void camelot_png_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
{
iostream *fp = (iostream *)png_get_io_ptr(png_ptr);
png_uint_32 check = png_uint_32(length);
if (fp)
fp->write((const char*)data, check);
else
png_error(png_ptr, "Write Error");
if (check != length)
{
png_error(png_ptr, "Write Error");
}
}
bool PNGImageFileType::write(const Image *OSG_PNG_ARG(pImage ),
std::ostream &OSG_PNG_ARG(os ),
const std::string &OSG_PNG_ARG(mimetype))
{
#ifdef OSG_WITH_PNG
png_structp png_ptr;
png_infop info_ptr;
if(pImage->getDimension() < 1 || pImage->getDimension() > 2)
{
FWARNING(("PNGImageFileType::write: invalid dimension %d!\n",
pImage->getDimension()));
return false;
}
/* Create and initialize the png_struct with the desired error handler
* functions. If you want to use the default stderr and longjump method,
* you can supply NULL for the last three parameters. We also check that
* the library version is compatible with the one used at compile time,
* in case we are using dynamically linked libraries. REQUIRED.
*/
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
0, &errorOutput, &warningOutput);
if(png_ptr == NULL)
return false;
/* Allocate/initialize the image information data. REQUIRED */
info_ptr = png_create_info_struct(png_ptr);
if(info_ptr == NULL)
{
png_destroy_write_struct(&png_ptr, NULL);
return false;
}
/* set up the output handlers */
png_set_write_fn(png_ptr, &os, &osWriteFunc, &osFlushFunc);
/* This is the hard way */
/* Set the image information here. Width and height are up to 2^31,
* bit_depth is one of 1, 2, 4, 8, or 16, but valid values also depend on
* the color_type selected. color_type is one of PNG_COLOR_TYPE_GRAY,
* PNG_COLOR_TYPE_GRAY_ALPHA, PNG_COLOR_TYPE_PALETTE, PNG_COLOR_TYPE_RGB,
* or PNG_COLOR_TYPE_RGB_ALPHA. interlace is either PNG_INTERLACE_NONE or
* PNG_INTERLACE_ADAM7, and the compression_type and filter_type MUST
* currently be PNG_COMPRESSION_TYPE_BASE and PNG_FILTER_TYPE_BASE. REQUIRED
*/
Int32 ctype;
switch(pImage->getPixelFormat())
{
case Image::OSG_L_PF:
ctype = PNG_COLOR_TYPE_GRAY;
break;
case Image::OSG_LA_PF:
ctype = PNG_COLOR_TYPE_GRAY_ALPHA;
break;
#if defined(GL_BGR) || defined(GL_BGR_EXT)
case Image::OSG_BGR_PF:
#endif
case Image::OSG_RGB_PF:
ctype = PNG_COLOR_TYPE_RGB;
break;
#if defined(GL_BGRA) || defined(GL_BGRA_EXT)
case Image::OSG_BGRA_PF:
#endif
case Image::OSG_RGBA_PF:
ctype = PNG_COLOR_TYPE_RGB_ALPHA;
break;
default:
FWARNING(("PNGImageFileType::write: unknown pixel format %d!\n",
pImage->getPixelFormat()));
png_destroy_write_struct(&png_ptr, NULL);
return false;
}
Int32 bit_depth;
switch(pImage->getDataType())
{
case Image::OSG_UINT8_IMAGEDATA:
bit_depth = 8;
break;
case Image::OSG_UINT16_IMAGEDATA:
bit_depth = 16;
break;
default:
FWARNING (("Invalid pixeldepth, cannot store data\n"));
return false;
};
png_set_IHDR(png_ptr, info_ptr, pImage->getWidth(), pImage->getHeight(),
bit_depth,ctype,
PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_BASE,
PNG_FILTER_TYPE_BASE);
// set resolution png supports only meter per pixel,
// so we do a conversion from dpi with some rounding.
png_uint_32 res_x = png_uint_32(pImage->getResX());
png_uint_32 res_y = png_uint_32(pImage->getResY());
if(pImage->getResUnit() == Image::OSG_RESUNIT_INCH)
{
res_x = png_uint_32((pImage->getResX() * 39.37007874f) < 0.0f ?
(pImage->getResX() * 39.37007874f) - 0.5f :
(pImage->getResX() * 39.37007874f) + 0.5f);
res_y = png_uint_32((pImage->getResY() * 39.37007874f) < 0.0f ?
(pImage->getResY() * 39.37007874f) - 0.5f :
(pImage->getResY() * 39.37007874f) + 0.5f);
}
png_set_pHYs(png_ptr, info_ptr, res_x, res_y,
PNG_RESOLUTION_METER);
#if 0
/* optional significant bit chunk */
/* if we are dealing with a grayscale image then */
sig_bit.gray = true_bit_depth;
/* otherwise, if we are dealing with a color image then */
sig_bit.red = true_red_bit_depth;
sig_bit.green = true_green_bit_depth;
sig_bit.blue = true_blue_bit_depth;
/* if the image has an alpha channel then */
sig_bit.alpha = true_alpha_bit_depth;
png_set_sBIT(png_ptr, info_ptr, sig_bit);
/* Optional gamma chunk is strongly suggested if you have any guess
* as to the correct gamma of the image.
*/
png_set_gAMA(png_ptr, info_ptr, gamma);
/* Optionally write comments into the image */
text_ptr[0].key = "Title";
text_ptr[0].text = "Mona Lisa";
text_ptr[0].compression = PNG_TEXT_COMPRESSION_NONE;
text_ptr[1].key = "Author";
text_ptr[1].text = "Leonardo DaVinci";
text_ptr[1].compression = PNG_TEXT_COMPRESSION_NONE;
text_ptr[2].key = "Description";
text_ptr[2].text = "<long text>";
text_ptr[2].compression = PNG_TEXT_COMPRESSION_zTXt;
#ifdef PNG_iTXt_SUPPORTED
text_ptr[0].lang = NULL;
text_ptr[1].lang = NULL;
text_ptr[2].lang = NULL;
#endif
png_set_text(png_ptr, info_ptr, text_ptr, 3);
#endif
/* other optional chunks like cHRM, bKGD, tRNS, tIME, oFFs, pHYs, */
/* note that if sRGB is present the gAMA and cHRM chunks must be ignored
* on read and must be written in accordance with the sRGB profile */
/* Write the file header information. REQUIRED */
png_write_info(png_ptr, info_ptr);
#if BYTE_ORDER == LITTLE_ENDIAN
if (bit_depth == 16)
png_set_swap(png_ptr);
#endif
#if 0
/* invert monochrome pixels */
png_set_invert_mono(png_ptr);
/* Shift the pixels up to a legal bit depth and fill in
* as appropriate to correctly scale the image.
*/
png_set_shift(png_ptr, &sig_bit);
/* pack pixels into bytes */
png_set_packing(png_ptr);
/* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into
* RGB (4 channels -> 3 channels). The second parameter is not used.
*/
png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
/* swap bytes of 16-bit files to most significant byte first */
png_set_swap(png_ptr);
/* swap bits of 1, 2, 4 bit packed pixel formats */
png_set_packswap(png_ptr);
#endif
if(pImage->getPixelFormat() == Image::OSG_BGR_PF ||
pImage->getPixelFormat() == Image::OSG_BGRA_PF )
{
/* flip BGR pixels to RGB */
png_set_bgr(png_ptr);
/* swap location of alpha bytes from ARGB to RGBA */
png_set_swap_alpha(png_ptr);
}
/* The easiest way to write the image (you may have a different memory
* layout, however, so choose what fits your needs best). You need to
* use the first method if you aren't handling interlacing yourself.
*/
png_bytep *row_pointers = new png_bytep [pImage->getHeight()];
for(Int32 k = 0; k < pImage->getHeight(); k++)
{
row_pointers[k] =
(const_cast<UInt8 *>(pImage->getData())) +
(pImage->getHeight() - 1 - k) *
pImage->getWidth() * pImage->getBpp();
}
/* write out the entire image data in one call */
png_write_image(png_ptr, row_pointers);
/* It is REQUIRED to call this to finish writing the rest of the file */
png_write_end(png_ptr, info_ptr);
/* clean up after the write, and free any memory allocated */
png_destroy_write_struct(&png_ptr, &info_ptr);
delete [] row_pointers;
/* that's it */
return true;
#else
SWARNING << getMimeType()
<< " write is not compiled into the current binary "
<< endLog;
return false;
#endif
}
bool PNGImageFileType::read( Image *OSG_PNG_ARG(pImage ),
std::istream &OSG_PNG_ARG(is ),
const std::string &OSG_PNG_ARG(mimetype))
{
#ifdef OSG_WITH_PNG
bool retCode;
Image::PixelFormat pixelFormat = OSG::Image::OSG_INVALID_PF;
png_structp png_ptr;
png_infop info_ptr;
png_uint_32 width, wc, height, h, i, res_x, res_y;
png_byte bit_depth, channels, color_type;
png_bytep *row_pointers, base;
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
if(!png_ptr)
return false;
png_set_error_fn(png_ptr, 0, &errorOutput, &warningOutput);
info_ptr = png_create_info_struct(png_ptr);
if(!info_ptr)
{
png_destroy_read_struct(&png_ptr, 0, 0);
return false;
}
if(setjmp(png_ptr->jmpbuf))
{
png_destroy_read_struct(&png_ptr, &info_ptr, 0);
return false;
}
png_set_read_fn(png_ptr, &is, &isReadFunc);
png_read_info(png_ptr, info_ptr);
width = png_get_image_width(png_ptr, info_ptr);
height = png_get_image_height(png_ptr, info_ptr);
bit_depth = png_get_bit_depth(png_ptr, info_ptr);
res_x = png_get_x_pixels_per_meter(png_ptr, info_ptr);
res_y = png_get_y_pixels_per_meter(png_ptr, info_ptr);
channels = png_get_channels(png_ptr, info_ptr);
color_type = png_get_color_type(png_ptr, info_ptr);
// Convert paletted images to RGB
if (color_type == PNG_COLOR_TYPE_PALETTE)
{
png_set_palette_to_rgb(png_ptr);
channels = 3;
bit_depth = 8;
}
// Convert < 8 bit to 8 bit
if(color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
{
png_set_gray_1_2_4_to_8(png_ptr);
bit_depth = 8;
}
#if BYTE_ORDER == LITTLE_ENDIAN
if (bit_depth == 16)
png_set_swap(png_ptr);
#endif
// Add a full alpha channel if there is transparency
// information in a tRNS chunk
if(png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
{
png_set_tRNS_to_alpha(png_ptr);
++channels;
}
Int32 dataType;
switch (bit_depth)
{
case 8:
dataType = Image::OSG_UINT8_IMAGEDATA;
break;
case 16:
dataType = Image::OSG_UINT16_IMAGEDATA;
break;
default:
FWARNING (( "Invalid bit_depth: %d, can not read png-data\n",
bit_depth ));
return false;
}
switch(channels)
{
case 1:
pixelFormat = Image::OSG_L_PF;
break;
case 2:
pixelFormat = Image::OSG_LA_PF;
break;
case 3:
pixelFormat = Image::OSG_RGB_PF;
break;
case 4:
pixelFormat = Image::OSG_RGBA_PF;
break;
};
if(pImage->set(pixelFormat, width, height,
1, 1, 1, 0.0, 0,
dataType))
{
// set resolution png supports only pixel per meter,
// so we do a conversion to dpi with some rounding.
res_x = png_uint_32((Real32(res_x) / 39.37007874f) < 0.0f ?
(Real32(res_x) / 39.37007874f) - 0.5f :
(Real32(res_x) / 39.37007874f) + 0.5f);
res_y = png_uint_32((Real32(res_y) / 39.37007874f) < 0.0f ?
(Real32(res_y) / 39.37007874f) - 0.5f :
(Real32(res_y) / 39.37007874f) + 0.5f);
pImage->setResX(Real32(res_x));
pImage->setResY(Real32(res_y));
pImage->setResUnit(Image::OSG_RESUNIT_INCH);
// Calculate the row pointers
row_pointers = new png_bytep[height];
wc = width * channels * (bit_depth / 8);
h = height - 1;
base = pImage->editData();
for(i = 0; i < height; ++i)
row_pointers[i] = base + (h - i) * wc;
// Read the image data
png_read_image(png_ptr, row_pointers);
delete[] row_pointers;
retCode = true;
}
else
{
retCode = false;
}
png_destroy_read_struct(&png_ptr, &info_ptr, 0);
return retCode;
#else
SWARNING << getMimeType()
<< " read is not compiled into the current binary "
<< std::endl;
return false;
#endif
}
