35 lines
1.5 KiB
C
35 lines
1.5 KiB
C
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/** \file sr_alg.h
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* few algebra functions */
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# ifndef SR_ALG_H
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# define SR_ALG_H
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/*! Solve polynomials of 2nd degree. The coefficients are given in c,
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where c[i] is the coefficient of the i-th power of the unknown variable.
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The roots are stored in s, and the number of stored roots is returned. */
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int sr_solve_quadric_polynomial ( double c[3], double s[2] );
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/*! Solve polynomials of 3rd degree. The coefficients are given in c,
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where c[i] is the coefficient of the i-th power of the unknown variable.
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The roots are stored in s, and the number of stored roots is returned. */
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int sr_solve_cubic_polynomial ( double c[4], double s[3] );
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/*! Solve polynomials of 4th degree. The coefficients are given in c,
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where c[i] is the coefficient of the i-th power of the unknown variable.
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The roots are stored in s, and the number of stored roots is returned. */
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int sr_solve_quartic_polynomial ( double c[5], double s[4] );
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/*! Returns <0 if (x,y) is inside the ellipse with radius (a,b), returns
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0 if it is on the ellipse, and returns >0 if it is outside */
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float sr_in_ellipse ( float x, float y, float a, float b );
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/*! This function replaces the given point (x,y) by the closest point
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on the ellipse whose semi-axes are of length a and b. The solution
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is derived analyticaly, solving a quartic polynomial */
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void sr_get_closest_on_ellipse ( float a, float b, float& x, float& y );
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//============================== end of file ===============================
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# endif // SR_ALG_H
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