more graphics woes
lazarus / 39-Graphics

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liewald · 2019-01-30 09:53

Lazarus 1.8.4 r57972 FPC 3.0.4 x86_64-win64-win32/win64

Simple one this time I hope

For some reason drawing a TBGRABitmap to a form canvas is failing with
no error and no image begin displayed on the canvas

simple enough code

procedure TImageform.FormPaint(Sender: TObject);
begin
   imageform.Canvas.Draw(0,0,image.Bitmap);
end;

also tried

image.draw(imageform.canvas,0,0)

Thanks in advance

Dave

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circular · 2019-01-30 19:10

Surprising.

Have you checked that the image contains something for example by
doing image.SaveToFile ?

Regards

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liewald · 2019-01-30 19:35

Yup and I can assign it to a timage

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lucamar · 2019-01-30 20:12

See this: BGRABitmap tutorial (2) - Draw the bitmap

For more info: BGRABitmap Tutorial, a 16 wiki-pages tutorial on using
TBGRABitmap.

ETA

BTW, when using properties of a form inside its class you shouldn't
qualify them with the name of the instance i.e. this should be enough:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TImageform.FormPaint(Sender: TObject);begin   Canvas.Draw(0, 0,
image.Bitmap);{or at most, Self.Canvas.Draw(...)}{ Idem for: 
image.draw(Canvas, 0, 0);}end;

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liewald · 2019-01-30 21:34

Yup that was the original code. didn't work either been at this for 2
days

only thing a bit different is that the menu making the calls is on the
main form and the canvas is on a secondary form but the code is on the
canvas form.

Dave

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liewald · 2019-01-30 21:41

This is the setup I want. here I'm using a timage rather than the
canvas and it works ok but for a number of reasons I would rather use
a tcanvas!

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circular · 2019-01-31 18:10

Are you calling FormPaint ? This may not always work. Rather call
Invalidate.

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liewald · 2019-01-31 19:43

will give it a try

Dave

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liewald · 2019-02-11 11:03

got it thanks all