| 1 | ///////////////////////////////////////////////////////////////////////////// |
| 2 | // Name: imagpcx.cpp |
| 3 | // Purpose: wxImage PCX handler |
| 4 | // Author: Guillermo Rodriguez Garcia <guille@iies.es> |
| 5 | // Version: 1.1 |
| 6 | // CVS-ID: $Id$ |
| 7 | // Copyright: (c) 1999 Guillermo Rodriguez Garcia |
| 8 | // Licence: wxWindows licence |
| 9 | ///////////////////////////////////////////////////////////////////////////// |
| 10 | |
| 11 | #ifdef __GNUG__ |
| 12 | #pragma implementation "imagpcx.h" |
| 13 | #endif |
| 14 | |
| 15 | // For compilers that support precompilation, includes "wx.h". |
| 16 | #include "wx/wxprec.h" |
| 17 | |
| 18 | #ifdef __BORLANDC__ |
| 19 | #pragma hdrstop |
| 20 | #endif |
| 21 | |
| 22 | #ifndef WX_PRECOMP |
| 23 | # include "wx/defs.h" |
| 24 | #endif |
| 25 | |
| 26 | #if wxUSE_IMAGE && wxUSE_STREAMS && wxUSE_PCX |
| 27 | |
| 28 | #include "wx/imagpcx.h" |
| 29 | #include "wx/wfstream.h" |
| 30 | #include "wx/module.h" |
| 31 | #include "wx/log.h" |
| 32 | #include "wx/intl.h" |
| 33 | |
| 34 | #include "wx/hash.h" |
| 35 | #include "wx/list.h" |
| 36 | #include "wx/object.h" |
| 37 | |
| 38 | //----------------------------------------------------------------------------- |
| 39 | // RLE encoding and decoding |
| 40 | //----------------------------------------------------------------------------- |
| 41 | |
| 42 | void RLEencode(unsigned char *p, unsigned int size, wxOutputStream& s) |
| 43 | { |
| 44 | unsigned int data, last, cont; |
| 45 | |
| 46 | // Write 'size' bytes. The PCX official specs say there will be |
| 47 | // a decoding break at the end of each scanline, so in order to |
| 48 | // force this decoding break use this function to write, at most, |
| 49 | // _one_ complete scanline at a time. |
| 50 | |
| 51 | last = (unsigned char) *(p++); |
| 52 | cont = 1; |
| 53 | size--; |
| 54 | |
| 55 | while (size-- > 0) |
| 56 | { |
| 57 | data = (unsigned char) *(p++); |
| 58 | |
| 59 | // Up to 63 bytes with the same value can be stored using |
| 60 | // a single { cont, value } pair. |
| 61 | // |
| 62 | if ((data == last) && (cont < 63)) |
| 63 | { |
| 64 | cont++; |
| 65 | } |
| 66 | else |
| 67 | { |
| 68 | // need to write a 'counter' byte? |
| 69 | if ((cont > 1) || ((last & 0xC0) == 0xC0)) |
| 70 | s.PutC((char) (cont | 0xC0)); |
| 71 | |
| 72 | s.PutC((char) last); |
| 73 | last = data; |
| 74 | cont = 1; |
| 75 | } |
| 76 | } |
| 77 | |
| 78 | // write the last one and return; |
| 79 | if ((cont > 1) || ((last & 0xC0) == 0xC0)) |
| 80 | s.PutC((char) (cont | 0xC0)); |
| 81 | |
| 82 | s.PutC((char) last); |
| 83 | } |
| 84 | |
| 85 | void RLEdecode(unsigned char *p, unsigned int size, wxInputStream& s) |
| 86 | { |
| 87 | unsigned int i, data, cont; |
| 88 | |
| 89 | // Read 'size' bytes. The PCX official specs say there will be |
| 90 | // a decoding break at the end of each scanline (but not at the |
| 91 | // end of each plane inside a scanline). Only use this function |
| 92 | // to read one or more _complete_ scanlines. Else, more than |
| 93 | // 'size' bytes might be read and the buffer might overflow. |
| 94 | |
| 95 | while (size > 0) |
| 96 | { |
| 97 | data = (unsigned char)s.GetC(); |
| 98 | |
| 99 | // If ((data & 0xC0) != 0xC0), then the value read is a data |
| 100 | // byte. Else, it is a counter (cont = val & 0x3F) and the |
| 101 | // next byte is the data byte. |
| 102 | // |
| 103 | if ((data & 0xC0) != 0xC0) |
| 104 | { |
| 105 | *(p++) = (unsigned char)data; |
| 106 | size--; |
| 107 | } |
| 108 | else |
| 109 | { |
| 110 | cont = data & 0x3F; |
| 111 | data = (unsigned char)s.GetC(); |
| 112 | for (i = 1; i <= cont; i++) |
| 113 | *(p++) = (unsigned char)data; |
| 114 | size -= cont; |
| 115 | } |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | |
| 120 | //----------------------------------------------------------------------------- |
| 121 | // PCX reading and saving |
| 122 | //----------------------------------------------------------------------------- |
| 123 | |
| 124 | // PCX header |
| 125 | #define HDR_MANUFACTURER 0 |
| 126 | #define HDR_VERSION 1 |
| 127 | #define HDR_ENCODING 2 |
| 128 | #define HDR_BITSPERPIXEL 3 |
| 129 | #define HDR_XMIN 4 |
| 130 | #define HDR_YMIN 6 |
| 131 | #define HDR_XMAX 8 |
| 132 | #define HDR_YMAX 10 |
| 133 | #define HDR_NPLANES 65 |
| 134 | #define HDR_BYTESPERLINE 66 |
| 135 | #define HDR_PALETTEINFO 68 |
| 136 | |
| 137 | // image formats |
| 138 | enum { |
| 139 | wxPCX_8BIT, // 8 bpp, 1 plane (8 bit) |
| 140 | wxPCX_24BIT // 8 bpp, 3 planes (24 bit) |
| 141 | }; |
| 142 | |
| 143 | // error codes |
| 144 | enum { |
| 145 | wxPCX_OK = 0, // everything was OK |
| 146 | wxPCX_INVFORMAT = 1, // error in pcx file format |
| 147 | wxPCX_MEMERR = 2, // error allocating memory |
| 148 | wxPCX_VERERR = 3 // error in pcx version number |
| 149 | }; |
| 150 | |
| 151 | |
| 152 | // ReadPCX: |
| 153 | // Loads a PCX file into the wxImage object pointed by image. |
| 154 | // Returns wxPCX_OK on success, or an error code otherwise |
| 155 | // (see above for error codes) |
| 156 | // |
| 157 | int ReadPCX(wxImage *image, wxInputStream& stream) |
| 158 | { |
| 159 | unsigned char hdr[128]; // PCX header |
| 160 | unsigned char pal[768]; // palette for 8 bit images |
| 161 | unsigned char *p; // space to store one scanline |
| 162 | unsigned char *dst; // pointer into wxImage data |
| 163 | unsigned int width, height; // size of the image |
| 164 | unsigned int bytesperline; // bytes per line (each plane) |
| 165 | int bitsperpixel; // bits per pixel (each plane) |
| 166 | int nplanes; // number of planes |
| 167 | int encoding; // is the image RLE encoded? |
| 168 | int format; // image format (8 bit, 24 bit) |
| 169 | unsigned int i, j; |
| 170 | |
| 171 | // Read PCX header and check the version number (it must |
| 172 | // be at least 5 or higher for 8 bit and 24 bit images). |
| 173 | |
| 174 | stream.Read(hdr, 128); |
| 175 | |
| 176 | if (hdr[HDR_VERSION] < 5) return wxPCX_VERERR; |
| 177 | |
| 178 | // Extract all image info from the PCX header. |
| 179 | |
| 180 | encoding = hdr[HDR_ENCODING]; |
| 181 | nplanes = hdr[HDR_NPLANES]; |
| 182 | bitsperpixel = hdr[HDR_BITSPERPIXEL]; |
| 183 | bytesperline = hdr[HDR_BYTESPERLINE] + 256 * hdr[HDR_BYTESPERLINE + 1]; |
| 184 | width = (hdr[HDR_XMAX] + 256 * hdr[HDR_XMAX + 1]) - |
| 185 | (hdr[HDR_XMIN] + 256 * hdr[HDR_XMIN + 1]) + 1; |
| 186 | height = (hdr[HDR_YMAX] + 256 * hdr[HDR_YMAX + 1]) - |
| 187 | (hdr[HDR_YMIN] + 256 * hdr[HDR_YMIN + 1]) + 1; |
| 188 | |
| 189 | // Check image format. Currently supported formats are |
| 190 | // 8 bits (8 bpp, 1 plane) and 24 bits (8 bpp, 3 planes). |
| 191 | |
| 192 | if ((nplanes == 3) && (bitsperpixel == 8)) |
| 193 | format = wxPCX_24BIT; |
| 194 | else if ((nplanes == 1) && (bitsperpixel == 8)) |
| 195 | format = wxPCX_8BIT; |
| 196 | else |
| 197 | return wxPCX_INVFORMAT; |
| 198 | |
| 199 | // If the image is of type wxPCX_8BIT, then there is |
| 200 | // a palette at the end of the image data. If we were |
| 201 | // working with a file, we could seek at the end to the |
| 202 | // end (SeekI(-769, wxFromEnd) and read the palette |
| 203 | // before proceeding. Unfortunately, this would prevent |
| 204 | // loading several PCXs in a single stream, so we can't |
| 205 | // do it. Thus, 8-bit images will have to be decoded in |
| 206 | // two passes: one to read and decode the image data, |
| 207 | // and another to replace 'colour indexes' with RGB |
| 208 | // values. |
| 209 | |
| 210 | // Resize the image and allocate memory for a scanline. |
| 211 | |
| 212 | image->Create(width, height); |
| 213 | |
| 214 | if (!image->Ok()) |
| 215 | return wxPCX_MEMERR; |
| 216 | |
| 217 | if ((p = (unsigned char *) malloc(bytesperline * nplanes)) == NULL) |
| 218 | return wxPCX_MEMERR; |
| 219 | |
| 220 | // Now start reading the file, line by line, and store |
| 221 | // the data in the format required by wxImage. |
| 222 | |
| 223 | dst = image->GetData(); |
| 224 | |
| 225 | for (j = height; j; j--) |
| 226 | { |
| 227 | if (encoding) |
| 228 | RLEdecode(p, bytesperline * nplanes, stream); |
| 229 | else |
| 230 | stream.Read(p, bytesperline * nplanes); |
| 231 | |
| 232 | switch (format) |
| 233 | { |
| 234 | case wxPCX_8BIT: |
| 235 | { |
| 236 | for (i = 0; i < width; i++) |
| 237 | { |
| 238 | // first pass, just store the colour index |
| 239 | *dst = p[i]; |
| 240 | dst += 3; |
| 241 | } |
| 242 | break; |
| 243 | } |
| 244 | case wxPCX_24BIT: |
| 245 | { |
| 246 | for (i = 0; i < width; i++) |
| 247 | { |
| 248 | *(dst++) = p[i]; |
| 249 | *(dst++) = p[i + bytesperline]; |
| 250 | *(dst++) = p[i + 2 * bytesperline]; |
| 251 | } |
| 252 | break; |
| 253 | } |
| 254 | } |
| 255 | } |
| 256 | |
| 257 | free(p); |
| 258 | |
| 259 | // For 8 bit images, we read the palette, and then do a second |
| 260 | // pass replacing indexes with their RGB values; |
| 261 | |
| 262 | if (format == wxPCX_8BIT) |
| 263 | { |
| 264 | unsigned char index; |
| 265 | |
| 266 | if (stream.GetC() != 12) |
| 267 | return wxPCX_INVFORMAT; |
| 268 | |
| 269 | stream.Read(pal, 768); |
| 270 | |
| 271 | p = image->GetData(); |
| 272 | for (unsigned long k = height * width; k; k--) |
| 273 | { |
| 274 | index = *p; |
| 275 | *(p++) = pal[3 * index]; |
| 276 | *(p++) = pal[3 * index + 1]; |
| 277 | *(p++) = pal[3 * index + 2]; |
| 278 | } |
| 279 | |
| 280 | unsigned char* r = new unsigned char[256]; |
| 281 | unsigned char* g = new unsigned char[256]; |
| 282 | unsigned char* b = new unsigned char[256]; |
| 283 | for (i = 0; i < 256; i++) |
| 284 | { |
| 285 | r[i] = pal[3*i + 0]; |
| 286 | g[i] = pal[3*i + 1]; |
| 287 | b[i] = pal[3*i + 2]; |
| 288 | } |
| 289 | image->SetPalette(wxPalette(256, r, g, b)); |
| 290 | delete[] r; delete[] g; delete[] b; |
| 291 | } |
| 292 | |
| 293 | return wxPCX_OK; |
| 294 | } |
| 295 | |
| 296 | // SavePCX: |
| 297 | // Saves a PCX file into the wxImage object pointed by image. |
| 298 | // Returns wxPCX_OK on success, or an error code otherwise |
| 299 | // (see above for error codes). Will try to save as 8-bit |
| 300 | // PCX if possible, and then fall back to 24-bit if there |
| 301 | // are more than 256 different colours. |
| 302 | // |
| 303 | int SavePCX(wxImage *image, wxOutputStream& stream) |
| 304 | { |
| 305 | unsigned char hdr[128]; // PCX header |
| 306 | unsigned char pal[768]; // palette for 8 bit images |
| 307 | unsigned char *p; // space to store one scanline |
| 308 | unsigned char *src; // pointer into wxImage data |
| 309 | unsigned int width, height; // size of the image |
| 310 | unsigned int bytesperline; // bytes per line (each plane) |
| 311 | int nplanes = 3; // number of planes |
| 312 | int format = wxPCX_24BIT; // image format (8 bit, 24 bit) |
| 313 | wxHashTable h(wxKEY_INTEGER); // image histogram |
| 314 | unsigned long key; // key in the hashtable |
| 315 | unsigned int i; |
| 316 | |
| 317 | // See if we can save as 8 bit. |
| 318 | |
| 319 | if (image->CountColours(256) <= 256) |
| 320 | { |
| 321 | image->ComputeHistogram(h); |
| 322 | format = wxPCX_8BIT; |
| 323 | nplanes = 1; |
| 324 | } |
| 325 | |
| 326 | // Get image dimensions, calculate bytesperline (must be even, |
| 327 | // according to PCX specs) and allocate space for one complete |
| 328 | // scanline. |
| 329 | |
| 330 | if (!image->Ok()) |
| 331 | return wxPCX_INVFORMAT; |
| 332 | |
| 333 | width = image->GetWidth(); |
| 334 | height = image->GetHeight(); |
| 335 | bytesperline = width; |
| 336 | if (bytesperline % 2) |
| 337 | bytesperline++; |
| 338 | |
| 339 | if ((p = (unsigned char *) malloc(bytesperline * nplanes)) == NULL) |
| 340 | return wxPCX_MEMERR; |
| 341 | |
| 342 | // Build header data and write it to the stream. Initially, |
| 343 | // set all bytes to zero (most values default to zero). |
| 344 | |
| 345 | memset(hdr, 0, sizeof(hdr)); |
| 346 | |
| 347 | hdr[HDR_MANUFACTURER] = 10; |
| 348 | hdr[HDR_VERSION] = 5; |
| 349 | hdr[HDR_ENCODING] = 1; |
| 350 | hdr[HDR_NPLANES] = nplanes; |
| 351 | hdr[HDR_BITSPERPIXEL] = 8; |
| 352 | hdr[HDR_BYTESPERLINE] = (unsigned char)(bytesperline % 256); |
| 353 | hdr[HDR_BYTESPERLINE + 1] = (unsigned char)(bytesperline / 256); |
| 354 | hdr[HDR_XMAX] = (unsigned char)((width - 1) % 256); |
| 355 | hdr[HDR_XMAX + 1] = (unsigned char)((width - 1) / 256); |
| 356 | hdr[HDR_YMAX] = (unsigned char)((height - 1) % 256); |
| 357 | hdr[HDR_YMAX + 1] = (unsigned char)((height - 1) / 256); |
| 358 | hdr[HDR_PALETTEINFO] = 1; |
| 359 | |
| 360 | stream.Write(hdr, 128); |
| 361 | |
| 362 | // Encode image data line by line and write it to the stream |
| 363 | |
| 364 | src = image->GetData(); |
| 365 | |
| 366 | for (; height; height--) |
| 367 | { |
| 368 | switch (format) |
| 369 | { |
| 370 | case wxPCX_8BIT: |
| 371 | { |
| 372 | unsigned char r, g, b; |
| 373 | wxHNode *hnode; |
| 374 | |
| 375 | for (i = 0; i < width; i++) |
| 376 | { |
| 377 | r = *(src++); |
| 378 | g = *(src++); |
| 379 | b = *(src++); |
| 380 | key = (r << 16) | (g << 8) | b; |
| 381 | |
| 382 | hnode = (wxHNode *) h.Get(key); |
| 383 | p[i] = (unsigned char)hnode->index; |
| 384 | } |
| 385 | break; |
| 386 | } |
| 387 | case wxPCX_24BIT: |
| 388 | { |
| 389 | for (i = 0; i < width; i++) |
| 390 | { |
| 391 | p[i] = *(src++); |
| 392 | p[i + bytesperline] = *(src++); |
| 393 | p[i + 2 * bytesperline] = *(src++); |
| 394 | } |
| 395 | break; |
| 396 | } |
| 397 | } |
| 398 | |
| 399 | RLEencode(p, bytesperline * nplanes, stream); |
| 400 | } |
| 401 | |
| 402 | free(p); |
| 403 | |
| 404 | // For 8 bit images, build the palette and write it to the stream |
| 405 | |
| 406 | if (format == wxPCX_8BIT) |
| 407 | { |
| 408 | wxNode *node; |
| 409 | wxHNode *hnode; |
| 410 | |
| 411 | // zero unused colours |
| 412 | memset(pal, 0, sizeof(pal)); |
| 413 | |
| 414 | h.BeginFind(); |
| 415 | while ((node = h.Next()) != NULL) |
| 416 | { |
| 417 | key = node->GetKeyInteger(); |
| 418 | hnode = (wxHNode *) node->GetData(); |
| 419 | |
| 420 | pal[3 * hnode->index] = (unsigned char)(key >> 16); |
| 421 | pal[3 * hnode->index + 1] = (unsigned char)(key >> 8); |
| 422 | pal[3 * hnode->index + 2] = (unsigned char)(key); |
| 423 | delete hnode; |
| 424 | } |
| 425 | |
| 426 | stream.PutC(12); |
| 427 | stream.Write(pal, 768); |
| 428 | } |
| 429 | |
| 430 | return wxPCX_OK; |
| 431 | } |
| 432 | |
| 433 | //----------------------------------------------------------------------------- |
| 434 | // wxPCXHandler |
| 435 | //----------------------------------------------------------------------------- |
| 436 | |
| 437 | IMPLEMENT_DYNAMIC_CLASS(wxPCXHandler,wxImageHandler) |
| 438 | |
| 439 | bool wxPCXHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose, int WXUNUSED(index) ) |
| 440 | { |
| 441 | int error; |
| 442 | |
| 443 | if (!CanRead(stream)) |
| 444 | { |
| 445 | if (verbose) |
| 446 | wxLogError(_("PCX: this is not a PCX file.")); |
| 447 | |
| 448 | return FALSE; |
| 449 | } |
| 450 | |
| 451 | image->Destroy(); |
| 452 | |
| 453 | if ((error = ReadPCX(image, stream)) != wxPCX_OK) |
| 454 | { |
| 455 | if (verbose) |
| 456 | { |
| 457 | switch (error) |
| 458 | { |
| 459 | case wxPCX_INVFORMAT: wxLogError(_("PCX: image format unsupported")); break; |
| 460 | case wxPCX_MEMERR: wxLogError(_("PCX: couldn't allocate memory")); break; |
| 461 | case wxPCX_VERERR: wxLogError(_("PCX: version number too low")); break; |
| 462 | default: wxLogError(_("PCX: unknown error !!!")); |
| 463 | } |
| 464 | } |
| 465 | image->Destroy(); |
| 466 | return FALSE; |
| 467 | } |
| 468 | |
| 469 | return TRUE; |
| 470 | } |
| 471 | |
| 472 | bool wxPCXHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbose ) |
| 473 | { |
| 474 | int error; |
| 475 | |
| 476 | if ((error = SavePCX(image, stream)) != wxPCX_OK) |
| 477 | { |
| 478 | if (verbose) |
| 479 | { |
| 480 | switch (error) |
| 481 | { |
| 482 | case wxPCX_INVFORMAT: wxLogError(_("PCX: invalid image")); break; |
| 483 | case wxPCX_MEMERR: wxLogError(_("PCX: couldn't allocate memory")); break; |
| 484 | default: wxLogError(_("PCX: unknown error !!!")); |
| 485 | } |
| 486 | } |
| 487 | } |
| 488 | |
| 489 | return (error == wxPCX_OK); |
| 490 | } |
| 491 | |
| 492 | bool wxPCXHandler::DoCanRead( wxInputStream& stream ) |
| 493 | { |
| 494 | unsigned char c; |
| 495 | |
| 496 | c = stream.GetC(); |
| 497 | stream.SeekI(-1, wxFromCurrent); |
| 498 | |
| 499 | // not very safe, but this is all we can get from PCX header :-( |
| 500 | return (c == 10); |
| 501 | } |
| 502 | |
| 503 | #endif // wxUSE_STREAMS && wxUSE_PCX |
| 504 | |