Hello,

I was just wondering if anyone can explain me how in fact masked_blit works?

As we already know, masked_blit eliminates background that could be in various colors and displays sprite we want to blit to the screen.

Well, I would like to show you some example as I did experiment quite a bit with this command and I cant understand how and when it "removes" background and what are the cases needed to be satasfied in order it to do so?

1st example:

When I use masked_blit on this picture: http://img27.imageshack.us/i/doggle.png/

It sucssesfuly removes pink background and shows "doggy" in black screen background. Perfect!

2nd example:

But here I got Linux "Tux" mascot, that also has pink background. When I use masked_blit with it then it dosen't remove pink background - but in fact it displays it!

Why is that so? What needs to be done with picture in order to masked_blit only show sprite itself? Another color in bitmap's background?

I did set pixel_depth(32) also but problem with "Tux" still remains.

BUT - I did solve this in a specific way:

I used "Eyedroppe tool" from Photoshop and used "specific pink" from "doggy" picture and used it on "Tux" picture as background color.

After that - masked_blit with "Tux" picture worked PERFECT!.

So my questions is in fact:

Why does masked_blit only removes specific color of background and how to manipulate it better? Should I always color my pictures with that "specific pink" in order to masked_blit remove it afterwards? How it works is right question

Thanks!

Thanks,

Anyway, could anyone be more technical about this?

Also, when I did put "shade of pink" on background of "Tux", in my program masked_blit did remove background, but lines of "tux" bitmap did left pink colored.

Like this:
http://img132.imageshack.us/i/87703854.jpg/

What technique should I use to make most of my bitmap's background "pink shaded" so it works perfectly with masked_blit or even with draw_bitmap?

That topic did help me a lot, thanks.

Anyway, I just wanted to ask - no need to open another topic:

Is there easy way to me load .PNG files with Allegro? Some stabile and easy to use library with tutorials?

I am using Microsoft Visual Studio 2008 Express edition SP1.

Thanks.

Thanks, but can I use this library without installing libpng and zlib? Atleast basic functions like loading .PNG file and displaying it on screen?

Well in fact it is, because I don't get .lib files with it but need to get trough process of compiling them or whatnot and to things be better - it's so on Linux side of things and there is no tutorial how to implement this on VS 2008 Express SP1 IDE.

I think I will need to learn more about libraryes and process of their implementation before I can use these things. Any tutorials that are worth studying?

OK, I did try to use these libraryes and here is my test code :

I get this error:

1>Compiling...
1>Main.cpp
1>Linking...
1>LINK : C:\Users\ReiKo\Documents\Visual Studio 2008\Projects\Test3\Debug\Test3.exe not found or not built by the last incremental link; performing full link
1>Main.obj : error LNK2019: unresolved external symbol _load_png referenced in function "int __cdecl _mangled_main(void)" (?_mangled_main@@YAHXZ)
1>C:\Users\ReiKo\Documents\Visual Studio 2008\Projects\Test3\Debug\Test3.exe : fatal error LNK1120: 1 unresolved externals
1>Build log was saved at "file://c:\Users\ReiKo\Documents\Visual Studio 2008\Projects\Test3\Debug\BuildLog.htm"

I did link these libraryes:

alld.lib lpngce.lib zlibce.lib

Anything that I'm missing here? Maybe I should link loadpng .lib but I don't have any .lib files from that library. How to get them?

Sorry if questions are a bit stupid but I'm trying my best to learn.

Oh...I see, because I couldn't find libraryes for my platform as "Schyfis" said, there is only:

HP-UX
Linux
Solaris

I don't see any of them for Windows... maybe I should get Linux one and try it out? Or compile Linux one? It seems that getting this thing to work on Windows platfrom is not so easy or am I wrong?

Thanks.

I give up.

http://www.google.com/#hl=en&q=libpng+msvc+8&aq=f&oq=&aqi=&fp=VEE02fthf5k

Works for me

The stuff in the Google search box is
libpng msvc 8

Thanks on the link, currently I'm trying to compile dll's from "loadpng" library, I did include like it said "zdll.dll" and "libpng.dll" libraryes but I get this error:

1>LINK : fatal error LNK1561: entry point must be defined

I also did linked adll.lib from Allegro library.

I sense I'm close but some part of puzzle is missing

you need to somehow tell MSVC that you're creating a library when you're building zlib and libpng.

Not well enough it seems

Great hint, now I'm on right track, I did sucsessfuly(altough with 5 warnings) compiled loadpng library.