Modularize the libdimension codebase.

1 files changed, 0 insertions, 387 deletions

diff --git a/libdimension/geometry.c b/libdimension/geometry.c
deleted file mode 100644
index 4a16a3c..0000000
--- a/libdimension/geometry.c
+++ /dev/null
@@ -1,387 +0,0 @@
-/*************************************************************************
- * Copyright (C) 2009-2014 Tavian Barnes <tavianator@tavianator.com>     *
- *                                                                       *
- * This file is part of The Dimension Library.                           *
- *                                                                       *
- * The Dimension Library is free software; you can redistribute it and/  *
- * or modify it under the terms of the GNU Lesser General Public License *
- * as published by the Free Software Foundation; either version 3 of the *
- * License, or (at your option) any later version.                       *
- *                                                                       *
- * The Dimension Library 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  *
- * Lesser General Public License for more details.                       *
- *                                                                       *
- * You should have received a copy of the GNU Lesser General Public      *
- * License along with this program.  If not, see                         *
- * <http://www.gnu.org/licenses/>.                                       *
- *************************************************************************/
-
-/**
- * @file
- * Geometrical function implementations.
- */
-
-#include "dimension-internal.h"
-#include <math.h>
-
-// Identity matrix
-dmnsn_matrix
-dmnsn_identity_matrix(void)
-{
-  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);
-}
-
-// Scaling matrix
-dmnsn_matrix
-dmnsn_scale_matrix(dmnsn_vector s)
-{
-  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);
-}
-
-// Translation matrix
-dmnsn_matrix
-dmnsn_translation_matrix(dmnsn_vector d)
-{
-  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);
-}
-
-// Left-handed rotation matrix; theta/|theta| = axis, |theta| = angle
-dmnsn_matrix
-dmnsn_rotation_matrix(dmnsn_vector theta)
-{
-  // Two trig calls, 25 multiplications, 13 additions
-
-  double angle = dmnsn_vector_norm(theta);
-  if (fabs(angle) < dmnsn_epsilon) {
-    return dmnsn_identity_matrix();
-  }
-  dmnsn_vector axis = dmnsn_vector_div(theta, angle);
-
-  // Shorthand to make dmnsn_new_matrix() call legible
-
-  double s = sin(angle);
-  double t = 1.0 - cos(angle);
-
-  double x = axis.x;
-  double y = axis.y;
-  double z = axis.z;
-
-  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
-  );
-}
-
-// Find the angle between two vectors with respect to an axis
-static double
-dmnsn_axis_angle(dmnsn_vector from, dmnsn_vector to, dmnsn_vector axis)
-{
-  from = dmnsn_vector_sub(from, dmnsn_vector_proj(from, axis));
-  to   = dmnsn_vector_sub(to,   dmnsn_vector_proj(to, axis));
-
-  double fromnorm = dmnsn_vector_norm(from);
-  double tonorm   = dmnsn_vector_norm(to);
-  if (fromnorm < dmnsn_epsilon || tonorm < dmnsn_epsilon) {
-    return 0.0;
-  }
-
-  from = dmnsn_vector_div(from, fromnorm);
-  to   = dmnsn_vector_div(to,   tonorm);
-
-  double angle = acos(dmnsn_vector_dot(from, to));
-
-  if (dmnsn_vector_dot(dmnsn_vector_cross(from, to), axis) > 0.0) {
-    return angle;
-  } else {
-    return -angle;
-  }
-}
-
-// Alignment matrix
-dmnsn_matrix
-dmnsn_alignment_matrix(dmnsn_vector from, dmnsn_vector to,
-                       dmnsn_vector axis1, dmnsn_vector axis2)
-{
-  double theta1 = dmnsn_axis_angle(from, to, axis1);
-  dmnsn_matrix align1 = dmnsn_rotation_matrix(dmnsn_vector_mul(theta1, axis1));
-  from  = dmnsn_transform_direction(align1, from);
-  axis2 = dmnsn_transform_direction(align1, axis2);
-
-  double theta2 = dmnsn_axis_angle(from, to, axis2);
-  dmnsn_matrix align2 = dmnsn_rotation_matrix(dmnsn_vector_mul(theta2, axis2));
-
-  return dmnsn_matrix_mul(align2, align1);
-}
-
-// Matrix inversion helper functions
-
-/// A 2x2 matrix for inversion by partitioning.
-typedef struct { double n[2][2]; } dmnsn_matrix2;
-
-/// Construct a 2x2 matrix.
-static dmnsn_matrix2 dmnsn_new_matrix2(double a1, double a2,
-                                       double b1, double b2);
-/// Invert a 2x2 matrix.
-static dmnsn_matrix2 dmnsn_matrix2_inverse(dmnsn_matrix2 A);
-/// Negate a 2x2 matrix.
-static dmnsn_matrix2 dmnsn_matrix2_negate(dmnsn_matrix2 A);
-/// Subtract two 2x2 matricies.
-static dmnsn_matrix2 dmnsn_matrix2_sub(dmnsn_matrix2 lhs, dmnsn_matrix2 rhs);
-/// Add two 2x2 matricies.
-static dmnsn_matrix2 dmnsn_matrix2_mul(dmnsn_matrix2 lhs, dmnsn_matrix2 rhs);
-
-/// Invert a matrix with the slower cofactor algorithm, if partitioning failed.
-static dmnsn_matrix dmnsn_matrix_inverse_generic(dmnsn_matrix A);
-/// Get the [\p row, \p col] cofactor of A.
-static double dmnsn_matrix_cofactor(dmnsn_matrix A, size_t row, size_t col);
-
-// Invert a matrix, by partitioning
-dmnsn_matrix
-dmnsn_matrix_inverse(dmnsn_matrix A)
-{
-  // Use partitioning to invert a matrix:
-  //
-  //     [ P Q ] -1
-  //     [ R S ]
-  //
-  //   = [ PP QQ ]
-  //     [ RR SS ],
-  //
-  // with PP = inv(P) - inv(P)*Q*RR,
-  //      QQ = -inv(P)*Q*SS,
-  //      RR = -SS*R*inv(P), and
-  //      SS = inv(S - R*inv(P)*Q).
-
-  // The algorithm uses 2 inversions, 6 multiplications, and 2 subtractions,
-  // giving 52 multiplications, 34 additions, and 8 divisions.
-
-  dmnsn_matrix2 P, Q, R, S, Pi, RPi, PiQ, RPiQ, PP, QQ, RR, SS;
-  double Pdet = A.n[0][0]*A.n[1][1] - A.n[0][1]*A.n[1][0];
-
-  if (dmnsn_unlikely(fabs(Pdet) < dmnsn_epsilon)) {
-    // If P is close to singular, try a more generic algorithm; this is very
-    // unlikely, but not impossible, eg.
-    //   [ 1 1 0 0 ]
-    //   [ 1 1 1 0 ]
-    //   [ 0 1 1 0 ]
-    //   [ 0 0 0 1 ]
-    return dmnsn_matrix_inverse_generic(A);
-  }
-
-  // Partition the matrix
-  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],
-                        0.0,       0.0);
-  S = dmnsn_new_matrix2(A.n[2][2], A.n[2][3],
-                        0.0,       1.0);
-
-  // Do this inversion ourselves, since we already have the determinant
-  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);
-  PiQ  = dmnsn_matrix2_mul(Pi, Q);
-  RPiQ = dmnsn_matrix2_mul(R, PiQ);
-
-  // Calculate the partitioned inverse
-  SS = dmnsn_matrix2_inverse(dmnsn_matrix2_sub(S, RPiQ));
-  RR = dmnsn_matrix2_negate(dmnsn_matrix2_mul(SS, RPi));
-  QQ = dmnsn_matrix2_negate(dmnsn_matrix2_mul(PiQ, SS));
-  PP = dmnsn_matrix2_sub(Pi, dmnsn_matrix2_mul(PiQ, RR));
-
-  // Reconstruct the matrix
-  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]);
-}
-
-// For nice shorthand
-static dmnsn_matrix2
-dmnsn_new_matrix2(double a1, double a2, double b1, double b2)
-{
-  dmnsn_matrix2 m = { { { a1, a2 },
-                        { b1, b2 } } };
-  return m;
-}
-
-// Invert a 2x2 matrix
-static dmnsn_matrix2
-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_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_new_matrix2(-A.n[0][0], -A.n[0][1],
-                           -A.n[1][0], -A.n[1][1]);
-}
-
-// 2x2 matrix subtraction
-static dmnsn_matrix2
-dmnsn_matrix2_sub(dmnsn_matrix2 lhs, dmnsn_matrix2 rhs)
-{
-  // 4 additions
-  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]
-  );
-}
-
-// 2x2 matrix multiplication
-static dmnsn_matrix2
-dmnsn_matrix2_mul(dmnsn_matrix2 lhs, dmnsn_matrix2 rhs)
-{
-  // 8 multiplications, 4 additions
-  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],
-      lhs.n[1][0]*rhs.n[0][1] + lhs.n[1][1]*rhs.n[1][1]
-  );
-}
-
-// Invert a matrix, if partitioning failed (|P| == 0)
-static dmnsn_matrix
-dmnsn_matrix_inverse_generic(dmnsn_matrix A)
-{
-  // For A = [ A'      b ]  A^-1 = [ A'^-1   -(A'^-1)*b ]
-  //         [ 0 ... 0 1 ],        [ 0 ... 0      1     ].
-  //
-  // Invert A' by calculating its adjucate.
-  dmnsn_matrix inv;
-  double det = 0.0, C;
-
-  // Perform a Laplace expansion along the first row to give us the adjugate's
-  // first column and the determinant
-  for (size_t j = 0; j < 3; ++j) {
-    C = dmnsn_matrix_cofactor(A, 0, j);
-    det += A.n[0][j]*C;
-    inv.n[j][0] = C;
-  }
-
-  // Divide the first column by the determinant
-  for (size_t j = 0; j < 3; ++j) {
-    inv.n[j][0] /= det;
-  }
-
-  // Find the rest of A'
-  for (size_t j = 0; j < 3; ++j) {
-    for (size_t i = 1; i < 3; ++i) {
-      inv.n[j][i] = dmnsn_matrix_cofactor(A, i, j)/det;
-    }
-    inv.n[j][3] = 0.0;
-  }
-
-  // Find the translational component of the inverse
-  for (size_t i = 0; i < 3; ++i) {
-    for (size_t j = 0; j < 3; ++j) {
-      inv.n[i][3] -= inv.n[i][j]*A.n[j][3];
-    }
-  }
-
-  return inv;
-}
-
-// Gives the cofactor at row, col; the determinant of the matrix formed from the
-// upper-left 3x3 corner of A by ignoring row `row' and column `col',
-// times (-1)^(row + col)
-static double
-dmnsn_matrix_cofactor(dmnsn_matrix A, size_t row, size_t col)
-{
-  // 2 multiplications, 1 addition
-  double n[4];
-  size_t k = 0;
-  for (size_t i = 0; i < 3; ++i) {
-    for (size_t j = 0; j < 3; ++j) {
-      if (i != row && j != col) {
-        n[k] = A.n[i][j];
-        ++k;
-      }
-    }
-  }
-
-  double C = n[0]*n[3] - n[1]*n[2];
-  if ((row + col)%2 == 0) {
-    return C;
-  } else {
-    return -C;
-  }
-}
-
-// 4x4 matrix multiplication
-dmnsn_matrix
-dmnsn_matrix_mul(dmnsn_matrix lhs, dmnsn_matrix rhs)
-{
-  // 36 multiplications, 27 additions
-  dmnsn_matrix r;
-
-  r.n[0][0] = lhs.n[0][0]*rhs.n[0][0] + lhs.n[0][1]*rhs.n[1][0] + lhs.n[0][2]*rhs.n[2][0];
-  r.n[0][1] = lhs.n[0][0]*rhs.n[0][1] + lhs.n[0][1]*rhs.n[1][1] + lhs.n[0][2]*rhs.n[2][1];
-  r.n[0][2] = lhs.n[0][0]*rhs.n[0][2] + lhs.n[0][1]*rhs.n[1][2] + lhs.n[0][2]*rhs.n[2][2];
-  r.n[0][3] = lhs.n[0][0]*rhs.n[0][3] + lhs.n[0][1]*rhs.n[1][3] + lhs.n[0][2]*rhs.n[2][3] + lhs.n[0][3];
-
-  r.n[1][0] = lhs.n[1][0]*rhs.n[0][0] + lhs.n[1][1]*rhs.n[1][0] + lhs.n[1][2]*rhs.n[2][0];
-  r.n[1][1] = lhs.n[1][0]*rhs.n[0][1] + lhs.n[1][1]*rhs.n[1][1] + lhs.n[1][2]*rhs.n[2][1];
-  r.n[1][2] = lhs.n[1][0]*rhs.n[0][2] + lhs.n[1][1]*rhs.n[1][2] + lhs.n[1][2]*rhs.n[2][2];
-  r.n[1][3] = lhs.n[1][0]*rhs.n[0][3] + lhs.n[1][1]*rhs.n[1][3] + lhs.n[1][2]*rhs.n[2][3] + lhs.n[1][3];
-
-  r.n[2][0] = lhs.n[2][0]*rhs.n[0][0] + lhs.n[2][1]*rhs.n[1][0] + lhs.n[2][2]*rhs.n[2][0];
-  r.n[2][1] = lhs.n[2][0]*rhs.n[0][1] + lhs.n[2][1]*rhs.n[1][1] + lhs.n[2][2]*rhs.n[2][1];
-  r.n[2][2] = lhs.n[2][0]*rhs.n[0][2] + lhs.n[2][1]*rhs.n[1][2] + lhs.n[2][2]*rhs.n[2][2];
-  r.n[2][3] = lhs.n[2][0]*rhs.n[0][3] + lhs.n[2][1]*rhs.n[1][3] + lhs.n[2][2]*rhs.n[2][3] + lhs.n[2][3];
-
-  return r;
-}
-
-// Give an axis-aligned box that contains the given box transformed by `lhs'
-dmnsn_bounding_box
-dmnsn_transform_bounding_box(dmnsn_matrix trans, dmnsn_bounding_box box)
-{
-  // Infinite/zero bounding box support
-  if (isinf(box.min.x)) {
-    return box;
-  }
-
-  // Taking the "absolute value" of the matrix saves some min/max calculations
-  for (int i = 0; i < 3; ++i) {
-    for (int j = 0; j < 3; ++j) {
-      trans.n[i][j] = fabs(trans.n[i][j]);
-    }
-  }
-
-  dmnsn_vector Mt = dmnsn_matrix_column(trans, 3);
-  dmnsn_bounding_box ret = { Mt, Mt };
-
-  dmnsn_vector Mz = dmnsn_matrix_column(trans, 2);
-  ret.min = dmnsn_vector_add(ret.min, dmnsn_vector_mul(box.min.z, Mz));
-  ret.max = dmnsn_vector_add(ret.max, dmnsn_vector_mul(box.max.z, Mz));
-
-  dmnsn_vector My = dmnsn_matrix_column(trans, 1);
-  ret.min = dmnsn_vector_add(ret.min, dmnsn_vector_mul(box.min.y, My));
-  ret.max = dmnsn_vector_add(ret.max, dmnsn_vector_mul(box.max.y, My));
-
-  dmnsn_vector Mx = dmnsn_matrix_column(trans, 0);
-  ret.min = dmnsn_vector_add(ret.min, dmnsn_vector_mul(box.min.x, Mx));
-  ret.max = dmnsn_vector_add(ret.max, dmnsn_vector_mul(box.max.x, Mx));
-
-  return ret;
-}