Re: [boost] [GIL] trying to clean up a small block of adhoc code

From: Michael Marcin (mike.marcin_at_[hidden])
Date: 2008-06-16 13:27:35

Ok so should this function?

gray32f_view_t noise =
        interleaved_view( width, height
                     , (gray32f_pixel_t*) &pBuffer[0]
                     , width * sizeof(float) // bytes per scanline
     );

gray32f_view_t src = subimage_view(noise,0,0,half_width,half_height);

copy_pixels( flipped_left_right_view(src), 
subimage_view(noise,half_width,0,half_width,half_height) );

copy_pixels( flipped_up_down_view(src), 
subimage_view(noise,0,half_height,half_width,half_height) );

copy_pixels( transposed_view(src), 
subimage_view(noise,half_width,half_height,half_width,half_height) );

Christian Henning wrote:
> Michael,
> 
> here is my version of your algorithm. Please have a look:
> 
> std::vector<float> buffer( 1024 * 1024 );
> //GenerateNoise( pBuffer, 1024, 1024 )
> 
> gray32f_view_t src = interleaved_view( 1024, 1024
>                                      , (gray32f_pixel_t*) &buffer.front()
>                                      , 1024 * 4 // bytes per scanline
>                                      );
> 
> for( int y = 0; y < src.height(); ++y )
> {
>     gray32f_view_t::x_iterator src_it = src.row_begin( y );
> 
>     float ycopy = y;
>     if(y > 511)
>     {
>         ycopy = 511 - std::abs( 512.f - ycopy );
>     }
> 
>     for( int x = 0; x < src.width(); ++x )
>     {
>         float xcopy = x;
> 
>         if(x > 511)
>         {
>             xcopy = 511 - std::abs( 512.f - xcopy );
>         }
> 
>         src_it[x] = src[xcopy][ycopy];
>     }
> }
>