PNG Plugin

[shanefarris]

This was just a simple proof of concept that one of our developers here at Skyvu http://sky.vu/ put together. We are considering using Ogre as an engine in the future, and FreeImage wasn't an option for us because we didn't want to open our entire engine. This was just a simple test, and only built on Windows, but if you have any issues, let us know and we'll do our best to help.

Here's the source, do whatever you want with it, no license.
https://github.com/Skyvu/PNG_plugin

Just the logo being rendered with the plugin and not FreeImage.

[spacegaier]

Thanks a lot for sharing this!

[c6burns]

If you opt for the FreeImage Public License then you don't have to. Still this is cool!

[shanefarris]

If you opt for the FreeImage Public License then you don't have to. Still this is cool!

Ok, good to know, I will need to look into this some more.

[fractile]

Thanks. I've been thinking of cutting down some unneeded Ogre dependencies and this might be exactly what I need, since I use only PNG textures. I'll be looking into this..

[fractile]

I switched from FreeImage to this and I have one little problem with it. RGB and RGBA textures load just fine, but loading PNG with 8-bit grayscale + alpha (saved by GIMP) does not work right. All transparent pixels are rendered black. If I save the same texture as 32-bit RGBA, it renders as it should.

[Transporter]

I had similar problems with FIPL. A known lawyer was not so happy about the license text. I've written an email to the FreeImage team to clear the vague parts. The reply was the following:

Hi,

First, you may be interested by similar and recurrent questions :
http://ehc.ac/p/freeimage/discussion/search/?q=license

Note that § 1.9 of the FIPL is a definition, not a requirement

Next, all you need to know is explained here :
http://freeimage.sourceforge.net/license.html

When using FreeImage in your commercial application, you are REQUIRED to :
distribute the FIPL license with your application (i.e. the TXT file)
provide a suitable acknowledgment, either in the program's "About" box or in the user's manual (or both)

That's all !
=> if its not clear enough for you : you can use FreeImage the way you want (provided you use the FIPL license), as long as you acknowledge the origin of the sources.

NB: if you have a lawyer on hand, I'd be happy to have recommendations on possible changes to the communication on the license or the license itself, so that this kind of question is no longer asked.

Best regards,
Hervé Drolon
FreeImage Project Manager

[austinkoehler]

I switched from FreeImage to this and I have one little problem with it. RGB and RGBA textures load just fine, but loading PNG with 8-bit grayscale + alpha (saved by GIMP) does not work right. All transparent pixels are rendered black. If I save the same texture as 32-bit RGBA, it renders as it should.

Hello, I am the original author of this PNG plugin. I've looked into your issue, fractile, and believe it's because I somehow skipped over the 4/4 Alpha/Luminance format.

In SkyVuPNGCodec.cpp, at line 148 in the bit_depth switch, replace cases 1, 2, and 4 with the following:

Code: Select all

case 1: case 2:
	imgData->format = PF_L8;
	break;
case 4:
	if(imgData->flags & PFF_LUMINANCE)
	{
		if(imgData->flags & PFF_HASALPHA)
		{
			imgData->format = PF_A4L4;
		}
		else
		{
			imgData->format = PF_L8;
		}
	}
	else // rgb
	{
		stream->close();
		png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
		OGRE_EXCEPT(Exception::ERR_INVALIDPARAMS,
		"Error: Unsupported format.",
		"PNGCodec::decode");
	}
	break;

I'm not 100% sure that this will fix the issue, as 8-bit color tends towards palette territory which Ogre doesn't seem to support.