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Diffstat (limited to 'src/jogl/classes/com/jogamp/opengl/math/VectorUtil.java')
-rw-r--r-- | src/jogl/classes/com/jogamp/opengl/math/VectorUtil.java | 770 |
1 files changed, 0 insertions, 770 deletions
diff --git a/src/jogl/classes/com/jogamp/opengl/math/VectorUtil.java b/src/jogl/classes/com/jogamp/opengl/math/VectorUtil.java deleted file mode 100644 index e38501c73..000000000 --- a/src/jogl/classes/com/jogamp/opengl/math/VectorUtil.java +++ /dev/null @@ -1,770 +0,0 @@ -/** - * Copyright 2010-2023 JogAmp Community. All rights reserved. - * - * Redistribution and use in source and binary forms, with or without modification, are - * permitted provided that the following conditions are met: - * - * 1. Redistributions of source code must retain the above copyright notice, this list of - * conditions and the following disclaimer. - * - * 2. Redistributions in binary form must reproduce the above copyright notice, this list - * of conditions and the following disclaimer in the documentation and/or other materials - * provided with the distribution. - * - * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED - * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND - * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR - * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR - * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR - * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON - * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING - * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF - * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - * - * The views and conclusions contained in the software and documentation are those of the - * authors and should not be interpreted as representing official policies, either expressed - * or implied, of JogAmp Community. - */ -package com.jogamp.opengl.math; - -import java.util.ArrayList; - -import com.jogamp.graph.geom.plane.Winding; - -public final class VectorUtil { - /** - * Return true if 2D vector components are zero, no {@link FloatUtil#EPSILON} is taken into consideration. - */ - public static boolean isVec2Zero(final Vec3f vec) { - return 0f == vec.x() && 0f == vec.y(); - } - - /** - * Return true if all three vector components are zero, i.e. it's their absolute value < <code>epsilon</code>. - * <p> - * Implementation uses {@link FloatUtil#isZero(float, float)}, see API doc for details. - * </p> - */ - public static boolean isZero(final float x, final float y, final float z, final float epsilon) { - return FloatUtil.isZero(x, epsilon) && - FloatUtil.isZero(y, epsilon) && - FloatUtil.isZero(z, epsilon) ; - } - - /** - * Return true if all three vector components are zero, i.e. it's their absolute value < {@link FloatUtil#EPSILON}. - * <p> - * Implementation uses {@link FloatUtil#isZero(float)}, see API doc for details. - * </p> - */ - public static boolean isZero(final float x, final float y, final float z) { - return FloatUtil.isZero(x) && - FloatUtil.isZero(y) && - FloatUtil.isZero(z) ; - } - - /** - * Return the squared distance between the given two points described vector v1 and v2. - * <p> - * When comparing the relative distance between two points it is usually sufficient to compare the squared - * distances, thus avoiding an expensive square root operation. - * </p> - */ - public static float distSquareVec3(final float[] v1, final float[] v2) { - final float dx = v1[0] - v2[0]; - final float dy = v1[1] - v2[1]; - final float dz = v1[2] - v2[2]; - return dx * dx + dy * dy + dz * dz; - } - - /** - * Return the distance between the given two points described vector v1 and v2. - */ - public static float distVec3(final float[] v1, final float[] v2) { - return FloatUtil.sqrt(distSquareVec3(v1, v2)); - } - - /** - * Return the squared length of a vector, a.k.a the squared <i>norm</i> or squared <i>magnitude</i> - */ - public static float normSquareVec2(final float[] vec) { - return vec[0]*vec[0] + vec[1]*vec[1]; - } - - /** - * Return the squared length of a vector, a.k.a the squared <i>norm</i> or squared <i>magnitude</i> - */ - public static float normSquareVec3(final float[] vec) { - return vec[0]*vec[0] + vec[1]*vec[1] + vec[2]*vec[2]; - } - - /** - * Return the squared length of a vector, a.k.a the squared <i>norm</i> or squared <i>magnitude</i> - */ - public static float normSquareVec3(final float[] vec, final int offset) { - float v = vec[0+offset]; - float r = v*v; - v = vec[1+offset]; - r += v*v; - v = vec[2+offset]; - return r + v*v; - } - - /** - * Return the length of a vector, a.k.a the <i>norm</i> or <i>magnitude</i> - */ - public static float normVec2(final float[] vec) { - return FloatUtil.sqrt(normSquareVec2(vec)); - } - - /** - * Normalize a vector in place - * @param vector input vector - * @return normalized output vector - */ - public static float[] normalizeVec3(final float[] vector) { - final float lengthSq = normSquareVec3(vector); - if ( FloatUtil.isZero(lengthSq, FloatUtil.EPSILON) ) { - vector[0] = 0f; - vector[1] = 0f; - vector[2] = 0f; - } else { - final float invSqr = 1f / FloatUtil.sqrt(lengthSq); - vector[0] *= invSqr; - vector[1] *= invSqr; - vector[2] *= invSqr; - } - return vector; - } - - /** - * Normalize a vector in place - * @param vector input vector - * @return normalized output vector - */ - public static float[] normalizeVec3(final float[] vector, final int offset) { - final float lengthSq = normSquareVec3(vector, offset); - if ( FloatUtil.isZero(lengthSq, FloatUtil.EPSILON) ) { - vector[0+offset] = 0f; - vector[1+offset] = 0f; - vector[2+offset] = 0f; - } else { - final float invSqr = 1f / FloatUtil.sqrt(lengthSq); - vector[0+offset] *= invSqr; - vector[1+offset] *= invSqr; - vector[2+offset] *= invSqr; - } - return vector; - } - - /** - * Scales a vector by param using given result float[], result = vector * scale - * @param result vector for the result, may be vector (in-place) - * @param vector input vector - * @param scale single scale constant for all vector components - * @return result vector for chaining - */ - public static float[] scaleVec2(final float[] result, final float[] vector, final float scale) { - result[0] = vector[0] * scale; - result[1] = vector[1] * scale; - return result; - } - - /** - * Scales a vector by param using given result float[], result = vector * scale - * @param result vector for the result, may be vector (in-place) - * @param vector input vector - * @param scale 2 component scale constant for each vector component - * @return result vector for chaining - */ - public static float[] scaleVec2(final float[] result, final float[] vector, final float[] scale) - { - result[0] = vector[0] * scale[0]; - result[1] = vector[1] * scale[1]; - return result; - } - - /** - * Divides a vector by param using given result float[], result = vector / scale - * @param result vector for the result, may be vector (in-place) - * @param vector input vector - * @param scale single scale constant for all vector components - * @return result vector for chaining - */ - public static float[] divVec2(final float[] result, final float[] vector, final float scale) { - result[0] = vector[0] / scale; - result[1] = vector[1] / scale; - return result; - } - - /** - * Divides a vector by param using given result float[], result = vector / scale - * @param result vector for the result, may be vector (in-place) - * @param vector input vector - * @param scale 2 component scale constant for each vector component - * @return result vector for chaining - */ - public static float[] divVec2(final float[] result, final float[] vector, final float[] scale) - { - result[0] = vector[0] / scale[0]; - result[1] = vector[1] / scale[1]; - return result; - } - - /** - * Adds two vectors, result = v1 + v2 - * @param result float[2] result vector, may be either v1 or v2 (in-place) - * @param v1 vector 1 - * @param v2 vector 2 - * @return result vector for chaining - */ - public static float[] addVec2(final float[] result, final float[] v1, final float[] v2) { - result[0] = v1[0] + v2[0]; - result[1] = v1[1] + v2[1]; - return result; - } - - /** - * Subtracts two vectors, result = v1 - v2 - * @param result float[2] result vector, may be either v1 or v2 (in-place) - * @param v1 vector 1 - * @param v2 vector 2 - * @return result vector for chaining - */ - public static float[] subVec2(final float[] result, final float[] v1, final float[] v2) { - result[0] = v1[0] - v2[0]; - result[1] = v1[1] - v2[1]; - return result; - } - - /** - * cross product vec1 x vec2 - * @param v1 vector 1 - * @param v2 vector 2 - * @return the resulting vector - */ - public static float[] crossVec3(final float[] r, final int r_offset, final float[] v1, final int v1_offset, final float[] v2, final int v2_offset) - { - r[0+r_offset] = v1[1+v1_offset] * v2[2+v2_offset] - v1[2+v1_offset] * v2[1+v2_offset]; - r[1+r_offset] = v1[2+v1_offset] * v2[0+v2_offset] - v1[0+v1_offset] * v2[2+v2_offset]; - r[2+r_offset] = v1[0+v1_offset] * v2[1+v2_offset] - v1[1+v1_offset] * v2[0+v2_offset]; - return r; - } - - /** - * Calculate the midpoint of two points - * @param p1 first point vector - * @param p2 second point vector - * @return midpoint - */ - public static Vec3f midVec3(final Vec3f result, final Vec3f p1, final Vec3f p2) { - result.set( (p1.x() + p2.x())*0.5f, - (p1.y() + p2.y())*0.5f, - (p1.z() + p2.z())*0.5f ); - return result; - } - - /** - * Return the determinant of 3 vectors - * @param a vector 1 - * @param b vector 2 - * @param c vector 3 - * @return the determinant value - */ - public static float determinantVec3(final Vec3f a, final Vec3f b, final Vec3f c) { - return a.x()*b.y()*c.z() + a.y()*b.z()*c.x() + a.z()*b.x()*c.y() - a.x()*b.z()*c.y() - a.y()*b.x()*c.z() - a.z()*b.y()*c.x(); - } - - /** - * Check if three vertices are colliniear - * @param v1 vertex 1 - * @param v2 vertex 2 - * @param v3 vertex 3 - * @return true if collinear, false otherwise - */ - public static boolean isCollinearVec3(final Vec3f v1, final Vec3f v2, final Vec3f v3) { - return FloatUtil.isZero( determinantVec3(v1, v2, v3), FloatUtil.EPSILON ); - } - - /** - * Check if vertices in triangle circumcircle - * @param a triangle vertex 1 - * @param b triangle vertex 2 - * @param c triangle vertex 3 - * @param d vertex in question - * @return true if the vertex d is inside the circle defined by the - * vertices a, b, c. from paper by Guibas and Stolfi (1985). - */ - public static boolean isInCircleVec2(final Vert2fImmutable a, final Vert2fImmutable b, final Vert2fImmutable c, final Vert2fImmutable d) { - return (a.x() * a.x() + a.y() * a.y()) * triAreaVec2(b, c, d) - - (b.x() * b.x() + b.y() * b.y()) * triAreaVec2(a, c, d) + - (c.x() * c.x() + c.y() * c.y()) * triAreaVec2(a, b, d) - - (d.x() * d.x() + d.y() * d.y()) * triAreaVec2(a, b, c) > 0; - } - - /** - * Computes oriented area of a triangle - * @param a first vertex - * @param b second vertex - * @param c third vertex - * @return compute twice the area of the oriented triangle (a,b,c), the area - * is positive if the triangle is oriented counterclockwise. - */ - public static float triAreaVec2(final Vert2fImmutable a, final Vert2fImmutable b, final Vert2fImmutable c){ - return (b.x() - a.x()) * (c.y() - a.y()) - (b.y() - a.y()) * (c.x() - a.x()); - } - - /** - * Check if a vertex is in triangle using barycentric coordinates computation. - * @param a first triangle vertex - * @param b second triangle vertex - * @param c third triangle vertex - * @param p the vertex in question - * @param ac temporary storage - * @param ab temporary storage - * @param ap temporary storage - * @return true if p is in triangle (a, b, c), false otherwise. - */ - public static boolean isInTriangleVec3(final Vec3f a, final Vec3f b, final Vec3f c, - final Vec3f p, - final Vec3f ac, final Vec3f ab, final Vec3f ap){ - // Compute vectors - ac.minus( c, a); // v0 - ab.minus( b, a); // v1 - ap.minus( p, a); // v2 - - // Compute dot products - final float dotAC_AC = ac.dot(ac); - final float dotAC_AB = ac.dot(ab); - final float dotAB_AB = ab.dot(ab); - final float dotAC_AP = ac.dot(ap); - final float dotAB_AP = ab.dot(ap); - - // Compute barycentric coordinates - final float invDenom = 1 / (dotAC_AC * dotAB_AB - dotAC_AB * dotAC_AB); - final float u = (dotAB_AB * dotAC_AP - dotAC_AB * dotAB_AP) * invDenom; - final float v = (dotAC_AC * dotAB_AP - dotAC_AB * dotAC_AP) * invDenom; - - // Check if point is in triangle - return (u >= 0) && (v >= 0) && (u + v < 1); - } - - /** - * Check if one of three vertices are in triangle using barycentric coordinates computation. - * @param a first triangle vertex - * @param b second triangle vertex - * @param c third triangle vertex - * @param p1 the vertex in question - * @param p2 the vertex in question - * @param p3 the vertex in question - * @param ac temporary storage - * @param ab temporary storage - * @param ap temporary storage - * @return true if p1 or p2 or p3 is in triangle (a, b, c), false otherwise. - */ - public static boolean isVec3InTriangle3(final Vec3f a, final Vec3f b, final Vec3f c, - final Vec3f p1, final Vec3f p2, final Vec3f p3, - final Vec3f ac, final Vec3f ab, final Vec3f ap){ - // Compute vectors - ac.minus(c, a); // v0 - ab.minus(b, a); // v1 - - // Compute dot products - final float dotAC_AC = ac.dot(ac); - final float dotAC_AB = ac.dot(ab); - final float dotAB_AB = ab.dot(ab); - - // Compute barycentric coordinates - final float invDenom = 1 / (dotAC_AC * dotAB_AB - dotAC_AB * dotAC_AB); - { - ap.minus(p1, a); // v2 - final float dotAC_AP1 = ac.dot(ap); - final float dotAB_AP1 = ab.dot(ap); - final float u = (dotAB_AB * dotAC_AP1 - dotAC_AB * dotAB_AP1) * invDenom; - final float v = (dotAC_AC * dotAB_AP1 - dotAC_AB * dotAC_AP1) * invDenom; - - // Check if point is in triangle - if ( (u >= 0) && (v >= 0) && (u + v < 1) ) { - return true; - } - } - - { - ap.minus(p2, a); // v2 - final float dotAC_AP2 = ac.dot(ap); - final float dotAB_AP2 = ab.dot(ap); - final float u = (dotAB_AB * dotAC_AP2 - dotAC_AB * dotAB_AP2) * invDenom; - final float v = (dotAC_AC * dotAB_AP2 - dotAC_AB * dotAC_AP2) * invDenom; - - // Check if point is in triangle - if ( (u >= 0) && (v >= 0) && (u + v < 1) ) { - return true; - } - } - - { - ap.minus(p3, a); // v3 - final float dotAC_AP3 = ac.dot(ap); - final float dotAB_AP3 = ab.dot(ap); - final float u = (dotAB_AB * dotAC_AP3 - dotAC_AB * dotAB_AP3) * invDenom; - final float v = (dotAC_AC * dotAB_AP3 - dotAC_AB * dotAC_AP3) * invDenom; - - // Check if point is in triangle - if ( (u >= 0) && (v >= 0) && (u + v < 1) ) { - return true; - } - } - return false; - } - /** - * Check if one of three vertices are in triangle using - * barycentric coordinates computation, using given epsilon for comparison. - * @param a first triangle vertex - * @param b second triangle vertex - * @param c third triangle vertex - * @param p1 the vertex in question - * @param p2 the vertex in question - * @param p3 the vertex in question - * @param tmpAC - * @param tmpAB - * @param tmpAP - * @return true if p1 or p2 or p3 is in triangle (a, b, c), false otherwise. - */ - public static boolean isVec3InTriangle3(final Vec3f a, final Vec3f b, final Vec3f c, - final Vec3f p1, final Vec3f p2, final Vec3f p3, - final Vec3f ac, final Vec3f ab, final Vec3f ap, - final float epsilon) { - // Compute vectors - ac.minus(c, a); // v0 - ab.minus(b, a); // v1 - - // Compute dot products - final float dotAC_AC = ac.dot(ac); - final float dotAC_AB = ac.dot(ab); - final float dotAB_AB = ab.dot(ab); - - // Compute barycentric coordinates - final float invDenom = 1 / (dotAC_AC * dotAB_AB - dotAC_AB * dotAC_AB); - { - ap.minus(p1, a); // v2 - final float dotAC_AP1 = ac.dot(ap); - final float dotAB_AP1 = ab.dot(ap); - final float u = (dotAB_AB * dotAC_AP1 - dotAC_AB * dotAB_AP1) * invDenom; - final float v = (dotAC_AC * dotAB_AP1 - dotAC_AB * dotAC_AP1) * invDenom; - - // Check if point is in triangle - if( FloatUtil.compare(u, 0.0f, epsilon) >= 0 && - FloatUtil.compare(v, 0.0f, epsilon) >= 0 && - FloatUtil.compare(u+v, 1.0f, epsilon) < 0 ) { - return true; - } - } - - { - ap.minus(p2, a); // v3 - final float dotAC_AP2 = ac.dot(ap); - final float dotAB_AP2 = ab.dot(ap); - final float u = (dotAB_AB * dotAC_AP2 - dotAC_AB * dotAB_AP2) * invDenom; - final float v = (dotAC_AC * dotAB_AP2 - dotAC_AB * dotAC_AP2) * invDenom; - - // Check if point is in triangle - if( FloatUtil.compare(u, 0.0f, epsilon) >= 0 && - FloatUtil.compare(v, 0.0f, epsilon) >= 0 && - FloatUtil.compare(u+v, 1.0f, epsilon) < 0 ) { - return true; - } - } - - { - ap.minus(p3, a); // v4 - final float dotAC_AP3 = ac.dot(ap); - final float dotAB_AP3 = ab.dot(ap); - final float u = (dotAB_AB * dotAC_AP3 - dotAC_AB * dotAB_AP3) * invDenom; - final float v = (dotAC_AC * dotAB_AP3 - dotAC_AB * dotAC_AP3) * invDenom; - - // Check if point is in triangle - if( FloatUtil.compare(u, 0.0f, epsilon) >= 0 && - FloatUtil.compare(v, 0.0f, epsilon) >= 0 && - FloatUtil.compare(u+v, 1.0f, epsilon) < 0 ) { - return true; - } - } - return false; - } - - /** - * Check if points are in ccw order - * @param a first vertex - * @param b second vertex - * @param c third vertex - * @return true if the points a,b,c are in a ccw order - */ - public static boolean isCCW(final Vert2fImmutable a, final Vert2fImmutable b, final Vert2fImmutable c){ - return triAreaVec2(a,b,c) > 0; - } - - /** - * Compute the winding of the 3 given points - * <p> - * Consider using {@link #getWinding(ArrayList)} using the {@link #area(ArrayList)} function over all points - * on complex shapes for a reliable result! - * </p> - * @param a first vertex - * @param b second vertex - * @param c third vertex - * @return {@link Winding#CCW} or {@link Winding#CW} - * @see #getWinding(ArrayList) - */ - public static Winding getWinding(final Vert2fImmutable a, final Vert2fImmutable b, final Vert2fImmutable c) { - return triAreaVec2(a,b,c) > 0 ? Winding.CCW : Winding.CW ; - } - - /** - * Computes the area of a list of vertices. - * <p> - * This method is utilized e.g. to reliably compute the {@link Winding} of complex shapes. - * </p> - * @param vertices - * @return positive area if ccw else negative area value - * @see #getWinding(ArrayList) - */ - public static float area(final ArrayList<? extends Vert2fImmutable> vertices) { - final int n = vertices.size(); - float area = 0.0f; - for (int p = n - 1, q = 0; q < n; p = q++) { - final Vert2fImmutable pCoord = vertices.get(p); - final Vert2fImmutable qCoord = vertices.get(q); - area += pCoord.x() * qCoord.y() - qCoord.x() * pCoord.y(); - } - return area; - } - - /** - * Compute the winding using the {@link #area(ArrayList)} function over all vertices for complex shapes. - * <p> - * Uses the {@link #area(ArrayList)} function over all points - * on complex shapes for a reliable result! - * </p> - * @param vertices array of Vertices - * @return {@link Winding#CCW} or {@link Winding#CW} - * @see #area(ArrayList) - */ - public static Winding getWinding(final ArrayList<? extends Vert2fImmutable> vertices) { - return area(vertices) >= 0 ? Winding.CCW : Winding.CW ; - } - - /** - * Finds the plane equation of a plane given its normal and a point on the plane. - * - * @param resultV4 vec4 plane equation - * @param normalVec3 - * @param pVec3 - * @return result for chaining - */ - public static Vec4f getPlaneVec3(final Vec4f resultV4, final Vec3f normalVec3, final Vec3f pVec3) { - /** - Ax + By + Cz + D == 0 ; - D = - ( Ax + By + Cz ) - = - ( A*a[0] + B*a[1] + C*a[2] ) - = - vec3Dot ( normal, a ) ; - */ - resultV4.set(normalVec3, -normalVec3.dot(pVec3)); - return resultV4; - } - - /** - * This finds the plane equation of a triangle given three vertices. - * - * @param resultVec4 vec4 plane equation - * @param v1 vec3 - * @param v2 vec3 - * @param v3 vec3 - * @param temp1V3 - * @param temp2V3 - * @return result for chaining - */ - public static Vec4f getPlaneVec3(final Vec4f resultVec4, final Vec3f v1, final Vec3f v2, final Vec3f v3, - final Vec3f temp1V3, final Vec3f temp2V3, final Vec3f temp3V3) { - /** - Ax + By + Cz + D == 0 ; - D = - ( Ax + By + Cz ) - = - ( A*a[0] + B*a[1] + C*a[2] ) - = - vec3Dot ( normal, a ) ; - */ - temp3V3.cross(temp1V3.minus(v2, v1), temp2V3.minus(v3, v1)).normalize(); - resultVec4.set(temp3V3, -temp3V3.dot(v1)); - return resultVec4; - } - - /** - * Return intersection of an infinite line with a plane if exists, otherwise null. - * <p> - * Thanks to <i>Norman Vine -- [email protected] (with hacks by Steve)</i> - * </p> - * - * @param result vec3 result buffer for intersecting coords - * @param ray here representing an infinite line, origin and direction. - * @param plane vec4 plane equation - * @param epsilon - * @return resulting intersecting if exists, otherwise null - */ - public static Vec3f line2PlaneIntersection(final Vec3f result, final Ray ray, final Vec4f plane, final float epsilon) { - final Vec3f plane3 = new Vec3f(plane); - final float tmp = ray.dir.dot(plane3); - - if ( Math.abs(tmp) < epsilon ) { - return null; // ray is parallel to plane - } - result.set( ray.dir ); - return result.scale( -( ray.orig.dot(plane3) + plane.w() ) / tmp ).add(ray.orig); - } - - /** Compute intersection between two segments - * @param a vertex 1 of first segment - * @param b vertex 2 of first segment - * @param c vertex 1 of second segment - * @param d vertex 2 of second segment - * @return the intersection coordinates if the segments intersect, otherwise returns null - */ - public static Vec3f seg2SegIntersection(final Vec3f result, final Vert2fImmutable a, final Vert2fImmutable b, final Vert2fImmutable c, final Vert2fImmutable d) { - final float determinant = (a.x()-b.x())*(c.y()-d.y()) - (a.y()-b.y())*(c.x()-d.x()); - - if (determinant == 0) - return null; - - final float alpha = (a.x()*b.y()-a.y()*b.x()); - final float beta = (c.x()*d.y()-c.y()*d.y()); - final float xi = ((c.x()-d.x())*alpha-(a.x()-b.x())*beta)/determinant; - final float yi = ((c.y()-d.y())*alpha-(a.y()-b.y())*beta)/determinant; - - final float gamma = (xi - a.x())/(b.x() - a.x()); - final float gamma1 = (xi - c.x())/(d.x() - c.x()); - if(gamma <= 0 || gamma >= 1) return null; - if(gamma1 <= 0 || gamma1 >= 1) return null; - - return result.set(xi, yi, 0); - } - - /** - * Compute intersection between two segments - * @param a vertex 1 of first segment - * @param b vertex 2 of first segment - * @param c vertex 1 of second segment - * @param d vertex 2 of second segment - * @return true if the segments intersect, otherwise returns false - */ - public static boolean testSeg2SegIntersection(final Vert2fImmutable a, final Vert2fImmutable b, - final Vert2fImmutable c, final Vert2fImmutable d) { - final float determinant = (a.x()-b.x())*(c.y()-d.y()) - (a.y()-b.y())*(c.x()-d.x()); - - if (determinant == 0) { - return false; - } - - final float alpha = (a.x()*b.y()-a.y()*b.x()); - final float beta = (c.x()*d.y()-c.y()*d.y()); - final float xi = ((c.x()-d.x())*alpha-(a.x()-b.x())*beta)/determinant; - - final float gamma0 = (xi - a.x())/(b.x() - a.x()); - final float gamma1 = (xi - c.x())/(d.x() - c.x()); - if(gamma0 <= 0 || gamma0 >= 1 || gamma1 <= 0 || gamma1 >= 1) { - return false; - } - - return true; - } - /** - * Compute intersection between two segments, using given epsilon for comparison. - * @param a vertex 1 of first segment - * @param b vertex 2 of first segment - * @param c vertex 1 of second segment - * @param d vertex 2 of second segment - * @return true if the segments intersect, otherwise returns false - */ - public static boolean testSeg2SegIntersection(final Vert2fImmutable a, final Vert2fImmutable b, - final Vert2fImmutable c, final Vert2fImmutable d, - final float epsilon) { - final float determinant = (a.x()-b.x())*(c.y()-d.y()) - (a.y()-b.y())*(c.x()-d.x()); - - if ( FloatUtil.isZero(determinant, epsilon) ) { - return false; - } - - final float alpha = (a.x()*b.y()-a.y()*b.x()); - final float beta = (c.x()*d.y()-c.y()*d.y()); - final float xi = ((c.x()-d.x())*alpha-(a.x()-b.x())*beta)/determinant; - - final float gamma0 = (xi - a.x())/(b.x() - a.x()); - final float gamma1 = (xi - c.x())/(d.x() - c.x()); - - if( FloatUtil.compare(gamma0, 0.0f, epsilon) <= 0 || - FloatUtil.compare(gamma0, 1.0f, epsilon) >= 0 || - FloatUtil.compare(gamma1, 0.0f, epsilon) <= 0 || - FloatUtil.compare(gamma1, 1.0f, epsilon) >= 0 ) { - return false; - } - - if(gamma0 <= 0 || gamma0 >= 1 || gamma1 <= 0 || gamma1 >= 1) { - return false; - } - - return true; - } - - /** - * Compute intersection between two lines - * @param a vertex 1 of first line - * @param b vertex 2 of first line - * @param c vertex 1 of second line - * @param d vertex 2 of second line - * @return the intersection coordinates if the lines intersect, otherwise - * returns null - */ - public static Vec3f line2lineIntersection(final Vec3f result, - final Vert2fImmutable a, final Vert2fImmutable b, - final Vert2fImmutable c, final Vert2fImmutable d) { - final float determinant = (a.x()-b.x())*(c.y()-d.y()) - (a.y()-b.y())*(c.x()-d.x()); - - if (determinant == 0) - return null; - - final float alpha = (a.x()*b.y()-a.y()*b.x()); - final float beta = (c.x()*d.y()-c.y()*d.y()); - final float xi = ((c.x()-d.x())*alpha-(a.x()-b.x())*beta)/determinant; - final float yi = ((c.y()-d.y())*alpha-(a.y()-b.y())*beta)/determinant; - - return result.set(xi, yi, 0); - } - - /** - * Check if a segment intersects with a triangle - * @param a vertex 1 of the triangle - * @param b vertex 2 of the triangle - * @param c vertex 3 of the triangle - * @param d vertex 1 of first segment - * @param e vertex 2 of first segment - * @return true if the segment intersects at least one segment of the triangle, false otherwise - */ - public static boolean testTri2SegIntersection(final Vert2fImmutable a, final Vert2fImmutable b, final Vert2fImmutable c, - final Vert2fImmutable d, final Vert2fImmutable e){ - return testSeg2SegIntersection(a, b, d, e) || - testSeg2SegIntersection(b, c, d, e) || - testSeg2SegIntersection(a, c, d, e) ; - } - /** - * Check if a segment intersects with a triangle, using given epsilon for comparison. - * @param a vertex 1 of the triangle - * @param b vertex 2 of the triangle - * @param c vertex 3 of the triangle - * @param d vertex 1 of first segment - * @param e vertex 2 of first segment - * @return true if the segment intersects at least one segment of the triangle, false otherwise - */ - public static boolean testTri2SegIntersection(final Vert2fImmutable a, final Vert2fImmutable b, final Vert2fImmutable c, - final Vert2fImmutable d, final Vert2fImmutable e, - final float epsilon){ - return testSeg2SegIntersection(a, b, d, e, epsilon) || - testSeg2SegIntersection(b, c, d, e, epsilon) || - testSeg2SegIntersection(a, c, d, e, epsilon) ; - } -} |