sfguofen

hello,I encountered some problems in my homework.I was working on one small software.It's to draw flowchart . I was asked to save my flowchart in png format,but I don't konw how to do it.the file system of png is to hard for me.I am wondering is there exists any library can help me to solve the problem.We cannot coding in c# or using .net.we can only using c++ or some libraries in c++.I was very worry about it ,because the deadline is coming.Can anyone give me any advice.

brewbuck

You want to use libpng.

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sfguofen

Yes , i konw the library , however , i don't know how to set up the libpng in visual c++ 6.0,would you give me some book or some ur related to setting up the libpng in visual c++

Mario F.

You should read the information available to you more closely...

• Go to libpng homepage.
• Take notice of the current version (1.2.39)
• There's a readme section, so you should read it. Clicking on the first link in this section (local website), you'll learn that the file to download for windows is named lbpng1239.zip. You can also download a .7z or a .tar.bz2 version.
• Going back to the homepage you'll scroll down to the download section, aptly named Source Code.
• You download the zip version.
• You open the zip file and read the INSTALL file within. It points you out to the location of the building instructions for windows: projects\visualc71\README.txt if you are using visual studio 2005 or later, or projects\visualc6\README.txt if you are using visual studio 6.0.
• You follow the instructions

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Originally Posted by brewbuck:
Reimplementing a large system in another language to get a 25% performance boost is nonsense. It would be cheaper to just get a computer which is 25% faster.

sfguofen

Thank you , I appreciate your help in setting up the libpng , but now another problem occured , It's that when I press CTRL+F5 to run the Pngtest , an message box about "Please specify the executable file.".It's said that the project need one .exe. but how can I build one executable file.

sfguofen

Thank you again.I have solve the problem, and I can run the pngtest.exe now .

Alex31

You don't need libpng or any lib on Windows (never, api does everything)
Png is native with Win32 api, like all formats (shell apis and others)

Mario F.

Win32API is a library. libpng is a library. He needs something (eve if it meant writing his own). The option that was offered to him is probably the simplest and easiest to use, since the win32 api comes with a steep learning curve and is overkill for the one and only requirement he mentioned; ability to create a png file.

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Originally Posted by brewbuck:
Reimplementing a large system in another language to get a 25% performance boost is nonsense. It would be cheaper to just get a computer which is 25% faster.

Dae

Ew. o.0

sfguofen

O ， I have read the manual of libpng ， but I think only read the manual is not enough , for example ,png_write_image(png_ptr, row_pointers) , I don't know how the rows is made up .I think i need some examples about , how to draw picture in memory that I can use png_write_image() to save my picture directly

sfguofen

I need to draw one flowchart in memory and save it in the png format . is there are any examples that can help me solve that problem.