galfar.imaginglib/Doc/VampyreDoc/Procedures/High/High.xml

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<doc>
  <title>How To ... (High Level)</title>
  <chapter>
    <title>How To ... (High Level)</title>

    <par>High Level interface in the current version is made of
    the base class <ref>TBaseImage</ref> and its two descendants
    <ref>TSingleImage</ref> and <ref>TMultiImage</ref>.
    More information on the current state of high level interface
    can be found in
    <link url="../Usage/HighLevel.xml">Usage/High Level Interface</link>
    section.</par>

    <par>You can learn how to use high level interface from the
    following code fragments or (more useful) high level
    <link url="../Demos/Pascal.xml">Pascal Demos</link>.</par>

    <code>
// high level interface test
<b>uses</b>
  ImagingTypes,
  // high level classes are declared in this unit
  ImagingClasses;
<b>var</b>
  // this is one level image container
  SImg: <ref>TSingleImage</ref>;
  // this is multi level image container
  MImg: <ref>TMultiImage</ref>;
<b>begin</b>
  // new 400x300x24 image is created
  SImg := <ref>TSingleImage</ref>.CreateFromParams(400, 300, ifR8G8B8);
  // resize image
  SImg.Resize(512, 384, rfBicubic);
  // you can find out whether image is valid or not this way:
  <b>if</b> SImg.Valid <b>then</b>
    WriteLn('Image is valid!');
  // you are free to use low level functions on high level classes
  // you can use ImageData property to get access to underlying structure
  SwapChannels(SImg.ImageDataPointer^, ChannelRed, ChannelGreen);
  // image can be converted to another format by simply setting Format property
  SImg.Format := ifIndex8;
  // extended format info is accessible trough FormatInfo property
  WriteLn('Image has ', SImg.FormatInfo.PaletteEntries, ' palette entries');

  // new multi image without parameters is created (default sized 1 level image
  // will be created)
  MImg := <ref>TMultiImage</ref>.Create;
  // single image is assigned to multi image - multi image will now have
  // one level identical to source single image
  MImg.Assign(SImg);
  // single image is resized
  SImg.Width := SImg.Width * 2;
  // new level is added to multi image (SImg is cloned)
  MImg.AddLevel(SImg);
  // single image is converted
  SImg.Format := ifR32F;
  // new level is inserted to multi image at index 0 (SImg is cloned)
  MImg.InsertLevel(0, SImg);
  // all levels of multi image are written to stream
  MImg.SaveMultiToStream('tga', SomeStream);

  // images are freed
  SImg.Free;
  MImg.Free;
<b>end.</b>
    </code>


  </chapter>
</doc>