Resolution in OSR Browser

[andreykrasnodar]

How to set high resolution (for example, 2560x2048 px) and display it on small (for example, 320x240) paintbox32?

[salvadordf]

You would need to use a hidden Tbitmap in the Tchromium.onpaint event instead of using the paintbox32 directly.
Then draw the tbitmap into the paintbox32.

[andreykrasnodar]

I do not understand. Do you have an example code?

[salvadordf]

I'm sorry but I don't have an example.

In fact, we repleaced the paintbox32 component long ago due to some resizing issues and now CEF4Delphi and OldCEF4Delphi use a custom made component.

[andreykrasnodar]

I still do not understand.
I need 2 things:
1. Resizing with scaling down (for example twice low).
2. Drawing cursor on browser.

[andreykrasnodar]

You would need to use a hidden Tbitmap in the Tchromium.onpaint event instead of using the paintbox32 directly.
Then draw the tbitmap into the paintbox32.

How can I send buffer of TChromium into TBitmap?

[salvadordf]

In OSR browser you have the bitmap with the browser contents in the TBufferPanel.Buffer property.

Don't forget to call TBufferPanel.BeginBufferDraw and TBufferPanel.EndBufferDraw before and after you read the bitmap.
https://github.com/salvadordf/OldCEF4De ... l.pas#L254

[andreykrasnodar]

I found the solution. To decrease screen size twice you should make 2 cycles.
1st from 0 to screen height (maybe screen height minus 1, does not matter) with skipping every 2nd line
2nd from 0 to screen width with moving 4 bytes (one pixel) from Chromium's buffer into PaintBox32's buffer and skipping next 4 bytes.
I have decreased my screen 4x. The code is (but it will not work in yours projects)

Code: Select all

  for j := 0 to height - 1 do       //построчный проход
  begin
    for i := 0 to (width) do        //каждый байт строки
    begin
        src := @PByte(buffer)[(width*j*4+i)*16];
        dst := @PByte(Bits)[(width*j+i)*4];
        Move(src^, dst^, 4);
    end;
  end;

But the next strings of code is

Code: Select all

        PaintBox.Flush(Rect(dirtyRects[j].x, dirtyRects[j].y,
        dirtyRects[j].x + dirtyRects[j].width,  dirtyRects[j].y + dirtyRects[j].height));
        finally
        Unlock;
        PaintBox.Canvas.Unlock;

I really do not know what are dirtyrects and how to repaint only rects that was changed.

[salvadordf]

The dirtyrects are the bitmap areas that need to be repainted.

The SimpleOSRBrowser uses that information to update the bitmap :
https://github.com/salvadordf/OldCEF4De ... r.pas#L456