Does GetPixel work with TBGRABitmap?
lazarus / 39-Graphics

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user5 · 2019-12-17 09:59

I can't get GetPixel(x,y) to work with TBGRABitmap. The code below
keeps coming up with clNone. Can someone show me what I'm doing wrong
or show me a simple example of how to use GetPixel with TBGRABitmap?
Thanks.

    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
TForm1.Button12Click(Sender: TObject);var mybitmap:TBitmap;   
bgra:TBGRABitmap;    tempcolor:TColor;   
tempstr:string;begin  mybitmap := TBitmap.create; mybitmap.width :=
image1.width; mybitmap.height := image1.height; mybitmap.assign(image1
.picture.bitmap); application.processmessages;  bgra := TBGRABitmap.cr
eate(mybitmap.width,mybitmap.height); bgra.assign(mybitmap);  tempcolo
r := bgra.GetPixel(30,30); tempstr :=
ColorToString(tempcolor); edit1.text :=
tempstr;  bgra.free; mybitmap.free; end;

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user5 · 2019-12-17 12:00

I did some research and testing and found something that works. If
anyone is interested the code below works with GetPixel and
BGRABitmap. Thanks anyway.

    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
TForm1.Button12Click(Sender: TObject);var mybitmap:TBitmap;   
bgra:TBGRABitmap;    tempcolor:TColor;    tempstr:string;    c:
TBGRAPixel;begin  mybitmap := TBitmap.create; mybitmap.width :=
image1.width; mybitmap.height := image1.height; mybitmap.assign(image1
.picture.bitmap); application.processmessages;  bgra := TBGRABitmap.cr
eate(mybitmap.width,mybitmap.height); bgra.assign(mybitmap);  c :=
bgra.GetPixel(30,30); tempcolor := BGRAToColor(c);  tempstr :=
ColorToString(tempcolor); edit1.text :=
tempstr;  bgra.free; mybitmap.free; end;

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circular · 2019-12-19 15:53

You can try something like
bgra.GetPixel(30,30).ToColor

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winni · 2019-12-19 16:29

@user5

You can simplify your code. Your lines 15 & 16 could be pulled to one
line.

From

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 bgra := TBG
RABitmap.create(mybitmap.width,mybitmap.height);bgra.assign(mybitmap);
To

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 bgra :=
TBGRABitmap.create(mybitmap); 
It creates a TBGRABitmap with height and width of myBitmap and then it
make a copy.

Winni