
 901 //              return true;\r
 902 //      }\r
 903 \r
 904         VGA_SelectBitPlanes02();\r
 905 \r
 906         setplzparas(k1,k2,k3,k4);\r
 907         for(y=0;y<MAXY;y+=2)\r
 908                 plzline(y,y*6);\r
 909         setplzparas(l1,l2,l3,l4);\r
 910         for(y=1;y<MAXY;y+=2)\r
 911                 plzline(y,y*6);\r
 912 \r
 913         VGA_SelectBitPlanes13();\r
 914 \r
 915         setplzparas(k1,k2,k3,k4);\r
 916         for(y=1;y<MAXY;y+=2)\r
 917                 plzline(y,y*6);\r
 918         setplzparas(l1,l2,l3,l4);\r
 919         for(y=0;y<MAXY;y+=2)\r
 920                 plzline(y,y*6);\r
 921 \r
 922         VGA_ShowFrameBuffer();\r
 923 \r
 924         return false;\r
 925 //      cop_drop=0;\r
 926 //      set_plzstart(500);\r
 927 //      cop_plz=0;\r
 928 }\r
 929 \r
 930 \r
 931 //--------------------------------------------------------------------------------------\r
 932 // Main\r
 933 \r
 934 function tmain()\r
 935 {\r
 936         // Create arrays.\r
 937         inittable[0] = [1000,2000,3000,4000,3500,2300,3900,3670];\r
 938         inittable[1] = [1000,2000,4000,4000,1500,2300,3900,1670];\r
 939         inittable[2] = [3500,1000,3000,1000,3500,3300,2900,2670];\r
 940         inittable[3] = [1000,2000,3000,4000,3500,2300,3900,3670];\r
 941         inittable[4] = [1000,2000,3000,4000,3500,2300,3900,3670];\r
 942         inittable[5] = [1000,2000,3000,4000,3500,2300,3900,3670];\r
 943 \r
 944         init_copper();\r
 945         init_plz();\r
 946         cop_drop = 128;\r
 947         cop_fadepal_SetSelectedPaletteIndex(curpal++);\r
 948 }\r
 949 \r
 950 \r
 951 //--------------------------------------------------------------------------------------\r
 952 // HTML5 specific code\r
 953 \r
 954 window.onload = function () {\r
 955         document.getElementsByTagName("body")[0].className = "js";\r
 956 \r
 957         start();\r
 958 };\r
 959 \r
 960 var canvas = null;\r
 961 var context = null;\r
 962 var fps = null;\r
 963 var tscale = 0.02;\r
 964 var lastTick = 0;\r
 965 var targetFps = 1;\r
 966 var image;\r
 967 var canvasId = "canvas";\r
 968 var fpsId = "fps";\r
 969 \r
 970 function init() {\r
 971         canvas = canvasId ? document.getElementById(canvasId) : null;\r
 972         fps = fpsId ? document.getElementById(fpsId) : null;\r
 973 \r
 974         if (canvas && canvas.getContext) {\r
 975                 //              canvas.width = width = window.innerWidth;\r
 976                 //              canvas.height = height = window.innerHeight;\r
 977                 canvas.width = 320;\r
 978                 canvas.height = 400;\r
 979 \r
 980                 context = canvas.getContext("2d");\r
 981 \r
 982                 if (context.createImageData) {\r
 983                         image = context.createImageData(canvas.width, canvas.height);\r
 984                 } else if (context.getImageData) {\r
 985                         image = context.getImageData(0, 0, canvas.width, canvas.height);\r
 986                 } else {\r
 987                         // it's Opera\r
 988                         image = { 'width': canvas.width, 'height': canvas.height,\r
 989                                 'data': new Array(canvas.width * canvas.height * 4)\r
 990                         }\r
 991                 }\r
 992 \r
 993                 for (i = 0; i < image.data.length; i++) {\r
 994                         image.data[i] = 255;\r
 995                 }\r
 996                 return true;\r
 997         } else {\r
 998                 return false;\r
 999         }\r
1000 }\r
1001 \r
1002 function draw() {\r
1003 \r
1004         // Clear to black.\r
1005         length = 320 * 400;\r
1006         var p = 0;\r
1007         for (var i = 0; i < length; i++) {\r
1008                 image.data[p] = 0;\r
1009                 p++;\r
1010                 image.data[p] = 0;\r
1011                 p++;\r
1012                 image.data[p] = 0;\r
1013                 p++;\r
1014                 image.data[p] = 0xFF;\r
1015                 p++;\r
1016         }\r
1017 \r
1018         IsComplete = plz();\r
1019 \r
1020         if (!image) {\r
1021                 return;\r
1022         }\r
1023 \r
1024         var x = 0;\r
1025         var y = 0;\r
1026 //      var x = (window.innerWidth - 320) / 2;\r
1027 //      var y = (window.innerHeight - 400) / 2;\r
1028 \r
1029         context.putImageData(image, x, y);\r
1030 }\r
1031 \r
1032 function tick() {\r
1033         var start, elapsed, sleep, target;\r
1034         start = new Date().getTime();\r
1035 \r
1036         // check if the canvas has been resized\r
1037 //      if ((canvas.clientWidth / 8) != width ||\r
1038 //        (canvas.clientHeight / 8) != height) {\r
1039 //              init();\r
1040 //      }\r
1041 \r
1042         if (!IsComplete) {\r
1043                 draw();\r
1044         }\r
1045 \r
1046         // calculate stable FPS \r
1047         elapsed = new Date().getTime() - start;\r
1048 \r
1049         target = 1000 / 60;\r
1050 \r
1051         // calculate sleep and schedule next tick\r
1052         sleep = target - elapsed;\r
1053         if (sleep < 1) {\r
1054                 sleep = 1;\r
1055         } else if (sleep > 1000) {\r
1056                 sleep = 1000;\r
1057         }\r
1058 \r
1059         lastTick = start;\r
1060         setTimeout(tick, sleep);\r
1061 }\r
1062 \r
1063 function start() {\r
1064         lastTick = new Date().getTime();\r
1065 \r
1066         tmain();\r
1067 \r
1068         if (init()) tick();\r
1069 }\r