glMultiTexCoord3fARB的问题

long_xz

下面这段代码中的
glMultiTexCoord3fARB是用作vertex shader的输入 还是fragment shader的输入？
glBegin(GL_QUADS); {
glNormal3f(0.0, 1.0, 0.0);

// tangent
glMultiTexCoord3fARB(GL_TEXTURE0 + 1, 1.0, 0.0, 0.0);
// binormal
glMultiTexCoord3fARB(GL_TEXTURE0 + 2, 0.0, 0.0, 1.0);

glTexCoord2f(0.0, 0.0);
glVertex3f(-1.0, 0.0, -1.0);

glTexCoord2f(0.0, 1.0);
glVertex3f(-1.0, 0.0, 1.0);

glTexCoord2f(1.0, 1.0);
glVertex3f(1.0, 0.0, 1.0);

glTexCoord2f(1.0, 0.0);
glVertex3f(1.0, 0.0, -1.0);
} glEnd();

vertex shader: write in sh

vsh = SH_BEGIN_VERTEX_PROGRAM {
ShInputPosition4f SH_DECL(ipos);
ShOutputPosition4f SH_DECL(opos);

ShInOutTexCoord3f SH_DECL(tc);
ShInputNormal3f SH_DECL(normal);
ShInputNormal3f SH_DECL(tangent);
ShInputNormal3f SH_DECL(binormal);
ShOutputVector3f SH_DECL(tan_eye);
ShOutputVector3f SH_DECL(tan_light);

// Transform position my modelview projection matrix
opos = ModelViewProjection | ipos;

// Set 3rd component of texture co-ordinate, it will be passed through automatically
tc(2) = 1.0;

// Map the eye vector into tangent space
ShVector3f SH_DECL(eye);
eye = (ModelViewInverse | ShPoint3f(0,0,0)) - ipos(0,1,2);
tan_eye = -ShVector3f(tangent | eye, binormal | eye, 1.0/bumpdepth * (normal | eye));

// Map the light vector into tangent space
ShVector3f SH_DECL(lightVec);
lightVec = lightPos - ipos(0,1,2);
tan_light = ShVector3f(tangent | lightVec, binormal | lightVec, normal | lightVec);

} SH_END;

fragment shader: write in sh
fsh = SH_BEGIN_FRAGMENT_PROGRAM {

ShInputPosition4f SH_DECL(pos);
ShInputTexCoord3f SH_DECL(itc);
ShInputVector3f SH_DECL(tan_eye);
ShInputVector3f SH_DECL(tan_light);

// Compute offset vector by normalizing and multiplying with normalization factor
ShVector3f offset = normalize(tan_eye);
offset(0,1) *= ((double)dmap_depth)/distmap.width();

// March a ray
ShTexCoord3f tc = itc;
for (int i = 0; i < iterations; i++) {
ShAttrib1f distance = distmap(tc);
tc = mad(distance, offset, tc);
}

// Compute derivatives of unperturbed texture coordinates
ShAttrib2f ddx = dx(itc(0,1));
ShAttrib2f ddy = dy(itc(0,1));

// Do tangent-space normal mapping
tan_light = normalize(tan_light);
ShNormal3f tan_normal;
if(filter) {
tan_normal = 2.0 * normals(tc(0,1), ddx, ddy) - 1.0;
} else {
tan_normal = 2.0 * normals(tc(0,1)) - 1.0;
}

// Apply lighting to base color
ShColor1f diffuse = tan_normal | tan_light;

ShOutputColor3f c;
if(filter) {
c = colors(tc(0,1), ddx, ddy) * diffuse;
} else {
c = colors(tc(0,1)) * diffuse;
}

} SH_END;