diff options
author | Kenneth Russel <[email protected]> | 2003-06-25 09:05:29 +0000 |
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committer | Kenneth Russel <[email protected]> | 2003-06-25 09:05:29 +0000 |
commit | 2179980ed660ef66a9c064d153c5de7994d431ab (patch) | |
tree | 926fa0ccc31737ad9753a64bf0451dd818652d1b /src/gleem/linalg/Rotf.java | |
parent | 1a1ad3a33b2932187410bc8bb4bf44362a26c8b0 (diff) |
Split up net.java.games.util; moved GLUT and BufferUtils into
net.java.games.jogl.util, and moved demo-specific utility classes into
jogl-demos project under demos.util. Added nearly all JavaOne demos
into jogl-demos project; rewrote where necessary to use
ClassLoader.getResourceAsStream() instead of flat files, put into
packages and added to Makefile. Added gleem to jogl-demos project.
Added jogl.jar build rule.
git-svn-id: file:///usr/local/projects/SUN/JOGL/git-svn/../svn-server-sync/jogl-demos/trunk@3 3298f667-5e0e-4b4a-8ed4-a3559d26a5f4
Diffstat (limited to 'src/gleem/linalg/Rotf.java')
-rw-r--r-- | src/gleem/linalg/Rotf.java | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/src/gleem/linalg/Rotf.java b/src/gleem/linalg/Rotf.java new file mode 100644 index 0000000..4e39c21 --- /dev/null +++ b/src/gleem/linalg/Rotf.java @@ -0,0 +1,309 @@ +/* + * gleem -- OpenGL Extremely Easy-To-Use Manipulators. + * Copyright (C) 1998-2003 Kenneth B. Russell ([email protected]) + * + * Copying, distribution and use of this software in source and binary + * forms, with or without modification, is permitted provided that the + * following conditions are met: + * + * Distributions of source code must reproduce the copyright notice, + * this list of conditions and the following disclaimer in the source + * code header files; and Distributions of binary code must reproduce + * the copyright notice, this list of conditions and the following + * disclaimer in the documentation, Read me file, license file and/or + * other materials provided with the software distribution. + * + * The names of Sun Microsystems, Inc. ("Sun") and/or the copyright + * holder may not be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED "AS IS," WITHOUT A WARRANTY OF ANY + * KIND. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND + * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE, NON-INTERFERENCE, ACCURACY OF + * INFORMATIONAL CONTENT OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. THE + * COPYRIGHT HOLDER, SUN AND SUN'S LICENSORS SHALL NOT BE LIABLE FOR + * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR + * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL THE + * COPYRIGHT HOLDER, SUN OR SUN'S LICENSORS BE LIABLE FOR ANY LOST + * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, + * CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND + * REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR + * INABILITY TO USE THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGES. YOU ACKNOWLEDGE THAT THIS SOFTWARE IS NOT + * DESIGNED, LICENSED OR INTENDED FOR USE IN THE DESIGN, CONSTRUCTION, + * OPERATION OR MAINTENANCE OF ANY NUCLEAR FACILITY. THE COPYRIGHT + * HOLDER, SUN AND SUN'S LICENSORS DISCLAIM ANY EXPRESS OR IMPLIED + * WARRANTY OF FITNESS FOR SUCH USES. + */ + +package gleem.linalg; + +/** Represents a rotation with single-precision components */ + +public class Rotf { + private static float EPSILON = 1.0e-7f; + + // Representation is a quaternion. Element 0 is the scalar part (= + // cos(theta/2)), elements 1..3 the imaginary/"vector" part (= + // sin(theta/2) * axis). + private float q0; + private float q1; + private float q2; + private float q3; + + /** Default constructor initializes to the identity quaternion */ + public Rotf() { + init(); + } + + public Rotf(Rotf arg) { + set(arg); + } + + /** Axis does not need to be normalized but must not be the zero + vector. Angle is in radians. */ + public Rotf(Vec3f axis, float angle) { + set(axis, angle); + } + + /** Creates a rotation which will rotate vector "from" into vector + "to". */ + public Rotf(Vec3f from, Vec3f to) { + set(from, to); + } + + /** Re-initialize this quaternion to be the identity quaternion "e" + (i.e., no rotation) */ + public void init() { + q0 = 1; + q1 = q2 = q3 = 0; + } + + /** Test for "approximate equality" -- performs componentwise test + to see whether difference between all components is less than + epsilon. */ + public boolean withinEpsilon(Rotf arg, float epsilon) { + return ((Math.abs(q0 - arg.q0) < epsilon) && + (Math.abs(q1 - arg.q1) < epsilon) && + (Math.abs(q2 - arg.q2) < epsilon) && + (Math.abs(q3 - arg.q3) < epsilon)); + } + + /** Axis does not need to be normalized but must not be the zero + vector. Angle is in radians. */ + public void set(Vec3f axis, float angle) { + float halfTheta = angle / 2.0f; + q0 = (float) Math.cos(halfTheta); + float sinHalfTheta = (float) Math.sin(halfTheta); + Vec3f realAxis = new Vec3f(axis); + realAxis.normalize(); + q1 = realAxis.x() * sinHalfTheta; + q2 = realAxis.y() * sinHalfTheta; + q3 = realAxis.z() * sinHalfTheta; + } + + public void set(Rotf arg) { + q0 = arg.q0; + q1 = arg.q1; + q2 = arg.q2; + q3 = arg.q3; + } + + /** Sets this rotation to that which will rotate vector "from" into + vector "to". from and to do not have to be the same length. */ + public void set(Vec3f from, Vec3f to) { + Vec3f axis = from.cross(to); + if (axis.lengthSquared() < EPSILON) { + init(); + return; + } + float dotp = from.dot(to); + float denom = from.length() * to.length(); + if (denom < EPSILON) { + init(); + return; + } + dotp /= denom; + set(axis, (float) Math.acos(dotp)); + } + + /** Returns angle (in radians) and mutates the given vector to be + the axis. */ + public float get(Vec3f axis) { + // FIXME: Is this numerically stable? Is there a better way to + // extract the angle from a quaternion? + // NOTE: remove (float) to illustrate compiler bug + float retval = (float) (2.0f * Math.acos(q0)); + axis.set(q1, q2, q3); + float len = axis.length(); + if (len == 0.0f) { + axis.set(0, 0, 1); + } else { + axis.scale(1.0f / len); + } + return retval; + } + + /** Returns inverse of this rotation; creates new rotation */ + public Rotf inverse() { + Rotf tmp = new Rotf(this); + tmp.invert(); + return tmp; + } + + /** Mutate this quaternion to be its inverse. This is equivalent to + the conjugate of the quaternion. */ + public void invert() { + q1 = -q1; + q2 = -q2; + q3 = -q3; + } + + /** Length of this quaternion in four-space */ + public float length() { + return (float) Math.sqrt(lengthSquared()); + } + + /** This dotted with this */ + public float lengthSquared() { + return (q0 * q0 + + q1 * q1 + + q2 * q2 + + q3 * q3); + } + + /** Make this quaternion a unit quaternion again. If you are + composing dozens of quaternions you probably should call this + periodically to ensure that you have a valid rotation. */ + public void normalize() { + float len = length(); + q0 /= len; + q1 /= len; + q2 /= len; + q3 /= len; + } + + /** Returns this * b, in that order; creates new rotation */ + public Rotf times(Rotf b) { + Rotf tmp = new Rotf(); + tmp.mul(this, b); + return tmp; + } + + /** Compose two rotations: this = A * B in that order. NOTE that + because we assume a column vector representation that this + implies that a vector rotated by the cumulative rotation will be + rotated first by B, then A. NOTE: "this" must be different than + both a and b. */ + public void mul(Rotf a, Rotf b) { + q0 = (a.q0 * b.q0 - a.q1 * b.q1 - + a.q2 * b.q2 - a.q3 * b.q3); + q1 = (a.q0 * b.q1 + a.q1 * b.q0 + + a.q2 * b.q3 - a.q3 * b.q2); + q2 = (a.q0 * b.q2 + a.q2 * b.q0 - + a.q1 * b.q3 + a.q3 * b.q1); + q3 = (a.q0 * b.q3 + a.q3 * b.q0 + + a.q1 * b.q2 - a.q2 * b.q1); + } + + /** Turns this rotation into a 3x3 rotation matrix. NOTE: only + mutates the upper-left 3x3 of the passed Mat4f. Implementation + from B. K. P. Horn's <u>Robot Vision</u> textbook. */ + public void toMatrix(Mat4f mat) { + float q00 = q0 * q0; + float q11 = q1 * q1; + float q22 = q2 * q2; + float q33 = q3 * q3; + // Diagonal elements + mat.set(0, 0, q00 + q11 - q22 - q33); + mat.set(1, 1, q00 - q11 + q22 - q33); + mat.set(2, 2, q00 - q11 - q22 + q33); + // 0,1 and 1,0 elements + float q03 = q0 * q3; + float q12 = q1 * q2; + mat.set(0, 1, 2.0f * (q12 - q03)); + mat.set(1, 0, 2.0f * (q03 + q12)); + // 0,2 and 2,0 elements + float q02 = q0 * q2; + float q13 = q1 * q3; + mat.set(0, 2, 2.0f * (q02 + q13)); + mat.set(2, 0, 2.0f * (q13 - q02)); + // 1,2 and 2,1 elements + float q01 = q0 * q1; + float q23 = q2 * q3; + mat.set(1, 2, 2.0f * (q23 - q01)); + mat.set(2, 1, 2.0f * (q01 + q23)); + } + + /** Turns the upper left 3x3 of the passed matrix into a rotation. + Implementation from Watt and Watt, <u>Advanced Animation and + Rendering Techniques</u>. + @see gleem.linalg.Mat4f#getRotation */ + public void fromMatrix(Mat4f mat) { + // FIXME: Should reimplement to follow Horn's advice of using + // eigenvector decomposition to handle roundoff error in given + // matrix. + + float tr, s; + int i, j, k; + + tr = mat.get(0, 0) + mat.get(1, 1) + mat.get(2, 2); + if (tr > 0.0) { + s = (float) Math.sqrt(tr + 1.0f); + q0 = s * 0.5f; + s = 0.5f / s; + q1 = (mat.get(2, 1) - mat.get(1, 2)) * s; + q2 = (mat.get(0, 2) - mat.get(2, 0)) * s; + q3 = (mat.get(1, 0) - mat.get(0, 1)) * s; + } else { + i = 0; + if (mat.get(1, 1) > mat.get(0, 0)) + i = 1; + if (mat.get(2, 2) > mat.get(i, i)) + i = 2; + j = (i+1)%3; + k = (j+1)%3; + s = (float) Math.sqrt( (mat.get(i, i) - (mat.get(j, j) + mat.get(k, k))) + 1.0f); + setQ(i+1, s * 0.5f); + s = 0.5f / s; + q0 = (mat.get(k, j) - mat.get(j, k)) * s; + setQ(j+1, (mat.get(j, i) + mat.get(i, j)) * s); + setQ(k+1, (mat.get(k, i) + mat.get(i, k)) * s); + } + } + + /** Rotate a vector by this quaternion. Implementation is from + Horn's <u>Robot Vision</u>. NOTE: src and dest must be different + vectors. */ + public void rotateVector(Vec3f src, Vec3f dest) { + Vec3f qVec = new Vec3f(q1, q2, q3); + Vec3f qCrossX = qVec.cross(src); + Vec3f qCrossXCrossQ = qCrossX.cross(qVec); + qCrossX.scale(2.0f * q0); + qCrossXCrossQ.scale(-2.0f); + dest.add(src, qCrossX); + dest.add(dest, qCrossXCrossQ); + } + + /** Rotate a vector by this quaternion, returning newly-allocated result. */ + public Vec3f rotateVector(Vec3f src) { + Vec3f tmp = new Vec3f(); + rotateVector(src, tmp); + return tmp; + } + + public String toString() { + return "(" + q0 + ", " + q1 + ", " + q2 + ", " + q3 + ")"; + } + + private void setQ(int i, float val) { + switch (i) { + case 0: q0 = val; break; + case 1: q1 = val; break; + case 2: q2 = val; break; + case 3: q3 = val; break; + default: throw new IndexOutOfBoundsException(); + } + } +} |