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From Farshid Lashkari, support for writing to istream for the the TIFF plugin and support for

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controlling PNG compression level via the the ReaderWriter::Option string "PNG_COMPRESSION <level>"
This commit is contained in:
Robert Osfield
2006-03-02 20:39:20 +00:00
parent 8796f37acb
commit cdc8b13f14
2 changed files with 179 additions and 3 deletions
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26
src/osgPlugins/png/ReaderWriterPNG.cpp
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@@ -8,6 +8,8 @@
#include <osgDB/FileUtils>
#include <osgDB/FileNameUtils>
#include <sstream>
using namespace osg;
extern "C"
@@ -54,7 +56,7 @@ class ReaderWriterPNG : public osgDB::ReaderWriter
virtual const char* className() const { return "PNG Image Reader/Writer"; }
virtual bool acceptsExtension(const std::string& extension) const { return osgDB::equalCaseInsensitive(extension,"png"); }
WriteResult::WriteStatus writePngStream(std::ostream& fout, const osg::Image& img) const
WriteResult::WriteStatus writePngStream(std::ostream& fout, const osg::Image& img, int compression_level) const
{
png_structp png = NULL;
png_infop info = NULL;
@@ -72,6 +74,9 @@ class ReaderWriterPNG : public osgDB::ReaderWriter
//Set custom write function so it will write to ostream
png_set_write_fn(png,&fout,png_write_ostream,png_flush_ostream);
//Set compression level
png_set_compression_level(png, compression_level);
switch(img.getPixelFormat()) {
case(GL_LUMINANCE): color = PNG_COLOR_TYPE_GRAY; break;
case(GL_ALPHA): color = PNG_COLOR_TYPE_GRAY; break; //Couldn't find a color type for pure alpha, using gray instead
@@ -259,6 +264,23 @@ class ReaderWriterPNG : public osgDB::ReaderWriter
return pOsgImage;
}
int getCompressionLevel(const osgDB::ReaderWriter::Options *options) const
{
if(options) {
std::istringstream iss(options->getOptionString());
std::string opt;
while (iss >> opt) {
if(opt=="PNG_COMPRESSION") {
int level;
iss >> level;
return level;
}
}
}
return Z_DEFAULT_COMPRESSION;
}
virtual ReadResult readImage(std::istream& fin,const Options* =NULL) const
{
return readPNGStream(fin);
@@ -281,7 +303,7 @@ class ReaderWriterPNG : public osgDB::ReaderWriter
virtual WriteResult writeImage(const osg::Image& img,std::ostream& fout,const osgDB::ReaderWriter::Options *options) const
{
WriteResult::WriteStatus ws = writePngStream(fout,img);
WriteResult::WriteStatus ws = writePngStream(fout,img,getCompressionLevel(options));
return ws;
}