Bitmap New/Graphic Window

[Walt Decker]

When defining a memory bitmap or a graphic window the width and height are specified, e.g.

BITMAP NEW 80, 80 TO BmpHndl
GRAPHIC WINDOW "", 0, 0, 80, 80 TO WinHndl

Does the width/height parameters define the bmp/graphic window from 0 (zero) to width/height or from 0 (zero) to width/height - 1?

[Chris Boss]

If it works the same as the API, then a bitmap which is 80 x 80 would have coordinates:

X - 0 to 79
Y - 0 to 79

when drawing, unless you change the viewport (which most don't).

[Petr Schreiber jr]

Hi,

I must admit I am little bit confused here.

Try following code:

#COMPILE EXE
#DIM ALL

FUNCTION PBMAIN () AS LONG

  ' Create and show a Graphic window on screen

  LOCAL hWin AS DWORD
  LOCAL hBmp AS DWORD
  LOCAL sBits AS STRING
                          
  GRAPHIC BITMAP NEW 130, 130 TO hBmp
  GRAPHIC WINDOW "Box", 300, 300, 130, 130 TO hWin
  GRAPHIC ATTACH hWin, 0
  GRAPHIC BOX (0, 0) - (130, 130), 0, %WHITE, %RED

  SLEEP 1000  ' show it for 5 seconds, then end
  
  GRAPHIC GET BITS TO sBits
  MSGBOX "Window resolution"+STR$(CVL(sBits,1))+STR$(CVL(sBits,5))
  
  GRAPHIC ATTACH hBmp, 0
  GRAPHIC GET BITS TO sBits
  MSGBOX "Bitmap resolution"+STR$(CVL(sBits,1))+STR$(CVL(sBits,5))

  GRAPHIC BITMAP END
  
  GRAPHIC ATTACH hWin, 0
  GRAPHIC WINDOW END
                      
END FUNCTION

Resolution for both bitmap and window is returned as 130x130. But in such a case one of the white contours of box should not be rendered, because (0,0)-(130,130) means having side of 131 pixels.
On my PC the box is rendered completely, nothing is missing.

Let me know if it is just my PC ( PowerBASIC for Windows, 8.04 ) or feature.


Petr

[Walt Decker]

Petr, I see two white lines, top and left.

[Walt Decker]

Thanks, Chris. I thought that was the way it worked, but wasn't sure.

[Petr Schreiber jr]

Thanks Walt,

output on your PC is what I would expect.
I will send report to PB tomorrow.


Petr