From:	Timo Asikainen <thka AT lyseo DOT edu DOT ouka DOT fi>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Problems with Allegro's texturemapping
Date:	Sun, 12 Jul 1998 18:03:58 -0700
Organization:	Oulu Polytechnic, Institute of Technology, Finland
Lines:	27
Message-ID:	<35A95CFE.2518@lyseo.edu.ouka.fi>
Reply-To:	thka AT lyseo DOT edu DOT ouka DOT fi
NNTP-Posting-Host:	anne86.wnet.opoy.fi
Mime-Version:	1.0
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

I'm programming a landscape engine for a game. The method I use is
simple:

I have a mesh in which all vertices have a height. These vertices are
connected to each other by lines which form triangles.

(Here's a nice ASCII pic:-))

+-+-+-+
|\|\|\|
+-+-+-+
|\|\|\|<---- a triangle
+-+-+-+<-----a vertex

Now, what I try to do is texturemap these triangles. I want to
texturemap them so that I can map a big photograph of for example grass
or rock onto this landscape. Or if the texture is a small one (for
example 64x64) I could tile it on the landscape. The problem is that in
Allegro I have to calculate proper texturemap coords. for each vertex of
a triangle and I don't know any good algorithm for calculating the
texmap coords. so that I could achieve what I want to do.

If anyone knows any good netsites on the subject or have some good
algorithms please let me know about them..

------
Timo Asikainen

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