/**
* Copyright 2010 JBoss Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.drools.benchmark.waltz;
/*
* Copyright 2005 JBoss Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @author Alexander Bagerman
*
*/
public class WaltzUtil {
private static double PI = 3.1415927;
private static int MOD_NUM = 100;
private static int get_y(int val) {
return val % MOD_NUM;
}
private static int get_x(int val) {
return (int) (val / MOD_NUM);
}
/***************************************************************************
* This function is passed two points and calculates the angle between the
* line defined by these points and the x-axis.
**************************************************************************/
private static double get_angle(int p1, int p2) {
int delta_x, delta_y;
double ret = 0.0;
/*
* Calculate (x2 - x1) and (y2 - y1). The points are passed in the form
* x1y1 and x2y2. get_x() and get_y() are passed these points and return
* the x and y values respectively. For example, get_x(1020) returns 10.
*/
delta_x = get_x(p2) - get_x(p1);
delta_y = get_y(p2) - get_y(p1);
if (delta_x == 0) {
if (delta_y > 0) {
ret = PI / 2;
} else if (delta_y < 0) {
ret = -PI / 2;
}
} else if (delta_y == 0) {
if (delta_x > 0) {
ret = 0.0;
} else if (delta_x < 0) {
ret = PI;
}
} else {
ret = Math.atan2(delta_y, delta_x);
}
return ret;
}
/***************************************************************************
* This procedure is passed the basepoint of the intersection of two lines
* as well as the other two endpoints of the lines and calculates the angle
* inscribed by these three points.
**************************************************************************/
private static double inscribed_angle(int basepoint, int p1, int p2) {
double angle1, angle2, temp;
/*
* Get the angle between line #1 and the origin and the angle between
* line #2 and the origin, and then subtract these values.
*/
angle1 = get_angle(basepoint, p1);
angle2 = get_angle(basepoint, p2);
temp = angle1 - angle2;
if (temp < 0.0)
temp = -temp;
/*
* We always want the smaller of the two angles inscribed, so if the
* answer is greater than 180 degrees, calculate the smaller angle and
* return it.
*/
if (temp > PI)
temp = 2 * PI - temp;
if (temp < 0.0)
return (-temp);
return (temp);
}
public static Junction make_3_junction(int basepoint, int p1, int p2, int p3) {
int shaft, barb1, barb2;
double angle12, angle13, angle23;
double sum, sum1213, sum1223, sum1323;
double delta;
String j_type;
angle12 = inscribed_angle(basepoint, p1, p2);
angle13 = inscribed_angle(basepoint, p1, p3);
angle23 = inscribed_angle(basepoint, p2, p3);
sum1213 = angle12 + angle13;
sum1223 = angle12 + angle23;
sum1323 = angle13 + angle23;
if (sum1213 < sum1223) {
if (sum1213 < sum1323) {
sum = sum1213;
shaft = p1;
barb1 = p2;
barb2 = p3;
} else {
sum = sum1323;
shaft = p3;
barb1 = p1;
barb2 = p2;
}
} else {
if (sum1223 < sum1323) {
sum = sum1223;
shaft = p2;
barb1 = p1;
barb2 = p3;
} else {
sum = sum1323;
shaft = p3;
barb1 = p1;
barb2 = p2;
}
}
delta = sum - PI;
if (delta < 0.0)
delta = -delta;
if (delta < 0.001) {
j_type = Junction.TEE;
} else if (sum > PI) {
j_type = Junction.FORK;
} else {
j_type = Junction.ARROW;
}
return new Junction(barb1, shaft, barb2, basepoint, j_type);
}
}