/Doc/Texture.html
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1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
2<html><head><meta content="text/html; charset=ISO-8859-1" http-equiv="content-type"><title>PyGUI - GL.Texture class</title></head>
3<body>
4<h1>class <span style="font-family: monospace;">GL.Texture</span></h1>
5The Texture class in the GL submodule provides a context-independent
6representation of an OpenGL texture. You can use a single Texture
7object with multiple GLViews and/or GLPixmaps without being concerned
8whether they are sharing texture spaces or not, and without having to
9keep track of OpenGL texture numbers.<br>
10<br>
11Texture is an abstract class. To use it, you subclass it and define the <span style="font-family: monospace;">do_setup</span>
12method to make whatever OpenGL calls are necessary to set up the
13texture. Then, when you want to draw with the texture, you call the <span style="font-family: monospace;">bind</span>
14method to make it the current OpenGL texture. Whenever the Texture is
15used in a context where it has not been used before, your <span style="font-family: monospace;">do_setup</span> method will be called to create a representation of the texture appropriate to that context.<br>
16<br>
17Keep in mind that any call to <span style="font-family: monospace;">bind</span> can trigger allocation of a texture number and a call to your <span style="font-family: monospace;">do_setup</span>
18method, and this will usually happen while you are in the middle of
19doing OpenGL drawing. If this would be inconvenient, you may need to
20"preload" the texture by calling the <span style="font-family: monospace;">bind</span> method once in each context where the texture might be used, before you start drawing.<br>
21<h2>Constructor</h2>
22<div style="margin-left: 40px;">
23<dl>
24 <dt style="font-family: monospace;">Texture(texture_type)</dt>
25 <dd>Constructs a texture of the given type. The <span style="font-style: italic;">texture_type</span> should be one of the OpenGL texture type constants (GL_TEXTURE_2D etc).<br>
26 </dd>
27</dl>
28</div>
29<h2>Methods</h2>
30<div style="margin-left: 40px;">
31<dl>
32 <dt style="font-family: monospace;">bind()</dt>
33 <dd>Makes this
34texture the current texture for the current context by calling
35glBindTexture. If this texture has not previously been used
36with the current context (or one with which it is sharing
37textures), an OpenGL texture number is allocated and <span style="font-family: monospace;">do_setup</span> is called to initialise a representation of the texture.<br>
38 <br>
39</dd><dt style="font-family: monospace;">deallocate()</dt>
40 <dd>Deallocates any OpenGL resources currently allocated to the Texture. If it is used again, new resources will be allocated.<br>
41 </dd>
42
43</dl>
44</div>
45<h2>Abstract methods</h2>
46<div style="margin-left: 40px;">
47<dl>
48 <dt style="font-family: monospace;">do_setup()</dt>
49 <dd>This method should be implemented to make the necessary OpenGL
50calls to initialise the texture. When this method is called, a texture
51number will already have been allocated and <span style="font-family: monospace;">glBindTexture</span> called to make it the current texture.<br>
52 </dd>
53</dl>
54</div>
55<br>
56</body></html>