Re: [Openexr-devel] C API calls

[Florian Kainz]

What does "fail" mean in this case?  Does the application crash?
If it does, have you tried using a debugger to get a stack trace?

Does ImfOpenOutputFile return a null pointer?  If you do get a null
pointer, have you tried calling ImfErrorMessage() to find get some
diagnostic output?  Your example contains no error checking code.
Unlike the C++ interface, the C interface does not throw exceptions;
you must explicitly check the return values of the functions you call.

Thomas Lock wrote:
> Hi Drew
>
>              I completely rewrote my code to meet the C API calls. This time
> i get zero warnings or errors but the app specifically fails on this call
> "file = ImfOpenOutputFile(filenames, header, IMF_WRITE_RGBA );". I tried a
> variety of filename options and nothing seems to work. I can't verify if my
> remaining code works, but i believe it is correct.
>
> extern "C" void WINAPI writeOpenEXR (char *filename, int width, int height,
> float* Bits128)
> {
>         int LineWidth=width*4;
>         float fwidth;
>         const char fileName[] = "c:\foo2.exr";
>         const char *filenames = "c:\foo2.exr";
>
>         ImfOutputFile *file;
>         ImfRgba *base;
>         base = (ImfRgba *)malloc(width * height * sizeof(ImfRgba));
>         fwidth = (float)width;
>         ImfHeader *header;
>         header = ImfNewHeader();
>         ImfHeaderSetDisplayWindow(header, 0, 0, width - 1, height - 1);
>         ImfHeaderSetDataWindow(header, 0, 0, width - 1, height - 1);
>         ImfHeaderSetScreenWindowWidth(header, fwidth);
>         file = ImfOpenOutputFile(filenames, header, IMF_WRITE_RGBA );
>
>         ImfDeleteHeader(header);
>
>         for(int h=0;h<height;h++)for(int b=0;b<width;b++)
>        {
>             ImfHalf half;
>
>             int i=h*LineWidth+(b<<2);
>             int j=h*LineWidth+b;
>
>             ImfFloatToHalf(Bits128[i], &half);
>             base[j].b = half;
>
>             ImfFloatToHalf(Bits128[i + 1], &half);
>             base[j].g = half;
>
>             ImfFloatToHalf(Bits128[i + 2], &half);
>             base[j].r = half;
>
>             ImfFloatToHalf(Bits128[i + 3], &half);
>             base[j].a = half;
>         }
>
>         ImfOutputSetFrameBuffer( file, base, 1, width );
>         ImfOutputWritePixels(file, height );
>         ImfCloseOutputFile(file);
>
>         free(base);
> }
>
>
>
>
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