| |
| /* |
| * 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 "SkImageDecoder.h" |
| #include "SkStream.h" |
| #include "SkColorPriv.h" |
| #include "SkTypes.h" |
| |
| class SkICOImageDecoder : public SkImageDecoder { |
| public: |
| SkICOImageDecoder(); |
| |
| virtual Format getFormat() const { |
| return kICO_Format; |
| } |
| |
| protected: |
| virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode); |
| }; |
| |
| #if 0 // UNUSED |
| SkImageDecoder* SkCreateICOImageDecoder() { |
| return new SkICOImageDecoder; |
| } |
| #endif |
| |
| ///////////////////////////////////////////////////////////////////////////////////////// |
| |
| //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]+(buffer[begin+1]<<8) |
| #define read4Bytes(buffer,begin) buffer[begin]+(buffer[begin+1]<<8)+(buffer[begin+2]<<16)+(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; |
| } |
| |
| bool SkICOImageDecoder::onDecode(SkStream* stream, SkBitmap* bm, Mode mode) |
| { |
| size_t length = stream->read(NULL, 0); |
| SkAutoMalloc autoMal(length); |
| unsigned char* buf = (unsigned char*)autoMal.get(); |
| if (stream->read((void*)buf, length) != length) { |
| return false; |
| } |
| |
| //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 false; |
| int count = read2Bytes(buf, 4); |
| |
| //need to at least have enough space to hold the initial table of info |
| if (length < (size_t)(6 + count*16)) |
| return false; |
| |
| int choice; |
| Chooser* chooser = this->getChooser(); |
| //FIXME:if no chooser, consider providing the largest color image |
| //what are the odds that the largest image would be monochrome? |
| if (NULL == chooser) { |
| choice = 0; |
| } else { |
| chooser->begin(count); |
| for (int i = 0; i < count; i++) |
| { |
| //need to find out the config, width, and height from the stream |
| int width = readByte(buf, 6 + i*16); |
| int height = readByte(buf, 7 + i*16); |
| int offset = read4Bytes(buf, 18 + i*16); |
| int bitCount = read2Bytes(buf, offset+14); |
| SkBitmap::Config c; |
| //currently only provide ARGB_8888_, but maybe we want kIndex8_Config for 1 and 4, and possibly 8? |
| //or maybe we'll determine this based on the provided config |
| switch (bitCount) |
| { |
| case 1: |
| case 4: |
| // In reality, at least for the moment, these will be decoded into kARGB_8888 bitmaps. |
| // However, this will be used to distinguish between the lower quality 1bpp and 4 bpp |
| // images and the higher quality images. |
| c = SkBitmap::kIndex8_Config; |
| break; |
| case 8: |
| case 24: |
| case 32: |
| c = SkBitmap::kARGB_8888_Config; |
| break; |
| default: |
| SkDEBUGF(("Image with %ibpp not supported\n", bitCount)); |
| continue; |
| } |
| chooser->inspect(i, c, width, height); |
| } |
| choice = chooser->choose(); |
| } |
| |
| //you never know what the chooser is going to supply |
| if (choice >= count || choice < 0) |
| return false; |
| |
| //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 + choice*16); |
| int h = readByte(buf, 7 + choice*16); |
| int colorCount = readByte(buf, 8 + choice*16); |
| //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 |
| int size = read4Bytes(buf, 14 + choice*16); //matters? |
| int offset = read4Bytes(buf, 18 + choice*16); |
| if ((size_t)(offset + size) > length) |
| return false; |
| //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?) |
| 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) = NULL; |
| 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 false; |
| } |
| |
| //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 = offset + 40; |
| //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 = NULL; |
| 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->setConfig(SkBitmap::kARGB_8888_Config, w, h, calculateRowBytesFor8888(w, bitCount)); |
| |
| if (SkImageDecoder::kDecodeBounds_Mode == mode) { |
| delete[] colors; |
| return true; |
| } |
| |
| if (!this->allocPixelRef(bm, NULL)) |
| { |
| delete[] colors; |
| return false; |
| } |
| |
| 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 true; |
| } //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); |
| ///////////////////////////////////////////////////////////////////////////////////////// |
| |
| #include "SkTRegistry.h" |
| |
| static SkImageDecoder* sk_libico_dfactory(SkStream* stream) { |
| // Check to see if the first four bytes are 0,0,1,0 |
| // FIXME: Is that required and sufficient? |
| SkAutoMalloc autoMal(4); |
| unsigned char* buf = (unsigned char*)autoMal.get(); |
| stream->read((void*)buf, 4); |
| int reserved = read2Bytes(buf, 0); |
| int type = read2Bytes(buf, 2); |
| if (reserved != 0 || type != 1) { |
| // This stream does not represent an ICO image. |
| return NULL; |
| } |
| return SkNEW(SkICOImageDecoder); |
| } |
| |
| static SkTRegistry<SkImageDecoder*, SkStream*> gReg(sk_libico_dfactory); |
| |
