summaryrefslogtreecommitdiffstats
path: root/src/GLSLShaderTest/phong.frag
blob: 41de179bbf096449f155a17b6d50f318a782b40c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
/*
 * $RCSfile$
 *
 * 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
 * maintenance of any nuclear facility.
 *
 * $Revision$
 * $Date$
 * $State$
 */

// A GLSL fragment program for handling 1 directional light with specular.
// This implements per-pixel lighting (Phong shading)

void directionalLight0(
    in    vec3 normal,
    inout vec4 ambient,
    inout vec4 diffuse,
    inout vec4 specular)
{
    // Normalized light direction and half vector
    vec3 lightDirection = normalize(vec3(gl_LightSource[0].position));
    vec3 halfVector = normalize(vec3(gl_LightSource[0].halfVector));

    float nDotVP; // normal . light_direction
    float nDotHV; // normal . light_half_vector
    float pf; // power factor

    nDotVP = max(0.0, dot(normal, lightDirection));
    nDotHV = max(0.0, dot(normal, halfVector));

    if (nDotVP == 0.0) {
	pf = 0.0;
    }
    else {
	pf = pow(nDotHV, gl_FrontMaterial.shininess);
    }

    ambient += gl_LightSource[0].ambient;
    diffuse += gl_LightSource[0].diffuse * nDotVP;
    specular += gl_LightSource[0].specular * pf;
}


// Per-pixel normal (input from vertex shader)
varying vec3  Normal;

void main()
{
    vec3 unitNorm = normalize(Normal);
    vec4 amb = vec4(0.0);
    vec4 diff = vec4(0.0);
    vec4 spec = vec4(0.0);
    int i;

    directionalLight0(unitNorm, amb, diff, spec);

    // Apply the result of the lighting equation
    vec4 secondaryColor = vec4(vec3(spec * gl_FrontMaterial.specular), 1.0);
    vec4 color = vec4(vec3(gl_FrontLightModelProduct.sceneColor +
		       amb * gl_FrontMaterial.ambient +
		       diff * gl_FrontMaterial.diffuse), 1.0);

    gl_FragColor = color + secondaryColor;
}