Images.cpp

   1 //
   2 // Copyright 2006 The Android Open Source Project
   3 //
   4 // Build resource files from raw assets.
   5 //
   6
   7 #define PNG_INTERNAL
   8
   9 #include "Images.h"
  10
  11 #include <utils/ResourceTypes.h>
  12 #include <utils/ByteOrder.h>
  13
  14 #include <png.h>
  15
  16 #define NOISY(x) //x
  17
  18 static void
  19 png_write_aapt_file(png_structp png_ptr, png_bytep data, png_size_t length)
  20 {
  21     status_t err = ((AaptFile*)png_ptr->io_ptr)->writeData(data, length);
  22     if (err != NO_ERROR) {
  23         png_error(png_ptr, "Write Error");
  24     }
  25 }
  26
  27
  28 static void
  29 png_flush_aapt_file(png_structp png_ptr)
  30 {
  31 }
  32
  33 // This holds an image as 8bpp RGBA.
  34 struct image_info
  35 {
  36     image_info() : rows(NULL), hasTransparency(true), is9Patch(false), allocRows(NULL) { }
  37     ~image_info() {
  38         if (rows && rows != allocRows) {
  39             free(rows);
  40         }
  41         if (allocRows) {
  42             for (int i=0; i<(int)allocHeight; i++) {
  43                 free(allocRows[i]);
  44             }
  45             free(allocRows);
  46         }
  47     }
  48
  49     png_uint_32 width;
  50     png_uint_32 height;
  51     png_bytepp rows;
  52
  53     bool hasTransparency;
  54
  55     // 9-patch info.
  56     bool is9Patch;
  57     Res_png_9patch info9Patch;
  58
  59     png_uint_32 allocHeight;
  60     png_bytepp allocRows;
  61 };
  62
  63 static void read_png(const char* imageName,
  64                      png_structp read_ptr, png_infop read_info,
  65                      image_info* outImageInfo)
  66 {
  67     int color_type;
  68     int bit_depth, interlace_type, compression_type;
  69     int i;
  70
  71     png_read_info(read_ptr, read_info);
  72
  73     png_get_IHDR(read_ptr, read_info, &outImageInfo->width,
  74        &outImageInfo->height, &bit_depth, &color_type,
  75        &interlace_type, &compression_type, NULL);
  76
  77     //printf("Image %s:\n", imageName);
  78     //printf("color_type=%d, bit_depth=%d, interlace_type=%d, compression_type=%d\n",
  79     //       color_type, bit_depth, interlace_type, compression_type);
  80
  81     if (color_type == PNG_COLOR_TYPE_PALETTE)
  82         png_set_palette_to_rgb(read_ptr);
  83
  84     if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
  85         png_set_gray_1_2_4_to_8(read_ptr);
  86
  87     if (png_get_valid(read_ptr, read_info, PNG_INFO_tRNS)) {
  88         //printf("Has PNG_INFO_tRNS!\n");
  89         png_set_tRNS_to_alpha(read_ptr);
  90     }
  91
  92     if (bit_depth == 16)
  93         png_set_strip_16(read_ptr);
  94
  95     if ((color_type&PNG_COLOR_MASK_ALPHA) == 0)
  96         png_set_add_alpha(read_ptr, 0xFF, PNG_FILLER_AFTER);
  97
  98     if (color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
  99         png_set_gray_to_rgb(read_ptr);
 100
 101     png_read_update_info(read_ptr, read_info);
 102
 103     outImageInfo->rows = (png_bytepp)malloc(
 104         outImageInfo->height * png_sizeof(png_bytep));
 105     outImageInfo->allocHeight = outImageInfo->height;
 106     outImageInfo->allocRows = outImageInfo->rows;
 107
 108     png_set_rows(read_ptr, read_info, outImageInfo->rows);
 109
 110     for (i = 0; i < (int)outImageInfo->height; i++)
 111     {
 112         outImageInfo->rows[i] = (png_bytep)
 113             malloc(png_get_rowbytes(read_ptr, read_info));
 114     }
 115
 116     png_read_image(read_ptr, outImageInfo->rows);
 117
 118     png_read_end(read_ptr, read_info);
 119
 120     NOISY(printf("Image %s: w=%d, h=%d, d=%d, colors=%d, inter=%d, comp=%d\n",
 121                  imageName,
 122                  (int)outImageInfo->width, (int)outImageInfo->height,
 123                  bit_depth, color_type,
 124                  interlace_type, compression_type));
 125
 126     png_get_IHDR(read_ptr, read_info, &outImageInfo->width,
 127        &outImageInfo->height, &bit_depth, &color_type,
 128        &interlace_type, &compression_type, NULL);
 129 }
 130
 131 static bool is_tick(png_bytep p, bool transparent, const char** outError)
 132 {
 133     if (transparent) {
 134         if (p[3] == 0) {
 135             return false;
 136         }
 137         if (p[3] != 0xff) {
 138             *outError = "Frame pixels must be either solid or transparent (not intermediate alphas)";
 139             return false;
 140         }
 141         if (p[0] != 0 || p[1] != 0 || p[2] != 0) {
 142             *outError = "Ticks in transparent frame must be black";
 143         }
 144         return true;
 145     }
 146
 147     if (p[3] != 0xFF) {
 148         *outError = "White frame must be a solid color (no alpha)";
 149     }
 150     if (p[0] == 0xFF && p[1] == 0xFF && p[2] == 0xFF) {
 151         return false;
 152     }
 153     if (p[0] != 0 || p[1] != 0 || p[2] != 0) {
 154         *outError = "Ticks in white frame must be black";
 155         return false;
 156     }
 157     return true;
 158 }
 159
 160 enum {
 161     TICK_START,
 162     TICK_INSIDE_1,
 163     TICK_OUTSIDE_1
 164 };
 165
 166 static status_t get_horizontal_ticks(
 167         png_bytep row, int width, bool transparent, bool required,
 168         int32_t* outLeft, int32_t* outRight, const char** outError,
 169         uint8_t* outDivs, bool multipleAllowed)
 170 {
 171     int i;
 172     *outLeft = *outRight = -1;
 173     int state = TICK_START;
 174     bool found = false;
 175
 176     for (i=1; i<width-1; i++) {
 177         if (is_tick(row+i*4, transparent, outError)) {
 178             if (state == TICK_START ||
 179                 (state == TICK_OUTSIDE_1 && multipleAllowed)) {
 180                 *outLeft = i-1;
 181                 *outRight = width-2;
 182                 found = true;
 183                 if (outDivs != NULL) {
 184                     *outDivs += 2;
 185                 }
 186                 state = TICK_INSIDE_1;
 187             } else if (state == TICK_OUTSIDE_1) {
 188                 *outError = "Can't have more than one marked region along edge";
 189                 *outLeft = i;
 190                 return UNKNOWN_ERROR;
 191             }
 192         } else if (*outError == NULL) {
 193             if (state == TICK_INSIDE_1) {
 194                 // We're done with this div.  Move on to the next.
 195                 *outRight = i-1;
 196                 outRight += 2;
 197                 outLeft += 2;
 198                 state = TICK_OUTSIDE_1;
 199             }
 200         } else {
 201             *outLeft = i;
 202             return UNKNOWN_ERROR;
 203         }
 204     }
 205
 206     if (required && !found) {
 207         *outError = "No marked region found along edge";
 208         *outLeft = -1;
 209         return UNKNOWN_ERROR;
 210     }
 211
 212     return NO_ERROR;
 213 }
 214
 215 static status_t get_vertical_ticks(
 216         png_bytepp rows, int offset, int height, bool transparent, bool required,
 217         int32_t* outTop, int32_t* outBottom, const char** outError,
 218         uint8_t* outDivs, bool multipleAllowed)
 219 {
 220     int i;
 221     *outTop = *outBottom = -1;
 222     int state = TICK_START;
 223     bool found = false;
 224
 225     for (i=1; i<height-1; i++) {
 226         if (is_tick(rows[i]+offset, transparent, outError)) {
 227             if (state == TICK_START ||
 228                 (state == TICK_OUTSIDE_1 && multipleAllowed)) {
 229                 *outTop = i-1;
 230                 *outBottom = height-2;
 231                 found = true;
 232                 if (outDivs != NULL) {
 233                     *outDivs += 2;
 234                 }
 235                 state = TICK_INSIDE_1;
 236             } else if (state == TICK_OUTSIDE_1) {
 237                 *outError = "Can't have more than one marked region along edge";
 238                 *outTop = i;
 239                 return UNKNOWN_ERROR;
 240             }
 241         } else if (*outError == NULL) {
 242             if (state == TICK_INSIDE_1) {
 243                 // We're done with this div.  Move on to the next.
 244                 *outBottom = i-1;
 245                 outTop += 2;
 246                 outBottom += 2;
 247                 state = TICK_OUTSIDE_1;
 248             }
 249         } else {
 250             *outTop = i;
 251             return UNKNOWN_ERROR;
 252         }
 253     }
 254
 255     if (required && !found) {
 256         *outError = "No marked region found along edge";
 257         *outTop = -1;
 258         return UNKNOWN_ERROR;
 259     }
 260
 261     return NO_ERROR;
 262 }
 263
 264 static uint32_t get_color(
 265     png_bytepp rows, int left, int top, int right, int bottom)
 266 {
 267     png_bytep color = rows[top] + left*4;
 268
 269     if (left > right || top > bottom) {
 270         return Res_png_9patch::TRANSPARENT_COLOR;
 271     }
 272
 273     while (top <= bottom) {
 274         for (int i = left; i <= right; i++) {
 275             png_bytep p = rows[top]+i*4;
 276             if (color[3] == 0) {
 277                 if (p[3] != 0) {
 278                     return Res_png_9patch::NO_COLOR;
 279                 }
 280             } else if (p[0] != color[0] || p[1] != color[1]
 281                        || p[2] != color[2] || p[3] != color[3]) {
 282                 return Res_png_9patch::NO_COLOR;
 283             }
 284         }
 285         top++;
 286     }
 287
 288     if (color[3] == 0) {
 289         return Res_png_9patch::TRANSPARENT_COLOR;
 290     }
 291     return (color[3]<<24) | (color[0]<<16) | (color[1]<<8) | color[2];
 292 }
 293
 294 static void select_patch(
 295     int which, int front, int back, int size, int* start, int* end)
 296 {
 297     switch (which) {
 298     case 0:
 299         *start = 0;
 300         *end = front-1;
 301         break;
 302     case 1:
 303         *start = front;
 304         *end = back-1;
 305         break;
 306     case 2:
 307         *start = back;
 308         *end = size-1;
 309         break;
 310     }
 311 }
 312
 313 static uint32_t get_color(image_info* image, int hpatch, int vpatch)
 314 {
 315     int left, right, top, bottom;
 316     select_patch(
 317         hpatch, image->info9Patch.xDivs[0], image->info9Patch.xDivs[1],
 318         image->width, &left, &right);
 319     select_patch(
 320         vpatch, image->info9Patch.yDivs[0], image->info9Patch.yDivs[1],
 321         image->height, &top, &bottom);
 322     //printf("Selecting h=%d v=%d: (%d,%d)-(%d,%d)\n",
 323     //       hpatch, vpatch, left, top, right, bottom);
 324     const uint32_t c = get_color(image->rows, left, top, right, bottom);
 325     NOISY(printf("Color in (%d,%d)-(%d,%d): #%08x\n", left, top, right, bottom, c));
 326     return c;
 327 }
 328
 329 static void examine_image(image_info* image)
 330 {
 331     bool hasTrans = false;
 332     for (int i=0; i<(int)image->height && !hasTrans; i++) {
 333         png_bytep p = image->rows[i];
 334         for (int j=0; j<(int)image->width; j++) {
 335             if (p[(j*4)+3] != 0xFF) {
 336                 hasTrans = true;
 337                 break;
 338             }
 339         }
 340     }
 341
 342     image->hasTransparency = hasTrans;
 343 }
 344
 345 static status_t do_9patch(const char* imageName, image_info* image)
 346 {
 347     image->is9Patch = true;
 348
 349     int W = image->width;
 350     int H = image->height;
 351     int i, j;
 352
 353     int maxSizeXDivs = (W / 2 + 1) * sizeof(int32_t);
 354     int maxSizeYDivs = (H / 2 + 1) * sizeof(int32_t);
 355     int32_t* xDivs = (int32_t*) malloc(maxSizeXDivs);
 356     int32_t* yDivs = (int32_t*) malloc(maxSizeYDivs);
 357     uint8_t  numXDivs = 0;
 358     uint8_t  numYDivs = 0;
 359     int8_t numColors;
 360     int numRows;
 361     int numCols;
 362     int top;
 363     int left;
 364     int right;
 365     int bottom;
 366     memset(xDivs, -1, maxSizeXDivs);
 367     memset(yDivs, -1, maxSizeYDivs);
 368     image->info9Patch.paddingLeft = image->info9Patch.paddingRight =
 369         image->info9Patch.paddingTop = image->info9Patch.paddingBottom = -1;
 370
 371     png_bytep p = image->rows[0];
 372     bool transparent = p[3] == 0;
 373     bool hasColor = false;
 374
 375     const char* errorMsg = NULL;
 376     int errorPixel = -1;
 377     const char* errorEdge = "";
 378
 379     int colorIndex = 0;
 380
 381     // Validate size...
 382     if (W < 3 || H < 3) {
 383         errorMsg = "Image must be at least 3x3 (1x1 without frame) pixels";
 384         goto getout;
 385     }
 386
 387     // Validate frame...
 388     if (!transparent &&
 389         (p[0] != 0xFF || p[1] != 0xFF || p[2] != 0xFF || p[3] != 0xFF)) {
 390         errorMsg = "Must have one-pixel frame that is either transparent or white";
 391         goto getout;
 392     }
 393
 394     // Find left and right of sizing areas...
 395     if (get_horizontal_ticks(p, W, transparent, true, &xDivs[0],
 396                              &xDivs[1], &errorMsg, &numXDivs, true) != NO_ERROR) {
 397         errorPixel = xDivs[0];
 398         errorEdge = "top";
 399         goto getout;
 400     }
 401
 402     // Find top and bottom of sizing areas...
 403     if (get_vertical_ticks(image->rows, 0, H, transparent, true, &yDivs[0],
 404                            &yDivs[1], &errorMsg, &numYDivs, true) != NO_ERROR) {
 405         errorPixel = yDivs[0];
 406         errorEdge = "left";
 407         goto getout;
 408     }
 409
 410     // Find left and right of padding area...
 411     if (get_horizontal_ticks(image->rows[H-1], W, transparent, false, &image->info9Patch.paddingLeft,
 412                              &image->info9Patch.paddingRight, &errorMsg, NULL, false) != NO_ERROR) {
 413         errorPixel = image->info9Patch.paddingLeft;
 414         errorEdge = "bottom";
 415         goto getout;
 416     }
 417
 418     // Find top and bottom of padding area...
 419     if (get_vertical_ticks(image->rows, (W-1)*4, H, transparent, false, &image->info9Patch.paddingTop,
 420                            &image->info9Patch.paddingBottom, &errorMsg, NULL, false) != NO_ERROR) {
 421         errorPixel = image->info9Patch.paddingTop;
 422         errorEdge = "right";
 423         goto getout;
 424     }
 425
 426     // Copy patch data into image
 427     image->info9Patch.numXDivs = numXDivs;
 428     image->info9Patch.numYDivs = numYDivs;
 429     image->info9Patch.xDivs = xDivs;
 430     image->info9Patch.yDivs = yDivs;
 431
 432     // If padding is not yet specified, take values from size.
 433     if (image->info9Patch.paddingLeft < 0) {
 434         image->info9Patch.paddingLeft = xDivs[0];
 435         image->info9Patch.paddingRight = W - 2 - xDivs[1];
 436     } else {
 437         // Adjust value to be correct!
 438         image->info9Patch.paddingRight = W - 2 - image->info9Patch.paddingRight;
 439     }
 440     if (image->info9Patch.paddingTop < 0) {
 441         image->info9Patch.paddingTop = yDivs[0];
 442         image->info9Patch.paddingBottom = H - 2 - yDivs[1];
 443     } else {
 444         // Adjust value to be correct!
 445         image->info9Patch.paddingBottom = H - 2 - image->info9Patch.paddingBottom;
 446     }
 447
 448     NOISY(printf("Size ticks for %s: x0=%d, x1=%d, y0=%d, y1=%d\n", imageName,
 449                  image->info9Patch.xDivs[0], image->info9Patch.xDivs[1],
 450                  image->info9Patch.yDivs[0], image->info9Patch.yDivs[1]));
 451     NOISY(printf("padding ticks for %s: l=%d, r=%d, t=%d, b=%d\n", imageName,
 452                  image->info9Patch.paddingLeft, image->info9Patch.paddingRight,
 453                  image->info9Patch.paddingTop, image->info9Patch.paddingBottom));
 454
 455     // Remove frame from image.
 456     image->rows = (png_bytepp)malloc((H-2) * png_sizeof(png_bytep));
 457     for (i=0; i<(H-2); i++) {
 458         image->rows[i] = image->allocRows[i+1];
 459         memmove(image->rows[i], image->rows[i]+4, (W-2)*4);
 460     }
 461     image->width -= 2;
 462     W = image->width;
 463     image->height -= 2;
 464     H = image->height;
 465
 466     // Figure out the number of rows and columns in the N-patch
 467     numCols = numXDivs + 1;
 468     if (xDivs[0] == 0) {  // Column 1 is strechable
 469         numCols--;
 470     }
 471     if (xDivs[numXDivs - 1] == W) {
 472         numCols--;
 473     }
 474     numRows = numYDivs + 1;
 475     if (yDivs[0] == 0) {  // Row 1 is strechable
 476         numRows--;
 477     }
 478     if (yDivs[numYDivs - 1] == H) {
 479         numRows--;
 480     }
 481     numColors = numRows * numCols;
 482     image->info9Patch.numColors = numColors;
 483     image->info9Patch.colors = (uint32_t*)malloc(numColors * sizeof(uint32_t));
 484
 485     // Fill in color information for each patch.
 486
 487     uint32_t c;
 488     top = 0;
 489
 490     // The first row always starts with the top being at y=0 and the bottom
 491     // being either yDivs[1] (if yDivs[0]=0) of yDivs[0].  In the former case
 492     // the first row is stretchable along the Y axis, otherwise it is fixed.
 493     // The last row always ends with the bottom being bitmap.height and the top
 494     // being either yDivs[numYDivs-2] (if yDivs[numYDivs-1]=bitmap.height) or
 495     // yDivs[numYDivs-1]. In the former case the last row is stretchable along
 496     // the Y axis, otherwise it is fixed.
 497     //
 498     // The first and last columns are similarly treated with respect to the X
 499     // axis.
 500     //
 501     // The above is to help explain some of the special casing that goes on the
 502     // code below.
 503
 504     // The initial yDiv and whether the first row is considered stretchable or
 505     // not depends on whether yDiv[0] was zero or not.
 506     for (j = (yDivs[0] == 0 ? 1 : 0);
 507           j <= numYDivs && top < H;
 508           j++) {
 509         if (j == numYDivs) {
 510             bottom = H;
 511         } else {
 512             bottom = yDivs[j];
 513         }
 514         left = 0;
 515         // The initial xDiv and whether the first column is considered
 516         // stretchable or not depends on whether xDiv[0] was zero or not.
 517         for (i = xDivs[0] == 0 ? 1 : 0;
 518               i <= numXDivs && left < W;
 519               i++) {
 520             if (i == numXDivs) {
 521                 right = W;
 522             } else {
 523                 right = xDivs[i];
 524             }
 525             c = get_color(image->rows, left, top, right - 1, bottom - 1);
 526             image->info9Patch.colors[colorIndex++] = c;
 527             NOISY(if (c != Res_png_9patch::NO_COLOR) hasColor = true);
 528             left = right;
 529         }
 530         top = bottom;
 531     }
 532
 533     assert(colorIndex == numColors);
 534
 535     for (i=0; i<numColors; i++) {
 536         if (hasColor) {
 537             if (i == 0) printf("Colors in %s:\n ", imageName);
 538             printf(" #%08x", image->info9Patch.colors[i]);
 539             if (i == numColors - 1) printf("\n");
 540         }
 541     }
 542
 543     image->is9Patch = true;
 544     image->info9Patch.deviceToFile();
 545
 546 getout:
 547     if (errorMsg) {
 548         fprintf(stderr,
 549             "ERROR: 9-patch image %s malformed.\n"
 550             "       %s.\n", imageName, errorMsg);
 551         if (errorPixel >= 0) {
 552             fprintf(stderr,
 553             "       Found at pixel #%d along %s edge.\n", errorPixel, errorEdge);
 554         } else {
 555             fprintf(stderr,
 556             "       Found along %s edge.\n", errorEdge);
 557         }
 558         return UNKNOWN_ERROR;
 559     }
 560     return NO_ERROR;
 561 }
 562
 563 static void checkNinePatchSerialization(Res_png_9patch* inPatch,  void * data)
 564 {
 565     if (sizeof(void*) != sizeof(int32_t)) {
 566         // can't deserialize on a non-32 bit system
 567         return;
 568     }
 569     size_t patchSize = inPatch->serializedSize();
 570     void * newData = malloc(patchSize);
 571     memcpy(newData, data, patchSize);
 572     Res_png_9patch* outPatch = inPatch->deserialize(newData);
 573     // deserialization is done in place, so outPatch == newData
 574     assert(outPatch == newData);
 575     assert(outPatch->numXDivs == inPatch->numXDivs);
 576     assert(outPatch->numYDivs == inPatch->numYDivs);
 577     assert(outPatch->paddingLeft == inPatch->paddingLeft);
 578     assert(outPatch->paddingRight == inPatch->paddingRight);
 579     assert(outPatch->paddingTop == inPatch->paddingTop);
 580     assert(outPatch->paddingBottom == inPatch->paddingBottom);
 581     for (int i = 0; i < outPatch->numXDivs; i++) {
 582         assert(outPatch->xDivs[i] == inPatch->xDivs[i]);
 583     }
 584     for (int i = 0; i < outPatch->numYDivs; i++) {
 585         assert(outPatch->yDivs[i] == inPatch->yDivs[i]);
 586     }
 587     for (int i = 0; i < outPatch->numColors; i++) {
 588         assert(outPatch->colors[i] == inPatch->colors[i]);
 589     }
 590     free(newData);
 591 }
 592
 593 static bool patch_equals(Res_png_9patch& patch1, Res_png_9patch& patch2) {
 594     if (!(patch1.numXDivs == patch2.numXDivs &&
 595           patch1.numYDivs == patch2.numYDivs &&
 596           patch1.numColors == patch2.numColors &&
 597           patch1.paddingLeft == patch2.paddingLeft &&
 598           patch1.paddingRight == patch2.paddingRight &&
 599           patch1.paddingTop == patch2.paddingTop &&
 600           patch1.paddingBottom == patch2.paddingBottom)) {
 601             return false;
 602     }
 603     for (int i = 0; i < patch1.numColors; i++) {
 604         if (patch1.colors[i] != patch2.colors[i]) {
 605             return false;
 606         }
 607     }
 608     for (int i = 0; i < patch1.numXDivs; i++) {
 609         if (patch1.xDivs[i] != patch2.xDivs[i]) {
 610             return false;
 611         }
 612     }
 613     for (int i = 0; i < patch1.numYDivs; i++) {
 614         if (patch1.yDivs[i] != patch2.yDivs[i]) {
 615             return false;
 616         }
 617     }
 618     return true;
 619 }
 620
 621
 622 static void analyze_image(image_info &imageInfo, png_colorp rgbPalette, png_bytep alphaPalette,
 623                           int *paletteEntries, bool *hasTransparency, int *colorType,
 624                           png_bytepp outRows)
 625 {
 626     int w = imageInfo.width;
 627     int h = imageInfo.height;
 628     bool trans = imageInfo.hasTransparency;
 629     int i, j, rr, gg, bb, aa, idx;
 630     uint32_t colors[256], col;
 631     int num_colors = 0;
 632
 633     bool isOpaque = true;
 634     bool isPalette = true;
 635     bool isGrayscale = true;
 636
 637     // Scan the entire image and determine if:
 638     // 1. Every pixel has R == G == B (grayscale)
 639     // 2. Every pixel has A == 255 (opaque)
 640     // 3. There are no more than 256 distinct RGBA colors
 641     for (j = 0; j < h; j++) {
 642         png_bytep row = imageInfo.rows[j];
 643         png_bytep out = outRows[j];
 644         for (i = 0; i < w; i++) {
 645             rr = *row++;
 646             gg = *row++;
 647             bb = *row++;
 648             aa = *row++;
 649             if (!trans) {
 650                 // Ignore the actually byte and assume alpha == 255
 651                 aa = 0xff;
 652             }
 653
 654             // Check if image is really grayscale
 655             if (isGrayscale) {
 656               if (rr != gg || rr != bb) {
 657                 isGrayscale = false;
 658               }
 659             }
 660
 661             // Check if image is really opaque
 662             if (isOpaque) {
 663               if (aa != 0xff) {
 664                 isOpaque = false;
 665               }
 666             }
 667
 668             // Check if image is really <= 256 colors
 669             if (isPalette) {
 670                 col = (uint32_t) ((rr << 24) | (gg << 16) | (bb << 8) | aa);
 671                 bool match = false;
 672                 for (idx = 0; idx < num_colors; idx++) {
 673                     if (colors[idx] == col) {
 674                         match = true;
 675                         break;
 676                     }
 677                 }
 678
 679                 // Write the palette index for the pixel to outRows optimistically
 680                 // We might overwrite it later if we decide to encode as gray or
 681                 // gray + alpha
 682                 *out++ = idx;
 683                 if (!match) {
 684                     if (num_colors == 256) {
 685                         isPalette = false;
 686                     } else {
 687                         colors[num_colors++] = col;
 688                     }
 689                 }
 690             }
 691         }
 692     }
 693
 694     *paletteEntries = 0;
 695     *hasTransparency = !isOpaque;
 696     int bpp = isOpaque ? 3 : 4;
 697     int paletteSize = w * h + bpp * num_colors;
 698
 699     // Choose the best color type for the image.
 700     // 1. Opaque gray - use COLOR_TYPE_GRAY at 1 byte/pixel
 701     // 2. Gray + alpha - use COLOR_TYPE_PALETTE if the number of distinct combinations
 702     //     is sufficiently small, otherwise use COLOR_TYPE_GRAY_ALPHA
 703     // 3. RGB(A) - use COLOR_TYPE_PALETTE if the number of distinct colors is sufficiently
 704     //     small, otherwise use COLOR_TYPE_RGB{_ALPHA}
 705     if (isGrayscale) {
 706         if (isOpaque) {
 707             *colorType = PNG_COLOR_TYPE_GRAY; // 1 byte/pixel
 708         } else {
 709             // Use a simple heuristic to determine whether using a palette will
 710             // save space versus using gray + alpha for each pixel.
 711             // This doesn't take into account chunk overhead, filtering, LZ
 712             // compression, etc.
 713             if (isPalette && (paletteSize < 2 * w * h)) {
 714                 *colorType = PNG_COLOR_TYPE_PALETTE; // 1 byte/pixel + 4 bytes/color
 715             } else {
 716                 *colorType = PNG_COLOR_TYPE_GRAY_ALPHA; // 2 bytes per pixel
 717             }
 718         }
 719     } else if (isPalette && (paletteSize < bpp * w * h)) {
 720         *colorType = PNG_COLOR_TYPE_PALETTE;
 721     } else {
 722         *colorType = isOpaque ? PNG_COLOR_TYPE_RGB : PNG_COLOR_TYPE_RGB_ALPHA;
 723     }
 724
 725     // Perform postprocessing of the image or palette data based on the final
 726     // color type chosen
 727
 728     if (*colorType == PNG_COLOR_TYPE_PALETTE) {
 729         // Create separate RGB and Alpha palettes and set the number of colors
 730         *paletteEntries = num_colors;
 731
 732         // Create the RGB and alpha palettes
 733         for (int idx = 0; idx < num_colors; idx++) {
 734             col = colors[idx];
 735             rgbPalette[idx].red   = (png_byte) ((col >> 24) & 0xff);
 736             rgbPalette[idx].green = (png_byte) ((col >> 16) & 0xff);
 737             rgbPalette[idx].blue  = (png_byte) ((col >>  8) & 0xff);
 738             alphaPalette[idx]     = (png_byte)  (col        & 0xff);
 739         }
 740     } else if (*colorType == PNG_COLOR_TYPE_GRAY || *colorType == PNG_COLOR_TYPE_GRAY_ALPHA) {
 741         // If the image is gray or gray + alpha, compact the pixels into outRows
 742         for (j = 0; j < h; j++) {
 743             png_bytep row = imageInfo.rows[j];
 744             png_bytep out = outRows[j];
 745             for (i = 0; i < w; i++) {
 746                 rr = *row++;
 747                 gg = *row++;
 748                 bb = *row++;
 749                 aa = *row++;
 750
 751                 *out++ = rr;
 752                 if (!isOpaque) {
 753                     *out++ = aa;
 754                 }
 755             }
 756         }
 757     }
 758 }
 759
 760
 761 static void write_png(const char* imageName,
 762                       png_structp write_ptr, png_infop write_info,
 763                       image_info& imageInfo)
 764 {
 765     bool optimize = true;
 766     png_uint_32 width, height;
 767     int color_type;
 768     int bit_depth, interlace_type, compression_type;
 769     int i;
 770
 771     png_unknown_chunk unknowns[1];
 772
 773     png_bytepp outRows = (png_bytepp) malloc((int) imageInfo.height * png_sizeof(png_bytep));
 774     if (outRows == (png_bytepp) 0) {
 775         printf("Can't allocate output buffer!\n");
 776         exit(1);
 777     }
 778     for (i = 0; i < (int) imageInfo.height; i++) {
 779         outRows[i] = (png_bytep) malloc(2 * (int) imageInfo.width);
 780         if (outRows[i] == (png_bytep) 0) {
 781             printf("Can't allocate output buffer!\n");
 782             exit(1);
 783         }
 784     }
 785
 786     png_set_compression_level(write_ptr, Z_BEST_COMPRESSION);
 787
 788     NOISY(printf("Writing image %s: w = %d, h = %d, trans = %s\n", imageName,
 789           (int) imageInfo.width, (int) imageInfo.height,
 790           imageInfo.hasTransparency ? "true" : "false"));
 791
 792     png_color rgbPalette[256];
 793     png_byte alphaPalette[256];
 794     bool hasTransparency;
 795     int paletteEntries;
 796
 797     if (optimize) {
 798         analyze_image(imageInfo, rgbPalette, alphaPalette, &paletteEntries, &hasTransparency,
 799                       &color_type, outRows);
 800         switch (color_type) {
 801         case PNG_COLOR_TYPE_PALETTE:
 802             NOISY(printf("Image %s has %d colors%s, using PNG_COLOR_TYPE_PALETTE\n",
 803                          imageName, paletteEntries,
 804                          hasTransparency ? " (with alpha)" : ""));
 805             break;
 806         case PNG_COLOR_TYPE_GRAY:
 807             NOISY(printf("Image %s is opaque gray, using PNG_COLOR_TYPE_GRAY\n", imageName));
 808             break;
 809         case PNG_COLOR_TYPE_GRAY_ALPHA:
 810             NOISY(printf("Image %s is gray + alpha, using PNG_COLOR_TYPE_GRAY_ALPHA\n", imageName));
 811             break;
 812         case PNG_COLOR_TYPE_RGB:
 813             NOISY(printf("Image %s is opaque RGB, using PNG_COLOR_TYPE_RGB\n", imageName));
 814             break;
 815         case PNG_COLOR_TYPE_RGB_ALPHA:
 816             NOISY(printf("Image %s is RGB + alpha, using PNG_COLOR_TYPE_RGB_ALPHA\n", imageName));
 817             break;
 818         }
 819     } else {
 820         // Force RGB or RGB_ALPHA color type, copy transparency from input
 821         paletteEntries = 0;
 822         hasTransparency = imageInfo.hasTransparency;
 823         color_type = hasTransparency ? PNG_COLOR_TYPE_RGB_ALPHA : PNG_COLOR_TYPE_RGB;
 824     }
 825
 826     png_set_IHDR(write_ptr, write_info, imageInfo.width, imageInfo.height,
 827                  8, color_type, PNG_INTERLACE_NONE,
 828                  PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
 829
 830     if (color_type == PNG_COLOR_TYPE_PALETTE) {
 831         png_set_PLTE(write_ptr, write_info, rgbPalette, paletteEntries);
 832         if (hasTransparency) {
 833             png_set_tRNS(write_ptr, write_info, alphaPalette, paletteEntries, (png_color_16p) 0);
 834         }
 835        png_set_filter(write_ptr, 0, PNG_NO_FILTERS);
 836     } else {
 837        png_set_filter(write_ptr, 0, PNG_ALL_FILTERS);
 838     }
 839
 840     if (imageInfo.is9Patch) {
 841         NOISY(printf("Adding 9-patch info...\n"));
 842         strcpy((char*)unknowns[0].name, "npTc");
 843         unknowns[0].data = (png_byte*)imageInfo.info9Patch.serialize();
 844         unknowns[0].size = imageInfo.info9Patch.serializedSize();
 845         // TODO: remove the check below when everything works
 846         checkNinePatchSerialization(&imageInfo.info9Patch, unknowns[0].data);
 847         png_set_keep_unknown_chunks(write_ptr, PNG_HANDLE_CHUNK_ALWAYS,
 848                                     (png_byte*)"npTc", 1);
 849         png_set_unknown_chunks(write_ptr, write_info, unknowns, 1);
 850         // XXX I can't get this to work without forcibly changing
 851         // the location to what I want...  which apparently is supposed
 852         // to be a private API, but everything else I have tried results
 853         // in the location being set to what I -last- wrote so I never
 854         // get written. :p
 855         png_set_unknown_chunk_location(write_ptr, write_info, 0, PNG_HAVE_PLTE);
 856     }
 857
 858     png_write_info(write_ptr, write_info);
 859
 860     if (!imageInfo.hasTransparency) {
 861         png_set_filler(write_ptr, 0, PNG_FILLER_AFTER);
 862     }
 863
 864     if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
 865         png_write_image(write_ptr, imageInfo.rows);
 866     } else {
 867         png_write_image(write_ptr, outRows);
 868     }
 869
 870     png_write_end(write_ptr, write_info);
 871
 872     for (i = 0; i < (int) imageInfo.height; i++) {
 873         free(outRows[i]);
 874     }
 875     free(outRows);
 876
 877     png_get_IHDR(write_ptr, write_info, &width, &height,
 878        &bit_depth, &color_type, &interlace_type,
 879        &compression_type, NULL);
 880
 881     NOISY(printf("Image written: w=%d, h=%d, d=%d, colors=%d, inter=%d, comp=%d\n",
 882                  (int)width, (int)height, bit_depth, color_type, interlace_type,
 883                  compression_type));
 884 }
 885
 886 status_t preProcessImage(Bundle* bundle, const sp<AaptAssets>& assets,
 887                          const sp<AaptFile>& file, String8* outNewLeafName)
 888 {
 889     String8 ext(file->getPath().getPathExtension());
 890
 891     // We currently only process PNG images.
 892     if (strcmp(ext.string(), ".png") != 0) {
 893         return NO_ERROR;
 894     }
 895
 896     // Example of renaming a file:
 897     //*outNewLeafName = file->getPath().getBasePath().getFileName();
 898     //outNewLeafName->append(".nupng");
 899
 900     String8 printableName(file->getPrintableSource());
 901
 902     png_structp read_ptr = NULL;
 903     png_infop read_info = NULL;
 904     FILE* fp;
 905
 906     image_info imageInfo;
 907
 908     png_structp write_ptr = NULL;
 909     png_infop write_info = NULL;
 910
 911     status_t error = UNKNOWN_ERROR;
 912
 913     const size_t nameLen = file->getPath().length();
 914
 915     fp = fopen(file->getSourceFile().string(), "rb");
 916     if (fp == NULL) {
 917         fprintf(stderr, "%s: ERROR: Unable to open PNG file\n", printableName.string());
 918         goto bail;
 919     }
 920
 921     read_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, (png_error_ptr)NULL,
 922                                         (png_error_ptr)NULL);
 923     if (!read_ptr) {
 924         goto bail;
 925     }
 926
 927     read_info = png_create_info_struct(read_ptr);
 928     if (!read_info) {
 929         goto bail;
 930     }
 931
 932     if (setjmp(png_jmpbuf(read_ptr))) {
 933         goto bail;
 934     }
 935
 936     png_init_io(read_ptr, fp);
 937
 938     read_png(printableName.string(), read_ptr, read_info, &imageInfo);
 939
 940     examine_image(&imageInfo);
 941
 942     if (nameLen > 6) {
 943         const char* name = file->getPath().string();
 944         if (name[nameLen-5] == '9' && name[nameLen-6] == '.') {
 945             if (do_9patch(printableName.string(), &imageInfo) != NO_ERROR) {
 946                 goto bail;
 947             }
 948         }
 949     }
 950
 951     write_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, 0, (png_error_ptr)NULL,
 952                                         (png_error_ptr)NULL);
 953     if (!write_ptr)
 954     {
 955         goto bail;
 956     }
 957
 958     write_info = png_create_info_struct(write_ptr);
 959     if (!write_info)
 960     {
 961         goto bail;
 962     }
 963
 964     png_set_write_fn(write_ptr, (void*)file.get(),
 965                      png_write_aapt_file, png_flush_aapt_file);
 966
 967     if (setjmp(png_jmpbuf(write_ptr)))
 968     {
 969         goto bail;
 970     }
 971
 972     write_png(printableName.string(), write_ptr, write_info, imageInfo);
 973
 974     error = NO_ERROR;
 975
 976     if (bundle->getVerbose()) {
 977         fseek(fp, 0, SEEK_END);
 978         size_t oldSize = (size_t)ftell(fp);
 979         size_t newSize = file->getSize();
 980         float factor = ((float)newSize)/oldSize;
 981         int percent = (int)(factor*100);
 982         printf("    (processed image %s: %d%% size of source)\n", printableName.string(), percent);
 983     }
 984
 985 bail:
 986     if (read_ptr) {
 987         png_destroy_read_struct(&read_ptr, &read_info, (png_infopp)NULL);
 988     }
 989     if (fp) {
 990         fclose(fp);
 991     }
 992     if (write_ptr) {
 993         png_destroy_write_struct(&write_ptr, &write_info);
 994     }
 995
 996     if (error != NO_ERROR) {
 997         fprintf(stderr, "ERROR: Failure processing PNG image %s\n",
 998                 file->getPrintableSource().string());
 999     }
1000     return error;
1001 }
1002
1003
1004
1005 status_t postProcessImage(const sp<AaptAssets>& assets,
1006                           ResourceTable* table, const sp<AaptFile>& file)
1007 {
1008     String8 ext(file->getPath().getPathExtension());
1009
1010     // At this point, now that we have all the resource data, all we need to
1011     // do is compile XML files.
1012     if (strcmp(ext.string(), ".xml") == 0) {
1013         return compileXmlFile(assets, file, table);
1014     }
1015
1016     return NO_ERROR;
1017 }