C++ BinaryOutput::setEndian方法代码示例

void GImage::encodeJPEG(
    BinaryOutput&           out) const {

	if (channels != 3) {
		// Convert to three channel
		GImage tmp = *this;
		tmp.convertToRGB();
		tmp.encodeJPEG(out);
		return;
	}

    debugAssert(channels == 3);
    out.setEndian(G3D_LITTLE_ENDIAN);

    // Allocate and initialize a compression object
    jpeg_compress_struct    cinfo;
    jpeg_error_mgr          jerr;

	cinfo.err = jpeg_std_error(&jerr);
	jpeg_create_compress(&cinfo);

    // Specify the destination for the compressed data.
    // (Overestimate the size)
    int buffer_size = width * height * 3 + 200;
    JOCTET* compressed_data = (JOCTET*)System::malloc(buffer_size);
	jpeg_memory_dest(&cinfo, compressed_data, buffer_size);


    cinfo.image_width       = width;
    cinfo.image_height      = height;

	// # of color components per pixel
    cinfo.input_components  = 3;

    // colorspace of input image
    cinfo.in_color_space    = JCS_RGB; 
    cinfo.input_gamma       = 1.0;
    
    // Set parameters for compression, including image size & colorspace
    jpeg_set_defaults(&cinfo);
    jpeg_set_quality(&cinfo, jpegQuality, false);
    cinfo.smoothing_factor = 0;
    cinfo.optimize_coding = TRUE;
//    cinfo.dct_method = JDCT_FLOAT;
    cinfo.dct_method = JDCT_ISLOW;
    cinfo.jpeg_color_space = JCS_YCbCr;

    // Initialize the compressor
    jpeg_start_compress(&cinfo, TRUE);

    // Iterate over all scanlines from top to bottom
	// pointer to a single row
    JSAMPROW row_pointer[1];
    
    // JSAMPLEs per row in image_buffer
    int row_stride = cinfo.image_width * 3;
    while (cinfo.next_scanline < cinfo.image_height) {
	    row_pointer[0] = &(_byte[cinfo.next_scanline * row_stride]);
	    jpeg_write_scanlines(&cinfo, row_pointer, 1);
    }

    // Shut down the compressor
    jpeg_finish_compress(&cinfo);
    
    // Figure out how big the result was.
    int outLength = ((mem_dest_ptr)cinfo.dest)->count;

    //	Release the JPEG compression object
    jpeg_destroy_compress(&cinfo);

    // Copy into an appropriately sized output buffer.
    out.writeBytes(compressed_data, outLength);

    // Free the conservative buffer.
    System::free(compressed_data);
    compressed_data = NULL;
}

void GImage::encodeTGA(
    BinaryOutput&       out) const {

    out.setEndian(G3D_LITTLE_ENDIAN);

    // ID length
    out.writeUInt8(0);

    // Color map Type
    out.writeUInt8(0);

    // Type
    out.writeUInt8(2);

    // Color map
    out.skip(5);

    // x, y offsets
    out.writeUInt16(0);
    out.writeUInt16(0);

    // Width & height
    out.writeUInt16(m_width);
    out.writeUInt16(m_height);

    // Color depth
    if (m_channels == 1) {
        // Force RGB mode
        out.writeUInt8(8 * 3);
    } else {
        out.writeUInt8(8 * m_channels);
    }

    // Image descriptor
    if (m_channels < 4) {
        // 0 alpha bits
        out.writeUInt8(0);
    } else {
        // 8 alpha bits
        out.writeUInt8(8);
    }

    // Image ID (zero length)

    if (m_channels == 1) {
        // Pixels are upside down in BGR format.
        for (int y = m_height - 1; y >= 0; --y) {
            for (int x = 0; x < m_width; ++x) {
                uint8 p = (m_byte[(y * m_width + x)]);
                out.writeUInt8(p);
                out.writeUInt8(p);
                out.writeUInt8(p);
            }
        }
    } else if (m_channels == 3) {
        // Pixels are upside down in BGR format.
        for (int y = m_height - 1; y >= 0; --y) {
            for (int x = 0; x < m_width; ++x) {
                uint8* p = &(m_byte[3 * (y * m_width + x)]);
                out.writeUInt8(p[2]);
                out.writeUInt8(p[1]);
                out.writeUInt8(p[0]);
            }
        }
    } else {
        // Pixels are upside down in BGRA format.
        for (int y = m_height - 1; y >= 0; --y) {
            for (int x = 0; x < m_width; ++x) {
                uint8* p = &(m_byte[4 * (y * m_width + x)]);
                out.writeUInt8(p[2]);
                out.writeUInt8(p[1]);
                out.writeUInt8(p[0]);
                out.writeUInt8(p[3]);
            }
        }
    }

    // Write "TRUEVISION-XFILE " 18 bytes from the end
    // (with null termination)
    out.writeString("TRUEVISION-XFILE ");
}