Delphi: How to print multiple images in one page using Printer? - delphi

Question

I cannot seem to figure out how to print multiple images in one page using Printer,
I want to display images side by side like this:
But the problem is the images always display in full page like this:
I have this code:
procedure TForm1.Button1Click(Sender: TObject);
var
MyRect: TRect;
scale: Double;
Bitmap : TBitmap;
i: integer;
begin
try
Bitmap := TBitmap.Create;
Bitmap.Width := Image1.Picture.Width;
Bitmap.Height := Image1.Picture.Height;
Bitmap.Canvas.Draw(0,0,Image1.Picture.Graphic);
if PrintDialog1.Execute then
begin
if Printer.Orientation = poPortrait then
scale := GetDeviceCaps(Printer.Handle, LOGPIXELSX) / Screen.PixelsPerInch
else
scale := GetDeviceCaps(Printer.Handle, LOGPIXELSY) / Screen.pixelsperinch;
Printer.BeginDoc;
MyRect := Rect(0,0, trunc(Bitmap.Width * scale), trunc(Bitmap.Height * scale));
Printer.Canvas.StretchDraw(MyRect, Bitmap);
Printer.EndDoc;
end;
finally
Bitmap.Free;
end;
end;
I want to the printer to printout images side by side, how can I accomplish that?
Can any one help me please?
Update:
procedure TForm1.Button1Click(Sender: TObject);
var
MyRect: TRect;
scale: Double;
Bitmap : TBitmap;
i, x, y, width, height, img_count: integer;
begin
Bitmap := TBitmap.Create;
x := 0;
y := 0;
img_count := 3;
try
begin
Bitmap.Width := Image1.Picture.Width;
Bitmap.Height := Image1.Picture.Height;
Bitmap.Canvas.Draw(0,0,Image1.Picture.Graphic);
if PrintDialog1.Execute then
begin
if Printer.Orientation = poPortrait then
scale := GetDeviceCaps(Printer.Handle, LOGPIXELSX) / Screen.PixelsPerInch
else
scale := GetDeviceCaps(Printer.Handle, LOGPIXELSY) / Screen.pixelsperinch;
Printer.BeginDoc;
for i := 1 to img_count do
begin
width := trunc(Bitmap.Width * scale / img_count);
height := trunc(Bitmap.Height * scale / img_count);
MyRect := Rect(x, y, width, height);
Printer.Canvas.StretchDraw(MyRect, Bitmap);
x := x + width;
end;
Printer.EndDoc;
end;
end;
finally
Bitmap.Free;
end;
end;
Now it displays the images like sticking at each other, an I want them to display with a little margin between them:
This is when I add margins:
This is without margins:

Answer 1

You have to halfway understand your code, then it will all become obvious. Canvas and Rect are literally just that - and if you max your rectangle out by scale you'll never put two pictures side by side. Cut the values in half and use understand the parameters of functions - I'll use more variables to make it more obvious why your approach is very easy to solve:
var
x, y, width, height: Integer;
...
begin
...
Printer.BeginDoc;
x:= 0; // Start on top left
y:= 0;
width:= trunc( Bitmap1.Width* scale/ 2 ); // Half of the size
height:= trunc( Bitmap1.Height* scale/ 2 )
Printer.Canvas.StretchDraw( Rect( x, y, width, height ), Bitmap1 );
x:= width; // Continue after picture on the right side
width:= trunc( Bitmap2.Width* scale/ 2 ); // Again half of the size
height:= trunc( Bitmap2.Height* scale/ 2 )
Printer.Canvas.StretchDraw( Rect( x, y, width, height ), Bitmap2 );
Printer.EndDoc;
This example presumes Bitmap1 and Bitmap2 have similar dimensions.