Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!seismo!gatech!hao!oddjob!gargoyle!ihnp4!cuae2!killer!jlsoft!stdoil!marquez
From: marquez@stdoil.uucp (Manlio D. Marquez)
Newsgroups: comp.windows.x,comp.sys.pyramid
Subject: Porting X windows to Pyramid
Message-ID: <135@stdoil.uucp>
Date: Mon, 10-Aug-87 09:59:57 EDT
Article-I.D.: stdoil.135
Posted: Mon Aug 10 09:59:57 1987
Date-Received: Thu, 13-Aug-87 05:47:43 EDT
Organization: Standard Oil Production Company, Dallas
Lines: 77
Keywords: X windows Pyramid
Xref: mnetor comp.windows.x:1230 comp.sys.pyramid:45



Symptom:
When trying to install X windows V10R4 on a Pyramid 98x, programs that should
draw boxes instead draw garbage lines.

Cause:
X saves the vertices for line drawing in arrays of the structure Vertex

	 typedef struct _Vertex {
		 short x, y;
		 unsigned short flags;
	 } Vertex;

The Pyramid forces each array member to start on an integer (4 byte)
boundary with a 2 bytes filler between each element.  X uses a bcopy to
pack the data to be send to the server.  This causes the vertex array to
become skewed at the server end with filler bytes (zeros) being
interpreted as data.

Cure:
The routines that use Vertices (XDraw.c, XDrawDashed.c, XDrawFilled.c,
XDrawPatternd.c, XDrawTiled.c) should be changed to use a new routine
PackVert instead of PackData as follows:

(patch is for XDraw.c, others are similar)

25a26
> #ifndef PYRAMID
27a29,31
> #else
> 	PackVert(dpy, vlist, vcount);
> #endif

Change Xlib/XlibInternal.h as follows:

87c87,89
< 
---
> #ifndef PYRAMID
> #define PackVert	PackData
> #endif


Change Xlib/XlibInternal.c as follows:

397a398,417
> 
> #ifdef PYRAMID
> PackVert(dpy,vert,vcount)
> Display *dpy;
> Vertex *vert;
> int vcount;
> {
> 	register int j;
> 	register unsigned short *s = (unsigned short *)dpy->bufptr;
> 
> 	for(j = 0; j < vcount; j++) {
> 		*s++ = vert[j].x;
> 		*s++ = vert[j].y;
> 		*s++ = vert[j].flags;
> 	}
> 	dpy->bufptr = (char *)s;
> 	dpy->bufptr += 3;		/* pad */
> 	dpy->bufptr = (char *)((int)dpy->bufptr & ~3);
> }
> #endif

Make sure that PYRAMID is defined somewhere in the programs.

Similar changes may have to be made for version 11 of X windows.

Manlio D. Marquez
Standard Oil Production Company
(214)701-4027

(convex, texsun, smu, jlsoft)!stdoil!marquez