Number: 1665

Date: 18-Jul-84 15':25':45

Submitter: Burton.pa

Source: kaplan.pa

Subject: draw curve overflows

Lisp Version: 15-Jul-84 23':23':32

Description: from ar 1614':'
Date':  4 JUL 84 17':03 PDT'
From': KAPLAN.PA'
Subject': DRAWCURVE flakiness'
To':   LISPSUPPORT, SYBALSKY, BURTON'
'
Goes into raid if dashing is non-NIL, and also seems to go bananas in certain situations when the knots get fairly big negatively (-2000).  I can replicate the example.'
'
--Ron'
'
rrb':  A test case that screws up (DRAWCURVE ''((100 . 100) (-2200 . 0)(100 . -2200) T 1 NIL window).  It causes vertical lines to be drawn across the window.'
'
The code inside \CURVE which does the calculations in done in rationals with 12 bits of integer part.  If the numbers in the knots get less than -2048 overflow occurs.  It would be a significant amount of work to redo it.  Hopefully  the boxing solution will allow us to use floating pt instead.  Status change to wait for floating pt.'
'
'


Workaround: 

Test Case: 

Edit-By: 

Edit-Date: 18-Jul-84 15':25':45

Attn: Burton

Assigned To: burton, kaplan

In/By: 

Disposition: 

System: Windows and Graphics

Subsystem: Window System

Machine: 

Disk: 

Microcode Version: 5124

Memory Size: 4096

File Server: 

Server Software Version: 

Difficulty: Moderate

Frequency: Intermittent

Impact: Annoying

Priority: Perhaps

Status: Open

Problem Type: Bug

Source Files: