xenocara/dist/Mesa/progs/glsl/CH06-brick.vert

42 lines
1.1 KiB
GLSL

//
// Vertex shader for procedural bricks
//
// Authors: Dave Baldwin, Steve Koren, Randi Rost
// based on a shader by Darwyn Peachey
//
// Copyright (c) 2002-2006 3Dlabs Inc. Ltd.
//
// See 3Dlabs-License.txt for license information
//
uniform vec3 LightPosition;
const float SpecularContribution = 0.3;
const float DiffuseContribution = 1.0 - SpecularContribution;
varying float LightIntensity;
varying vec2 MCposition;
void main()
{
vec3 ecPosition = vec3(gl_ModelViewMatrix * gl_Vertex);
vec3 tnorm = normalize(gl_NormalMatrix * gl_Normal);
vec3 lightVec = normalize(LightPosition - ecPosition);
vec3 reflectVec = reflect(-lightVec, tnorm);
vec3 viewVec = normalize(-ecPosition);
float diffuse = max(dot(lightVec, tnorm), 0.0);
float spec = 0.0;
if (diffuse > 0.0)
{
spec = max(dot(reflectVec, viewVec), 0.0);
spec = pow(spec, 16.0);
}
LightIntensity = DiffuseContribution * diffuse +
SpecularContribution * spec;
MCposition = gl_Vertex.xy;
gl_Position = ftransform();
}