diff options
Diffstat (limited to 'libdimension/geometry.c')
| -rw-r--r-- | libdimension/geometry.c | 90 |
1 files changed, 44 insertions, 46 deletions
diff --git a/libdimension/geometry.c b/libdimension/geometry.c index 6df0102..cbcc2c1 100644 --- a/libdimension/geometry.c +++ b/libdimension/geometry.c @@ -25,30 +25,30 @@ dmnsn_matrix dmnsn_identity_matrix() { - return dmnsn_matrix_construct(1.0, 0.0, 0.0, 0.0, - 0.0, 1.0, 0.0, 0.0, - 0.0, 0.0, 1.0, 0.0, - 0.0, 0.0, 0.0, 1.0); + return dmnsn_new_matrix(1.0, 0.0, 0.0, 0.0, + 0.0, 1.0, 0.0, 0.0, + 0.0, 0.0, 1.0, 0.0, + 0.0, 0.0, 0.0, 1.0); } /* Scaling matrix */ dmnsn_matrix dmnsn_scale_matrix(dmnsn_vector s) { - return dmnsn_matrix_construct(s.x, 0.0, 0.0, 0.0, - 0.0, s.y, 0.0, 0.0, - 0.0, 0.0, s.z, 0.0, - 0.0, 0.0, 0.0, 1.0); + return dmnsn_new_matrix(s.x, 0.0, 0.0, 0.0, + 0.0, s.y, 0.0, 0.0, + 0.0, 0.0, s.z, 0.0, + 0.0, 0.0, 0.0, 1.0); } /* Translation matrix */ dmnsn_matrix dmnsn_translation_matrix(dmnsn_vector d) { - return dmnsn_matrix_construct(1.0, 0.0, 0.0, d.x, - 0.0, 1.0, 0.0, d.y, - 0.0, 0.0, 1.0, d.z, - 0.0, 0.0, 0.0, 1.0); + return dmnsn_new_matrix(1.0, 0.0, 0.0, d.x, + 0.0, 1.0, 0.0, d.y, + 0.0, 0.0, 1.0, d.z, + 0.0, 0.0, 0.0, 1.0); } /* Left-handed rotation matrix; theta/|theta| = axis, |theta| = angle */ @@ -56,25 +56,23 @@ dmnsn_matrix dmnsn_rotation_matrix(dmnsn_vector theta) { /* Two trig calls, 25 multiplications, 13 additions */ - dmnsn_vector axis; - double angle, s, t, x, y, z; - angle = dmnsn_vector_norm(theta); + double angle = dmnsn_vector_norm(theta); if (angle == 0.0) { return dmnsn_identity_matrix(); } - axis = dmnsn_vector_normalize(theta); + dmnsn_vector axis = dmnsn_vector_normalize(theta); - /* Shorthand to make dmnsn_matrix_construct() call legible */ + /* Shorthand to make dmnsn_new_matrix() call legible */ - s = sin(angle); - t = 1.0 - cos(angle); + double s = sin(angle); + double t = 1.0 - cos(angle); - x = axis.x; - y = axis.y; - z = axis.z; + double x = axis.x; + double y = axis.y; + double z = axis.z; - return dmnsn_matrix_construct( + return dmnsn_new_matrix( 1.0 + t*(x*x - 1.0), -z*s + t*x*y, y*s + t*x*z, 0.0, z*s + t*x*y, 1.0 + t*(y*y - 1.0), -x*s + t*y*z, 0.0, -y*s + t*x*z, x*s + t*y*z, 1.0 + t*(z*z - 1.0), 0.0, @@ -86,8 +84,8 @@ dmnsn_rotation_matrix(dmnsn_vector theta) typedef struct { double n[2][2]; } dmnsn_matrix2; -static dmnsn_matrix2 dmnsn_matrix2_construct(double a1, double a2, - double b1, double b2); +static dmnsn_matrix2 dmnsn_new_matrix2(double a1, double a2, + double b1, double b2); static dmnsn_matrix2 dmnsn_matrix2_inverse(dmnsn_matrix2 A); static dmnsn_matrix2 dmnsn_matrix2_negate(dmnsn_matrix2 A); static dmnsn_matrix2 dmnsn_matrix2_sub(dmnsn_matrix2 lhs, dmnsn_matrix2 rhs); @@ -134,18 +132,18 @@ dmnsn_matrix_inverse(dmnsn_matrix A) } /* Partition the matrix */ - P = dmnsn_matrix2_construct(A.n[0][0], A.n[0][1], - A.n[1][0], A.n[1][1]); - Q = dmnsn_matrix2_construct(A.n[0][2], A.n[0][3], - A.n[1][2], A.n[1][3]); - R = dmnsn_matrix2_construct(A.n[2][0], A.n[2][1], - A.n[3][0], A.n[3][1]); - S = dmnsn_matrix2_construct(A.n[2][2], A.n[2][3], - A.n[3][2], A.n[3][3]); + P = dmnsn_new_matrix2(A.n[0][0], A.n[0][1], + A.n[1][0], A.n[1][1]); + Q = dmnsn_new_matrix2(A.n[0][2], A.n[0][3], + A.n[1][2], A.n[1][3]); + R = dmnsn_new_matrix2(A.n[2][0], A.n[2][1], + A.n[3][0], A.n[3][1]); + S = dmnsn_new_matrix2(A.n[2][2], A.n[2][3], + A.n[3][2], A.n[3][3]); /* Do this inversion ourselves, since we already have the determinant */ - Pi = dmnsn_matrix2_construct( P.n[1][1]/Pdet, -P.n[0][1]/Pdet, - -P.n[1][0]/Pdet, P.n[0][0]/Pdet); + Pi = dmnsn_new_matrix2( P.n[1][1]/Pdet, -P.n[0][1]/Pdet, + -P.n[1][0]/Pdet, P.n[0][0]/Pdet); /* Calculate R*inv(P), inv(P)*Q, and R*inv(P)*Q */ RPi = dmnsn_matrix2_mul(R, Pi); @@ -159,15 +157,15 @@ dmnsn_matrix_inverse(dmnsn_matrix A) PP = dmnsn_matrix2_sub(Pi, dmnsn_matrix2_mul(PiQ, RR)); /* Reconstruct the matrix */ - return dmnsn_matrix_construct(PP.n[0][0], PP.n[0][1], QQ.n[0][0], QQ.n[0][1], - PP.n[1][0], PP.n[1][1], QQ.n[1][0], QQ.n[1][1], - RR.n[0][0], RR.n[0][1], SS.n[0][0], SS.n[0][1], - RR.n[1][0], RR.n[1][1], SS.n[1][0], SS.n[1][1]); + return dmnsn_new_matrix(PP.n[0][0], PP.n[0][1], QQ.n[0][0], QQ.n[0][1], + PP.n[1][0], PP.n[1][1], QQ.n[1][0], QQ.n[1][1], + RR.n[0][0], RR.n[0][1], SS.n[0][0], SS.n[0][1], + RR.n[1][0], RR.n[1][1], SS.n[1][0], SS.n[1][1]); } /* For nice shorthand */ static dmnsn_matrix2 -dmnsn_matrix2_construct(double a1, double a2, double b1, double b2) +dmnsn_new_matrix2(double a1, double a2, double b1, double b2) { dmnsn_matrix2 m = { { { a1, a2 }, { b1, b2 } } }; @@ -180,16 +178,16 @@ dmnsn_matrix2_inverse(dmnsn_matrix2 A) { /* 4 divisions, 2 multiplications, 1 addition */ double det = A.n[0][0]*A.n[1][1] - A.n[0][1]*A.n[1][0]; - return dmnsn_matrix2_construct( A.n[1][1]/det, -A.n[0][1]/det, - -A.n[1][0]/det, A.n[0][0]/det); + return dmnsn_new_matrix2( A.n[1][1]/det, -A.n[0][1]/det, + -A.n[1][0]/det, A.n[0][0]/det); } /* Also basically a shorthand */ static dmnsn_matrix2 dmnsn_matrix2_negate(dmnsn_matrix2 A) { - return dmnsn_matrix2_construct(-A.n[0][0], -A.n[0][1], - -A.n[1][0], -A.n[1][1]); + return dmnsn_new_matrix2(-A.n[0][0], -A.n[0][1], + -A.n[1][0], -A.n[1][1]); } /* 2x2 matrix subtraction */ @@ -197,7 +195,7 @@ static dmnsn_matrix2 dmnsn_matrix2_sub(dmnsn_matrix2 lhs, dmnsn_matrix2 rhs) { /* 4 additions */ - return dmnsn_matrix2_construct( + return dmnsn_new_matrix2( lhs.n[0][0] - rhs.n[0][0], lhs.n[0][1] - rhs.n[0][1], lhs.n[1][0] - rhs.n[1][0], lhs.n[1][1] - rhs.n[1][1] ); @@ -208,7 +206,7 @@ static dmnsn_matrix2 dmnsn_matrix2_mul(dmnsn_matrix2 lhs, dmnsn_matrix2 rhs) { /* 8 multiplications, 4 additions */ - return dmnsn_matrix2_construct( + return dmnsn_new_matrix2( lhs.n[0][0]*rhs.n[0][0] + lhs.n[0][1]*rhs.n[1][0], lhs.n[0][0]*rhs.n[0][1] + lhs.n[0][1]*rhs.n[1][1], lhs.n[1][0]*rhs.n[0][0] + lhs.n[1][1]*rhs.n[1][0], |