Index: src/images/SkImageDecoder_libico.cpp |
diff --git a/src/images/SkImageDecoder_libico.cpp b/src/images/SkImageDecoder_libico.cpp |
new file mode 100644 |
index 0000000000000000000000000000000000000000..ff04d74d066f936b941602f9cd5b34972a29e528 |
--- /dev/null |
+++ b/src/images/SkImageDecoder_libico.cpp |
@@ -0,0 +1,456 @@ |
+/* |
+ * Copyright 2006 The Android Open Source Project |
+ * |
+ * Use of this source code is governed by a BSD-style license that can be |
+ * found in the LICENSE file. |
+ */ |
+ |
+#include "SkColorPriv.h" |
+#include "SkData.h" |
+#include "SkImageDecoder.h" |
+#include "SkStream.h" |
+#include "SkStreamPriv.h" |
+#include "SkTypes.h" |
+ |
+class SkICOImageDecoder : public SkImageDecoder { |
+public: |
+ SkICOImageDecoder(); |
+ |
+ Format getFormat() const override { |
+ return kICO_Format; |
+ } |
+ |
+protected: |
+ Result onDecode(SkStream* stream, SkBitmap* bm, Mode) override; |
+ |
+private: |
+ typedef SkImageDecoder INHERITED; |
+}; |
+ |
+///////////////////////////////////////////////////////////////////////////////////////// |
+ |
+//read bytes starting from the begin-th index in the buffer |
+//read in Intel order, and return an integer |
+ |
+#define readByte(buffer,begin) buffer[begin] |
+#define read2Bytes(buffer,begin) buffer[begin]+SkLeftShift(buffer[begin+1],8) |
+#define read4Bytes(buffer,begin) buffer[begin]+SkLeftShift(buffer[begin+1],8)+SkLeftShift(buffer[begin+2],16)+SkLeftShift(buffer[begin+3],24) |
+ |
+///////////////////////////////////////////////////////////////////////////////////////// |
+ |
+SkICOImageDecoder::SkICOImageDecoder() |
+{ |
+} |
+ |
+//helpers - my function pointer will call one of these, depending on the bitCount, each time through the inner loop |
+static void editPixelBit1(const int pixelNo, const unsigned char* buf, |
+ const int xorOffset, int& x, int y, const int w, |
+ SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors); |
+static void editPixelBit4(const int pixelNo, const unsigned char* buf, |
+ const int xorOffset, int& x, int y, const int w, |
+ SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors); |
+static void editPixelBit8(const int pixelNo, const unsigned char* buf, |
+ const int xorOffset, int& x, int y, const int w, |
+ SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors); |
+static void editPixelBit24(const int pixelNo, const unsigned char* buf, |
+ const int xorOffset, int& x, int y, const int w, |
+ SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors); |
+static void editPixelBit32(const int pixelNo, const unsigned char* buf, |
+ const int xorOffset, int& x, int y, const int w, |
+ SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors); |
+ |
+ |
+static int calculateRowBytesFor8888(int w, int bitCount) |
+{ |
+ // Default rowBytes is w << 2 for kARGB_8888 |
+ // In the case of a 4 bit image with an odd width, we need to add some |
+ // so we can go off the end of the drawn bitmap. |
+ // Add 4 to ensure that it is still a multiple of 4. |
+ if (4 == bitCount && (w & 0x1)) { |
+ return (w + 1) << 2; |
+ } |
+ // Otherwise return 0, which will allow it to be calculated automatically. |
+ return 0; |
+} |
+ |
+SkImageDecoder::Result SkICOImageDecoder::onDecode(SkStream* stream, SkBitmap* bm, Mode mode) { |
+ auto data = SkCopyStreamToData(stream); |
+ if (!data) { |
+ return kFailure; |
+ } |
+ |
+ const size_t length = data->size(); |
+ // Check that the buffer is large enough to read the directory header |
+ if (length < 6) { |
+ return kFailure; |
+ } |
+ |
+ unsigned char* buf = (unsigned char*) data->data(); |
+ |
+ //these should always be the same - should i use for error checking? - what about files that have some |
+ //incorrect values, but still decode properly? |
+ int reserved = read2Bytes(buf, 0); // 0 |
+ int type = read2Bytes(buf, 2); // 1 |
+ if (reserved != 0 || type != 1) { |
+ return kFailure; |
+ } |
+ |
+ int count = read2Bytes(buf, 4); |
+ // Check that there are directory entries |
+ if (count < 1) { |
+ return kFailure; |
+ } |
+ |
+ // Check that buffer is large enough to read directory entries. |
+ // We are guaranteed that count is at least 1. We might as well assume |
+ // count is 1 because this deprecated decoder only looks at the first |
+ // directory entry. |
+ if (length < (size_t)(6 + count*16)) { |
+ return kFailure; |
+ } |
+ |
+ //skip ahead to the correct header |
+ //commented out lines are not used, but if i switch to other read method, need to know how many to skip |
+ //otherwise, they could be used for error checking |
+ int w = readByte(buf, 6); |
+ int h = readByte(buf, 7); |
+ SkASSERT(w >= 0 && h >= 0); |
+ int colorCount = readByte(buf, 8); |
+ //int reservedToo = readByte(buf, 9 + choice*16); //0 |
+ //int planes = read2Bytes(buf, 10 + choice*16); //1 - but often 0 |
+ //int fakeBitCount = read2Bytes(buf, 12 + choice*16); //should be real - usually 0 |
+ const size_t size = read4Bytes(buf, 14); //matters? |
+ const size_t offset = read4Bytes(buf, 18); |
+ // promote the sum to 64-bits to avoid overflow |
+ // Check that buffer is large enough to read image data |
+ if (offset > length || size > length || ((uint64_t)offset + size) > length) { |
+ return kFailure; |
+ } |
+ |
+ // Check to see if this is a PNG image inside the ICO |
+ { |
+ SkMemoryStream subStream(buf + offset, size, false); |
+ SkAutoTDelete<SkImageDecoder> otherDecoder(SkImageDecoder::Factory(&subStream)); |
+ if (otherDecoder.get() != nullptr) { |
+ // Disallow nesting ICO files within one another |
+ // FIXME: Can ICO files contain other formats besides PNG? |
+ if (otherDecoder->getFormat() == SkImageDecoder::kICO_Format) { |
+ return kFailure; |
+ } |
+ // Set fields on the other decoder to be the same as this one. |
+ this->copyFieldsToOther(otherDecoder.get()); |
+ const Result result = otherDecoder->decode(&subStream, bm, this->getDefaultPref(), |
+ mode); |
+ // FIXME: Should we just return result here? Is it possible that data that looked like |
+ // a subimage was not, but was actually a valid ICO? |
+ if (result != kFailure) { |
+ return result; |
+ } |
+ } |
+ } |
+ |
+ //int infoSize = read4Bytes(buf, offset); //40 |
+ //int width = read4Bytes(buf, offset+4); //should == w |
+ //int height = read4Bytes(buf, offset+8); //should == 2*h |
+ //int planesToo = read2Bytes(buf, offset+12); //should == 1 (does it?) |
+ |
+ // For ico images, only a byte is used to store each dimension |
+ // 0 is used to represent 256 |
+ if (w == 0) { |
+ w = 256; |
+ } |
+ if (h == 0) { |
+ h = 256; |
+ } |
+ |
+ // Check that buffer is large enough to read the bit depth |
+ if (length < offset + 16) { |
+ return kFailure; |
+ } |
+ int bitCount = read2Bytes(buf, offset+14); |
+ |
+ void (*placePixel)(const int pixelNo, const unsigned char* buf, |
+ const int xorOffset, int& x, int y, const int w, |
+ SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors) = nullptr; |
+ switch (bitCount) |
+ { |
+ case 1: |
+ placePixel = &editPixelBit1; |
+ colorCount = 2; |
+ break; |
+ case 4: |
+ placePixel = &editPixelBit4; |
+ colorCount = 16; |
+ break; |
+ case 8: |
+ placePixel = &editPixelBit8; |
+ colorCount = 256; |
+ break; |
+ case 24: |
+ placePixel = &editPixelBit24; |
+ colorCount = 0; |
+ break; |
+ case 32: |
+ placePixel = &editPixelBit32; |
+ colorCount = 0; |
+ break; |
+ default: |
+ SkDEBUGF(("Decoding %ibpp is unimplemented\n", bitCount)); |
+ return kFailure; |
+ } |
+ |
+ //these should all be zero, but perhaps are not - need to check |
+ //int compression = read4Bytes(buf, offset+16); //0 |
+ //int imageSize = read4Bytes(buf, offset+20); //0 - sometimes has a value |
+ //int xPixels = read4Bytes(buf, offset+24); //0 |
+ //int yPixels = read4Bytes(buf, offset+28); //0 |
+ //int colorsUsed = read4Bytes(buf, offset+32) //0 - might have an actual value though |
+ //int colorsImportant = read4Bytes(buf, offset+36); //0 |
+ |
+ int begin = SkToInt(offset + 40); |
+ // Check that the buffer is large enough to read the color table |
+ // For bmp-in-icos, there should be 4 bytes per color |
+ if (length < (size_t) (begin + 4*colorCount)) { |
+ return kFailure; |
+ } |
+ |
+ //this array represents the colortable |
+ //if i allow other types of bitmaps, it may actually be used as a part of the bitmap |
+ SkPMColor* colors = nullptr; |
+ int blue, green, red; |
+ if (colorCount) |
+ { |
+ colors = new SkPMColor[colorCount]; |
+ for (int j = 0; j < colorCount; j++) |
+ { |
+ //should this be a function - maybe a #define? |
+ blue = readByte(buf, begin + 4*j); |
+ green = readByte(buf, begin + 4*j + 1); |
+ red = readByte(buf, begin + 4*j + 2); |
+ colors[j] = SkPackARGB32(0xFF, red & 0xFF, green & 0xFF, blue & 0xFF); |
+ } |
+ } |
+ int bitWidth = w*bitCount; |
+ int test = bitWidth & 0x1F; |
+ int mask = -(((test >> 4) | (test >> 3) | (test >> 2) | (test >> 1) | test) & 0x1); //either 0xFFFFFFFF or 0 |
+ int lineBitWidth = (bitWidth & 0xFFFFFFE0) + (0x20 & mask); |
+ int lineWidth = lineBitWidth/bitCount; |
+ |
+ int xorOffset = begin + colorCount*4; //beginning of the color bitmap |
+ //other read method means we will just be here already |
+ int andOffset = xorOffset + ((lineWidth*h*bitCount) >> 3); |
+ |
+ /*int */test = w & 0x1F; //the low 5 bits - we are rounding up to the next 32 (2^5) |
+ /*int */mask = -(((test >> 4) | (test >> 3) | (test >> 2) | (test >> 1) | test) & 0x1); //either 0xFFFFFFFF or 0 |
+ int andLineWidth = (w & 0xFFFFFFE0) + (0x20 & mask); |
+ //if we allow different Configs, everything is the same til here |
+ //change the config, and use different address getter, and place index vs color, and add the color table |
+ //FIXME: what is the tradeoff in size? |
+ //if the andbitmap (mask) is all zeroes, then we can easily do an index bitmap |
+ //however, with small images with large colortables, maybe it's better to still do argb_8888 |
+ |
+ bm->setInfo(SkImageInfo::MakeN32Premul(w, h), calculateRowBytesFor8888(w, bitCount)); |
+ |
+ if (SkImageDecoder::kDecodeBounds_Mode == mode) { |
+ delete[] colors; |
+ return kSuccess; |
+ } |
+ |
+ if (!this->allocPixelRef(bm, nullptr)) |
+ { |
+ delete[] colors; |
+ return kFailure; |
+ } |
+ |
+ // The AND mask is a 1-bit alpha mask for each pixel that comes after the |
+ // XOR mask in the bmp. If we check that the largest AND offset is safe, |
+ // it should mean all other buffer accesses will be at smaller indices and |
+ // will therefore be safe. |
+ size_t maxAndOffset = andOffset + ((andLineWidth*(h-1)+(w-1)) >> 3); |
+ if (length <= maxAndOffset) { |
+ return kFailure; |
+ } |
+ |
+ // Here we assert that all reads from the buffer using the XOR offset are |
+ // less than the AND offset. This should be guaranteed based on the above |
+ // calculations. |
+#ifdef SK_DEBUG |
+ int maxPixelNum = lineWidth*(h-1)+w-1; |
+ int maxByte; |
+ switch (bitCount) { |
+ case 1: |
+ maxByte = maxPixelNum >> 3; |
+ break; |
+ case 4: |
+ maxByte = maxPixelNum >> 1; |
+ break; |
+ case 8: |
+ maxByte = maxPixelNum; |
+ break; |
+ case 24: |
+ maxByte = maxPixelNum * 3 + 2; |
+ break; |
+ case 32: |
+ maxByte = maxPixelNum * 4 + 3; |
+ break; |
+ default: |
+ SkASSERT(false); |
+ return kFailure; |
+ } |
+ int maxXOROffset = xorOffset + maxByte; |
+ SkASSERT(maxXOROffset < andOffset); |
+#endif |
+ |
+ SkAutoLockPixels alp(*bm); |
+ |
+ for (int y = 0; y < h; y++) |
+ { |
+ for (int x = 0; x < w; x++) |
+ { |
+ //U32* address = bm->getAddr32(x, y); |
+ |
+ //check the alpha bit first, but pass it along to the function to figure out how to deal with it |
+ int andPixelNo = andLineWidth*(h-y-1)+x; |
+ //only need to get a new alphaByte when x %8 == 0 |
+ //but that introduces an if and a mod - probably much slower |
+ //that's ok, it's just a read of an array, not a stream |
+ int alphaByte = readByte(buf, andOffset + (andPixelNo >> 3)); |
+ int shift = 7 - (andPixelNo & 0x7); |
+ int m = 1 << shift; |
+ |
+ int pixelNo = lineWidth*(h-y-1)+x; |
+ placePixel(pixelNo, buf, xorOffset, x, y, w, bm, alphaByte, m, shift, colors); |
+ |
+ } |
+ } |
+ |
+ delete [] colors; |
+ //ensure we haven't read off the end? |
+ //of course this doesn't help us if the andOffset was a lie... |
+ //return andOffset + (andLineWidth >> 3) <= length; |
+ return kSuccess; |
+} //onDecode |
+ |
+//function to place the pixel, determined by the bitCount |
+static void editPixelBit1(const int pixelNo, const unsigned char* buf, |
+ const int xorOffset, int& x, int y, const int w, |
+ SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors) |
+{ |
+ // note that this should be the same as/similar to the AND bitmap |
+ SkPMColor* address = bm->getAddr32(x,y); |
+ int byte = readByte(buf, xorOffset + (pixelNo >> 3)); |
+ int colorBit; |
+ int alphaBit; |
+ // Read all of the bits in this byte. |
+ int i = x + 8; |
+ // Pin to the width so we do not write outside the bounds of |
+ // our color table. |
+ i = i > w ? w : i; |
+ // While loop to check all 8 bits individually. |
+ while (x < i) |
+ { |
+ |
+ colorBit = (byte & m) >> shift; |
+ alphaBit = (alphaByte & m) >> shift; |
+ *address = (alphaBit-1)&(colors[colorBit]); |
+ x++; |
+ // setup for the next pixel |
+ address = address + 1; |
+ m = m >> 1; |
+ shift -= 1; |
+ } |
+ x--; |
+} |
+static void editPixelBit4(const int pixelNo, const unsigned char* buf, |
+ const int xorOffset, int& x, int y, const int w, |
+ SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors) |
+{ |
+ SkPMColor* address = bm->getAddr32(x, y); |
+ int byte = readByte(buf, xorOffset + (pixelNo >> 1)); |
+ int pixel = (byte >> 4) & 0xF; |
+ int alphaBit = (alphaByte & m) >> shift; |
+ *address = (alphaBit-1)&(colors[pixel]); |
+ x++; |
+ //if w is odd, x may be the same as w, which means we are writing to an unused portion of the bitmap |
+ //but that's okay, since i've added an extra rowByte for just this purpose |
+ address = address + 1; |
+ pixel = byte & 0xF; |
+ m = m >> 1; |
+ alphaBit = (alphaByte & m) >> (shift-1); |
+ //speed up trick here |
+ *address = (alphaBit-1)&(colors[pixel]); |
+} |
+ |
+static void editPixelBit8(const int pixelNo, const unsigned char* buf, |
+ const int xorOffset, int& x, int y, const int w, |
+ SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors) |
+{ |
+ SkPMColor* address = bm->getAddr32(x, y); |
+ int pixel = readByte(buf, xorOffset + pixelNo); |
+ int alphaBit = (alphaByte & m) >> shift; |
+ *address = (alphaBit-1)&(colors[pixel]); |
+} |
+ |
+static void editPixelBit24(const int pixelNo, const unsigned char* buf, |
+ const int xorOffset, int& x, int y, const int w, |
+ SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors) |
+{ |
+ SkPMColor* address = bm->getAddr32(x, y); |
+ int blue = readByte(buf, xorOffset + 3*pixelNo); |
+ int green = readByte(buf, xorOffset + 3*pixelNo + 1); |
+ int red = readByte(buf, xorOffset + 3*pixelNo + 2); |
+ int alphaBit = (alphaByte & m) >> shift; |
+ //alphaBit == 1 => alpha = 0 |
+ int alpha = (alphaBit-1) & 0xFF; |
+ *address = SkPreMultiplyARGB(alpha, red, green, blue); |
+} |
+ |
+static void editPixelBit32(const int pixelNo, const unsigned char* buf, |
+ const int xorOffset, int& x, int y, const int w, |
+ SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors) |
+{ |
+ SkPMColor* address = bm->getAddr32(x, y); |
+ int blue = readByte(buf, xorOffset + 4*pixelNo); |
+ int green = readByte(buf, xorOffset + 4*pixelNo + 1); |
+ int red = readByte(buf, xorOffset + 4*pixelNo + 2); |
+ int alphaBit = (alphaByte & m) >> shift; |
+#if 1 // don't trust the alphaBit for 32bit images <mrr> |
+ alphaBit = 0; |
+#endif |
+ int alpha = readByte(buf, xorOffset + 4*pixelNo + 3) & ((alphaBit-1)&0xFF); |
+ *address = SkPreMultiplyARGB(alpha, red, green, blue); |
+} |
+ |
+/////////////////////////////////////////////////////////////////////////////// |
+DEFINE_DECODER_CREATOR(ICOImageDecoder); |
+///////////////////////////////////////////////////////////////////////////////////////// |
+ |
+static bool is_ico(SkStreamRewindable* stream) { |
+ // Check to see if the first four bytes are 0,0,1,0 |
+ // FIXME: Is that required and sufficient? |
+ char buf[4]; |
+ if (stream->read((void*)buf, 4) != 4) { |
+ return false; |
+ } |
+ int reserved = read2Bytes(buf, 0); |
+ int type = read2Bytes(buf, 2); |
+ return 0 == reserved && 1 == type; |
+} |
+ |
+static SkImageDecoder* sk_libico_dfactory(SkStreamRewindable* stream) { |
+ if (is_ico(stream)) { |
+ return new SkICOImageDecoder; |
+ } |
+ return nullptr; |
+} |
+ |
+static SkImageDecoder_DecodeReg gReg(sk_libico_dfactory); |
+ |
+static SkImageDecoder::Format get_format_ico(SkStreamRewindable* stream) { |
+ if (is_ico(stream)) { |
+ return SkImageDecoder::kICO_Format; |
+ } |
+ return SkImageDecoder::kUnknown_Format; |
+} |
+ |
+static SkImageDecoder_FormatReg gFormatReg(get_format_ico); |