michael@0: /*
michael@0:  * Copyright 2006 The Android Open Source Project
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #include "SkColorPriv.h"
michael@0: #include "SkImageDecoder.h"
michael@0: #include "SkStream.h"
michael@0: #include "SkStreamHelpers.h"
michael@0: #include "SkTypes.h"
michael@0: 
michael@0: class SkICOImageDecoder : public SkImageDecoder {
michael@0: public:
michael@0:     SkICOImageDecoder();
michael@0: 
michael@0:     virtual Format getFormat() const SK_OVERRIDE {
michael@0:         return kICO_Format;
michael@0:     }
michael@0: 
michael@0: protected:
michael@0:     virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode) SK_OVERRIDE;
michael@0: 
michael@0: private:
michael@0:     typedef SkImageDecoder INHERITED;
michael@0: };
michael@0: 
michael@0: /////////////////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: //read bytes starting from the begin-th index in the buffer
michael@0: //read in Intel order, and return an integer
michael@0: 
michael@0: #define readByte(buffer,begin) buffer[begin]
michael@0: #define read2Bytes(buffer,begin) buffer[begin]+(buffer[begin+1]<<8)
michael@0: #define read4Bytes(buffer,begin) buffer[begin]+(buffer[begin+1]<<8)+(buffer[begin+2]<<16)+(buffer[begin+3]<<24)
michael@0: 
michael@0: /////////////////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: SkICOImageDecoder::SkICOImageDecoder()
michael@0: {
michael@0: }
michael@0: 
michael@0: //helpers - my function pointer will call one of these, depending on the bitCount, each time through the inner loop
michael@0: static void editPixelBit1(const int pixelNo, const unsigned char* buf,
michael@0:             const int xorOffset, int& x, int y, const int w,
michael@0:             SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors);
michael@0: static void editPixelBit4(const int pixelNo, const unsigned char* buf,
michael@0:             const int xorOffset, int& x, int y, const int w,
michael@0:             SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors);
michael@0: static void editPixelBit8(const int pixelNo, const unsigned char* buf,
michael@0:             const int xorOffset, int& x, int y, const int w,
michael@0:             SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors);
michael@0: static void editPixelBit24(const int pixelNo, const unsigned char* buf,
michael@0:             const int xorOffset, int& x, int y, const int w,
michael@0:             SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors);
michael@0: static void editPixelBit32(const int pixelNo, const unsigned char* buf,
michael@0:             const int xorOffset, int& x, int y, const int w,
michael@0:             SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors);
michael@0: 
michael@0: 
michael@0: static int calculateRowBytesFor8888(int w, int bitCount)
michael@0: {
michael@0:     //  Default rowBytes is w << 2 for kARGB_8888
michael@0:     //  In the case of a 4 bit image with an odd width, we need to add some
michael@0:     //  so we can go off the end of the drawn bitmap.
michael@0:     //  Add 4 to ensure that it is still a multiple of 4.
michael@0:     if (4 == bitCount && (w & 0x1)) {
michael@0:         return (w + 1) << 2;
michael@0:     }
michael@0:     //  Otherwise return 0, which will allow it to be calculated automatically.
michael@0:     return 0;
michael@0: }
michael@0: 
michael@0: bool SkICOImageDecoder::onDecode(SkStream* stream, SkBitmap* bm, Mode mode)
michael@0: {
michael@0:     SkAutoMalloc autoMal;
michael@0:     const size_t length = CopyStreamToStorage(&autoMal, stream);
michael@0:     if (0 == length) {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     unsigned char* buf = (unsigned char*)autoMal.get();
michael@0: 
michael@0:     //these should always be the same - should i use for error checking? - what about files that have some
michael@0:     //incorrect values, but still decode properly?
michael@0:     int reserved = read2Bytes(buf, 0);    // 0
michael@0:     int type = read2Bytes(buf, 2);        // 1
michael@0:     if (reserved != 0 || type != 1)
michael@0:         return false;
michael@0:     int count = read2Bytes(buf, 4);
michael@0: 
michael@0:     //need to at least have enough space to hold the initial table of info
michael@0:     if (length < (size_t)(6 + count*16))
michael@0:         return false;
michael@0: 
michael@0:     int choice;
michael@0:     Chooser* chooser = this->getChooser();
michael@0:     //FIXME:if no chooser, consider providing the largest color image
michael@0:     //what are the odds that the largest image would be monochrome?
michael@0:     if (NULL == chooser) {
michael@0:         choice = 0;
michael@0:     } else {
michael@0:         chooser->begin(count);
michael@0:         for (int i = 0; i < count; i++)
michael@0:         {
michael@0:             //need to find out the config, width, and height from the stream
michael@0:             int width = readByte(buf, 6 + i*16);
michael@0:             int height = readByte(buf, 7 + i*16);
michael@0:             int offset = read4Bytes(buf, 18 + i*16);
michael@0:             int bitCount = read2Bytes(buf, offset+14);
michael@0:             SkBitmap::Config c;
michael@0:             //currently only provide ARGB_8888_, but maybe we want kIndex8_Config for 1 and 4, and possibly 8?
michael@0:             //or maybe we'll determine this based on the provided config
michael@0:             switch (bitCount)
michael@0:             {
michael@0:                 case 1:
michael@0:                 case 4:
michael@0:                     // In reality, at least for the moment, these will be decoded into kARGB_8888 bitmaps.
michael@0:                     // However, this will be used to distinguish between the lower quality 1bpp and 4 bpp
michael@0:                     // images and the higher quality images.
michael@0:                     c = SkBitmap::kIndex8_Config;
michael@0:                     break;
michael@0:                 case 8:
michael@0:                 case 24:
michael@0:                 case 32:
michael@0:                     c = SkBitmap::kARGB_8888_Config;
michael@0:                     break;
michael@0:                 default:
michael@0:                     SkDEBUGF(("Image with %ibpp not supported\n", bitCount));
michael@0:                     continue;
michael@0:             }
michael@0:             chooser->inspect(i, c, width, height);
michael@0:         }
michael@0:         choice = chooser->choose();
michael@0:     }
michael@0: 
michael@0:     //you never know what the chooser is going to supply
michael@0:     if (choice >= count || choice < 0)
michael@0:         return false;
michael@0: 
michael@0:     //skip ahead to the correct header
michael@0:     //commented out lines are not used, but if i switch to other read method, need to know how many to skip
michael@0:     //otherwise, they could be used for error checking
michael@0:     int w = readByte(buf, 6 + choice*16);
michael@0:     int h = readByte(buf, 7 + choice*16);
michael@0:     int colorCount = readByte(buf, 8 + choice*16);
michael@0:     //int reservedToo = readByte(buf, 9 + choice*16);   //0
michael@0:     //int planes = read2Bytes(buf, 10 + choice*16);       //1 - but often 0
michael@0:     //int fakeBitCount = read2Bytes(buf, 12 + choice*16); //should be real - usually 0
michael@0:     int size = read4Bytes(buf, 14 + choice*16);           //matters?
michael@0:     int offset = read4Bytes(buf, 18 + choice*16);
michael@0:     if ((size_t)(offset + size) > length)
michael@0:         return false;
michael@0: 
michael@0:     // Check to see if this is a PNG image inside the ICO
michael@0:     {
michael@0:         SkMemoryStream subStream(buf + offset, size, false);
michael@0:         SkAutoTDelete<SkImageDecoder> otherDecoder(SkImageDecoder::Factory(&subStream));
michael@0:         if (otherDecoder.get() != NULL) {
michael@0:             // Set fields on the other decoder to be the same as this one.
michael@0:             this->copyFieldsToOther(otherDecoder.get());
michael@0:             if(otherDecoder->decode(&subStream, bm, this->getDefaultPref(), mode)) {
michael@0:                 return true;
michael@0:             }
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     //int infoSize = read4Bytes(buf, offset);             //40
michael@0:     //int width = read4Bytes(buf, offset+4);              //should == w
michael@0:     //int height = read4Bytes(buf, offset+8);             //should == 2*h
michael@0:     //int planesToo = read2Bytes(buf, offset+12);         //should == 1 (does it?)
michael@0:     int bitCount = read2Bytes(buf, offset+14);
michael@0: 
michael@0:     void (*placePixel)(const int pixelNo, const unsigned char* buf,
michael@0:         const int xorOffset, int& x, int y, const int w,
michael@0:         SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors) = NULL;
michael@0:     switch (bitCount)
michael@0:     {
michael@0:         case 1:
michael@0:             placePixel = &editPixelBit1;
michael@0:             colorCount = 2;
michael@0:             break;
michael@0:         case 4:
michael@0:             placePixel = &editPixelBit4;
michael@0:             colorCount = 16;
michael@0:             break;
michael@0:         case 8:
michael@0:             placePixel = &editPixelBit8;
michael@0:             colorCount = 256;
michael@0:             break;
michael@0:         case 24:
michael@0:             placePixel = &editPixelBit24;
michael@0:             colorCount = 0;
michael@0:             break;
michael@0:         case 32:
michael@0:             placePixel = &editPixelBit32;
michael@0:             colorCount = 0;
michael@0:             break;
michael@0:         default:
michael@0:             SkDEBUGF(("Decoding %ibpp is unimplemented\n", bitCount));
michael@0:             return false;
michael@0:     }
michael@0: 
michael@0:     //these should all be zero, but perhaps are not - need to check
michael@0:     //int compression = read4Bytes(buf, offset+16);       //0
michael@0:     //int imageSize = read4Bytes(buf, offset+20);         //0 - sometimes has a value
michael@0:     //int xPixels = read4Bytes(buf, offset+24);           //0
michael@0:     //int yPixels = read4Bytes(buf, offset+28);           //0
michael@0:     //int colorsUsed = read4Bytes(buf, offset+32)         //0 - might have an actual value though
michael@0:     //int colorsImportant = read4Bytes(buf, offset+36);   //0
michael@0: 
michael@0:     int begin = offset + 40;
michael@0:     //this array represents the colortable
michael@0:     //if i allow other types of bitmaps, it may actually be used as a part of the bitmap
michael@0:     SkPMColor* colors = NULL;
michael@0:     int blue, green, red;
michael@0:     if (colorCount)
michael@0:     {
michael@0:         colors = new SkPMColor[colorCount];
michael@0:         for (int j = 0; j < colorCount; j++)
michael@0:         {
michael@0:             //should this be a function - maybe a #define?
michael@0:             blue = readByte(buf, begin + 4*j);
michael@0:             green = readByte(buf, begin + 4*j + 1);
michael@0:             red = readByte(buf, begin + 4*j + 2);
michael@0:             colors[j] = SkPackARGB32(0xFF, red & 0xFF, green & 0xFF, blue & 0xFF);
michael@0:         }
michael@0:     }
michael@0:     int bitWidth = w*bitCount;
michael@0:     int test = bitWidth & 0x1F;
michael@0:     int mask = -(((test >> 4) | (test >> 3) | (test >> 2) | (test >> 1) | test) & 0x1);    //either 0xFFFFFFFF or 0
michael@0:     int lineBitWidth = (bitWidth & 0xFFFFFFE0) + (0x20 & mask);
michael@0:     int lineWidth = lineBitWidth/bitCount;
michael@0: 
michael@0:     int xorOffset = begin + colorCount*4;   //beginning of the color bitmap
michael@0:                                             //other read method means we will just be here already
michael@0:     int andOffset = xorOffset + ((lineWidth*h*bitCount) >> 3);
michael@0: 
michael@0:     /*int */test = w & 0x1F;   //the low 5 bits - we are rounding up to the next 32 (2^5)
michael@0:     /*int */mask = -(((test >> 4) | (test >> 3) | (test >> 2) | (test >> 1) | test) & 0x1);    //either 0xFFFFFFFF or 0
michael@0:     int andLineWidth = (w & 0xFFFFFFE0) + (0x20 & mask);
michael@0:     //if we allow different Configs, everything is the same til here
michael@0:     //change the config, and use different address getter, and place index vs color, and add the color table
michael@0:     //FIXME: what is the tradeoff in size?
michael@0:     //if the andbitmap (mask) is all zeroes, then we can easily do an index bitmap
michael@0:     //however, with small images with large colortables, maybe it's better to still do argb_8888
michael@0: 
michael@0:     bm->setConfig(SkBitmap::kARGB_8888_Config, w, h, calculateRowBytesFor8888(w, bitCount));
michael@0: 
michael@0:     if (SkImageDecoder::kDecodeBounds_Mode == mode) {
michael@0:         delete[] colors;
michael@0:         return true;
michael@0:     }
michael@0: 
michael@0:     if (!this->allocPixelRef(bm, NULL))
michael@0:     {
michael@0:         delete[] colors;
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     SkAutoLockPixels alp(*bm);
michael@0: 
michael@0:     for (int y = 0; y < h; y++)
michael@0:     {
michael@0:         for (int x = 0; x < w; x++)
michael@0:         {
michael@0:             //U32* address = bm->getAddr32(x, y);
michael@0: 
michael@0:             //check the alpha bit first, but pass it along to the function to figure out how to deal with it
michael@0:             int andPixelNo = andLineWidth*(h-y-1)+x;
michael@0:             //only need to get a new alphaByte when x %8 == 0
michael@0:             //but that introduces an if and a mod - probably much slower
michael@0:             //that's ok, it's just a read of an array, not a stream
michael@0:             int alphaByte = readByte(buf, andOffset + (andPixelNo >> 3));
michael@0:             int shift = 7 - (andPixelNo & 0x7);
michael@0:             int m = 1 << shift;
michael@0: 
michael@0:             int pixelNo = lineWidth*(h-y-1)+x;
michael@0:             placePixel(pixelNo, buf, xorOffset, x, y, w, bm, alphaByte, m, shift, colors);
michael@0: 
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     delete [] colors;
michael@0:     //ensure we haven't read off the end?
michael@0:     //of course this doesn't help us if the andOffset was a lie...
michael@0:     //return andOffset + (andLineWidth >> 3) <= length;
michael@0:     return true;
michael@0: }   //onDecode
michael@0: 
michael@0: //function to place the pixel, determined by the bitCount
michael@0: static void editPixelBit1(const int pixelNo, const unsigned char* buf,
michael@0:             const int xorOffset, int& x, int y, const int w,
michael@0:             SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors)
michael@0: {
michael@0:     // note that this should be the same as/similar to the AND bitmap
michael@0:     SkPMColor* address = bm->getAddr32(x,y);
michael@0:     int byte = readByte(buf, xorOffset + (pixelNo >> 3));
michael@0:     int colorBit;
michael@0:     int alphaBit;
michael@0:     // Read all of the bits in this byte.
michael@0:     int i = x + 8;
michael@0:     // Pin to the width so we do not write outside the bounds of
michael@0:     // our color table.
michael@0:     i = i > w ? w : i;
michael@0:     // While loop to check all 8 bits individually.
michael@0:     while (x < i)
michael@0:     {
michael@0: 
michael@0:         colorBit = (byte & m) >> shift;
michael@0:         alphaBit = (alphaByte & m) >> shift;
michael@0:         *address = (alphaBit-1)&(colors[colorBit]);
michael@0:         x++;
michael@0:         // setup for the next pixel
michael@0:         address = address + 1;
michael@0:         m = m >> 1;
michael@0:         shift -= 1;
michael@0:     }
michael@0:     x--;
michael@0: }
michael@0: static void editPixelBit4(const int pixelNo, const unsigned char* buf,
michael@0:             const int xorOffset, int& x, int y, const int w,
michael@0:             SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors)
michael@0: {
michael@0:     SkPMColor* address = bm->getAddr32(x, y);
michael@0:     int byte = readByte(buf, xorOffset + (pixelNo >> 1));
michael@0:     int pixel = (byte >> 4) & 0xF;
michael@0:     int alphaBit = (alphaByte & m) >> shift;
michael@0:     *address = (alphaBit-1)&(colors[pixel]);
michael@0:     x++;
michael@0:     //if w is odd, x may be the same as w, which means we are writing to an unused portion of the bitmap
michael@0:     //but that's okay, since i've added an extra rowByte for just this purpose
michael@0:     address = address + 1;
michael@0:     pixel = byte & 0xF;
michael@0:     m = m >> 1;
michael@0:     alphaBit = (alphaByte & m) >> (shift-1);
michael@0:     //speed up trick here
michael@0:     *address = (alphaBit-1)&(colors[pixel]);
michael@0: }
michael@0: 
michael@0: static void editPixelBit8(const int pixelNo, const unsigned char* buf,
michael@0:             const int xorOffset, int& x, int y, const int w,
michael@0:             SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors)
michael@0: {
michael@0:     SkPMColor* address = bm->getAddr32(x, y);
michael@0:     int pixel = readByte(buf, xorOffset + pixelNo);
michael@0:     int alphaBit = (alphaByte & m) >> shift;
michael@0:     *address = (alphaBit-1)&(colors[pixel]);
michael@0: }
michael@0: 
michael@0: static void editPixelBit24(const int pixelNo, const unsigned char* buf,
michael@0:             const int xorOffset, int& x, int y, const int w,
michael@0:             SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors)
michael@0: {
michael@0:     SkPMColor* address = bm->getAddr32(x, y);
michael@0:     int blue = readByte(buf, xorOffset + 3*pixelNo);
michael@0:     int green = readByte(buf, xorOffset + 3*pixelNo + 1);
michael@0:     int red = readByte(buf, xorOffset + 3*pixelNo + 2);
michael@0:     int alphaBit = (alphaByte & m) >> shift;
michael@0:     //alphaBit == 1 => alpha = 0
michael@0:     int alpha = (alphaBit-1) & 0xFF;
michael@0:     *address = SkPreMultiplyARGB(alpha, red, green, blue);
michael@0: }
michael@0: 
michael@0: static void editPixelBit32(const int pixelNo, const unsigned char* buf,
michael@0:             const int xorOffset, int& x, int y, const int w,
michael@0:             SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors)
michael@0: {
michael@0:     SkPMColor* address = bm->getAddr32(x, y);
michael@0:     int blue = readByte(buf, xorOffset + 4*pixelNo);
michael@0:     int green = readByte(buf, xorOffset + 4*pixelNo + 1);
michael@0:     int red = readByte(buf, xorOffset + 4*pixelNo + 2);
michael@0:     int alphaBit = (alphaByte & m) >> shift;
michael@0: #if 1 // don't trust the alphaBit for 32bit images <mrr>
michael@0:     alphaBit = 0;
michael@0: #endif
michael@0:     int alpha = readByte(buf, xorOffset + 4*pixelNo + 3) & ((alphaBit-1)&0xFF);
michael@0:     *address = SkPreMultiplyARGB(alpha, red, green, blue);
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: DEFINE_DECODER_CREATOR(ICOImageDecoder);
michael@0: /////////////////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: static bool is_ico(SkStreamRewindable* stream) {
michael@0:     // Check to see if the first four bytes are 0,0,1,0
michael@0:     // FIXME: Is that required and sufficient?
michael@0:     SkAutoMalloc autoMal(4);
michael@0:     unsigned char* buf = (unsigned char*)autoMal.get();
michael@0:     stream->read((void*)buf, 4);
michael@0:     int reserved = read2Bytes(buf, 0);
michael@0:     int type = read2Bytes(buf, 2);
michael@0:     if (reserved != 0 || type != 1) {
michael@0:         // This stream does not represent an ICO image.
michael@0:         return false;
michael@0:     }
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: static SkImageDecoder* sk_libico_dfactory(SkStreamRewindable* stream) {
michael@0:     if (is_ico(stream)) {
michael@0:         return SkNEW(SkICOImageDecoder);
michael@0:     }
michael@0:     return NULL;
michael@0: }
michael@0: 
michael@0: static SkImageDecoder_DecodeReg gReg(sk_libico_dfactory);
michael@0: 
michael@0: static SkImageDecoder::Format get_format_ico(SkStreamRewindable* stream) {
michael@0:     if (is_ico(stream)) {
michael@0:         return SkImageDecoder::kICO_Format;
michael@0:     }
michael@0:     return SkImageDecoder::kUnknown_Format;
michael@0: }
michael@0: 
michael@0: static SkImageDecoder_FormatReg gFormatReg(get_format_ico);