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14<h1 align="left">tex-tlut32</h1>
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16<h2>Description</h2>
17<P>This demo demonstrates a method for emulating 32-bit color indexed format textures.</P>
18<P>The Wii hardware does not directly support 32-bit color indexed texture format. This is due to tradeoffs in the graphics pipeline, resulting in it being optimized for 16-bits per texture sample per read cycle. However, 32-bit palettes with an 8-bit index is a format which some developers find useful. Fortunately, it is fairly easy to implement 32-bit color indexed textures on Wii by using two TEV stages.</P>
19<P>The best way to implement 32-bit indexed format is by splitting the 32-bit palette into two 16-bit palettes &mdash; one with the Red and Green components, the other with the Blue and Alpha components of the color, and referencing them from the same texture map in two TEV stages. This produces the same result as a texture with a single palette of <CODE>GX_TL_RGBA8</CODE> format.</P>
20<P>This demo demonstrates a texture using a 256 entry palette. The texture is created procedurally as a set of concentric circles, and alpha-blended on top of a checkered background. The palette is set to be a smooth gradient between two RGBA values in order to demonstrate that the palette is indeed 32-bit. The palette is animated in real-time (without animating the texture pattern), by changing the endpoints of the gradient to give a color cycling effect.</P>
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22<h2>Using the Demo</h2>
23<P>Press PAUSE to end.</P>
24
25<h2>Snapshot</h2>
26<P>An 8-bit indexed texture with a 32-bit palette is overlayed on a checkered background.</P>
27<P><IMG src="./images/tex-tlut32.jpg" alt="tex-tlut32.jpg (9018 bytes)" width="640" height="448"></p>
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29<h2>Required Data Files</h2>
30<p>None.</p>
31
32<H2>Revision History</H2>
33<P>
342006/03/01 Initial version.<br>
35</P>
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37<hr><p>CONFIDENTIAL</p></body>
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