--- /dev/null
+/*
+ * The 3D Studio File Format Library
+ * Copyright (C) 1996-2001 by J.E. Hoffmann <je-h@gmx.net>
+ * All rights reserved.
+ *
+ * This program 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 2.1 of the License, or (at
+ * your option) any later version.
+ *
+ * This program 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, write to the Free Software Foundation,
+ * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * $Id: vector.c,v 1.9 2004/11/16 07:41:44 efalk Exp $
+ */
+#define LIB3DS_EXPORT
+#include <lib3ds/vector.h>
+#include <math.h>
+
+
+/*!
+ * \defgroup vector Vector Mathematics
+ *
+ * \author J.E. Hoffmann <je-h@gmx.net>
+ */
+/*!
+ * \typedef Lib3dsVector
+ * \ingroup vector
+ */
+
+
+/*!
+ * Clear a vector to zero.
+ *
+ * \param c Vector to clear.
+ *
+ * \ingroup vector
+ */
+void
+lib3ds_vector_zero(Lib3dsVector c)
+{
+ int i;
+ for (i=0; i<3; ++i) {
+ c[i]=0.0f;
+ }
+}
+
+
+/*!
+ * Copy a vector.
+ *
+ * \param dest Destination vector.
+ * \param src Source vector.
+ *
+ * \ingroup vector
+ */
+void
+lib3ds_vector_copy(Lib3dsVector dest, Lib3dsVector src)
+{
+ int i;
+ for (i=0; i<3; ++i) {
+ dest[i]=src[i];
+ }
+}
+
+
+/*!
+ * Negate a vector.
+ *
+ * \param c Vector to negate.
+ *
+ * \ingroup vector
+ */
+void
+lib3ds_vector_neg(Lib3dsVector c)
+{
+ int i;
+ for (i=0; i<3; ++i) {
+ c[i]=-c[i];
+ }
+}
+
+
+/*!
+ * Add two vectors.
+ *
+ * \param c Result.
+ * \param a First addend.
+ * \param b Second addend.
+ *
+ * \ingroup vector
+ */
+void
+lib3ds_vector_add(Lib3dsVector c, Lib3dsVector a, Lib3dsVector b)
+{
+ int i;
+ for (i=0; i<3; ++i) {
+ c[i]=a[i]+b[i];
+ }
+}
+
+
+/*!
+ * Subtract two vectors.
+ *
+ * \param c Result.
+ * \param a Addend.
+ * \param b Minuend.
+ *
+ * \ingroup vector
+ */
+void
+lib3ds_vector_sub(Lib3dsVector c, Lib3dsVector a, Lib3dsVector b)
+{
+ int i;
+ for (i=0; i<3; ++i) {
+ c[i]=a[i]-b[i];
+ }
+}
+
+
+/*!
+ * Multiply a vector by a scalar.
+ *
+ * \param c Vector to be multiplied.
+ * \param k Scalar.
+ *
+ * \ingroup vector
+ */
+void
+lib3ds_vector_scalar(Lib3dsVector c, Lib3dsFloat k)
+{
+ int i;
+ for (i=0; i<3; ++i) {
+ c[i]*=k;
+ }
+}
+
+
+/*!
+ * Compute cross product.
+ *
+ * \param c Result.
+ * \param a First vector.
+ * \param b Second vector.
+ *
+ * \ingroup vector
+ */
+void
+lib3ds_vector_cross(Lib3dsVector c, Lib3dsVector a, Lib3dsVector b)
+{
+ c[0]=a[1]*b[2] - a[2]*b[1];
+ c[1]=a[2]*b[0] - a[0]*b[2];
+ c[2]=a[0]*b[1] - a[1]*b[0];
+}
+
+
+/*!
+ * Compute dot product.
+ *
+ * \param a First vector.
+ * \param b Second vector.
+ *
+ * \return Dot product.
+ *
+ * \ingroup vector
+ */
+Lib3dsFloat
+lib3ds_vector_dot(Lib3dsVector a, Lib3dsVector b)
+{
+ return(a[0]*b[0] + a[1]*b[1] + a[2]*b[2]);
+}
+
+
+/*!
+ * Compute square of vector.
+ *
+ * Computes x*x + y*y + z*z.
+ *
+ * \param c Vector to square.
+ *
+ * \return Square of vector.
+ *
+ * \ingroup vector
+ */
+Lib3dsFloat
+lib3ds_vector_squared(Lib3dsVector c)
+{
+ return(c[0]*c[0] + c[1]*c[1] + c[2]*c[2]);
+}
+
+
+/*!
+ * Compute length of vector.
+ *
+ * Computes |c| = sqrt(x*x + y*y + z*z)
+ *
+ * \param c Vector to compute.
+ *
+ * \return Length of vector.
+ *
+ * \ingroup vector
+ */
+Lib3dsFloat
+lib3ds_vector_length(Lib3dsVector c)
+{
+ return((Lib3dsFloat)sqrt(c[0]*c[0] + c[1]*c[1] + c[2]*c[2]));
+}
+
+
+/*!
+ * Normalize a vector.
+ *
+ * Scales a vector so that its length is 1.0.
+ *
+ * \param c Vector to normalize.
+ *
+ * \ingroup vector
+ */
+void
+lib3ds_vector_normalize(Lib3dsVector c)
+{
+ Lib3dsFloat l,m;
+
+ l=(Lib3dsFloat)sqrt(c[0]*c[0] + c[1]*c[1] + c[2]*c[2]);
+ if (fabs(l)<LIB3DS_EPSILON) {
+ if ((c[0]>=c[1]) && (c[0]>=c[2])) {
+ c[0]=1.0f;
+ c[1]=c[2]=0.0f;
+ }
+ else
+ if (c[1]>=c[2]) {
+ c[1]=1.0f;
+ c[0]=c[2]=0.0f;
+ }
+ else {
+ c[2]=1.0f;
+ c[0]=c[1]=0.0f;
+ }
+ }
+ else {
+ m=1.0f/l;
+ c[0]*=m;
+ c[1]*=m;
+ c[2]*=m;
+ }
+}
+
+
+/*!
+ * Compute a vector normal to two line segments.
+ *
+ * Computes the normal vector to the lines b-a and b-c.
+ *
+ * \param n Returned normal vector.
+ * \param a Endpoint of first line.
+ * \param b Base point of both lines.
+ * \param c Endpoint of second line.
+ *
+ * \ingroup vector
+ */
+void
+lib3ds_vector_normal(Lib3dsVector n, Lib3dsVector a, Lib3dsVector b, Lib3dsVector c)
+{
+ Lib3dsVector p,q;
+
+ lib3ds_vector_sub(p,c,b);
+ lib3ds_vector_sub(q,a,b);
+ lib3ds_vector_cross(n,p,q);
+ lib3ds_vector_normalize(n);
+}
+
+
+/*!
+ * Multiply a point by a transformation matrix.
+ *
+ * Applies the given transformation matrix to the given point. With some
+ * transformation matrices, a vector may also be transformed.
+ *
+ * \param c Result.
+ * \param m Transformation matrix.
+ * \param a Input point.
+ *
+ * \ingroup vector
+ */
+void
+lib3ds_vector_transform(Lib3dsVector c, Lib3dsMatrix m, Lib3dsVector a)
+{
+ c[0]= m[0][0]*a[0] + m[1][0]*a[1] + m[2][0]*a[2] + m[3][0];
+ c[1]= m[0][1]*a[0] + m[1][1]*a[1] + m[2][1]*a[2] + m[3][1];
+ c[2]= m[0][2]*a[0] + m[1][2]*a[1] + m[2][2]*a[2] + m[3][2];
+}
+
+
+/*!
+ * Compute a point on a cubic spline.
+ *
+ * Computes a point on a parametric Bezier spline.
+ *
+ * \param c Result.
+ * \param a First endpoint of the spline.
+ * \param p First tangent vector of the spline.
+ * \param q Second tangent vector of the spline.
+ * \param b Second endpoint of the spline.
+ * \param t Spline parameter [0. 1.]
+ *
+ * \ingroup vector
+ */
+void
+lib3ds_vector_cubic(Lib3dsVector c, Lib3dsVector a, Lib3dsVector p, Lib3dsVector q,
+ Lib3dsVector b, Lib3dsFloat t)
+{
+ Lib3dsDouble x,y,z,w;
+
+ x=2*t*t*t - 3*t*t + 1;
+ y=-2*t*t*t + 3*t*t;
+ z=t*t*t - 2*t*t + t;
+ w=t*t*t - t*t;
+ c[0]=(Lib3dsFloat)(x*a[0] + y*b[0] + z*p[0] + w*q[0]);
+ c[1]=(Lib3dsFloat)(x*a[1] + y*b[1] + z*p[1] + w*q[1]);
+ c[2]=(Lib3dsFloat)(x*a[2] + y*b[2] + z*p[2] + w*q[2]);
+}
+
+
+/*!
+ * c[i] = min(c[i], a[i]);
+ *
+ * Computes minimum values of x,y,z independently.
+ *
+ * \ingroup vector
+ */
+void
+lib3ds_vector_min(Lib3dsVector c, Lib3dsVector a)
+{
+ int i;
+ for (i=0; i<3; ++i) {
+ if (a[i]<c[i]) {
+ c[i] = a[i];
+ }
+ }
+}
+
+
+/*!
+ * c[i] = max(c[i], a[i]);
+ *
+ * Computes maximum values of x,y,z independently.
+ *
+ * \ingroup vector
+ */
+void
+lib3ds_vector_max(Lib3dsVector c, Lib3dsVector a)
+{
+ int i;
+ for (i=0; i<3; ++i) {
+ if (a[i]>c[i]) {
+ c[i] = a[i];
+ }
+ }
+}
+
+
+/*!
+ * \ingroup vector
+ */
+void
+lib3ds_vector_dump(Lib3dsVector c)
+{
+ fprintf(stderr, "%f %f %f\n", c[0], c[1], c[2]);
+}
+
projects / summerhack / blobdiff