C++ BinaryInput::size方法代码示例

void GImage::decodeTGA(
    BinaryInput&        input) {

    // This is a simple TGA loader that can handle uncompressed
    // truecolor TGA files (TGA type 2).
    // Verify this is a TGA file by looking for the TRUEVISION tag.
    int pos = input.getPosition();
    input.setPosition(input.size() - 18);
    std::string tag = input.readString(16);
    if (tag != "TRUEVISION-XFILE") {
        throw Error("Not a TGA file", input.getFilename());
    }

    input.setPosition(pos);

    int IDLength     = input.readUInt8();
    int colorMapType = input.readUInt8();
    int imageType    = input.readUInt8();

    (void)colorMapType;

    // 2 is the type supported by this routine.
    if (imageType != 2 && imageType != 10) {
        throw Error("TGA images must be type 2 (Uncompressed truecolor) or 10 (Run-length truecolor)", input.getFilename());
    }

    // Color map specification
    input.skip(5);

    // Image specification

    // Skip x and y offsets
    input.skip(4);

    m_width  = input.readInt16();
    m_height = input.readInt16();

    int colorDepth = input.readUInt8();

    if ((colorDepth != 24) && (colorDepth != 32)) {
        throw Error("TGA files must be 24 or 32 bit.", input.getFilename());
    }

    if (colorDepth == 32) {
        m_channels = 4;
    } else {
        m_channels = 3;
    }

    // Image descriptor contains overlay data as well
    // as data indicating where the origin is
    int imageDescriptor = input.readUInt8();
    (void)imageDescriptor;

    // Image ID
    input.skip(IDLength);

    m_byte = (uint8*)m_memMan->alloc(m_width * m_height * m_channels);
    debugAssert(m_byte);

    // Pixel data
    int x;
    int y;

    if (imageType == 2) {
        // Uncompressed
        if (m_channels == 3) {
            for (y = m_height - 1; y >= 0; --y) {
              for (x = 0; x < m_width; ++x) {
                int i = (x + y * m_width) * 3;
                readBGR(m_byte + i, input);
              }
            }
        } else {
            for (y = m_height - 1; y >= 0; --y) {
              for (x = 0; x < m_width; ++x) {
                 int i = (x + y * m_width) * 4;
                 readBGRA(m_byte + i, input);
              }
            }
        }
    } else if (imageType == 10) {

        // Run-length encoded
        for (y = m_height - 1; y >= 0; --y) {
            for (int x = 0; x < m_width; /* intentionally no x increment */) {
                // The specification guarantees that no packet will wrap past the end of a row
                const uint8 repetitionCount = input.readUInt8();
                const uint8 numValues = (repetitionCount & (~128)) + 1;
                int byteOffset = (x + y * m_width) * 3;

                if (repetitionCount & 128) {
                    // When the high bit is 1, this is a run-length packet
                    if (m_channels == 3) {
                        Color3uint8 value;
                        readBGR((uint8*)(&value), input);
                        for (int i = 0; i < numValues; ++i, ++x) {
                            for (int b = 0; b < 3; ++b, ++byteOffset) {
                                m_byte[byteOffset] = value[b];
                            }
//.........这里部分代码省略.........

void GImage::decodeJPEG(
    BinaryInput&                input) {

	struct jpeg_decompress_struct   cinfo;
	struct jpeg_error_mgr           jerr;
    int                             loc = 0;

    channels = 3;
    // We have to set up the error handler, in case initialization fails.
	cinfo.err = jpeg_std_error(&jerr);

    // Initialize the JPEG decompression object.
	jpeg_create_decompress(&cinfo);

	// Specify data source (eg, a file, for us, memory)
	jpeg_memory_src(&cinfo, const_cast<uint8*>(input.getCArray()), input.size());

	// Read the parameters with jpeg_read_header()
	jpeg_read_header(&cinfo, TRUE);

	// Set parameters for decompression
	// (We do nothing here since the defaults are fine)

	// Start decompressor
	jpeg_start_decompress(&cinfo);

	// Get and set the values of interest to this object
	this->width     = cinfo.output_width;
	this->height    = cinfo.output_height;

	// Prepare the pointer object for the pixel data
    _byte = (uint8*)System::malloc(width * height * 3);

 	// JSAMPLEs per row in output buffer
    int bpp         = cinfo.output_components;
    int row_stride  = cinfo.output_width * bpp;

	// Make a one-row-high sample array that will go away when done with image
    JSAMPARRAY temp = (*cinfo.mem->alloc_sarray)
		((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);

    // Read data on a scanline by scanline basis
	while (cinfo.output_scanline < cinfo.output_height) {

        // We may need to adjust the output based on the
        // number of channels it has.
        switch (bpp) {
	    case 1:
            // Grayscale; decompress to temp.
    		jpeg_read_scanlines(&cinfo, temp, 1);

            // Expand to three channels
            {
                uint8* scan     = &(_byte[loc * 3]);
                uint8* endScan  = scan + (width * 3);
                uint8* t        = *temp;

                while (scan < endScan) {
                    uint8 value = t[0];

                    // Spread the value 3x.
                    scan[0] = value;
                    scan[1] = value;
                    scan[2] = value;

                    scan    += 3;
                    t       += 1;
                }
            }
		    break;

	    case 3:
            // Read directly into the array
            {
                // Need one extra level of indirection.
                uint8*     scan = _byte + loc;
                JSAMPARRAY ptr  = &scan;
    		    jpeg_read_scanlines(&cinfo, ptr, 1);
            }
		    break;

	    case 4:
            // RGBA; decompress to temp.
    		jpeg_read_scanlines(&cinfo, temp, 1);

            // Drop the 3rd channel
            {
                uint8* scan     = &(_byte[loc * 3]);
                uint8* endScan  = scan + width * 3;
                uint8* t        = *temp;

                while (scan < endScan) {
                    scan[0] = t[0];
                    scan[1] = t[1];
                    scan[2] = t[2];
                    
                    scan    += 3;
                    t       += 4;
                }
            }
//.........这里部分代码省略.........

void GImage::decodeTGA(
    BinaryInput&        input) {

    // This is a simple TGA loader that can handle uncompressed
    // truecolor TGA files (TGA type 2). 
    // Verify this is a TGA file by looking for the TRUEVISION tag.
    int pos = input.getPosition();
    input.setPosition(input.size() - 18);
    std::string tag = input.readString(16);
    if (tag != "TRUEVISION-XFILE") {
        throw Error("Not a TGA file", input.getFilename());
    }

    input.setPosition(pos);

    int IDLength     = input.readUInt8();
    int colorMapType = input.readUInt8();
    int imageType    = input.readUInt8();

    (void)colorMapType;
	
    // 2 is the type supported by this routine.
    if (imageType != 2) {
        throw Error("TGA images must be type 2 (Uncompressed truecolor)", input.getFilename());
    }
	
    // Color map specification
    input.skip(5);

    // Image specification

    // Skip x and y offsets
    input.skip(4); 

    m_width  = input.readInt16();
    m_height = input.readInt16();

    int colorDepth = input.readUInt8();

    if ((colorDepth != 24) && (colorDepth != 32)) {
        throw Error("TGA files must be 24 or 32 bit.", input.getFilename());
    }

    if (colorDepth == 32) {
        m_channels = 4;
    } else {
        m_channels = 3;
    }

    // Image descriptor contains overlay data as well
    // as data indicating where the origin is
    int imageDescriptor = input.readUInt8();
    (void)imageDescriptor;
	
    // Image ID
    input.skip(IDLength);

    m_byte = (uint8*)m_memMan->alloc(m_width * m_height * m_channels);
    debugAssert(m_byte);
	
    // Pixel data
    int x;
    int y;

    if (m_channels == 3) {
        for (y = m_height - 1; y >= 0; --y) {
          for (x = 0; x < m_width; ++x) {
            int b = input.readUInt8();
            int g = input.readUInt8();
            int r = input.readUInt8();
		    
            int i = (x + y * m_width) * 3;
            m_byte[i + 0] = r;
            m_byte[i + 1] = g;
            m_byte[i + 2] = b;
          }
        }
    } else {
        for (y = m_height - 1; y >= 0; --y) {
          for (x = 0; x < m_width; ++x) {
            int b = input.readUInt8();
            int g = input.readUInt8();
            int r = input.readUInt8();
            int a = input.readUInt8();
		    
            int i = (x + y * m_width) * 4;
            m_byte[i + 0] = r;
            m_byte[i + 1] = g;
            m_byte[i + 2] = b;
            m_byte[i + 3] = a;
          }
        }
    }
}