hej!
boy.. did i screw up! ? :(
ok.. i sat back and had a serious redesign of the Cube3D
application - started using the -Wall option - cleaned up
all data types etc.
if i do this:
scrnBuffer = WinGetDrawWindow();
backBuffer = WinCreateOffscreenWindow();
and every time i draw something i do this:
SetDrawWindow(backBuffer);
WinDraw...
SetDrawWindow(scrnBuffer);
and then forget to do this:
WinCopyRectangle(backBuffer, scrnBuffer, ...);
i should get NOTHING on the screen? this is because all the
drawing occurs to the buffer, and it is never copied to the
screen.
i commented out the WinCopyRectangle, and it still drew to the
screen. why? because i had done something really STUPID in
my attempt to try and get this stuff working.
the problem is WinInitializeWindow()
here are the specs:
---
Purpose: Initialize the screen-dependant members of a
WindowType structure and set the window's
clipping bounds to the window's bounds.
Prototype: void WinInitializeWindow(WinHandle winHandle)
Parameters: winHandle Handle of a window.
Result: Returns nothing.
See Also: WinCreateWindow
---
my interpretation was that the scrnBuffer and backBuffer
objects would have the same properties.. (as in size,
clipping etc)..
what i overlooked was that one of these properties was the
screen address (in memory).
hence the double buffering did not work.
(ie: the backBuffer was the scrnBuffer)
i should have dug around the header files a bit more to see
what the hell this "WindowType" structure was.
---
typedef struct WinTypeStruct {
Word displayWidth;
Word displayHeight;
VoidPtr displayAddr; <---- this!!
WindowFlagsType windowFlags;
RectangleType windowBounds;
AbsRectType clippingBounds;
PointType viewOrigin;
FrameBitsType frameType;
GraphicStatePtr gstate;
struct WinTypeStruct *nextWindow;
} WindowType;
typedef WindowType *WinPtr;
typedef WinPtr WinHandle;
---
my screw up. removed the function call, and now it all works like
a dream.
however, i did find the documentation a bit hard to understand as
there is no stated relationship between WinHandle and WindowType.
(maybe there is - but i have not read the whole document yet)
it is only available if one looks inside the <UI/Window.h>
header file.
at least we know the answer to this question if it pops up again!
cheers.
az.
--
Aaron Ardiri
Lecturer http://www.hig.se/~ardiri/
University-College i G�vle mailto:[EMAIL PROTECTED]
SE 801 76 G�vle SWEDEN
Tel: +46 26 64 87 38 Fax: +46 26 64 87 88
Mob: +46 70 352 8192 A/H: +46 26 10 16 11
