Design Scripting Documentation


	Read bitmap pixel from file (slower access, lower memory)


	Inputs:

the bitmap object
the x, y coordinates


	Outputs:

color value of the pixel

Implementation

01  function bmp_readpixel( bitmap, x, y )
02    dim bpp: bpp = bitmap( BMP_INFO )( BMP_BITS ) \ 8
03    dim bps: bps = ( ( ( bitmap( BMP_INFO )( BMP_WIDTH ) * bitmap( BMP_INFO )( BMP_BITS ) ) + 31 ) \ 32 ) * 4
04    dim offset: offset = bitmap( BMP_HEADER )( BMP_BITOFFSET ) + x * bpp + y * bps
05    call file_moveto( bitmap( BMP_FILE ), offset )
06    select case bitmap( BMP_INFO )( BMP_BITS )
07      case 32
08        bmp_readpixel = file_readdword( bitmap( BMP_FILE ) )
09      case 24
10        dim b: b = file_readbyte( bitmap( BMP_FILE ) )
11        dim g: g = file_readbyte( bitmap( BMP_FILE ) )
12        dim r: r = file_readbyte( bitmap( BMP_FILE ) )
13        bmp_readpixel = rgb( r, g, b )
14      case else
15        bmp_readpixel = -1
16    end select
17  end function

The Design Scripting Library, including its sources, online documentation and graphics, are licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License.

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Page timestamp: { Feb. 2, 2006 }