overte/interface/resources/shaders/point_light.frag
2014-09-18 16:12:46 -07:00

69 lines
2.4 KiB
GLSL

#version 120
//
// spot_light.frag
// fragment shader
//
// Created by Andrzej Kapolka on 9/18/14.
// Copyright 2014 High Fidelity, Inc.
//
// Distributed under the Apache License, Version 2.0.
// See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//
// the diffuse texture
uniform sampler2D diffuseMap;
// the normal texture
uniform sampler2D normalMap;
// the specular texture
uniform sampler2D specularMap;
// the depth texture
uniform sampler2D depthMap;
// the distance to the near clip plane
uniform float near;
// scale factor for depth: (far - near) / far
uniform float depthScale;
// offset for depth texture coordinates
uniform vec2 depthTexCoordOffset;
// scale for depth texture coordinates
uniform vec2 depthTexCoordScale;
// the radius (hard cutoff) of the light effect
uniform float radius;
void main(void) {
// compute the view space position using the depth
float z = near / (texture2D(depthMap, gl_TexCoord[0].st).r * depthScale - 1.0);
vec4 position = vec4((depthTexCoordOffset + gl_TexCoord[0].st * depthTexCoordScale) * z, z, 1.0);
// get the normal from the map
vec4 normal = texture2D(normalMap, gl_TexCoord[0].st);
vec4 normalizedNormal = normalize(normal * 2.0 - vec4(1.0, 1.0, 1.0, 2.0));
// compute the base color based on OpenGL lighting model
vec4 lightVector = gl_LightSource[1].position - position;
float lightDistance = length(lightVector);
lightVector = lightVector / lightDistance;
float diffuse = dot(normalizedNormal, lightVector);
float facingLight = step(0.0, diffuse);
vec4 baseColor = texture2D(diffuseMap, gl_TexCoord[0].st) * (gl_FrontLightProduct[1].ambient +
gl_FrontLightProduct[1].diffuse * (diffuse * facingLight));
// compute attenuation based on distance, etc.
float attenuation = step(lightDistance, radius) / dot(vec3(gl_LightSource[1].constantAttenuation,
gl_LightSource[1].linearAttenuation, gl_LightSource[1].quadraticAttenuation),
vec3(1.0, lightDistance, lightDistance * lightDistance));
// add base to specular, modulate by attenuation
float specular = facingLight * max(0.0, dot(normalize(lightVector - normalize(vec4(position.xyz, 0.0))),
normalizedNormal));
vec4 specularColor = texture2D(specularMap, gl_TexCoord[0].st);
gl_FragColor = vec4((baseColor.rgb + pow(specular, specularColor.a * 128.0) * specularColor.rgb) * attenuation, 0.0);
}