Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!apple!uokmax!drtiller
From: drtiller@uokmax.uucp (Donald Richard Tillery Jr)
Newsgroups: comp.sys.amiga
Subject: QBSBlit() problems - for Dave Haynie ?
Summary: I need help.
Keywords: DAVE HAYNIE C PROGRAMMING BLITTER
Message-ID: <1990Jul19.213606.23011@uokmax.uucp>
Date: 19 Jul 90 21:36:06 GMT
Sender: Rick Tillery for Eric McVicker
Organization: Engineering Computer Network, University of Oklahoma, Norman, OK
Lines: 51

Posted for Eric McVicker:

Dave,
 
I have a problem with QBSBlit(). The problem is it doesn't work!
I'm not sure about the bltnode structure or my C function it calls.
In the RKMs it has bltnode defined as...
                    struct bltnode {
                    struct bltnode *Next,
                    int (*function)(),
                    char stat,
                    char beamsync,
                    short blitsize,
                    int (*(cleanup)() };
I have it set up in my program as...
                    struct bltnode *MyBlitNode = {
                    NULL,        /* no other links */
                    &BlitScroll, /* my function */
                    0,           /* no cleanup */
                    189,         /* the scan line to cause the interrupt */
                    0,           /* DAVE, DOES BLITSIZE NEED TO BE SPECIFIED,
                                    AND IF SO HOW DO I FIND IT? */
                    NULL };      /* no cleanup function to call.
                                    DAVE, DO YOU NEED TO SPECIFY A CLEANUP
                                    FUNCTION EVEN IF YOU DONT NEED ONE */
The function I use for the interrupt is simple...
int BlitScroll()
{
   ...
   BlitBitMapRastPort(SourceBitMap, SourceX, SourceY, DestRastPort, DestX,
                      DestY, SizeX, SizeY, mask);
   return(0);
}
Thats not the exact function but thats all that uses the blitter. I return 0
because QBSBlit() says I must have a RTS at the end of my function and return 0
to show I'm done with the blitter.
If I use the function without trying to use QBSBlit() it works fine, but I get
screen flash, which is why I'm hassling with this.
When I use QBSBlit() it locks-up when I call QBSBlit().
So, what I'm asking is, is this function format legal? Do I need to know
blitsize? Or anything else you can tell me.
If you would like to post a code sample to explain the solution that would be
fine. I would appreciate any help I can get on this.
In case you need to know I'm using Manx C 3.6a.
 
                                        Thanks,
                                        Eric McVicker
                                        Gigabyte Programming

Any info for him can be addressed to me.  Thanx.
Rick Tillery