undefined reference to `GUI_PNG_DrawEx' after adding png.h

janos · Apr 28th 2015, 5:41pm

Hello!

I downloaded the mentioned library, included gui\png\png.h to my code, but still I have undefined reference to GUI_PNG_DrawEx() function.
Do you have any idea? Are there any restrictions regarding the placing of the png library?

Thanks for your further answer!

SEGGER - Adrian · May 5th 2015, 10:49am

Hello,

Please add all of the files included in the PNG library to your project.

Best regards,
Adrian

janos · May 7th 2015, 9:54am

It happened, and it works.
Now the problem is that the GUI_PNG_DrawEx() function returns with 1 and picture is nit appearing. I have read that in case of PNG support emwin needs more RAM memory. How can be this requirement supported?

SEGGER - Adrian · May 7th 2015, 11:41am

Hello,

Please adapt the file GUIConf.c in order to assign more memory to emWin.

Best regards,
Adrian

smorgan · May 8th 2015, 4:26pm

I have also encountered the same issue when using the PNG library and had to allocate more memory for decoding. Also be aware that PNG decoding can be slow and will cause a longer rendering time than if you use a BMP for the graphic but it does give you a nice small memory footprint for the images you are rendering. If your graphics are very small the rendering time will not be noticeable but as the graphics get larger (>200x200 pixels) depending on the speed of your microprocessor you can find a noticeable rendering delay when the PNG library is decoding your graphics.

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