// Add a filler byte on read, or remove a filler or alpha byte on write.
// The filler type has changed in v0.95 to allow future 2-byte fillers
// for 48-bit input data, as well as to avoid problems with some compilers
// that don't like bytes as parameters.
public void png_set_filler(uint filler, PNG_FILLER filler_loc)
{
transformations |= PNG_TRANSFORMATION.FILLER;
this.filler = (ushort)filler;
if (filler_loc == PNG_FILLER.AFTER)
{
flags |= PNG_FLAG.FILLER_AFTER;
}
else
{
flags &= ~PNG_FLAG.FILLER_AFTER;
}
// This should probably go in the "do_read_filler" routine.
// I attempted to do that in libpng-1.0.1a but that caused problems
// so I restored it in libpng-1.0.2a
if (color_type == PNG_COLOR_TYPE.RGB)
{
usr_channels = 4;
}
// Also I added this in libpng-1.0.2a (what happens when we expand
// a less-than-8-bit grayscale to GA?
if (color_type == PNG_COLOR_TYPE.GRAY && bit_depth >= 8)
{
usr_channels = 2;
}
}
// Add a filler byte on read, or remove a filler or alpha byte on write.
// The filler type has changed in v0.95 to allow future 2-byte fillers
// for 48-bit input data, as well as to avoid problems with some compilers
// that don't like bytes as parameters.
public void png_set_filler(uint filler, PNG_FILLER filler_loc)
{
transformations|=PNG_TRANSFORMATION.FILLER;
this.filler=(ushort)filler;
if(filler_loc==PNG_FILLER.AFTER) flags|=PNG_FLAG.FILLER_AFTER;
else flags&=~PNG_FLAG.FILLER_AFTER;
// This should probably go in the "do_read_filler" routine.
// I attempted to do that in libpng-1.0.1a but that caused problems
// so I restored it in libpng-1.0.2a
if(color_type==PNG_COLOR_TYPE.RGB) usr_channels=4;
// Also I added this in libpng-1.0.2a (what happens when we expand
// a less-than-8-bit grayscale to GA?
if(color_type==PNG_COLOR_TYPE.GRAY&&bit_depth>=8) usr_channels=2;
}
public void png_set_add_alpha(uint filler, PNG_FILLER filler_loc)
{
png_set_filler(filler, filler_loc);
transformations |= PNG_TRANSFORMATION.ADD_ALPHA;
}
public void png_set_add_alpha(uint filler, PNG_FILLER filler_loc)
{
png_set_filler(filler, filler_loc);
transformations|=PNG_TRANSFORMATION.ADD_ALPHA;
}