/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "util/BigBuffer.h"
#include "Png.h"
#include "Source.h"
#include "util/Util.h"
#include <androidfw/ResourceTypes.h>
#include <iostream>
#include <png.h>
#include <sstream>
#include <string>
#include <vector>
#include <zlib.h>
namespace aapt {
constexpr bool kDebug = false;
constexpr size_t kPngSignatureSize = 8u;
struct PngInfo {
~PngInfo() {
for (png_bytep row : rows) {
if (row != nullptr) {
delete[] row;
}
}
delete[] xDivs;
delete[] yDivs;
}
void* serialize9Patch() {
void* serialized = android::Res_png_9patch::serialize(info9Patch, xDivs, yDivs,
colors.data());
reinterpret_cast<android::Res_png_9patch*>(serialized)->deviceToFile();
return serialized;
}
uint32_t width = 0;
uint32_t height = 0;
std::vector<png_bytep> rows;
bool is9Patch = false;
android::Res_png_9patch info9Patch;
int32_t* xDivs = nullptr;
int32_t* yDivs = nullptr;
std::vector<uint32_t> colors;
// Layout padding.
bool haveLayoutBounds = false;
int32_t layoutBoundsLeft;
int32_t layoutBoundsTop;
int32_t layoutBoundsRight;
int32_t layoutBoundsBottom;
// Round rect outline description.
int32_t outlineInsetsLeft;
int32_t outlineInsetsTop;
int32_t outlineInsetsRight;
int32_t outlineInsetsBottom;
float outlineRadius;
uint8_t outlineAlpha;
};
static void readDataFromStream(png_structp readPtr, png_bytep data, png_size_t length) {
std::istream* input = reinterpret_cast<std::istream*>(png_get_io_ptr(readPtr));
if (!input->read(reinterpret_cast<char*>(data), length)) {
png_error(readPtr, strerror(errno));
}
}
static void writeDataToStream(png_structp writePtr, png_bytep data, png_size_t length) {
BigBuffer* outBuffer = reinterpret_cast<BigBuffer*>(png_get_io_ptr(writePtr));
png_bytep buf = outBuffer->nextBlock<png_byte>(length);
memcpy(buf, data, length);
}
static void flushDataToStream(png_structp /*writePtr*/) {
}
static void logWarning(png_structp readPtr, png_const_charp warningMessage) {
IDiagnostics* diag = reinterpret_cast<IDiagnostics*>(png_get_error_ptr(readPtr));
diag->warn(DiagMessage() << warningMessage);
}
static bool readPng(IDiagnostics* diag, png_structp readPtr, png_infop infoPtr, PngInfo* outInfo) {
if (setjmp(png_jmpbuf(readPtr))) {
diag->error(DiagMessage() << "failed reading png");
return false;
}
png_set_sig_bytes(readPtr, kPngSignatureSize);
png_read_info(readPtr, infoPtr);
int colorType, bitDepth, interlaceType, compressionType;
png_get_IHDR(readPtr, infoPtr, &outInfo->width, &outInfo->height, &bitDepth, &colorType,
&interlaceType, &compressionType, nullptr);
if (colorType == PNG_COLOR_TYPE_PALETTE) {
png_set_palette_to_rgb(readPtr);
}
if (colorType == PNG_COLOR_TYPE_GRAY && bitDepth < 8) {
png_set_expand_gray_1_2_4_to_8(readPtr);
}
if (png_get_valid(readPtr, infoPtr, PNG_INFO_tRNS)) {
png_set_tRNS_to_alpha(readPtr);
}
if (bitDepth == 16) {
png_set_strip_16(readPtr);
}
if (!(colorType & PNG_COLOR_MASK_ALPHA)) {
png_set_add_alpha(readPtr, 0xFF, PNG_FILLER_AFTER);
}
if (colorType == PNG_COLOR_TYPE_GRAY || colorType == PNG_COLOR_TYPE_GRAY_ALPHA) {
png_set_gray_to_rgb(readPtr);
}
png_set_interlace_handling(readPtr);
png_read_update_info(readPtr, infoPtr);
const uint32_t rowBytes = png_get_rowbytes(readPtr, infoPtr);
outInfo->rows.resize(outInfo->height);
for (size_t i = 0; i < outInfo->height; i++) {
outInfo->rows[i] = new png_byte[rowBytes];
}
png_read_image(readPtr, outInfo->rows.data());
png_read_end(readPtr, infoPtr);
return true;
}
static void checkNinePatchSerialization(android::Res_png_9patch* inPatch, void* data) {
size_t patchSize = inPatch->serializedSize();
void* newData = malloc(patchSize);
memcpy(newData, data, patchSize);
android::Res_png_9patch* outPatch = inPatch->deserialize(newData);
outPatch->fileToDevice();
// deserialization is done in place, so outPatch == newData
assert(outPatch == newData);
assert(outPatch->numXDivs == inPatch->numXDivs);
assert(outPatch->numYDivs == inPatch->numYDivs);
assert(outPatch->paddingLeft == inPatch->paddingLeft);
assert(outPatch->paddingRight == inPatch->paddingRight);
assert(outPatch->paddingTop == inPatch->paddingTop);
assert(outPatch->paddingBottom == inPatch->paddingBottom);
/* for (int i = 0; i < outPatch->numXDivs; i++) {
assert(outPatch->getXDivs()[i] == inPatch->getXDivs()[i]);
}
for (int i = 0; i < outPatch->numYDivs; i++) {
assert(outPatch->getYDivs()[i] == inPatch->getYDivs()[i]);
}
for (int i = 0; i < outPatch->numColors; i++) {
assert(outPatch->getColors()[i] == inPatch->getColors()[i]);
}*/
free(newData);
}
/*static void dump_image(int w, int h, const png_byte* const* rows, int color_type) {
int i, j, rr, gg, bb, aa;
int bpp;
if (color_type == PNG_COLOR_TYPE_PALETTE || color_type == PNG_COLOR_TYPE_GRAY) {
bpp = 1;
} else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
bpp = 2;
} else if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
// We use a padding byte even when there is no alpha
bpp = 4;
} else {
printf("Unknown color type %d.\n", color_type);
}
for (j = 0; j < h; j++) {
const png_byte* row = rows[j];
for (i = 0; i < w; i++) {
rr = row[0];
gg = row[1];
bb = row[2];
aa = row[3];
row += bpp;
if (i == 0) {
printf("Row %d:", j);
}
switch (bpp) {
case 1:
printf(" (%d)", rr);
break;
case 2:
printf(" (%d %d", rr, gg);
break;
case 3:
printf(" (%d %d %d)", rr, gg, bb);
break;
case 4:
printf(" (%d %d %d %d)", rr, gg, bb, aa);
break;
}
if (i == (w - 1)) {
printf("\n");
}
}
}
}*/
#define MAX(a,b) ((a)>(b)?(a):(b))
#define ABS(a) ((a)<0?-(a):(a))
static void analyze_image(IDiagnostics* diag, const PngInfo& imageInfo, int grayscaleTolerance,
png_colorp rgbPalette, png_bytep alphaPalette,
int *paletteEntries, bool *hasTransparency, int *colorType,
png_bytepp outRows) {
int w = imageInfo.width;
int h = imageInfo.height;
int i, j, rr, gg, bb, aa, idx;
uint32_t colors[256], col;
int num_colors = 0;
int maxGrayDeviation = 0;
bool isOpaque = true;
bool isPalette = true;
bool isGrayscale = true;
// Scan the entire image and determine if:
// 1. Every pixel has R == G == B (grayscale)
// 2. Every pixel has A == 255 (opaque)
// 3. There are no more than 256 distinct RGBA colors
if (kDebug) {
printf("Initial image data:\n");
//dump_image(w, h, imageInfo.rows.data(), PNG_COLOR_TYPE_RGB_ALPHA);
}
for (j = 0; j < h; j++) {
const png_byte* row = imageInfo.rows[j];
png_bytep out = outRows[j];
for (i = 0; i < w; i++) {
rr = *row++;
gg = *row++;
bb = *row++;
aa = *row++;
int odev = maxGrayDeviation;
maxGrayDeviation = MAX(ABS(rr - gg), maxGrayDeviation);
maxGrayDeviation = MAX(ABS(gg - bb), maxGrayDeviation);
maxGrayDeviation = MAX(ABS(bb - rr), maxGrayDeviation);
if (maxGrayDeviation > odev) {
if (kDebug) {
printf("New max dev. = %d at pixel (%d, %d) = (%d %d %d %d)\n",
maxGrayDeviation, i, j, rr, gg, bb, aa);
}
}
// Check if image is really grayscale
if (isGrayscale) {
if (rr != gg || rr != bb) {
if (kDebug) {
printf("Found a non-gray pixel at %d, %d = (%d %d %d %d)\n",
i, j, rr, gg, bb, aa);
}
isGrayscale = false;
}
}
// Check if image is really opaque
if (isOpaque) {
if (aa != 0xff) {
if (kDebug) {
printf("Found a non-opaque pixel at %d, %d = (%d %d %d %d)\n",
i, j, rr, gg, bb, aa);
}
isOpaque = false;
}
}
// Check if image is really <= 256 colors
if (isPalette) {
col = (uint32_t) ((rr << 24) | (gg << 16) | (bb << 8) | aa);
bool match = false;
for (idx = 0; idx < num_colors; idx++) {
if (colors[idx] == col) {
match = true;
break;
}
}
// Write the palette index for the pixel to outRows optimistically
// We might overwrite it later if we decide to encode as gray or
// gray + alpha
*out++ = idx;
if (!match) {
if (num_colors == 256) {
if (kDebug) {
printf("Found 257th color at %d, %d\n", i, j);
}
isPalette = false;
} else {
colors[num_colors++] = col;
}
}
}
}
}
*paletteEntries = 0;
*hasTransparency = !isOpaque;
int bpp = isOpaque ? 3 : 4;
int paletteSize = w * h + bpp * num_colors;
if (kDebug) {
printf("isGrayscale = %s\n", isGrayscale ? "true" : "false");
printf("isOpaque = %s\n", isOpaque ? "true" : "false");
printf("isPalette = %s\n", isPalette ? "true" : "false");
printf("Size w/ palette = %d, gray+alpha = %d, rgb(a) = %d\n",
paletteSize, 2 * w * h, bpp * w * h);
printf("Max gray deviation = %d, tolerance = %d\n", maxGrayDeviation, grayscaleTolerance);
}
// Choose the best color type for the image.
// 1. Opaque gray - use COLOR_TYPE_GRAY at 1 byte/pixel
// 2. Gray + alpha - use COLOR_TYPE_PALETTE if the number of distinct combinations
// is sufficiently small, otherwise use COLOR_TYPE_GRAY_ALPHA
// 3. RGB(A) - use COLOR_TYPE_PALETTE if the number of distinct colors is sufficiently
// small, otherwise use COLOR_TYPE_RGB{_ALPHA}
if (isGrayscale) {
if (isOpaque) {
*colorType = PNG_COLOR_TYPE_GRAY; // 1 byte/pixel
} else {
// Use a simple heuristic to determine whether using a palette will
// save space versus using gray + alpha for each pixel.
// This doesn't take into account chunk overhead, filtering, LZ
// compression, etc.
if (isPalette && (paletteSize < 2 * w * h)) {
*colorType = PNG_COLOR_TYPE_PALETTE; // 1 byte/pixel + 4 bytes/color
} else {
*colorType = PNG_COLOR_TYPE_GRAY_ALPHA; // 2 bytes per pixel
}
}
} else if (isPalette && (paletteSize < bpp * w * h)) {
*colorType = PNG_COLOR_TYPE_PALETTE;
} else {
if (maxGrayDeviation <= grayscaleTolerance) {
diag->note(DiagMessage()
<< "forcing image to gray (max deviation = "
<< maxGrayDeviation << ")");
*colorType = isOpaque ? PNG_COLOR_TYPE_GRAY : PNG_COLOR_TYPE_GRAY_ALPHA;
} else {
*colorType = isOpaque ? PNG_COLOR_TYPE_RGB : PNG_COLOR_TYPE_RGB_ALPHA;
}
}
// Perform postprocessing of the image or palette data based on the final
// color type chosen
if (*colorType == PNG_COLOR_TYPE_PALETTE) {
// Create separate RGB and Alpha palettes and set the number of colors
*paletteEntries = num_colors;
// Create the RGB and alpha palettes
for (int idx = 0; idx < num_colors; idx++) {
col = colors[idx];
rgbPalette[idx].red = (png_byte) ((col >> 24) & 0xff);
rgbPalette[idx].green = (png_byte) ((col >> 16) & 0xff);
rgbPalette[idx].blue = (png_byte) ((col >> 8) & 0xff);
alphaPalette[idx] = (png_byte) (col & 0xff);
}
} else if (*colorType == PNG_COLOR_TYPE_GRAY || *colorType == PNG_COLOR_TYPE_GRAY_ALPHA) {
// If the image is gray or gray + alpha, compact the pixels into outRows
for (j = 0; j < h; j++) {
const png_byte* row = imageInfo.rows[j];
png_bytep out = outRows[j];
for (i = 0; i < w; i++) {
rr = *row++;
gg = *row++;
bb = *row++;
aa = *row++;
if (isGrayscale) {
*out++ = rr;
} else {
*out++ = (png_byte) (rr * 0.2126f + gg * 0.7152f + bb * 0.0722f);
}
if (!isOpaque) {
*out++ = aa;
}
}
}
}
}
static bool writePng(IDiagnostics* diag, png_structp writePtr, png_infop infoPtr, PngInfo* info,
int grayScaleTolerance) {
if (setjmp(png_jmpbuf(writePtr))) {
diag->error(DiagMessage() << "failed to write png");
return false;
}
uint32_t width, height;
int colorType, bitDepth, interlaceType, compressionType;
png_unknown_chunk unknowns[3];
unknowns[0].data = nullptr;
unknowns[1].data = nullptr;
unknowns[2].data = nullptr;
png_bytepp outRows = (png_bytepp) malloc((int) info->height * sizeof(png_bytep));
if (outRows == (png_bytepp) 0) {
printf("Can't allocate output buffer!\n");
exit(1);
}
for (uint32_t i = 0; i < info->height; i++) {
outRows[i] = (png_bytep) malloc(2 * (int) info->width);
if (outRows[i] == (png_bytep) 0) {
printf("Can't allocate output buffer!\n");
exit(1);
}
}
png_set_compression_level(writePtr, Z_BEST_COMPRESSION);
if (kDebug) {
diag->note(DiagMessage()
<< "writing image: w = " << info->width
<< ", h = " << info->height);
}
png_color rgbPalette[256];
png_byte alphaPalette[256];
bool hasTransparency;
int paletteEntries;
analyze_image(diag, *info, grayScaleTolerance, rgbPalette, alphaPalette,
&paletteEntries, &hasTransparency, &colorType, outRows);
// If the image is a 9-patch, we need to preserve it as a ARGB file to make
// sure the pixels will not be pre-dithered/clamped until we decide they are
if (info->is9Patch && (colorType == PNG_COLOR_TYPE_RGB ||
colorType == PNG_COLOR_TYPE_GRAY || colorType == PNG_COLOR_TYPE_PALETTE)) {
colorType = PNG_COLOR_TYPE_RGB_ALPHA;
}
if (kDebug) {
switch (colorType) {
case PNG_COLOR_TYPE_PALETTE:
diag->note(DiagMessage()
<< "has " << paletteEntries
<< " colors" << (hasTransparency ? " (with alpha)" : "")
<< ", using PNG_COLOR_TYPE_PALLETTE");
break;
case PNG_COLOR_TYPE_GRAY:
diag->note(DiagMessage() << "is opaque gray, using PNG_COLOR_TYPE_GRAY");
break;
case PNG_COLOR_TYPE_GRAY_ALPHA:
diag->note(DiagMessage() << "is gray + alpha, using PNG_COLOR_TYPE_GRAY_ALPHA");
break;
case PNG_COLOR_TYPE_RGB:
diag->note(DiagMessage() << "is opaque RGB, using PNG_COLOR_TYPE_RGB");
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
diag->note(DiagMessage() << "is RGB + alpha, using PNG_COLOR_TYPE_RGB_ALPHA");
break;
}
}
png_set_IHDR(writePtr, infoPtr, info->width, info->height, 8, colorType,
PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
if (colorType == PNG_COLOR_TYPE_PALETTE) {
png_set_PLTE(writePtr, infoPtr, rgbPalette, paletteEntries);
if (hasTransparency) {
png_set_tRNS(writePtr, infoPtr, alphaPalette, paletteEntries, (png_color_16p) 0);
}
png_set_filter(writePtr, 0, PNG_NO_FILTERS);
} else {
png_set_filter(writePtr, 0, PNG_ALL_FILTERS);
}
if (info->is9Patch) {
int chunkCount = 2 + (info->haveLayoutBounds ? 1 : 0);
int pIndex = info->haveLayoutBounds ? 2 : 1;
int bIndex = 1;
int oIndex = 0;
// Chunks ordered thusly because older platforms depend on the base 9 patch data being last
png_bytep chunkNames = info->haveLayoutBounds
? (png_bytep)"npOl\0npLb\0npTc\0"
: (png_bytep)"npOl\0npTc";
// base 9 patch data
if (kDebug) {
diag->note(DiagMessage() << "adding 9-patch info..");
}
strcpy((char*)unknowns[pIndex].name, "npTc");
unknowns[pIndex].data = (png_byte*) info->serialize9Patch();
unknowns[pIndex].size = info->info9Patch.serializedSize();
// TODO: remove the check below when everything works
checkNinePatchSerialization(&info->info9Patch, unknowns[pIndex].data);
// automatically generated 9 patch outline data
int chunkSize = sizeof(png_uint_32) * 6;
strcpy((char*)unknowns[oIndex].name, "npOl");
unknowns[oIndex].data = (png_byte*) calloc(chunkSize, 1);
png_byte outputData[chunkSize];
memcpy(&outputData, &info->outlineInsetsLeft, 4 * sizeof(png_uint_32));
((float*) outputData)[4] = info->outlineRadius;
((png_uint_32*) outputData)[5] = info->outlineAlpha;
memcpy(unknowns[oIndex].data, &outputData, chunkSize);
unknowns[oIndex].size = chunkSize;
// optional optical inset / layout bounds data
if (info->haveLayoutBounds) {
int chunkSize = sizeof(png_uint_32) * 4;
strcpy((char*)unknowns[bIndex].name, "npLb");
unknowns[bIndex].data = (png_byte*) calloc(chunkSize, 1);
memcpy(unknowns[bIndex].data, &info->layoutBoundsLeft, chunkSize);
unknowns[bIndex].size = chunkSize;
}
for (int i = 0; i < chunkCount; i++) {
unknowns[i].location = PNG_HAVE_PLTE;
}
png_set_keep_unknown_chunks(writePtr, PNG_HANDLE_CHUNK_ALWAYS,
chunkNames, chunkCount);
png_set_unknown_chunks(writePtr, infoPtr, unknowns, chunkCount);
#if PNG_LIBPNG_VER < 10600
// Deal with unknown chunk location bug in 1.5.x and earlier.
png_set_unknown_chunk_location(writePtr, infoPtr, 0, PNG_HAVE_PLTE);
if (info->haveLayoutBounds) {
png_set_unknown_chunk_location(writePtr, infoPtr, 1, PNG_HAVE_PLTE);
}
#endif
}
png_write_info(writePtr, infoPtr);
png_bytepp rows;
if (colorType == PNG_COLOR_TYPE_RGB || colorType == PNG_COLOR_TYPE_RGB_ALPHA) {
if (colorType == PNG_COLOR_TYPE_RGB) {
png_set_filler(writePtr, 0, PNG_FILLER_AFTER);
}
rows = info->rows.data();
} else {
rows = outRows;
}
png_write_image(writePtr, rows);
if (kDebug) {
printf("Final image data:\n");
//dump_image(info->width, info->height, rows, colorType);
}
png_write_end(writePtr, infoPtr);
for (uint32_t i = 0; i < info->height; i++) {
free(outRows[i]);
}
free(outRows);
free(unknowns[0].data);
free(unknowns[1].data);
free(unknowns[2].data);
png_get_IHDR(writePtr, infoPtr, &width, &height, &bitDepth, &colorType, &interlaceType,
&compressionType, nullptr);
if (kDebug) {
diag->note(DiagMessage()
<< "image written: w = " << width << ", h = " << height
<< ", d = " << bitDepth << ", colors = " << colorType
<< ", inter = " << interlaceType << ", comp = " << compressionType);
}
return true;
}
constexpr uint32_t kColorWhite = 0xffffffffu;
constexpr uint32_t kColorTick = 0xff000000u;
constexpr uint32_t kColorLayoutBoundsTick = 0xff0000ffu;
enum class TickType {
kNone,
kTick,
kLayoutBounds,
kBoth
};
static TickType tickType(png_bytep p, bool transparent, const char** outError) {
png_uint_32 color = p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
if (transparent) {
if (p[3] == 0) {
return TickType::kNone;
}
if (color == kColorLayoutBoundsTick) {
return TickType::kLayoutBounds;
}
if (color == kColorTick) {
return TickType::kTick;
}
// Error cases
if (p[3] != 0xff) {
*outError = "Frame pixels must be either solid or transparent "
"(not intermediate alphas)";
return TickType::kNone;
}
if (p[0] != 0 || p[1] != 0 || p[2] != 0) {
*outError = "Ticks in transparent frame must be black or red";
}
return TickType::kTick;
}
if (p[3] != 0xFF) {
*outError = "White frame must be a solid color (no alpha)";
}
if (color == kColorWhite) {
return TickType::kNone;
}
if (color == kColorTick) {
return TickType::kTick;
}
if (color == kColorLayoutBoundsTick) {
return TickType::kLayoutBounds;
}
if (p[0] != 0 || p[1] != 0 || p[2] != 0) {
*outError = "Ticks in white frame must be black or red";
return TickType::kNone;
}
return TickType::kTick;
}
enum class TickState {
kStart,
kInside1,
kOutside1
};
static bool getHorizontalTicks(png_bytep row, int width, bool transparent, bool required,
int32_t* outLeft, int32_t* outRight, const char** outError,
uint8_t* outDivs, bool multipleAllowed) {
*outLeft = *outRight = -1;
TickState state = TickState::kStart;
bool found = false;
for (int i = 1; i < width - 1; i++) {
if (tickType(row+i*4, transparent, outError) == TickType::kTick) {
if (state == TickState::kStart ||
(state == TickState::kOutside1 && multipleAllowed)) {
*outLeft = i-1;
*outRight = width-2;
found = true;
if (outDivs != NULL) {
*outDivs += 2;
}
state = TickState::kInside1;
} else if (state == TickState::kOutside1) {
*outError = "Can't have more than one marked region along edge";
*outLeft = i;
return false;
}
} else if (!*outError) {
if (state == TickState::kInside1) {
// We're done with this div. Move on to the next.
*outRight = i-1;
outRight += 2;
outLeft += 2;
state = TickState::kOutside1;
}
} else {
*outLeft = i;
return false;
}
}
if (required && !found) {
*outError = "No marked region found along edge";
*outLeft = -1;
return false;
}
return true;
}
static bool getVerticalTicks(png_bytepp rows, int offset, int height, bool transparent,
bool required, int32_t* outTop, int32_t* outBottom,
const char** outError, uint8_t* outDivs, bool multipleAllowed) {
*outTop = *outBottom = -1;
TickState state = TickState::kStart;
bool found = false;
for (int i = 1; i < height - 1; i++) {
if (tickType(rows[i]+offset, transparent, outError) == TickType::kTick) {
if (state == TickState::kStart ||
(state == TickState::kOutside1 && multipleAllowed)) {
*outTop = i-1;
*outBottom = height-2;
found = true;
if (outDivs != NULL) {
*outDivs += 2;
}
state = TickState::kInside1;
} else if (state == TickState::kOutside1) {
*outError = "Can't have more than one marked region along edge";
*outTop = i;
return false;
}
} else if (!*outError) {
if (state == TickState::kInside1) {
// We're done with this div. Move on to the next.
*outBottom = i-1;
outTop += 2;
outBottom += 2;
state = TickState::kOutside1;
}
} else {
*outTop = i;
return false;
}
}
if (required && !found) {
*outError = "No marked region found along edge";
*outTop = -1;
return false;
}
return true;
}
static bool getHorizontalLayoutBoundsTicks(png_bytep row, int width, bool transparent,
bool /* required */, int32_t* outLeft,
int32_t* outRight, const char** outError) {
*outLeft = *outRight = 0;
// Look for left tick
if (tickType(row + 4, transparent, outError) == TickType::kLayoutBounds) {
// Starting with a layout padding tick
int i = 1;
while (i < width - 1) {
(*outLeft)++;
i++;
if (tickType(row + i * 4, transparent, outError) != TickType::kLayoutBounds) {
break;
}
}
}
// Look for right tick
if (tickType(row + (width - 2) * 4, transparent, outError) == TickType::kLayoutBounds) {
// Ending with a layout padding tick
int i = width - 2;
while (i > 1) {
(*outRight)++;
i--;
if (tickType(row+i*4, transparent, outError) != TickType::kLayoutBounds) {
break;
}
}
}
return true;
}
static bool getVerticalLayoutBoundsTicks(png_bytepp rows, int offset, int height, bool transparent,
bool /* required */, int32_t* outTop, int32_t* outBottom,
const char** outError) {
*outTop = *outBottom = 0;
// Look for top tick
if (tickType(rows[1] + offset, transparent, outError) == TickType::kLayoutBounds) {
// Starting with a layout padding tick
int i = 1;
while (i < height - 1) {
(*outTop)++;
i++;
if (tickType(rows[i] + offset, transparent, outError) != TickType::kLayoutBounds) {
break;
}
}
}
// Look for bottom tick
if (tickType(rows[height - 2] + offset, transparent, outError) == TickType::kLayoutBounds) {
// Ending with a layout padding tick
int i = height - 2;
while (i > 1) {
(*outBottom)++;
i--;
if (tickType(rows[i] + offset, transparent, outError) != TickType::kLayoutBounds) {
break;
}
}
}
return true;
}
static void findMaxOpacity(png_bytepp rows, int startX, int startY, int endX, int endY,
int dX, int dY, int* outInset) {
uint8_t maxOpacity = 0;
int inset = 0;
*outInset = 0;
for (int x = startX, y = startY; x != endX && y != endY; x += dX, y += dY, inset++) {
png_byte* color = rows[y] + x * 4;
uint8_t opacity = color[3];
if (opacity > maxOpacity) {
maxOpacity = opacity;
*outInset = inset;
}
if (opacity == 0xff) return;
}
}
static uint8_t maxAlphaOverRow(png_bytep row, int startX, int endX) {
uint8_t maxAlpha = 0;
for (int x = startX; x < endX; x++) {
uint8_t alpha = (row + x * 4)[3];
if (alpha > maxAlpha) maxAlpha = alpha;
}
return maxAlpha;
}
static uint8_t maxAlphaOverCol(png_bytepp rows, int offsetX, int startY, int endY) {
uint8_t maxAlpha = 0;
for (int y = startY; y < endY; y++) {
uint8_t alpha = (rows[y] + offsetX * 4)[3];
if (alpha > maxAlpha) maxAlpha = alpha;
}
return maxAlpha;
}
static void getOutline(PngInfo* image) {
int midX = image->width / 2;
int midY = image->height / 2;
int endX = image->width - 2;
int endY = image->height - 2;
// find left and right extent of nine patch content on center row
if (image->width > 4) {
findMaxOpacity(image->rows.data(), 1, midY, midX, -1, 1, 0, &image->outlineInsetsLeft);
findMaxOpacity(image->rows.data(), endX, midY, midX, -1, -1, 0,
&image->outlineInsetsRight);
} else {
image->outlineInsetsLeft = 0;
image->outlineInsetsRight = 0;
}
// find top and bottom extent of nine patch content on center column
if (image->height > 4) {
findMaxOpacity(image->rows.data(), midX, 1, -1, midY, 0, 1, &image->outlineInsetsTop);
findMaxOpacity(image->rows.data(), midX, endY, -1, midY, 0, -1,
&image->outlineInsetsBottom);
} else {
image->outlineInsetsTop = 0;
image->outlineInsetsBottom = 0;
}
int innerStartX = 1 + image->outlineInsetsLeft;
int innerStartY = 1 + image->outlineInsetsTop;
int innerEndX = endX - image->outlineInsetsRight;
int innerEndY = endY - image->outlineInsetsBottom;
int innerMidX = (innerEndX + innerStartX) / 2;
int innerMidY = (innerEndY + innerStartY) / 2;
// assuming the image is a round rect, compute the radius by marching
// diagonally from the top left corner towards the center
image->outlineAlpha = std::max(
maxAlphaOverRow(image->rows[innerMidY], innerStartX, innerEndX),
maxAlphaOverCol(image->rows.data(), innerMidX, innerStartY, innerStartY));
int diagonalInset = 0;
findMaxOpacity(image->rows.data(), innerStartX, innerStartY, innerMidX, innerMidY, 1, 1,
&diagonalInset);
/* Determine source radius based upon inset:
* sqrt(r^2 + r^2) = sqrt(i^2 + i^2) + r
* sqrt(2) * r = sqrt(2) * i + r
* (sqrt(2) - 1) * r = sqrt(2) * i
* r = sqrt(2) / (sqrt(2) - 1) * i
*/
image->outlineRadius = 3.4142f * diagonalInset;
if (kDebug) {
printf("outline insets %d %d %d %d, rad %f, alpha %x\n",
image->outlineInsetsLeft,
image->outlineInsetsTop,
image->outlineInsetsRight,
image->outlineInsetsBottom,
image->outlineRadius,
image->outlineAlpha);
}
}
static uint32_t getColor(png_bytepp rows, int left, int top, int right, int bottom) {
png_bytep color = rows[top] + left*4;
if (left > right || top > bottom) {
return android::Res_png_9patch::TRANSPARENT_COLOR;
}
while (top <= bottom) {
for (int i = left; i <= right; i++) {
png_bytep p = rows[top]+i*4;
if (color[3] == 0) {
if (p[3] != 0) {
return android::Res_png_9patch::NO_COLOR;
}
} else if (p[0] != color[0] || p[1] != color[1] ||
p[2] != color[2] || p[3] != color[3]) {
return android::Res_png_9patch::NO_COLOR;
}
}
top++;
}
if (color[3] == 0) {
return android::Res_png_9patch::TRANSPARENT_COLOR;
}
return (color[3]<<24) | (color[0]<<16) | (color[1]<<8) | color[2];
}
static bool do9Patch(PngInfo* image, std::string* outError) {
image->is9Patch = true;
int W = image->width;
int H = image->height;
int i, j;
const int maxSizeXDivs = W * sizeof(int32_t);
const int maxSizeYDivs = H * sizeof(int32_t);
int32_t* xDivs = image->xDivs = new int32_t[W];
int32_t* yDivs = image->yDivs = new int32_t[H];
uint8_t numXDivs = 0;
uint8_t numYDivs = 0;
int8_t numColors;
int numRows;
int numCols;
int top;
int left;
int right;
int bottom;
memset(xDivs, -1, maxSizeXDivs);
memset(yDivs, -1, maxSizeYDivs);
image->info9Patch.paddingLeft = image->info9Patch.paddingRight = -1;
image->info9Patch.paddingTop = image->info9Patch.paddingBottom = -1;
image->layoutBoundsLeft = image->layoutBoundsRight = 0;
image->layoutBoundsTop = image->layoutBoundsBottom = 0;
png_bytep p = image->rows[0];
bool transparent = p[3] == 0;
bool hasColor = false;
const char* errorMsg = nullptr;
int errorPixel = -1;
const char* errorEdge = nullptr;
int colorIndex = 0;
std::vector<png_bytep> newRows;
// Validate size...
if (W < 3 || H < 3) {
errorMsg = "Image must be at least 3x3 (1x1 without frame) pixels";
goto getout;
}
// Validate frame...
if (!transparent &&
(p[0] != 0xFF || p[1] != 0xFF || p[2] != 0xFF || p[3] != 0xFF)) {
errorMsg = "Must have one-pixel frame that is either transparent or white";
goto getout;
}
// Find left and right of sizing areas...
if (!getHorizontalTicks(p, W, transparent, true, &xDivs[0], &xDivs[1], &errorMsg, &numXDivs,
true)) {
errorPixel = xDivs[0];
errorEdge = "top";
goto getout;
}
// Find top and bottom of sizing areas...
if (!getVerticalTicks(image->rows.data(), 0, H, transparent, true, &yDivs[0], &yDivs[1],
&errorMsg, &numYDivs, true)) {
errorPixel = yDivs[0];
errorEdge = "left";
goto getout;
}
// Copy patch size data into image...
image->info9Patch.numXDivs = numXDivs;
image->info9Patch.numYDivs = numYDivs;
// Find left and right of padding area...
if (!getHorizontalTicks(image->rows[H-1], W, transparent, false,
&image->info9Patch.paddingLeft, &image->info9Patch.paddingRight,
&errorMsg, nullptr, false)) {
errorPixel = image->info9Patch.paddingLeft;
errorEdge = "bottom";
goto getout;
}
// Find top and bottom of padding area...
if (!getVerticalTicks(image->rows.data(), (W-1)*4, H, transparent, false,
&image->info9Patch.paddingTop, &image->info9Patch.paddingBottom,
&errorMsg, nullptr, false)) {
errorPixel = image->info9Patch.paddingTop;
errorEdge = "right";
goto getout;
}
// Find left and right of layout padding...
getHorizontalLayoutBoundsTicks(image->rows[H-1], W, transparent, false,
&image->layoutBoundsLeft, &image->layoutBoundsRight, &errorMsg);
getVerticalLayoutBoundsTicks(image->rows.data(), (W-1)*4, H, transparent, false,
&image->layoutBoundsTop, &image->layoutBoundsBottom, &errorMsg);
image->haveLayoutBounds = image->layoutBoundsLeft != 0
|| image->layoutBoundsRight != 0
|| image->layoutBoundsTop != 0
|| image->layoutBoundsBottom != 0;
if (image->haveLayoutBounds) {
if (kDebug) {
printf("layoutBounds=%d %d %d %d\n", image->layoutBoundsLeft, image->layoutBoundsTop,
image->layoutBoundsRight, image->layoutBoundsBottom);
}
}
// use opacity of pixels to estimate the round rect outline
getOutline(image);
// If padding is not yet specified, take values from size.
if (image->info9Patch.paddingLeft < 0) {
image->info9Patch.paddingLeft = xDivs[0];
image->info9Patch.paddingRight = W - 2 - xDivs[1];
} else {
// Adjust value to be correct!
image->info9Patch.paddingRight = W - 2 - image->info9Patch.paddingRight;
}
if (image->info9Patch.paddingTop < 0) {
image->info9Patch.paddingTop = yDivs[0];
image->info9Patch.paddingBottom = H - 2 - yDivs[1];
} else {
// Adjust value to be correct!
image->info9Patch.paddingBottom = H - 2 - image->info9Patch.paddingBottom;
}
/* if (kDebug) {
printf("Size ticks for %s: x0=%d, x1=%d, y0=%d, y1=%d\n", imageName,
xDivs[0], xDivs[1],
yDivs[0], yDivs[1]);
printf("padding ticks for %s: l=%d, r=%d, t=%d, b=%d\n", imageName,
image->info9Patch.paddingLeft, image->info9Patch.paddingRight,
image->info9Patch.paddingTop, image->info9Patch.paddingBottom);
}*/
// Remove frame from image.
newRows.resize(H - 2);
for (i = 0; i < H - 2; i++) {
newRows[i] = image->rows[i + 1];
memmove(newRows[i], newRows[i] + 4, (W - 2) * 4);
}
image->rows.swap(newRows);
image->width -= 2;
W = image->width;
image->height -= 2;
H = image->height;
// Figure out the number of rows and columns in the N-patch
numCols = numXDivs + 1;
if (xDivs[0] == 0) { // Column 1 is strechable
numCols--;
}
if (xDivs[numXDivs - 1] == W) {
numCols--;
}
numRows = numYDivs + 1;
if (yDivs[0] == 0) { // Row 1 is strechable
numRows--;
}
if (yDivs[numYDivs - 1] == H) {
numRows--;
}
// Make sure the amount of rows and columns will fit in the number of
// colors we can use in the 9-patch format.
if (numRows * numCols > 0x7F) {
errorMsg = "Too many rows and columns in 9-patch perimeter";
goto getout;
}
numColors = numRows * numCols;
image->info9Patch.numColors = numColors;
image->colors.resize(numColors);
// Fill in color information for each patch.
uint32_t c;
top = 0;
// The first row always starts with the top being at y=0 and the bottom
// being either yDivs[1] (if yDivs[0]=0) of yDivs[0]. In the former case
// the first row is stretchable along the Y axis, otherwise it is fixed.
// The last row always ends with the bottom being bitmap.height and the top
// being either yDivs[numYDivs-2] (if yDivs[numYDivs-1]=bitmap.height) or
// yDivs[numYDivs-1]. In the former case the last row is stretchable along
// the Y axis, otherwise it is fixed.
//
// The first and last columns are similarly treated with respect to the X
// axis.
//
// The above is to help explain some of the special casing that goes on the
// code below.
// The initial yDiv and whether the first row is considered stretchable or
// not depends on whether yDiv[0] was zero or not.
for (j = (yDivs[0] == 0 ? 1 : 0); j <= numYDivs && top < H; j++) {
if (j == numYDivs) {
bottom = H;
} else {
bottom = yDivs[j];
}
left = 0;
// The initial xDiv and whether the first column is considered
// stretchable or not depends on whether xDiv[0] was zero or not.
for (i = xDivs[0] == 0 ? 1 : 0; i <= numXDivs && left < W; i++) {
if (i == numXDivs) {
right = W;
} else {
right = xDivs[i];
}
c = getColor(image->rows.data(), left, top, right - 1, bottom - 1);
image->colors[colorIndex++] = c;
if (kDebug) {
if (c != android::Res_png_9patch::NO_COLOR) {
hasColor = true;
}
}
left = right;
}
top = bottom;
}
assert(colorIndex == numColors);
if (kDebug && hasColor) {
for (i = 0; i < numColors; i++) {
if (i == 0) printf("Colors:\n");
printf(" #%08x", image->colors[i]);
if (i == numColors - 1) printf("\n");
}
}
getout:
if (errorMsg) {
std::stringstream err;
err << "9-patch malformed: " << errorMsg;
if (errorEdge) {
err << "." << std::endl;
if (errorPixel >= 0) {
err << "Found at pixel #" << errorPixel << " along " << errorEdge << " edge";
} else {
err << "Found along " << errorEdge << " edge";
}
}
*outError = err.str();
return false;
}
return true;
}
bool Png::process(const Source& source, std::istream* input, BigBuffer* outBuffer,
const PngOptions& options) {
png_byte signature[kPngSignatureSize];
// Read the PNG signature first.
if (!input->read(reinterpret_cast<char*>(signature), kPngSignatureSize)) {
mDiag->error(DiagMessage() << strerror(errno));
return false;
}
// If the PNG signature doesn't match, bail early.
if (png_sig_cmp(signature, 0, kPngSignatureSize) != 0) {
mDiag->error(DiagMessage() << "not a valid png file");
return false;
}
bool result = false;
png_structp readPtr = nullptr;
png_infop infoPtr = nullptr;
png_structp writePtr = nullptr;
png_infop writeInfoPtr = nullptr;
PngInfo pngInfo = {};
readPtr = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, nullptr, nullptr);
if (!readPtr) {
mDiag->error(DiagMessage() << "failed to allocate read ptr");
goto bail;
}
infoPtr = png_create_info_struct(readPtr);
if (!infoPtr) {
mDiag->error(DiagMessage() << "failed to allocate info ptr");
goto bail;
}
png_set_error_fn(readPtr, reinterpret_cast<png_voidp>(mDiag), nullptr, logWarning);
// Set the read function to read from std::istream.
png_set_read_fn(readPtr, (png_voidp) input, readDataFromStream);
if (!readPng(mDiag, readPtr, infoPtr, &pngInfo)) {
goto bail;
}
if (util::stringEndsWith<char>(source.path, ".9.png")) {
std::string errorMsg;
if (!do9Patch(&pngInfo, &errorMsg)) {
mDiag->error(DiagMessage() << errorMsg);
goto bail;
}
}
writePtr = png_create_write_struct(PNG_LIBPNG_VER_STRING, 0, nullptr, nullptr);
if (!writePtr) {
mDiag->error(DiagMessage() << "failed to allocate write ptr");
goto bail;
}
writeInfoPtr = png_create_info_struct(writePtr);
if (!writeInfoPtr) {
mDiag->error(DiagMessage() << "failed to allocate write info ptr");
goto bail;
}
png_set_error_fn(writePtr, nullptr, nullptr, logWarning);
// Set the write function to write to std::ostream.
png_set_write_fn(writePtr, (png_voidp)outBuffer, writeDataToStream, flushDataToStream);
if (!writePng(mDiag, writePtr, writeInfoPtr, &pngInfo, options.grayScaleTolerance)) {
goto bail;
}
result = true;
bail:
if (readPtr) {
png_destroy_read_struct(&readPtr, &infoPtr, nullptr);
}
if (writePtr) {
png_destroy_write_struct(&writePtr, &writeInfoPtr);
}
return result;
}
} // namespace aapt