Add option to embed PVSM state file text in PNG
PNG images can store arbitrary text in key/value pairs. See the function vtkPNGWriter::AddText(const char* key, const char* value)
for details.
Add an option in the Save Screenshot feature that will create the text for a PVSM state file and save that text in the PNG.
Note that the current key/value storage mechanism in vtkPNGWriter
uses compression PNG_TEXT_COMPRESSION_NONE
because the text is expected to be small. For large chunks of text, like a PVSM file, it is recommended to use PNG_TEXT_COMPRESSION_zTXt
.