Changes between Version 5 and Version 6 of FDORfc1


Ignore:
Timestamp:
03/13/07 20:17:29 (18 years ago)
Author:
gregboone
Comment:

--

Legend:

Unmodified
Added
Removed
Modified

  • FDORfc1

    v5 v6  
    2727== Motivation ==
    2828
    29 The FDO API FdoRasterDataModel class currently includes a property to determine the number of bits per pixel returned in an FdoIRaster data stream. The FdoIRaster data stream contains the raw raster image data.
     29The FDO API !FdoRasterDataModel class currently includes a property to determine the number of bits per pixel returned in an FdoIRaster data stream. The FdoIRaster data stream contains the raw raster image data.
    3030
    3131/// \brief[[BR]]
    32 /// The FdoRasterDataModel specifies the data type and organization[[BR]]
     32/// The !FdoRasterDataModel specifies the data type and organization[[BR]]
    3333/// of raster data retrieved and stored. Using this class and the image[[BR]]
    3434/// extents in width and length, the binary format of the image data returned[[BR]]
    3535/// by and accepted by the FdoIStreamReader class can be interpreted.[[BR]]
    36 class FdoRasterDataModel: public FdoIDisposable[[BR]]
    37 {[[BR]]
    38 public:[[BR]]
    39 
    40 …[[BR]]
    41 …[[BR]]
    42 [[BR]]
    43     /// \brief[[BR]]
    44     /// Get the number of bits per pixel.[[BR]]
    45     /// [[BR]]
    46     /// \return[[BR]]
    47     /// Returns the number of bits for each pixel. For multi-channel[[BR]]
    48     /// data the bits per channel will be this value devided by the numer of[[BR]]
    49     /// channels. For example, RGB data has three channels, so if this[[BR]]
    50     /// method returns twelve, each channel is four bits.[[BR]]
    51     /// [[BR]]
    52     FDO_API virtual FdoInt32 GetBitsPerPixel ();[[BR]]
    53 
    54     /// \brief[[BR]]
    55     /// Set the number of bits per pixel.[[BR]]
    56     /// [[BR]]
    57     /// \param bpp [[BR]]
    58     /// The number of bits per pixel desired.[[BR]]
    59     /// Values of 1, 4, 8, 16, 24, 32, 48 and 64 bits per channel may[[BR]]
    60     /// be supported. Others values (i.e. indivisible by the number of channels)[[BR]]
    61     /// are likely to raise a FdoException.[[BR]]
    62     /// [[BR]]
    63     FDO_API virtual void SetBitsPerPixel (FdoInt32 bpp);[[BR]]
    64 …[[BR]]
    65 …[[BR]]
    66 [[BR]]
    67 };[[BR]]
    68 
    69 However, returning only the bits per pixel is not sufficient to quickly and efficiently process the raster stream. The user should also be made aware of the bits used per pixel. In certain circumstances, the raster image does not completely use all available bits and pads the extra bits in the raster stream with NULL values. Without knowing the bits used per pixel, the client has to spend processing cycles determining how many bits are used thus affecting the performance of their applications.
    70 
    71 This issue was identified by IKonus, a corporate user of the FDO API.
    72 
    73 == Proposed Solution ==
    74 
    75 The FDO FdoRasterDataModel class will be extended to export the number of bits used per pixel.
    76 
    77 /// \brief[[BR]]
    78 /// The FdoRasterDataModel specifies the data type and organization[[BR]]
    79 /// of raster data retrieved and stored. Using this class and the image[[BR]]
    80 /// extents in width and length, the binary format of the image data returned[[BR]]
    81 /// by and accepted by the FdoIStreamReader class can be interpreted.[[BR]]
    82 class FdoRasterDataModel: public FdoIDisposable[[BR]]
     36class !FdoRasterDataModel: public !FdoIDisposable[[BR]]
    8337{[[BR]]
    8438public:[[BR]]
    … …  
    9650    /// method returns twelve, each channel is four bits.[[BR]]
    9751    /// [[BR]]
    98     FDO_API virtual FdoInt32 GetBitsPerPixel ();[[BR]]
     52    FDO_API virtual !FdoInt32 !GetBitsPerPixel ();
    9953
    10054    /// \brief[[BR]]
    … …  
    10559    /// Values of 1, 4, 8, 16, 24, 32, 48 and 64 bits per channel may[[BR]]
    10660    /// be supported. Others values (i.e. indivisible by the number of channels)[[BR]]
    107     /// are likely to raise a FdoException.[[BR]]
     61    /// are likely to raise a !FdoException.[[BR]]
    10862    /// [[BR]]
    109     FDO_API virtual void SetBitsPerPixel (FdoInt32 bpp);[[BR]]
     63    FDO_API virtual void !SetBitsPerPixel (!FdoInt32 bpp);
     64
     65…[[BR]]
     66…[[BR]]
     67
     68};[[BR]]
     69
     70However, returning only the bits per pixel is not sufficient to quickly and efficiently process the raster stream. The user should also be made aware of the bits used per pixel. In certain circumstances, the raster image does not completely use all available bits and pads the extra bits in the raster stream with NULL values. Without knowing the bits used per pixel, the client has to spend processing cycles determining how many bits are used thus affecting the performance of their applications.
     71
     72This issue was identified by IKonus, a corporate user of the FDO API.
     73
     74== Proposed Solution ==
     75
     76The FDO !FdoRasterDataModel class will be extended to export the number of bits used per pixel.
     77
     78/// \brief[[BR]]
     79/// The !FdoRasterDataModel specifies the data type and organization[[BR]]
     80/// of raster data retrieved and stored. Using this class and the image[[BR]]
     81/// extents in width and length, the binary format of the image data returned[[BR]]
     82/// by and accepted by the FdoIStreamReader class can be interpreted.[[BR]]
     83class !FdoRasterDataModel: public !FdoIDisposable[[BR]]
     84{[[BR]]
     85public:[[BR]]
     86
     87…[[BR]]
     88…[[BR]]
     89
     90    /// \brief[[BR]]
     91    /// Get the number of bits per pixel.[[BR]]
     92    /// [[BR]]
     93    /// \return[[BR]]
     94    /// Returns the number of bits for each pixel. For multi-channel[[BR]]
     95    /// data the bits per channel will be this value devided by the numer of[[BR]]
     96    /// channels. For example, RGB data has three channels, so if this[[BR]]
     97    /// method returns twelve, each channel is four bits.[[BR]]
     98    /// [[BR]]
     99    FDO_API virtual !FdoInt32 !GetBitsPerPixel ();[[BR]]
     100
     101    /// \brief[[BR]]
     102    /// Set the number of bits per pixel.[[BR]]
     103    /// [[BR]]
     104    /// \param bpp [[BR]]
     105    /// The number of bits per pixel desired.[[BR]]
     106    /// Values of 1, 4, 8, 16, 24, 32, 48 and 64 bits per channel may[[BR]]
     107    /// be supported. Others values (i.e. indivisible by the number of channels)[[BR]]
     108    /// are likely to raise an !FdoException.[[BR]]
     109    /// [[BR]]
     110    FDO_API virtual void !SetBitsPerPixel (!FdoInt32 bpp);[[BR]]
    110111
    111112    /// \brief[[BR]]
    … …  
    118119    /// method returns twelve, each channel uses four bits.[[BR]]
    119120    /// [[BR]]
    120     FDO_API virtual FdoInt32 GetBitsUsedPerPixel ();[[BR]]
     121    FDO_API virtual !FdoInt32 !GetBitsUsedPerPixel ();[[BR]]
    121122
    122123    /// \brief[[BR]]
    … …  
    129130    /// This method is primarily being defined for object construction purposes[[BR]]
    130131    /// within the provider and would not be called by client applications.[[BR]]
    131     FDO_API virtual void SetBitsUsedPerPixel (FdoInt32 bpp);[[BR]]
     132    FDO_API virtual void !SetBitsUsedPerPixel (!FdoInt32 bpp);[[BR]]
    132133
    133134…[[BR]]
    … …  
    142143This API change is applicable for all raster formats. Image formats who do not explicitly advertise their bitsUserPerPixel will have this value set to the value of bitsPerPixel.
    143144
    144 This ECO is being written in order to better support ongoing development using the FDO Raster providers. Existing customers such as AutoCAD Map and MapGuide have implemented work-arounds to calculate the bitsUsedPerPixel manually.  While this calculation affects performance, the cost is slight. 
     145This ECO is being written in order to better support ongoing development using the FDO Raster providers. Existing customers such as AutoCAD Map and !MapGuide have implemented work-arounds to calculate the bitsUsedPerPixel manually.  While this calculation affects performance, the cost is slight. 
    145146
    146147== Test Plan ==
    147148
    148 Raster Provider unit tests should be expanded to include usage of the new GetBitsUsedPerPixel Property
     149Raster Provider unit tests should be expanded to include usage of the new !GetBitsUsedPerPixel Property
    149150
    150151== Impact of Not Implementing this ECO ==