workaround: don't call IMGDECMP.DLL

by **CodeFlatter** » Apr 5, 2009 @ 1:10pm

Ok, this workaround fixes all of my problems with this dll and call's of ::DecompressImageIndirect( &dii );

1. create a new method prototype
after line 52 at image.h

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// Load an image from a file
Surface* LoadImage( const TCHAR* filename );

// new code!
// Load an image from a file
Surface* LoadImageSH( const TCHAR* filename );[/b]
6 lines; 2 keywds; 0 nums; 13 ops; 0 strs; 3 coms    Syntactic Coloring v0.4 - Dan East

LoadImageSH calls SHLoadImageFile and don't needs separate memory mapping or decompress.

2. implement the new method at image.cpp
after line 240:

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Surface* LoadImage( const TCHAR* filename )
{
    Internal::MemoryFile file( filename );
    if (!file.IsOpen())
        return 0;

    return DecompressImage( file.begin(), file.end() );
}

// new code!
Surface* LoadImageSH( const TCHAR* filename )
{
    Surface* pSurface = NULL;

    HBITMAP hBitmap = SHLoadImageFile( filename );

    if( NULL != hBitmap )
    {
        pSurface = CreateSurface( hBitmap );
        DeleteObject( hBitmap );
    }

    return pSurface;
}
24 lines; 7 keywds; 1 nums; 55 ops; 0 strs; 1 coms    Syntactic Coloring v0.4 - Dan East

3. add pragma comment to image.cpp for new bindings
after line 24:

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#ifdef _WIN32_WCE
   #include "foreign/imgdecmp/imgdecmp.h"
   #pragma comment( lib, "imgdecmp.lib" )
// new code
   #pragma comment( lib, "Aygshell.lib" ) //new lib!
#else
6 lines; 5 keywds; 0 nums; 6 ops; 3 strs; 2 coms    Syntactic Coloring v0.4 - Dan East

4. don't call

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Surface* pSurface = LoadImage( pDisplay, _T( "\\Program Files\\...\\gfx.png" ) );
// or
Surface* pSurface = LoadImage( _T( "\\Program Files\\...\\gfx.png" ) );
3 lines; 0 keywds; 0 nums; 15 ops; 2 strs; 1 coms    Syntactic Coloring v0.4 - Dan East

better call

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Surface* pSurface = LoadImageSH( _T( "\\Program Files\\...\\gfx.png" ) );
1 lines; 0 keywds; 0 nums; 7 ops; 1 strs; 0 coms    Syntactic Coloring v0.4 - Dan East

5. recompile PocketFrog AND replace the lib's...

this works fine for me...[/code]

by **PsychoChris** » Apr 5, 2009 @ 8:37pm

Hi CodeFlatter,

i would suggest to completely avoid using SHLoadImageFile() for Windows Mobile 5.x and higher since it has some known issues regarding large images that lead to unpredictable failures while loading some images. Also avoid imgdecmp since it is deprecated. Better use the Imaging API.
It also supports loading thumbs, sizing operations, different decoders and also runs under pure WinCE. Only drawback: A little bit more code and usage of COM. But it is worth the effort.

Regards,
Chris[/url]

by **Presto** » Apr 6, 2009 @ 2:43pm

All of my games use the SHLoadImageFile, and I haven't run into any problems. In fact, I don't think I even started using that until WM5 because the original code became deprecated.

PsychoChris, do you know how large the image needs to be to start having problems? I know 240x1400ish work just fine.

-John

by **CodeFlatter** » Apr 6, 2009 @ 8:44pm

Thanks at PsychoChris and Presto!

I will see if I find code examples to use imaging api, com code is more complex...

Best regards
CF :roll:

by **PsychoChris** » Apr 6, 2009 @ 10:58pm

@ Presto:
We encountered not clearly reproducable problems using SHLoadImageFile() with images of dimensions 1600x1200 or larger. Especially images created by cameras of mobile devices. Those images loaded most times fine in the emulator but return NULL handles on devices although memory on the device was more than sufficiant. You can find similar issues by googling around. Solutions suggested by microsoft developers always pointed out avoiding that function and using Imaging API (see this link for instance).
Using the Imaging API we didn't encounter those problems anymore.

@ CodeFlatter:
Take a look at this link. It shows you how to implement loading images with Imaging API for WM 5.x and higher and also includes a fallback solution for older devices not providing that API.

Regards,
Chris

by **CodeFlatter** » Apr 7, 2009 @ 9:24am

Hello PsychoChris,

thx 4 the link, this page is helpfull - but use MFC code (no one of my mobile app's use MFC).
I need an example without MFC (using of MFC is impossible for me) or an simple code snipped...

Regards, CF

by **PsychoChris** » Apr 7, 2009 @ 12:57pm

Hi CodeFlatter,

the only function using MFC is LoadImageWithImagingApi(). Since MFC just wraps the Windows API you can actually unwrap the code and use Windows API calls instead. Here is how i would do it:

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HBITMAP LoadImageWithImagingApi(LPCTSTR lpFileName)
{
    IImagingFactory* pImgFactory = NULL;
    IImage*          pImage      = NULL;
    HBITMAP          hResultBmp  = NULL;

    ::CoInitializeEx(NULL, COINIT_MULTITHREADED);

    if( SUCCEEDED(CoCreateInstance( CLSID_ImagingFactory,
                                    NULL,
                                    CLSCTX_INPROC_SERVER,
                                    IID_IImagingFactory,
                                    (VOID**)&pImgFactory) ) )
    {
        ImageInfo imageInfo;

        if(     SUCCEEDED(pImgFactory->CreateImageFromFile(lpFileName, &pImage))
            &&  SUCCEEDED(pImage->GetImageInfo(&imageInfo))                      )
        {
            HDC     hDc       = ::GetDC(NULL);
            HDC     hDcBitmap = ::CreateCompatibleDC(hDc);
            HBITMAP hBitmap   = ::CreateCompatibleBitmap(hDc, imageInfo.Width, imageInfo.Height);
            if( hBitmap )
            {
                RECT    rcBitmap;
                HGDIOBJ hOldBitmap = ::SelectObject(hDcBitmap, hBitmap);
                if(    ::SetRect(&rcBitmap, 0, 0, imageInfo.Width, imageInfo.Height)
                    && pImage->Draw(hDcBitmap, &rcBitmap, NULL) == S_OK              )
                    hResultBmp = hBitmap;

                ::SelectObject(hDcBitmap, hOldBitmap);
            }

            ::ReleaseDC(NULL, hDc);
            ::ReleaseDC(NULL, hDcBitmap);

            pImage->Release();
        }
        pImgFactory->Release();
    }

    ::CoUninitialize();

    return hResultBmp;
}
45 lines; 5 keywds; 2 nums; 151 ops; 0 strs; 0 coms    Syntactic Coloring v0.4 - Dan East

Regards,
Chris

by **CodeFlatter** » Apr 7, 2009 @ 1:08pm

Hi Chris,

thats's really nice, thank you very much!!!

Best regards, CF

...and works fine! i'm happy now :lol:

by **Presto** » Apr 8, 2009 @ 2:27pm

Thanks for the great info and code, Chris!

Good luck with your app, CF!

by **CodeFlatter** » Apr 9, 2009 @ 9:14am

Thx Presto and dito. :-)

workaround: don't call IMGDECMP.DLL

workaround: don't call IMGDECMP.DLL

Thx 4 info

THX

Nice!

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`1 2 3 4 5 6`	`// Load an image from a file Surface* LoadImage( const TCHAR* filename ); // new code! // Load an image from a file Surface* LoadImageSH( const TCHAR* filename );[/b]`
	6 lines; 2 keywds; 0 nums; 13 ops; 0 strs; 3 coms Syntactic Coloring v0.4 - Dan East

`1 2 3 4 5 6`	`#ifdef _WIN32_WCE #include "foreign/imgdecmp/imgdecmp.h" #pragma comment( lib, "imgdecmp.lib" ) // new code #pragma comment( lib, "Aygshell.lib" ) //new lib! #else`
	6 lines; 5 keywds; 0 nums; 6 ops; 3 strs; 2 coms Syntactic Coloring v0.4 - Dan East

`1 2 3`	`Surface* pSurface = LoadImage( pDisplay, _T( "\\Program Files\\...\\gfx.png" ) ); // or Surface* pSurface = LoadImage( _T( "\\Program Files\\...\\gfx.png" ) );`
	3 lines; 0 keywds; 0 nums; 15 ops; 2 strs; 1 coms Syntactic Coloring v0.4 - Dan East

`1`	`Surface* pSurface = LoadImageSH( _T( "\\Program Files\\...\\gfx.png" ) );`
	1 lines; 0 keywds; 0 nums; 7 ops; 1 strs; 0 coms Syntactic Coloring v0.4 - Dan East