simple_fp.cg

java 3d编程的一些例子源代码

/*
 * $RCSfile: simple_fp.cg,v $
 *
 * Copyright (c) 2006 Sun Microsystems, Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistribution of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistribution in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in
 *   the documentation and/or other materials provided with the
 *   distribution.
 *
 * Neither the name of Sun Microsystems, Inc. or the names of
 * contributors may be used to endorse or promote products derived
 * from this software without specific prior written permission.
 *
 * This software is provided "AS IS," without a warranty of any
 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND
 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
 * EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL
 * NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF
 * USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR
 * ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL,
 * CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND
 * REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR
 * INABILITY TO USE THIS SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * You acknowledge that this software is not designed, licensed or
 * intended for use in the design, construction, operation or
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 *
 * $Revision: 1.1 $
 * $Date: 2006/02/01 01:32:25 $
 * $State: Exp $
 */

// Simple fragment program to attenuate the input fragment color as a
// function of the distance of the fragment position from the center
// of the window

// define inputs from vertex shader to fragment shader
struct vertin
{
    float4 HPosition  : POSITION;
    float4 FragPos    : TEXCOORD0;
    float4 Color0     : COLOR0;
};

float4 main(vertin IN) : COLOR
{
    // Compute distance from center in range [0.0, 1.0]
    float2 dist = min(abs(IN.FragPos.xy), 1.0f);
    float2 invDist = 1.0f - dist;

    // Compute attenuation
    float atten = invDist.x * invDist.y;
    float4 outcolor = float4(IN.Color0 * atten);

    return outcolor;
}