Files
linguist/samples/GLSL/shader.fp
Julik Tarkhanov a93e9493e2 Add OpenGL shading language (GLSL)
This is the language used for writing OpenGL shaders, which are becoming much more mainstream lately.
2013-08-17 14:31:28 +02:00

69 lines
2.6 KiB
GLSL

/*
* Copyright (C) 2010 Josh A. Beam
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
const int NUM_LIGHTS = 3;
const vec3 AMBIENT = vec3(0.1, 0.1, 0.1);
const float MAX_DIST = 2.5;
const float MAX_DIST_SQUARED = MAX_DIST * MAX_DIST;
uniform vec3 lightColor[NUM_LIGHTS];
varying vec3 fragmentNormal;
varying vec3 cameraVector;
varying vec3 lightVector[NUM_LIGHTS];
void
main()
{
// initialize diffuse/specular lighting
vec3 diffuse = vec3(0.0, 0.0, 0.0);
vec3 specular = vec3(0.0, 0.0, 0.0);
// normalize the fragment normal and camera direction
vec3 normal = normalize(fragmentNormal);
vec3 cameraDir = normalize(cameraVector);
// loop through each light
for(int i = 0; i < NUM_LIGHTS; ++i) {
// calculate distance between 0.0 and 1.0
float dist = min(dot(lightVector[i], lightVector[i]), MAX_DIST_SQUARED) / MAX_DIST_SQUARED;
float distFactor = 1.0 - dist;
// diffuse
vec3 lightDir = normalize(lightVector[i]);
float diffuseDot = dot(normal, lightDir);
diffuse += lightColor[i] * clamp(diffuseDot, 0.0, 1.0) * distFactor;
// specular
vec3 halfAngle = normalize(cameraDir + lightDir);
vec3 specularColor = min(lightColor[i] + 0.5, 1.0);
float specularDot = dot(normal, halfAngle);
specular += specularColor * pow(clamp(specularDot, 0.0, 1.0), 16.0) * distFactor;
}
vec4 sample = vec4(1.0, 1.0, 1.0, 1.0);
gl_FragColor = vec4(clamp(sample.rgb * (diffuse + AMBIENT) + specular, 0.0, 1.0), sample.a);
}