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| From | Keith Thompson <kst-u@mib.org> |
| Newsgroups | comp.lang.c |
| Subject | Re: chosing "small 2d graphics library" interface |
| Date | Thu, 02 Apr 2015 10:47:36 -0700 |
| Organization | None to speak of |
| Lines | 62 |
| Message-ID | <87384iifrb.fsf@kst-u.example.com> (permalink) |
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Richard Heathfield <rjh@cpax.org.uk> writes:
[...]
> #define NUM_DIMENSIONS 2
>
> struct point
> {
> double dimension[NUM_DIMENSIONS];
> };
>
> For notational convenience, let's alias that type:
>
> typedef struct point Point;
[...]
> struct edge
> {
> Point vertex[2];
> };
>
> and again, let's alias the type:
>
> typedef struct edge Edge;
>
> A "face" is a series of edges that, taken together, mark off a region
> of our universe. A face can have many edges, but it turns out to be
> convenient to restrict ourselves to three, forming a triangle. Why is
> this convenient? Well, firstly, we can use triangles to build up any
> other shape we want, so it doesn't cost us much, but more importantly
> we can specify exactly 3 of something really easily, whereas
> specifying n of anything requires us to play games with dynamic
> allocation. We will have to do that anyway at some time, but there's
> no need to have that level of complexity at this primitive a
> level. So:
>
> struct face
> {
> Edge edge[3];
> };
>
> typedef struct face Face;
[...]
With this representation, a Face (representing a triangle) stores each
vertex point twice. It can also represent a triangle whose edges are
disconnected, which I presume would be invalid.
I suggest:
struct face
{
Point vertex[3];
};
And perhaps "struct triangle" would be clearer than "struct face", since
you've already decided (reasonably IMHO) that all faces are triangles.
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
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chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-03-28 18:43 -0700
Re: chosing "small 2d graphics library" interface Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-03-29 02:59 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-03-29 03:51 -0700
Re: chosing "small 2d graphics library" interface Richard Heathfield <rjh@cpax.org.uk> - 2015-03-29 12:03 +0100
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-03-29 05:00 -0700
Re: chosing "small 2d graphics library" interface gof@somewhere.invalid (Gof) - 2015-04-01 08:02 +0000
Re: chosing "small 2d graphics library" interface Richard Heathfield <rjh@cpax.org.uk> - 2015-04-01 09:40 +0100
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-01 04:04 -0700
Re: chosing "small 2d graphics library" interface Nobody <nobody@nowhere.invalid> - 2015-03-29 12:50 +0100
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-03-29 05:08 -0700
Re: chosing "small 2d graphics library" interface Jeff Higgins <jeff@invalid.invalid> - 2015-03-29 09:33 -0400
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-03-29 07:00 -0700
Re: chosing "small 2d graphics library" interface Jeff Higgins <jeff@invalid.invalid> - 2015-03-29 10:38 -0400
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-03-29 07:43 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-03-29 07:24 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-03-29 07:32 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-01 05:00 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-01 07:25 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-03-29 07:36 -0700
Re: chosing "small 2d graphics library" interface Jeff Higgins <jeff@invalid.invalid> - 2015-03-29 14:33 -0400
Re: chosing "small 2d graphics library" interface Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-03-29 12:36 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-03-29 13:01 -0700
chosing "small 2d graphics library" interface asetofsymbols@gmail.com - 2015-04-02 04:12 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-02 04:56 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-02 05:10 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-02 05:31 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-02 09:40 -0700
Re: chosing "small 2d graphics library" interface Richard Heathfield <rjh@cpax.org.uk> - 2015-04-02 13:32 +0100
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-02 05:50 -0700
Re: chosing "small 2d graphics library" interface Richard Heathfield <rjh@cpax.org.uk> - 2015-04-02 14:01 +0100
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-02 06:37 -0700
Re: chosing "small 2d graphics library" interface Richard Heathfield <rjh@cpax.org.uk> - 2015-04-02 14:58 +0100
Re: chosing "small 2d graphics library" interface Bartc <bc@freeuk.com> - 2015-04-02 15:11 +0100
Re: chosing "small 2d graphics library" interface Richard Heathfield <rjh@cpax.org.uk> - 2015-04-02 15:18 +0100
Re: chosing "small 2d graphics library" interface Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-04-02 09:21 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-02 09:34 -0700
Re: chosing "small 2d graphics library" interface Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-04-02 09:47 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-02 09:45 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-02 09:57 -0700
Re: chosing "small 2d graphics library" interface Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-04-02 10:15 -0700
Re: chosing "small 2d graphics library" interface Richard Heathfield <rjh@cpax.org.uk> - 2015-04-02 18:34 +0100
Re: chosing "small 2d graphics library" interface Richard Heathfield <rjh@cpax.org.uk> - 2015-04-02 18:35 +0100
Re: chosing "small 2d graphics library" interface Richard Heathfield <rjh@cpax.org.uk> - 2015-04-02 17:45 +0100
Re: chosing "small 2d graphics library" interface Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-04-02 10:12 -0700
Re: chosing "small 2d graphics library" interface Richard Heathfield <rjh@cpax.org.uk> - 2015-04-02 18:28 +0100
Re: chosing "small 2d graphics library" interface Bartc <bc@freeuk.com> - 2015-04-03 01:06 +0100
Re: chosing "small 2d graphics library" interface luser droog <luser.droog@gmail.com> - 2015-04-02 17:05 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-02 07:51 -0700
Re: chosing "small 2d graphics library" interface Richard Heathfield <rjh@cpax.org.uk> - 2015-04-02 15:56 +0100
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-02 08:14 -0700
Re: chosing "small 2d graphics library" interface Richard Heathfield <rjh@cpax.org.uk> - 2015-04-02 16:25 +0100
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-02 08:45 -0700
Re: chosing "small 2d graphics library" interface Richard Heathfield <rjh@cpax.org.uk> - 2015-04-02 17:00 +0100
Re: chosing "small 2d graphics library" interface Keith Thompson <kst-u@mib.org> - 2015-04-02 13:03 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-05 14:25 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-02 09:06 -0700
Re: chosing "small 2d graphics library" interface Rosario19 <Ros@invalid.invalid> - 2015-04-02 18:22 +0200
Re: chosing "small 2d graphics library" interface Rosario19 <Ros@invalid.invalid> - 2015-04-02 18:40 +0200
Re: chosing "small 2d graphics library" interface Robert Wessel <robertwessel2@yahoo.com> - 2015-04-03 00:20 -0500
Re: chosing "small 2d graphics library" interface Rosario19 <Ros@invalid.invalid> - 2015-04-04 10:35 +0200
Re: chosing "small 2d graphics library" interface CHIN Dihedral <dihedral88888@gmail.com> - 2015-04-04 09:53 -0700
Re: chosing "small 2d graphics library" interface Noob <root@127.0.0.1> - 2015-04-03 14:27 +0200
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-03 05:38 -0700
Re: chosing "small 2d graphics library" interface Jeff Higgins <jeff@invalid.invalid> - 2015-04-02 19:23 -0400
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-02 23:46 -0700
Re: chosing "small 2d graphics library" interface asetofsymbols@gmail.com - 2015-04-02 08:03 -0700
Re: chosing "small 2d graphics library" interface Richard Heathfield <rjh@cpax.org.uk> - 2015-04-02 16:14 +0100
Re: chosing "small 2d graphics library" interface Keith Thompson <kst-u@mib.org> - 2015-04-02 12:42 -0700
Re: chosing "small 2d graphics library" interface CHIN Dihedral <dihedral88888@gmail.com> - 2015-04-03 14:27 -0700
Re: chosing "small 2d graphics library" interface Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-04-03 14:50 -0700
Re: chosing "small 2d graphics library" interface Keith Thompson <kst-u@mib.org> - 2015-04-02 10:47 -0700
Re: chosing "small 2d graphics library" interface Bartc <bc@freeuk.com> - 2015-04-02 20:09 +0100
Re: chosing "small 2d graphics library" interface Richard Heathfield <rjh@cpax.org.uk> - 2015-04-03 06:02 +0100
Re: chosing "small 2d graphics library" interface Bartc <bc@freeuk.com> - 2015-04-03 11:40 +0100
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-03 03:52 -0700
Re: chosing "small 2d graphics library" interface Bartc <bc@freeuk.com> - 2015-04-03 12:05 +0100
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-03 04:36 -0700
Re: chosing "small 2d graphics library" interface Bartc <bc@freeuk.com> - 2015-04-03 13:28 +0100
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-03 06:04 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-03 07:28 -0700
Re: chosing "small 2d graphics library" interface fir <profesor.fir@gmail.com> - 2015-04-03 12:43 -0700
Re: chosing "small 2d graphics library" interface Richard Heathfield <rjh@cpax.org.uk> - 2015-04-03 12:57 +0100
Re: chosing "small 2d graphics library" interface asetofsymbols@gmail.com - 2015-04-03 22:25 -0700
Re: chosing "small 2d graphics library" interface asetofsymbols@gmail.com - 2015-04-03 22:34 -0700
Re: chosing "small 2d graphics library" interface asetofsymbols@gmail.com - 2015-04-03 23:09 -0700
Re: chosing "small 2d graphics library" interface Richard Heathfield <rjh@cpax.org.uk> - 2015-04-04 09:23 +0100
chosing "small 2d graphics library" interface asetofsymbols@gmail.com - 2015-04-02 07:26 -0700
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