Images.cpp revision 076357b8567458d4b6dfdcf839ef751634cd2bfb 
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
18static void
19png_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
28static void
29png_flush_aapt_file(png_structp png_ptr)
30{
31}
32
33// This holds an image as 8bpp RGBA.
34struct image_info
35{
36    image_info() : rows(NULL), 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    // 9-patch info.
54    bool is9Patch;
55    Res_png_9patch info9Patch;
56
57    png_uint_32 allocHeight;
58    png_bytepp allocRows;
59};
60
61static void read_png(const char* imageName,
62                     png_structp read_ptr, png_infop read_info,
63                     image_info* outImageInfo)
64{
65    int color_type;
66    int bit_depth, interlace_type, compression_type;
67    int i;
68
69    png_read_info(read_ptr, read_info);
70
71    png_get_IHDR(read_ptr, read_info, &outImageInfo->width,
72       &outImageInfo->height, &bit_depth, &color_type,
73       &interlace_type, &compression_type, NULL);
74
75    //printf("Image %s:\n", imageName);
76    //printf("color_type=%d, bit_depth=%d, interlace_type=%d, compression_type=%d\n",
77    //       color_type, bit_depth, interlace_type, compression_type);
78
79    if (color_type == PNG_COLOR_TYPE_PALETTE)
80        png_set_palette_to_rgb(read_ptr);
81
82    if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
83        png_set_gray_1_2_4_to_8(read_ptr);
84
85    if (png_get_valid(read_ptr, read_info, PNG_INFO_tRNS)) {
86        //printf("Has PNG_INFO_tRNS!\n");
87        png_set_tRNS_to_alpha(read_ptr);
88    }
89
90    if (bit_depth == 16)
91        png_set_strip_16(read_ptr);
92
93    if ((color_type&PNG_COLOR_MASK_ALPHA) == 0)
94        png_set_add_alpha(read_ptr, 0xFF, PNG_FILLER_AFTER);
95
96    if (color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
97        png_set_gray_to_rgb(read_ptr);
98
99    png_read_update_info(read_ptr, read_info);
100
101    outImageInfo->rows = (png_bytepp)malloc(
102        outImageInfo->height * png_sizeof(png_bytep));
103    outImageInfo->allocHeight = outImageInfo->height;
104    outImageInfo->allocRows = outImageInfo->rows;
105
106    png_set_rows(read_ptr, read_info, outImageInfo->rows);
107
108    for (i = 0; i < (int)outImageInfo->height; i++)
109    {
110        outImageInfo->rows[i] = (png_bytep)
111            malloc(png_get_rowbytes(read_ptr, read_info));
112    }
113
114    png_read_image(read_ptr, outImageInfo->rows);
115
116    png_read_end(read_ptr, read_info);
117
118    NOISY(printf("Image %s: w=%d, h=%d, d=%d, colors=%d, inter=%d, comp=%d\n",
119                 imageName,
120                 (int)outImageInfo->width, (int)outImageInfo->height,
121                 bit_depth, color_type,
122                 interlace_type, compression_type));
123
124    png_get_IHDR(read_ptr, read_info, &outImageInfo->width,
125       &outImageInfo->height, &bit_depth, &color_type,
126       &interlace_type, &compression_type, NULL);
127}
128
129static bool is_tick(png_bytep p, bool transparent, const char** outError)
130{
131    if (transparent) {
132        if (p[3] == 0) {
133            return false;
134        }
135        if (p[3] != 0xff) {
136            *outError = "Frame pixels must be either solid or transparent (not intermediate alphas)";
137            return false;
138        }
139        if (p[0] != 0 || p[1] != 0 || p[2] != 0) {
140            *outError = "Ticks in transparent frame must be black";
141        }
142        return true;
143    }
144
145    if (p[3] != 0xFF) {
146        *outError = "White frame must be a solid color (no alpha)";
147    }
148    if (p[0] == 0xFF && p[1] == 0xFF && p[2] == 0xFF) {
149        return false;
150    }
151    if (p[0] != 0 || p[1] != 0 || p[2] != 0) {
152        *outError = "Ticks in white frame must be black";
153        return false;
154    }
155    return true;
156}
157
158enum {
159    TICK_START,
160    TICK_INSIDE_1,
161    TICK_OUTSIDE_1
162};
163
164static status_t get_horizontal_ticks(
165        png_bytep row, int width, bool transparent, bool required,
166        int32_t* outLeft, int32_t* outRight, const char** outError,
167        uint8_t* outDivs, bool multipleAllowed)
168{
169    int i;
170    *outLeft = *outRight = -1;
171    int state = TICK_START;
172    bool found = false;
173
174    for (i=1; i<width-1; i++) {
175        if (is_tick(row+i*4, transparent, outError)) {
176            if (state == TICK_START ||
177                (state == TICK_OUTSIDE_1 && multipleAllowed)) {
178                *outLeft = i-1;
179                *outRight = width-2;
180                found = true;
181                if (outDivs != NULL) {
182                    *outDivs += 2;
183                }
184                state = TICK_INSIDE_1;
185            } else if (state == TICK_OUTSIDE_1) {
186                *outError = "Can't have more than one marked region along edge";
187                *outLeft = i;
188                return UNKNOWN_ERROR;
189            }
190        } else if (*outError == NULL) {
191            if (state == TICK_INSIDE_1) {
192                // We're done with this div.  Move on to the next.
193                *outRight = i-1;
194                outRight += 2;
195                outLeft += 2;
196                state = TICK_OUTSIDE_1;
197            }
198        } else {
199            *outLeft = i;
200            return UNKNOWN_ERROR;
201        }
202    }
203
204    if (required && !found) {
205        *outError = "No marked region found along edge";
206        *outLeft = -1;
207        return UNKNOWN_ERROR;
208    }
209
210    return NO_ERROR;
211}
212
213static status_t get_vertical_ticks(
214        png_bytepp rows, int offset, int height, bool transparent, bool required,
215        int32_t* outTop, int32_t* outBottom, const char** outError,
216        uint8_t* outDivs, bool multipleAllowed)
217{
218    int i;
219    *outTop = *outBottom = -1;
220    int state = TICK_START;
221    bool found = false;
222
223    for (i=1; i<height-1; i++) {
224        if (is_tick(rows[i]+offset, transparent, outError)) {
225            if (state == TICK_START ||
226                (state == TICK_OUTSIDE_1 && multipleAllowed)) {
227                *outTop = i-1;
228                *outBottom = height-2;
229                found = true;
230                if (outDivs != NULL) {
231                    *outDivs += 2;
232                }
233                state = TICK_INSIDE_1;
234            } else if (state == TICK_OUTSIDE_1) {
235                *outError = "Can't have more than one marked region along edge";
236                *outTop = i;
237                return UNKNOWN_ERROR;
238            }
239        } else if (*outError == NULL) {
240            if (state == TICK_INSIDE_1) {
241                // We're done with this div.  Move on to the next.
242                *outBottom = i-1;
243                outTop += 2;
244                outBottom += 2;
245                state = TICK_OUTSIDE_1;
246            }
247        } else {
248            *outTop = i;
249            return UNKNOWN_ERROR;
250        }
251    }
252
253    if (required && !found) {
254        *outError = "No marked region found along edge";
255        *outTop = -1;
256        return UNKNOWN_ERROR;
257    }
258
259    return NO_ERROR;
260}
261
262static uint32_t get_color(
263    png_bytepp rows, int left, int top, int right, int bottom)
264{
265    png_bytep color = rows[top] + left*4;
266
267    if (left > right || top > bottom) {
268        return Res_png_9patch::TRANSPARENT_COLOR;
269    }
270
271    while (top <= bottom) {
272        for (int i = left; i <= right; i++) {
273            png_bytep p = rows[top]+i*4;
274            if (color[3] == 0) {
275                if (p[3] != 0) {
276                    return Res_png_9patch::NO_COLOR;
277                }
278            } else if (p[0] != color[0] || p[1] != color[1]
279                       || p[2] != color[2] || p[3] != color[3]) {
280                return Res_png_9patch::NO_COLOR;
281            }
282        }
283        top++;
284    }
285
286    if (color[3] == 0) {
287        return Res_png_9patch::TRANSPARENT_COLOR;
288    }
289    return (color[3]<<24) | (color[0]<<16) | (color[1]<<8) | color[2];
290}
291
292static void select_patch(
293    int which, int front, int back, int size, int* start, int* end)
294{
295    switch (which) {
296    case 0:
297        *start = 0;
298        *end = front-1;
299        break;
300    case 1:
301        *start = front;
302        *end = back-1;
303        break;
304    case 2:
305        *start = back;
306        *end = size-1;
307        break;
308    }
309}
310
311static uint32_t get_color(image_info* image, int hpatch, int vpatch)
312{
313    int left, right, top, bottom;
314    select_patch(
315        hpatch, image->info9Patch.xDivs[0], image->info9Patch.xDivs[1],
316        image->width, &left, &right);
317    select_patch(
318        vpatch, image->info9Patch.yDivs[0], image->info9Patch.yDivs[1],
319        image->height, &top, &bottom);
320    //printf("Selecting h=%d v=%d: (%d,%d)-(%d,%d)\n",
321    //       hpatch, vpatch, left, top, right, bottom);
322    const uint32_t c = get_color(image->rows, left, top, right, bottom);
323    NOISY(printf("Color in (%d,%d)-(%d,%d): #%08x\n", left, top, right, bottom, c));
324    return c;
325}
326
327static status_t do_9patch(const char* imageName, image_info* image)
328{
329    image->is9Patch = true;
330
331    int W = image->width;
332    int H = image->height;
333    int i, j;
334
335    int maxSizeXDivs = (W / 2 + 1) * sizeof(int32_t);
336    int maxSizeYDivs = (H / 2 + 1) * sizeof(int32_t);
337    int32_t* xDivs = (int32_t*) malloc(maxSizeXDivs);
338    int32_t* yDivs = (int32_t*) malloc(maxSizeYDivs);
339    uint8_t  numXDivs = 0;
340    uint8_t  numYDivs = 0;
341    int8_t numColors;
342    int numRows;
343    int numCols;
344    int top;
345    int left;
346    int right;
347    int bottom;
348    memset(xDivs, -1, maxSizeXDivs);
349    memset(yDivs, -1, maxSizeYDivs);
350    image->info9Patch.paddingLeft = image->info9Patch.paddingRight =
351        image->info9Patch.paddingTop = image->info9Patch.paddingBottom = -1;
352
353    png_bytep p = image->rows[0];
354    bool transparent = p[3] == 0;
355    bool hasColor = false;
356
357    const char* errorMsg = NULL;
358    int errorPixel = -1;
359    const char* errorEdge = "";
360
361    int colorIndex = 0;
362
363    // Validate size...
364    if (W < 3 || H < 3) {
365        errorMsg = "Image must be at least 3x3 (1x1 without frame) pixels";
366        goto getout;
367    }
368
369    // Validate frame...
370    if (!transparent &&
371        (p[0] != 0xFF || p[1] != 0xFF || p[2] != 0xFF || p[3] != 0xFF)) {
372        errorMsg = "Must have one-pixel frame that is either transparent or white";
373        goto getout;
374    }
375
376    // Find left and right of sizing areas...
377    if (get_horizontal_ticks(p, W, transparent, true, &xDivs[0],
378                             &xDivs[1], &errorMsg, &numXDivs, true) != NO_ERROR) {
379        errorPixel = xDivs[0];
380        errorEdge = "top";
381        goto getout;
382    }
383
384    // Find top and bottom of sizing areas...
385    if (get_vertical_ticks(image->rows, 0, H, transparent, true, &yDivs[0],
386                           &yDivs[1], &errorMsg, &numYDivs, true) != NO_ERROR) {
387        errorPixel = yDivs[0];
388        errorEdge = "left";
389        goto getout;
390    }
391
392    // Find left and right of padding area...
393    if (get_horizontal_ticks(image->rows[H-1], W, transparent, false, &image->info9Patch.paddingLeft,
394                             &image->info9Patch.paddingRight, &errorMsg, NULL, false) != NO_ERROR) {
395        errorPixel = image->info9Patch.paddingLeft;
396        errorEdge = "bottom";
397        goto getout;
398    }
399
400    // Find top and bottom of padding area...
401    if (get_vertical_ticks(image->rows, (W-1)*4, H, transparent, false, &image->info9Patch.paddingTop,
402                           &image->info9Patch.paddingBottom, &errorMsg, NULL, false) != NO_ERROR) {
403        errorPixel = image->info9Patch.paddingTop;
404        errorEdge = "right";
405        goto getout;
406    }
407
408    // Copy patch data into image
409    image->info9Patch.numXDivs = numXDivs;
410    image->info9Patch.numYDivs = numYDivs;
411    image->info9Patch.xDivs = xDivs;
412    image->info9Patch.yDivs = yDivs;
413
414    // If padding is not yet specified, take values from size.
415    if (image->info9Patch.paddingLeft < 0) {
416        image->info9Patch.paddingLeft = xDivs[0];
417        image->info9Patch.paddingRight = W - 2 - xDivs[1];
418    } else {
419        // Adjust value to be correct!
420        image->info9Patch.paddingRight = W - 2 - image->info9Patch.paddingRight;
421    }
422    if (image->info9Patch.paddingTop < 0) {
423        image->info9Patch.paddingTop = yDivs[0];
424        image->info9Patch.paddingBottom = H - 2 - yDivs[1];
425    } else {
426        // Adjust value to be correct!
427        image->info9Patch.paddingBottom = H - 2 - image->info9Patch.paddingBottom;
428    }
429
430    NOISY(printf("Size ticks for %s: x0=%d, x1=%d, y0=%d, y1=%d\n", imageName,
431                 image->info9Patch.xDivs[0], image->info9Patch.xDivs[1],
432                 image->info9Patch.yDivs[0], image->info9Patch.yDivs[1]));
433    NOISY(printf("padding ticks for %s: l=%d, r=%d, t=%d, b=%d\n", imageName,
434                 image->info9Patch.paddingLeft, image->info9Patch.paddingRight,
435                 image->info9Patch.paddingTop, image->info9Patch.paddingBottom));
436
437    // Remove frame from image.
438    image->rows = (png_bytepp)malloc((H-2) * png_sizeof(png_bytep));
439    for (i=0; i<(H-2); i++) {
440        image->rows[i] = image->allocRows[i+1];
441        memmove(image->rows[i], image->rows[i]+4, (W-2)*4);
442    }
443    image->width -= 2;
444    W = image->width;
445    image->height -= 2;
446    H = image->height;
447
448    // Figure out the number of rows and columns in the N-patch
449    numCols = numXDivs + 1;
450    if (xDivs[0] == 0) {  // Column 1 is strechable
451        numCols--;
452    }
453    if (xDivs[numXDivs - 1] == W) {
454        numCols--;
455    }
456    numRows = numYDivs + 1;
457    if (yDivs[0] == 0) {  // Row 1 is strechable
458        numRows--;
459    }
460    if (yDivs[numYDivs - 1] == H) {
461        numRows--;
462    }
463    numColors = numRows * numCols;
464    image->info9Patch.numColors = numColors;
465    image->info9Patch.colors = (uint32_t*)malloc(numColors * sizeof(uint32_t));
466
467    // Fill in color information for each patch.
468
469    uint32_t c;
470    top = 0;
471
472    // The first row always starts with the top being at y=0 and the bottom
473    // being either yDivs[1] (if yDivs[0]=0) of yDivs[0].  In the former case
474    // the first row is stretchable along the Y axis, otherwise it is fixed.
475    // The last row always ends with the bottom being bitmap.height and the top
476    // being either yDivs[numYDivs-2] (if yDivs[numYDivs-1]=bitmap.height) or
477    // yDivs[numYDivs-1]. In the former case the last row is stretchable along
478    // the Y axis, otherwise it is fixed.
479    //
480    // The first and last columns are similarly treated with respect to the X
481    // axis.
482    //
483    // The above is to help explain some of the special casing that goes on the
484    // code below.
485
486    // The initial yDiv and whether the first row is considered stretchable or
487    // not depends on whether yDiv[0] was zero or not.
488    for (j = (yDivs[0] == 0 ? 1 : 0);
489          j <= numYDivs && top < H;
490          j++) {
491        if (j == numYDivs) {
492            bottom = H;
493        } else {
494            bottom = yDivs[j];
495        }
496        left = 0;
497        // The initial xDiv and whether the first column is considered
498        // stretchable or not depends on whether xDiv[0] was zero or not.
499        for (i = xDivs[0] == 0 ? 1 : 0;
500              i <= numXDivs && left < W;
501              i++) {
502            if (i == numXDivs) {
503                right = W;
504            } else {
505                right = xDivs[i];
506            }
507            c = get_color(image->rows, left, top, right - 1, bottom - 1);
508            image->info9Patch.colors[colorIndex++] = c;
509            NOISY(if (c != Res_png_9patch::NO_COLOR) hasColor = true);
510            left = right;
511        }
512        top = bottom;
513    }
514
515    assert(colorIndex == numColors);
516
517    for (i=0; i<numColors; i++) {
518        if (hasColor) {
519            if (i == 0) printf("Colors in %s:\n ", imageName);
520            printf(" #%08x", image->info9Patch.colors[i]);
521            if (i == numColors - 1) printf("\n");
522        }
523    }
524
525    image->is9Patch = true;
526    image->info9Patch.deviceToFile();
527
528getout:
529    if (errorMsg) {
530        fprintf(stderr,
531            "ERROR: 9-patch image %s malformed.\n"
532            "       %s.\n", imageName, errorMsg);
533        if (errorPixel >= 0) {
534            fprintf(stderr,
535            "       Found at pixel #%d along %s edge.\n", errorPixel, errorEdge);
536        } else {
537            fprintf(stderr,
538            "       Found along %s edge.\n", errorEdge);
539        }
540        return UNKNOWN_ERROR;
541    }
542    return NO_ERROR;
543}
544
545static void checkNinePatchSerialization(Res_png_9patch* inPatch,  void * data)
546{
547    if (sizeof(void*) != sizeof(int32_t)) {
548        // can't deserialize on a non-32 bit system
549        return;
550    }
551    size_t patchSize = inPatch->serializedSize();
552    void * newData = malloc(patchSize);
553    memcpy(newData, data, patchSize);
554    Res_png_9patch* outPatch = inPatch->deserialize(newData);
555    // deserialization is done in place, so outPatch == newData
556    assert(outPatch == newData);
557    assert(outPatch->numXDivs == inPatch->numXDivs);
558    assert(outPatch->numYDivs == inPatch->numYDivs);
559    assert(outPatch->paddingLeft == inPatch->paddingLeft);
560    assert(outPatch->paddingRight == inPatch->paddingRight);
561    assert(outPatch->paddingTop == inPatch->paddingTop);
562    assert(outPatch->paddingBottom == inPatch->paddingBottom);
563    for (int i = 0; i < outPatch->numXDivs; i++) {
564        assert(outPatch->xDivs[i] == inPatch->xDivs[i]);
565    }
566    for (int i = 0; i < outPatch->numYDivs; i++) {
567        assert(outPatch->yDivs[i] == inPatch->yDivs[i]);
568    }
569    for (int i = 0; i < outPatch->numColors; i++) {
570        assert(outPatch->colors[i] == inPatch->colors[i]);
571    }
572    free(newData);
573}
574
575static bool patch_equals(Res_png_9patch& patch1, Res_png_9patch& patch2) {
576    if (!(patch1.numXDivs == patch2.numXDivs &&
577          patch1.numYDivs == patch2.numYDivs &&
578          patch1.numColors == patch2.numColors &&
579          patch1.paddingLeft == patch2.paddingLeft &&
580          patch1.paddingRight == patch2.paddingRight &&
581          patch1.paddingTop == patch2.paddingTop &&
582          patch1.paddingBottom == patch2.paddingBottom)) {
583            return false;
584    }
585    for (int i = 0; i < patch1.numColors; i++) {
586        if (patch1.colors[i] != patch2.colors[i]) {
587            return false;
588        }
589    }
590    for (int i = 0; i < patch1.numXDivs; i++) {
591        if (patch1.xDivs[i] != patch2.xDivs[i]) {
592            return false;
593        }
594    }
595    for (int i = 0; i < patch1.numYDivs; i++) {
596        if (patch1.yDivs[i] != patch2.yDivs[i]) {
597            return false;
598        }
599    }
600    return true;
601}
602
603static void dump_image(int w, int h, png_bytepp rows, int color_type)
604{
605    int i, j, rr, gg, bb, aa;
606
607    int bpp;
608    if (color_type == PNG_COLOR_TYPE_PALETTE || color_type == PNG_COLOR_TYPE_GRAY) {
609        bpp = 1;
610    } else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
611        bpp = 2;
612    } else if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
613	    // We use a padding byte even when there is no alpha
614        bpp = 4;
615    } else {
616        printf("Unknown color type %d.\n", color_type);
617    }
618
619    for (j = 0; j < h; j++) {
620        png_bytep row = rows[j];
621        for (i = 0; i < w; i++) {
622            rr = row[0];
623            gg = row[1];
624            bb = row[2];
625            aa = row[3];
626            row += bpp;
627
628            if (i == 0) {
629                printf("Row %d:", j);
630            }
631            switch (bpp) {
632            case 1:
633                printf(" (%d)", rr);
634                break;
635            case 2:
636                printf(" (%d %d", rr, gg);
637                break;
638            case 3:
639                printf(" (%d %d %d)", rr, gg, bb);
640                break;
641            case 4:
642                printf(" (%d %d %d %d)", rr, gg, bb, aa);
643                break;
644            }
645            if (i == (w - 1)) {
646                NOISY(printf("\n"));
647            }
648        }
649    }
650}
651
652#define MAX(a,b) ((a)>(b)?(a):(b))
653#define ABS(a)   ((a)<0?-(a):(a))
654
655static void analyze_image(const char *imageName, image_info &imageInfo, int grayscaleTolerance,
656                          png_colorp rgbPalette, png_bytep alphaPalette,
657                          int *paletteEntries, bool *hasTransparency, int *colorType,
658                          png_bytepp outRows)
659{
660    int w = imageInfo.width;
661    int h = imageInfo.height;
662    int i, j, rr, gg, bb, aa, idx;
663    uint32_t colors[256], col;
664    int num_colors = 0;
665    int maxGrayDeviation = 0;
666
667    bool isOpaque = true;
668    bool isPalette = true;
669    bool isGrayscale = true;
670
671    // Scan the entire image and determine if:
672    // 1. Every pixel has R == G == B (grayscale)
673    // 2. Every pixel has A == 255 (opaque)
674    // 3. There are no more than 256 distinct RGBA colors
675
676    // NOISY(printf("Initial image data:\n"));
677    // dump_image(w, h, imageInfo.rows, PNG_COLOR_TYPE_RGB_ALPHA);
678
679    for (j = 0; j < h; j++) {
680        png_bytep row = imageInfo.rows[j];
681        png_bytep out = outRows[j];
682        for (i = 0; i < w; i++) {
683            rr = *row++;
684            gg = *row++;
685            bb = *row++;
686            aa = *row++;
687
688            int odev = maxGrayDeviation;
689            maxGrayDeviation = MAX(ABS(rr - gg), maxGrayDeviation);
690            maxGrayDeviation = MAX(ABS(gg - bb), maxGrayDeviation);
691            maxGrayDeviation = MAX(ABS(bb - rr), maxGrayDeviation);
692            if (maxGrayDeviation > odev) {
693                NOISY(printf("New max dev. = %d at pixel (%d, %d) = (%d %d %d %d)\n",
694                             maxGrayDeviation, i, j, rr, gg, bb, aa));
695            }
696
697            // Check if image is really grayscale
698            if (isGrayscale) {
699                if (rr != gg || rr != bb) {
700                     NOISY(printf("Found a non-gray pixel at %d, %d = (%d %d %d %d)\n",
701                                  i, j, rr, gg, bb, aa));
702                    isGrayscale = false;
703                }
704            }
705
706            // Check if image is really opaque
707            if (isOpaque) {
708                if (aa != 0xff) {
709                    NOISY(printf("Found a non-opaque pixel at %d, %d = (%d %d %d %d)\n",
710                                 i, j, rr, gg, bb, aa));
711                    isOpaque = false;
712                }
713            }
714
715            // Check if image is really <= 256 colors
716            if (isPalette) {
717                col = (uint32_t) ((rr << 24) | (gg << 16) | (bb << 8) | aa);
718                bool match = false;
719                for (idx = 0; idx < num_colors; idx++) {
720                    if (colors[idx] == col) {
721                        match = true;
722                        break;
723                    }
724                }
725
726                // Write the palette index for the pixel to outRows optimistically
727                // We might overwrite it later if we decide to encode as gray or
728                // gray + alpha
729                *out++ = idx;
730                if (!match) {
731                    if (num_colors == 256) {
732                        NOISY(printf("Found 257th color at %d, %d\n", i, j));
733                        isPalette = false;
734                    } else {
735                        colors[num_colors++] = col;
736                    }
737                }
738            }
739        }
740    }
741
742    *paletteEntries = 0;
743    *hasTransparency = !isOpaque;
744    int bpp = isOpaque ? 3 : 4;
745    int paletteSize = w * h + bpp * num_colors;
746
747    NOISY(printf("isGrayscale = %s\n", isGrayscale ? "true" : "false"));
748    NOISY(printf("isOpaque = %s\n", isOpaque ? "true" : "false"));
749    NOISY(printf("isPalette = %s\n", isPalette ? "true" : "false"));
750    NOISY(printf("Size w/ palette = %d, gray+alpha = %d, rgb(a) = %d\n",
751                 paletteSize, 2 * w * h, bpp * w * h));
752    NOISY(printf("Max gray deviation = %d, tolerance = %d\n", maxGrayDeviation, grayscaleTolerance));
753
754    // Choose the best color type for the image.
755    // 1. Opaque gray - use COLOR_TYPE_GRAY at 1 byte/pixel
756    // 2. Gray + alpha - use COLOR_TYPE_PALETTE if the number of distinct combinations
757    //     is sufficiently small, otherwise use COLOR_TYPE_GRAY_ALPHA
758    // 3. RGB(A) - use COLOR_TYPE_PALETTE if the number of distinct colors is sufficiently
759    //     small, otherwise use COLOR_TYPE_RGB{_ALPHA}
760    if (isGrayscale) {
761        if (isOpaque) {
762            *colorType = PNG_COLOR_TYPE_GRAY; // 1 byte/pixel
763        } else {
764            // Use a simple heuristic to determine whether using a palette will
765            // save space versus using gray + alpha for each pixel.
766            // This doesn't take into account chunk overhead, filtering, LZ
767            // compression, etc.
768            if (isPalette && (paletteSize < 2 * w * h)) {
769                *colorType = PNG_COLOR_TYPE_PALETTE; // 1 byte/pixel + 4 bytes/color
770            } else {
771                *colorType = PNG_COLOR_TYPE_GRAY_ALPHA; // 2 bytes per pixel
772            }
773        }
774    } else if (isPalette && (paletteSize < bpp * w * h)) {
775        *colorType = PNG_COLOR_TYPE_PALETTE;
776    } else {
777        if (maxGrayDeviation <= grayscaleTolerance) {
778            printf("%s: forcing image to gray (max deviation = %d)\n", imageName, maxGrayDeviation);
779            *colorType = isOpaque ? PNG_COLOR_TYPE_GRAY : PNG_COLOR_TYPE_GRAY_ALPHA;
780        } else {
781            *colorType = isOpaque ? PNG_COLOR_TYPE_RGB : PNG_COLOR_TYPE_RGB_ALPHA;
782        }
783    }
784
785    // Perform postprocessing of the image or palette data based on the final
786    // color type chosen
787
788    if (*colorType == PNG_COLOR_TYPE_PALETTE) {
789        // Create separate RGB and Alpha palettes and set the number of colors
790        *paletteEntries = num_colors;
791
792        // Create the RGB and alpha palettes
793        for (int idx = 0; idx < num_colors; idx++) {
794            col = colors[idx];
795            rgbPalette[idx].red   = (png_byte) ((col >> 24) & 0xff);
796            rgbPalette[idx].green = (png_byte) ((col >> 16) & 0xff);
797            rgbPalette[idx].blue  = (png_byte) ((col >>  8) & 0xff);
798            alphaPalette[idx]     = (png_byte)  (col        & 0xff);
799        }
800    } else if (*colorType == PNG_COLOR_TYPE_GRAY || *colorType == PNG_COLOR_TYPE_GRAY_ALPHA) {
801        // If the image is gray or gray + alpha, compact the pixels into outRows
802        for (j = 0; j < h; j++) {
803            png_bytep row = imageInfo.rows[j];
804            png_bytep out = outRows[j];
805            for (i = 0; i < w; i++) {
806                rr = *row++;
807                gg = *row++;
808                bb = *row++;
809                aa = *row++;
810
811                if (isGrayscale) {
812                    *out++ = rr;
813                } else {
814                    *out++ = (png_byte) (rr * 0.2126f + gg * 0.7152f + bb * 0.0722f);
815                }
816                if (!isOpaque) {
817                    *out++ = aa;
818                }
819           }
820        }
821    }
822}
823
824
825static void write_png(const char* imageName,
826                      png_structp write_ptr, png_infop write_info,
827                      image_info& imageInfo, int grayscaleTolerance)
828{
829    bool optimize = true;
830    png_uint_32 width, height;
831    int color_type;
832    int bit_depth, interlace_type, compression_type;
833    int i;
834
835    png_unknown_chunk unknowns[1];
836
837    png_bytepp outRows = (png_bytepp) malloc((int) imageInfo.height * png_sizeof(png_bytep));
838    if (outRows == (png_bytepp) 0) {
839        printf("Can't allocate output buffer!\n");
840        exit(1);
841    }
842    for (i = 0; i < (int) imageInfo.height; i++) {
843        outRows[i] = (png_bytep) malloc(2 * (int) imageInfo.width);
844        if (outRows[i] == (png_bytep) 0) {
845            printf("Can't allocate output buffer!\n");
846            exit(1);
847        }
848    }
849
850    png_set_compression_level(write_ptr, Z_BEST_COMPRESSION);
851
852    NOISY(printf("Writing image %s: w = %d, h = %d\n", imageName,
853          (int) imageInfo.width, (int) imageInfo.height));
854
855    png_color rgbPalette[256];
856    png_byte alphaPalette[256];
857    bool hasTransparency;
858    int paletteEntries;
859
860    analyze_image(imageName, imageInfo, grayscaleTolerance, rgbPalette, alphaPalette,
861                  &paletteEntries, &hasTransparency, &color_type, outRows);
862    switch (color_type) {
863    case PNG_COLOR_TYPE_PALETTE:
864        NOISY(printf("Image %s has %d colors%s, using PNG_COLOR_TYPE_PALETTE\n",
865                     imageName, paletteEntries,
866                     hasTransparency ? " (with alpha)" : ""));
867        break;
868    case PNG_COLOR_TYPE_GRAY:
869        NOISY(printf("Image %s is opaque gray, using PNG_COLOR_TYPE_GRAY\n", imageName));
870        break;
871    case PNG_COLOR_TYPE_GRAY_ALPHA:
872        NOISY(printf("Image %s is gray + alpha, using PNG_COLOR_TYPE_GRAY_ALPHA\n", imageName));
873        break;
874    case PNG_COLOR_TYPE_RGB:
875        NOISY(printf("Image %s is opaque RGB, using PNG_COLOR_TYPE_RGB\n", imageName));
876        break;
877    case PNG_COLOR_TYPE_RGB_ALPHA:
878        NOISY(printf("Image %s is RGB + alpha, using PNG_COLOR_TYPE_RGB_ALPHA\n", imageName));
879        break;
880    }
881
882    png_set_IHDR(write_ptr, write_info, imageInfo.width, imageInfo.height,
883                 8, color_type, PNG_INTERLACE_NONE,
884                 PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
885
886    if (color_type == PNG_COLOR_TYPE_PALETTE) {
887        png_set_PLTE(write_ptr, write_info, rgbPalette, paletteEntries);
888        if (hasTransparency) {
889            png_set_tRNS(write_ptr, write_info, alphaPalette, paletteEntries, (png_color_16p) 0);
890        }
891       png_set_filter(write_ptr, 0, PNG_NO_FILTERS);
892    } else {
893       png_set_filter(write_ptr, 0, PNG_ALL_FILTERS);
894    }
895
896    if (imageInfo.is9Patch) {
897        NOISY(printf("Adding 9-patch info...\n"));
898        strcpy((char*)unknowns[0].name, "npTc");
899        unknowns[0].data = (png_byte*)imageInfo.info9Patch.serialize();
900        unknowns[0].size = imageInfo.info9Patch.serializedSize();
901        // TODO: remove the check below when everything works
902        checkNinePatchSerialization(&imageInfo.info9Patch, unknowns[0].data);
903        png_set_keep_unknown_chunks(write_ptr, PNG_HANDLE_CHUNK_ALWAYS,
904                                    (png_byte*)"npTc", 1);
905        png_set_unknown_chunks(write_ptr, write_info, unknowns, 1);
906        // XXX I can't get this to work without forcibly changing
907        // the location to what I want...  which apparently is supposed
908        // to be a private API, but everything else I have tried results
909        // in the location being set to what I -last- wrote so I never
910        // get written. :p
911        png_set_unknown_chunk_location(write_ptr, write_info, 0, PNG_HAVE_PLTE);
912    }
913
914    png_write_info(write_ptr, write_info);
915
916    png_bytepp rows;
917    if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
918        png_set_filler(write_ptr, 0, PNG_FILLER_AFTER);
919        rows = imageInfo.rows;
920    } else {
921        rows = outRows;
922    }
923    png_write_image(write_ptr, rows);
924
925//     NOISY(printf("Final image data:\n"));
926//     dump_image(imageInfo.width, imageInfo.height, rows, color_type);
927
928    png_write_end(write_ptr, write_info);
929
930    for (i = 0; i < (int) imageInfo.height; i++) {
931        free(outRows[i]);
932    }
933    free(outRows);
934
935    png_get_IHDR(write_ptr, write_info, &width, &height,
936       &bit_depth, &color_type, &interlace_type,
937       &compression_type, NULL);
938
939    NOISY(printf("Image written: w=%d, h=%d, d=%d, colors=%d, inter=%d, comp=%d\n",
940                 (int)width, (int)height, bit_depth, color_type, interlace_type,
941                 compression_type));
942}
943
944status_t preProcessImage(Bundle* bundle, const sp<AaptAssets>& assets,
945                         const sp<AaptFile>& file, String8* outNewLeafName)
946{
947    String8 ext(file->getPath().getPathExtension());
948
949    // We currently only process PNG images.
950    if (strcmp(ext.string(), ".png") != 0) {
951        return NO_ERROR;
952    }
953
954    // Example of renaming a file:
955    //*outNewLeafName = file->getPath().getBasePath().getFileName();
956    //outNewLeafName->append(".nupng");
957
958    String8 printableName(file->getPrintableSource());
959
960    png_structp read_ptr = NULL;
961    png_infop read_info = NULL;
962    FILE* fp;
963
964    image_info imageInfo;
965
966    png_structp write_ptr = NULL;
967    png_infop write_info = NULL;
968
969    status_t error = UNKNOWN_ERROR;
970
971    const size_t nameLen = file->getPath().length();
972
973    fp = fopen(file->getSourceFile().string(), "rb");
974    if (fp == NULL) {
975        fprintf(stderr, "%s: ERROR: Unable to open PNG file\n", printableName.string());
976        goto bail;
977    }
978
979    read_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, (png_error_ptr)NULL,
980                                        (png_error_ptr)NULL);
981    if (!read_ptr) {
982        goto bail;
983    }
984
985    read_info = png_create_info_struct(read_ptr);
986    if (!read_info) {
987        goto bail;
988    }
989
990    if (setjmp(png_jmpbuf(read_ptr))) {
991        goto bail;
992    }
993
994    png_init_io(read_ptr, fp);
995
996    read_png(printableName.string(), read_ptr, read_info, &imageInfo);
997
998    if (nameLen > 6) {
999        const char* name = file->getPath().string();
1000        if (name[nameLen-5] == '9' && name[nameLen-6] == '.') {
1001            if (do_9patch(printableName.string(), &imageInfo) != NO_ERROR) {
1002                goto bail;
1003            }
1004        }
1005    }
1006
1007    write_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, 0, (png_error_ptr)NULL,
1008                                        (png_error_ptr)NULL);
1009    if (!write_ptr)
1010    {
1011        goto bail;
1012    }
1013
1014    write_info = png_create_info_struct(write_ptr);
1015    if (!write_info)
1016    {
1017        goto bail;
1018    }
1019
1020    png_set_write_fn(write_ptr, (void*)file.get(),
1021                     png_write_aapt_file, png_flush_aapt_file);
1022
1023    if (setjmp(png_jmpbuf(write_ptr)))
1024    {
1025        goto bail;
1026    }
1027
1028    write_png(printableName.string(), write_ptr, write_info, imageInfo,
1029              bundle->getGrayscaleTolerance());
1030
1031    error = NO_ERROR;
1032
1033    if (bundle->getVerbose()) {
1034        fseek(fp, 0, SEEK_END);
1035        size_t oldSize = (size_t)ftell(fp);
1036        size_t newSize = file->getSize();
1037        float factor = ((float)newSize)/oldSize;
1038        int percent = (int)(factor*100);
1039        printf("    (processed image %s: %d%% size of source)\n", printableName.string(), percent);
1040    }
1041
1042bail:
1043    if (read_ptr) {
1044        png_destroy_read_struct(&read_ptr, &read_info, (png_infopp)NULL);
1045    }
1046    if (fp) {
1047        fclose(fp);
1048    }
1049    if (write_ptr) {
1050        png_destroy_write_struct(&write_ptr, &write_info);
1051    }
1052
1053    if (error != NO_ERROR) {
1054        fprintf(stderr, "ERROR: Failure processing PNG image %s\n",
1055                file->getPrintableSource().string());
1056    }
1057    return error;
1058}
1059
1060
1061
1062status_t postProcessImage(const sp<AaptAssets>& assets,
1063                          ResourceTable* table, const sp<AaptFile>& file)
1064{
1065    String8 ext(file->getPath().getPathExtension());
1066
1067    // At this point, now that we have all the resource data, all we need to
1068    // do is compile XML files.
1069    if (strcmp(ext.string(), ".xml") == 0) {
1070        return compileXmlFile(assets, file, table);
1071    }
1072
1073    return NO_ERROR;
1074}
1075