Number: 2180

Date: 14-Sep-84 09':21':16

Submitter: Sannella.PA

Source: tanner.pa

Subject: DRAWCURVE does bizarre things when the points are too far off the screen

Assigned To: 

Attn: Burton

Status: Open

In/By: 

Problem Type: Bug

Impact: Moderate

Difficulty: 

Frequency: 

Priority: Perhaps

System: Windows and Graphics

Subsystem: Window System

Machine: 1132

Disk: 

Lisp Version: 12-Sep-84 12':41':26

Source Files: 

Microcode Version: 5124

Memory Size: 4096

File Server: 

Server Software Version: 

Disposition: 

Description: '
Date': 13 Sep 84 14':37 PDT'
From': tanner.pa'
Subject': Lisp': DRAWCURVE does bizarre things when the points are too far off the screen'
To': LispSupport.pa'
cc': tanner.pa'
Lisp-System-Date':  3-Jul-84 16':01':03'
Machine-Type': Dandelion'
'
If the points passed to DRAWCURVE are far from the screen size, it draws  lines in some grid patterns. Call the following function  with': (Circle  300 300 2000 1 (CREATEW ''(100 100 400 400)))'
'
[DEFINEQ (CIRCLE'
(LAMBDA (x y r brush window) (* mct': "13-Sep-84 14':08") (DRAWCURVE (for theta from 0 to 360 by 10 collect (create POSITION XCOORD ← (PLUS x (TIMES r (COS theta))) YCOORD ← (PLUS y (TIMES r (SIN theta))))) T brush NIL window))]'
'
--Sanjay&Mike'
'
-----'
'
Date': 13 Sep 84 15':35 PDT'
From': tanner.pa'
Subject': Lisp': DRAWCURVE revisited'
To': LispSupport.pa'
cc': tanner.pa'
Lisp-System-Date':  3-Jul-84 16':01':03'
Machine-Type': Dandelion'
'
Regarding my earlier report on DRAWCURVE, the following, much simpler, code will trigger the problem':'
	'
	(DRAWCURVE ''((2000 . 200)(200 . 2000)(-2000 . 200)) '
				 T 1 NIL (CREATEW ''( 100 100 500 500)))'
'
It seems to be only closed curves that cause trouble.'
'
--mike'


Workaround: 

Test Case: 

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