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From Thibault Genessay, "The PNG plugin crashes when you try to read a malformed file (attached

Browse Source 
is an example). This can happen in circumstances that are not
manageable by the OSG itself (e.g. 3rd party buggy program) but one
would expect the plugin to be able to recover by returning
ReadResult::ERROR_IN_READING_FILE.

libpng provides two callbacks for warnings and errors - those are
currently unused. By default, they point to function that call exit()
or something similar (the default error callback never returns). This
patch registers the callbacks using libpng's mechanisms, makes the
warning callback emit an osg::notify(osg::WARN) message and the error
callback throw an error. The reading process is enclosed in a
try...catch block. Upon error, the memory is freed and
ReadResult::ERROR_IN_READING_FILE is returned.
"
This commit is contained in:
Robert Osfield
2008-05-28 13:51:56 +00:00
parent 7e0184f080
commit 8e91926ca5
1 changed files with 164 additions and 123 deletions
Download Patch File Download Diff File Expand all files Collapse all files

287
src/osgPlugins/png/ReaderWriterPNG.cpp
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@@ -32,6 +32,33 @@ typedef struct
unsigned int Alpha;
} pngInfo;
class PNGError
{
public:
PNGError(const char* message)
{
_message = "PNG lib error : ";
_message += message;
}
friend std::ostream& operator<<(std::ostream& stream, const PNGError& err)
{
stream << err._message;
return stream;
}
private:
std::string _message;
};
void user_error_fn(png_structp png_ptr, png_const_charp error_msg)
{
throw PNGError(error_msg);
}
void user_warning_fn(png_structp png_ptr, png_const_charp warning_msg)
{
osg::notify(osg::WARN) << "PNG lib warning : " << warning_msg << std::endl;
}
void png_read_istream(png_structp png_ptr, png_bytep data, png_size_t length)
{
std::istream *stream = (std::istream*)png_get_io_ptr(png_ptr); //Get pointer to istream
@@ -131,137 +158,151 @@ class ReaderWriterPNG : public osgDB::ReaderWriter
png_uint_32 i;
png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
info = png_create_info_struct(png);
endinfo = png_create_info_struct(png);
// Set custom error handlers
png_set_error_fn(png, png_get_error_ptr(png), user_error_fn, user_warning_fn);
fin.read((char*)header,8);
if (fin.gcount() == 8 && png_check_sig(header, 8))
png_set_read_fn(png,&fin,png_read_istream); //Use custom read function that will get data from istream
else
try
{
png_destroy_read_struct(&png, &info, &endinfo);
return ReadResult::FILE_NOT_HANDLED;
}
png_set_sig_bytes(png, 8);
png_read_info(png, info);
png_get_IHDR(png, info, &width, &height, &depth, &color, NULL, NULL, NULL);
info = png_create_info_struct(png);
endinfo = png_create_info_struct(png);
if (pinfo != NULL)
{
pinfo->Width = width;
pinfo->Height = height;
pinfo->Depth = depth;
}
osg::notify(osg::INFO)<<"width="<<width<<" height="<<height<<" depth="<<depth<<std::endl;
if ( color == PNG_COLOR_TYPE_RGB) osg::notify(osg::INFO) << "color == PNG_COLOR_TYPE_RGB "<<std::endl;
if ( color == PNG_COLOR_TYPE_GRAY) osg::notify(osg::INFO) << "color == PNG_COLOR_TYPE_GRAY "<<std::endl;
if ( color == PNG_COLOR_TYPE_GRAY_ALPHA) osg::notify(osg::INFO) << "color == PNG_COLOR_TYPE_GRAY_ALPHA"<<std::endl;
// png default to big endian, so we'll need to swap bytes if on a little endian machine.
if (depth>8 && getCpuByteOrder()==osg::LittleEndian)
png_set_swap(png);
if (color == PNG_COLOR_TYPE_GRAY || color == PNG_COLOR_TYPE_GRAY_ALPHA)
{
//png_set_gray_to_rgb(png);
}
if (color&PNG_COLOR_MASK_ALPHA && trans != PNG_ALPHA)
{
png_set_strip_alpha(png);
color &= ~PNG_COLOR_MASK_ALPHA;
}
// if (!(PalettedTextures && mipmap >= 0 && trans == PNG_SOLID))
//if (color == PNG_COLOR_TYPE_PALETTE)
// png_set_expand(png);
// In addition to expanding the palette, we also need to check
// to expand greyscale and alpha images. See libpng man page.
if (color == PNG_COLOR_TYPE_PALETTE)
png_set_palette_to_rgb(png);
if (color == PNG_COLOR_TYPE_GRAY && depth < 8)
png_set_gray_1_2_4_to_8(png);
if (png_get_valid(png, info, PNG_INFO_tRNS))
png_set_tRNS_to_alpha(png);
// Make sure that files of small depth are packed properly.
if (depth < 8)
png_set_packing(png);
/*--GAMMA--*/
// checkForGammaEnv();
double screenGamma = 2.2 / 1.0;
if (png_get_gAMA(png, info, &fileGamma))
png_set_gamma(png, screenGamma, fileGamma);
else
png_set_gamma(png, screenGamma, 1.0/2.2);
png_read_update_info(png, info);
data = (png_bytep) new unsigned char [png_get_rowbytes(png, info)*height];
row_p = new png_bytep [height];
bool StandardOrientation = true;
for (i = 0; i < height; i++)
{
if (StandardOrientation)
row_p[height - 1 - i] = &data[png_get_rowbytes(png, info)*i];
fin.read((char*)header,8);
if (fin.gcount() == 8 && png_check_sig(header, 8))
png_set_read_fn(png,&fin,png_read_istream); //Use custom read function that will get data from istream
else
row_p[i] = &data[png_get_rowbytes(png, info)*i];
{
png_destroy_read_struct(&png, &info, &endinfo);
return ReadResult::FILE_NOT_HANDLED;
}
png_set_sig_bytes(png, 8);
png_read_info(png, info);
png_get_IHDR(png, info, &width, &height, &depth, &color, NULL, NULL, NULL);
if (pinfo != NULL)
{
pinfo->Width = width;
pinfo->Height = height;
pinfo->Depth = depth;
}
osg::notify(osg::INFO)<<"width="<<width<<" height="<<height<<" depth="<<depth<<std::endl;
if ( color == PNG_COLOR_TYPE_RGB) osg::notify(osg::INFO) << "color == PNG_COLOR_TYPE_RGB "<<std::endl;
if ( color == PNG_COLOR_TYPE_GRAY) osg::notify(osg::INFO) << "color == PNG_COLOR_TYPE_GRAY "<<std::endl;
if ( color == PNG_COLOR_TYPE_GRAY_ALPHA) osg::notify(osg::INFO) << "color == PNG_COLOR_TYPE_GRAY_ALPHA"<<std::endl;
// png default to big endian, so we'll need to swap bytes if on a little endian machine.
if (depth>8 && getCpuByteOrder()==osg::LittleEndian)
png_set_swap(png);
if (color == PNG_COLOR_TYPE_GRAY || color == PNG_COLOR_TYPE_GRAY_ALPHA)
{
//png_set_gray_to_rgb(png);
}
if (color&PNG_COLOR_MASK_ALPHA && trans != PNG_ALPHA)
{
png_set_strip_alpha(png);
color &= ~PNG_COLOR_MASK_ALPHA;
}
// if (!(PalettedTextures && mipmap >= 0 && trans == PNG_SOLID))
//if (color == PNG_COLOR_TYPE_PALETTE)
// png_set_expand(png);
// In addition to expanding the palette, we also need to check
// to expand greyscale and alpha images. See libpng man page.
if (color == PNG_COLOR_TYPE_PALETTE)
png_set_palette_to_rgb(png);
if (color == PNG_COLOR_TYPE_GRAY && depth < 8)
png_set_gray_1_2_4_to_8(png);
if (png_get_valid(png, info, PNG_INFO_tRNS))
png_set_tRNS_to_alpha(png);
// Make sure that files of small depth are packed properly.
if (depth < 8)
png_set_packing(png);
/*--GAMMA--*/
// checkForGammaEnv();
double screenGamma = 2.2 / 1.0;
if (png_get_gAMA(png, info, &fileGamma))
png_set_gamma(png, screenGamma, fileGamma);
else
png_set_gamma(png, screenGamma, 1.0/2.2);
png_read_update_info(png, info);
data = (png_bytep) new unsigned char [png_get_rowbytes(png, info)*height];
row_p = new png_bytep [height];
bool StandardOrientation = true;
for (i = 0; i < height; i++)
{
if (StandardOrientation)
row_p[height - 1 - i] = &data[png_get_rowbytes(png, info)*i];
else
row_p[i] = &data[png_get_rowbytes(png, info)*i];
}
png_read_image(png, row_p);
delete [] row_p;
png_read_end(png, endinfo);
GLenum pixelFormat = 0;
GLenum dataType = depth<=8?GL_UNSIGNED_BYTE:GL_UNSIGNED_SHORT;
switch(color)
{
case(PNG_SOLID): pixelFormat = GL_LUMINANCE; break;
case(PNG_ALPHA): pixelFormat = GL_ALPHA; break;
case(PNG_COLOR_TYPE_GRAY): pixelFormat =GL_LUMINANCE ; break;
case(PNG_COLOR_TYPE_GRAY_ALPHA): pixelFormat = GL_LUMINANCE_ALPHA; break;
case(PNG_COLOR_TYPE_RGB): pixelFormat = GL_RGB; break;
case(PNG_COLOR_TYPE_PALETTE): pixelFormat = GL_RGB; break;
case(PNG_COLOR_TYPE_RGB_ALPHA): pixelFormat = GL_RGBA; break;
default: break;
}
// Some paletted images contain alpha information. To be
// able to give that back to the calling program, we need to
// check the number of channels in the image. However, the
// call might not return correct information unless
// png_read_end is called first. See libpng man page.
if (pixelFormat == GL_RGB && png_get_channels(png, info) == 4)
pixelFormat = GL_RGBA;
int internalFormat = pixelFormat;
png_destroy_read_struct(&png, &info, &endinfo);
// delete [] data;
if (pixelFormat==0)
return ReadResult::FILE_NOT_HANDLED;
osg::Image* pOsgImage = new osg::Image();
pOsgImage->setImage(width, height, 1,
internalFormat,
pixelFormat,
dataType,
data,
osg::Image::USE_NEW_DELETE);
return pOsgImage;
}
png_read_image(png, row_p);
delete [] row_p;
png_read_end(png, endinfo);
GLenum pixelFormat = 0;
GLenum dataType = depth<=8?GL_UNSIGNED_BYTE:GL_UNSIGNED_SHORT;
switch(color)
catch (PNGError& err)
{
case(PNG_SOLID): pixelFormat = GL_LUMINANCE; break;
case(PNG_ALPHA): pixelFormat = GL_ALPHA; break;
case(PNG_COLOR_TYPE_GRAY): pixelFormat =GL_LUMINANCE ; break;
case(PNG_COLOR_TYPE_GRAY_ALPHA): pixelFormat = GL_LUMINANCE_ALPHA; break;
case(PNG_COLOR_TYPE_RGB): pixelFormat = GL_RGB; break;
case(PNG_COLOR_TYPE_PALETTE): pixelFormat = GL_RGB; break;
case(PNG_COLOR_TYPE_RGB_ALPHA): pixelFormat = GL_RGBA; break;
default: break;
osg::notify(osg::WARN) << err << std::endl;
png_destroy_read_struct(&png, &info, &endinfo);
return ReadResult::ERROR_IN_READING_FILE;
}
// Some paletted images contain alpha information. To be
// able to give that back to the calling program, we need to
// check the number of channels in the image. However, the
// call might not return correct information unless
// png_read_end is called first. See libpng man page.
if (pixelFormat == GL_RGB && png_get_channels(png, info) == 4)
pixelFormat = GL_RGBA;
int internalFormat = pixelFormat;
png_destroy_read_struct(&png, &info, &endinfo);
// delete [] data;
if (pixelFormat==0)
return ReadResult::FILE_NOT_HANDLED;
osg::Image* pOsgImage = new osg::Image();
pOsgImage->setImage(width, height, 1,
internalFormat,
pixelFormat,
dataType,
data,
osg::Image::USE_NEW_DELETE);
return pOsgImage;
}
int getCompressionLevel(const osgDB::ReaderWriter::Options *options) const