oolite/Resources/Shaders/oolite-tangent-space-vertex.vertex

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/*
oolite-tangent-space-vertex.vertex
Basic vertex shader for Oolite ships using tangent-space effects.
© 2008 Jens Ayton
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, USA.
*/
attribute vec3 tangent;
// No vNormal, because normal is always 0,0,1 in tangent space.
varying vec3 vEyeVector;
varying vec2 vTexCoord;
varying vec3 vLight0Vector;
varying vec3 vLight1Vector;
void main(void)
{
// Build tangent basis
vec3 n = normalize(gl_NormalMatrix * gl_Normal);
vec3 t = normalize(gl_NormalMatrix * tangent);
vec3 b = cross(n, t);
mat3 TBN = mat3(t, b, n);
vec3 eyeVector = -vec3(gl_ModelViewMatrix * gl_Vertex);
vEyeVector = eyeVector * TBN;
vec3 light0Vector = gl_LightSource[0].position.xyz + eyeVector;
vLight0Vector = light0Vector * TBN;
vec3 light1Vector = gl_LightSource[1].position.xyz + eyeVector;
vLight1Vector = light1Vector * TBN;
vTexCoord = gl_MultiTexCoord0.st;
gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
}