Re: Problem drawing lines crossing image boundary

Article View: borland.public.cppbuilder.nativeapi

Article #14940

Back to borland.public.cppbuilder.nativeapi Previous Next

#14940

From: Hans Galema
Date: Mon, 28 Jul 2003 12:16

30 lines
1949 bytes

Ivan Johansen wrote:
> I am having trouble drawing lines that goes outside the image under 
> Windows 98.
 > ...
> This should show a vertical line, but instead it draws two lines: one 
> from (316,242) to (105,242) and one from (105,242) to approximate 
> (317,-16181).

Can confirm that for Win98SE.

 > ...
> I hope someone can tell me why this is happening or that it is a driver 
> problem.

Don't know why this is happening. If it goes ok on other OS's than
the calculations within MoveTo will be ok. But in the case of Win98SE
based upon wrong data the TCanvas gets from somewhere.

If it is only for a oneline at a time drawing you could easily
make your own DrawLine ( x1, y1, x2, y2 )
which checks for y2 being to large negative.
If y2 is to large then something like
   x2 = (x2-x1)/2 + x1;
   y2 = (y2-y1)/2 + y1;

and then apply MoveTo and LineTo.

Hans.

Hans.

Technical Details

Message-ID: <3f2513f3@newsgroups.borland.com>

Path:

arc1-ca.pugleaf.net!archiver1.google.com!news1.google.com!sn-xit-02!sn-xit-03!sn-xit-01!sn-xit-08!supernews.com!newsfeed.wirehub.nl!news.kweb.on.ca!KWeb!newsgroups.borland.com!not-for-mail

References: <3f245110@newsgroups.borland.com>

Show Full Headers

Complete Article Headers

X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 10cc67,c8c44e98956d82e9
X-Google-Attributes: gid10cc67,public
X-Google-ArrivalTime: 2003-07-28 05:22:36 PST
Date: Mon, 28 Jul 2003 14:16:53 +0200
From: Hans Galema <j.m.galema.dontusethis@maartens.nl>
User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.3.1) Gecko/20030425
X-Accept-Language: en-us, en
MIME-Version: 1.0
Newsgroups: borland.public.cppbuilder.nativeapi
Subject: Re: Problem drawing lines crossing image boundary
References: <3f245110@newsgroups.borland.com>
In-Reply-To: <3f245110@newsgroups.borland.com>
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
NNTP-Posting-Host: 129.125.108.11
Message-ID: <3f2513f3@newsgroups.borland.com>
X-Trace: newsgroups.borland.com 1059394547 129.125.108.11 (28 Jul 2003 05:15:47 -0700)
Lines: 31
Path: arc1-ca.pugleaf.net!archiver1.google.com!news1.google.com!sn-xit-02!sn-xit-03!sn-xit-01!sn-xit-08!supernews.com!newsfeed.wirehub.nl!news.kweb.on.ca!KWeb!newsgroups.borland.com!not-for-mail

Reply to Parent Message