48 lines
2.0 KiB
C++
48 lines
2.0 KiB
C++
// Filename: plane_src.cxx
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// Created by: drose (03Apr01)
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//
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////////////////////////////////////////////////////////////////////
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////////////////////////////////////////////////////////////////////
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// Function: Plane::get_reflection_mat
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// Access: Public
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// Description: This computes a transform matrix that performs the
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// perspective transform defined by the frustum,
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// accordinate to the indicated coordinate system.
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////////////////////////////////////////////////////////////////////
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FLOATNAME(LMatrix4) FLOATNAME(Plane)::
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get_reflection_mat(void) const {
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FLOATTYPE aa = _a * _a; FLOATTYPE ab = _a * _b; FLOATTYPE ac = _a * _c;
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FLOATTYPE ad = _a * _d;
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FLOATTYPE bb = _b * _b; FLOATTYPE bc = _b * _c; FLOATTYPE bd = _b * _d;
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FLOATTYPE cc = _c * _c; FLOATTYPE cd = _c * _d;
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return FLOATNAME(LMatrix4)( 1-2*aa, -2*ab, -2*ac, 0,
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-2*ab, 1-2*bb, -2*bc, 0,
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-2*ac, -2*bc, 1-2*cc, 0,
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-2*ad, -2*bd, -2*cd, 1 );
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}
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////////////////////////////////////////////////////////////////////
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// Function: Plane::get_point
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// Access: Public
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// Description: Returns an arbitrary point in the plane. This can be
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// used along with the normal returned by get_normal()
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// to reconstruct the plane.
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////////////////////////////////////////////////////////////////////
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FLOATNAME(LPoint3) FLOATNAME(Plane)::
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get_point() const {
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// Choose the denominator based on the largest axis in the normal.
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if (cabs(_a) >= cabs(_b) && cabs(_a) >= cabs(_c)) {
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nassertr(_a != 0.0, FLOATNAME(LPoint3)(0.0, 0.0, 0.0));
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return FLOATNAME(LPoint3)(-_d / _a, 0.0, 0.0);
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} else if (cabs(_b) >= cabs(_c)) {
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nassertr(_b != 0.0, FLOATNAME(LPoint3)(0.0, 0.0, 0.0));
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return FLOATNAME(LPoint3)(0.0, -_d / _b, 0.0);
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} else {
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nassertr(_c != 0.0, FLOATNAME(LPoint3)(0.0, 0.0, 0.0));
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return FLOATNAME(LPoint3)(0.0, 0.0, -_d / _c);
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}
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}
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