Q&A - Question

Hi
There is possible a minor bug there.

But try this (below). Same way you can draw PNG, BMP. JPG, SVG and WMF 

// global cache
mysymbol = SymbolList.Prepare( 'path\symbol.bmp?TRUE' ); // ?TRU to make it transparent


// and then upon drawing
mysymbol.Symbol.Prepare( Viewer,       // viewer reference
                         Size,       
                         Color,        // only vector symbols
                         OutlineColor, // only vector symbols
                         Angle,
                         0,            // gap only for fills
                         TGIS_LabelPosition.MiddleCenter,
                         True,         // if true then does not rotate with viewer rotation
                         renderer      // current renderer context
                       ) ;
mysymbol.Symbol.Draw( x, y ) ;
mysymbol.Symbol.Unprepare ;

So my attempt at implementing your solution has an invalid pointer exception when closing the custom paint demo. Wondering what I should be doing differently?

Here is what I did:
- I added GisSymbol to the uses list.

- I added a variable to the var list:
     symSchool    : TGIS_SymbolAbstract;

- I added this call in OnCreate:
     symSchool := TGIS_Utils.SymbolList.Prepare(sPath + '?TRUE');

- I added to OnDestroy:   FreeObject(symSchool);

- Then I added the following to GISPaintShapeEvent for Image2:
   var c : TGIS_Color; // undeclared, a dummy place holder for the Prepare method

    symSchool.Prepare(
      GIS,
      800,
      c,
      c,
      0,
      0,
      TGIS_LabelPosition.MiddleCenter,
      true);
    symSchool.Draw(pt.X, pt.Y);
    symSchool.Unprepare;

It draws with transparency, but on map close, I get the following now:
"Project CustomPaint.exe raised exception class EInvalidPointer with message 'Invalid pointer operation'. When I break, it heads into GisSymbol.pas.

What am I doing wrong?
Thanks,

Scott Lynn
 

 symSchool.Prepare(
      GIS,
      800,
      TGIS_Color.None,
      TGIS_Color.None,
      0,
      0,
      TGIS_LabelPosition.MiddleCenter,
      true);
    symSchool.Draw(pt.X, pt.Y);
    symSchool.Unprepare;

That works great. Thank you. We will work on converting our libraries to use these great new tools, especially to use PNGs instead of bitmaps anyway.

So back to my original question.
I have a B : TBitmap created by a function library. It is NOT loaded from a file path. It is in memory and ready to go.

How do I draw my B: TBitmap without saving it to a file and then loading it into a TGIS_Bitmap from that file. Or how do I convert a TBitmap to a TGIS_Bitmap in memory? Or draw it some other way?

Thanks,

Scott

procedure TForm1.GISPaintExtraEvent(_sender: TObject; _renderer: TGIS_RendererAbstract; _mode: TGIS_DrawMode);
var
  bmp_b  : TGIS_Bitmap;
  bmp_a : TBitmap;
begin
  bmp_a := TBitmap.Create;
  try
    bmp_a.LoadFromFile('police.bmp' );
    bmp_b := TGIS_Bitmap.Create;
    try
      bmp_b.LoadFromBitmap(bmp_a, '');
     _renderer.CanvasDrawBitmap( bmp_b, TRect.Create(0, 0, 32, 32) );
    finally
      bmp_b.Free ;
    end;
  finally
    bmp_a.Free ;
  end;
end;

a := SymboList.Prepare( 'mysymbol.bmp' );
b := SymboList.Prepare( 'mysymbol.bmp' );

// a is equal b

One more comment.

TGIS_Bitmap fully support ARGB while TBitmap (and generally Windows HBitmap) support for anything more than RGB is problematic.