[fpc-pascal] bug fpc-image

[Mattias Gaertner]

On Sat, 7 Jul 2012 14:40:14 +0200
tazio mirandola <devsmt at gmail.com> wrote:

> hi all,
> 
> i'm trying to resize a jpg via fpc-image, this is the relevant code(adapted
> from http://wiki.freepascal.org/fcl-image):
> 
> 
> uses
>   fpimage, fpcanvas, FPImgCanv,  fpreadjpeg,fpwritejpeg;
> 
> procedure TImgResize.Resample(AFileName:string);
> var
>     Image : TFPCustomImage;
>     writer : TFPCustomImageWriter;
>     Reader : TFPReaderJPEG;
>     Canvas : TFPCustomCanvas;
> begin
>   // Create an image
>   Image := TFPMemoryImage.Create(224,150);
> 
>   Reader := TFPReaderJPEG.Create;
>   Image.LoadFromFile(AFileName (*, Reader*) );
> 
>   //Image.SetSize(224,150);
> 
>   // Attach the image to the canvas
>   Canvas := TFPImageCanvas.Create(image);
> 
>   // Create the writer
>   Writer := TFPWriterJPEG.Create;
> 
>   // Save to file
>   Image.SetSize(224,150);
>   Image.SaveToFile(AFileName+'b.jpg' (*, writer*) );
> 
>   Canvas.Free;
>   Image.Free;
>   Writer.Free;
> end;
> 
> actually, Image.SetSize(224,150); causes half of the resulting image being
> black!
> is it a bug or am i colling it wrongly?

It seems a bug in TFPMemoryImage.SetSize.
The move moves only w byte, but it should move w*SizeOf(TFPColor) byte.
Please report.

BTW, SetSize does not scale the image.

Mattias