/**
* Calculates the area of a polygon according to formula from John Russ. Note that sub-areas are
* subtracted if polygon has the shape of an "8".
*
* @return polygon area
*/
public double calcArea() {
int size = this.size();
if (size <= 2) {
return 0;
}
double sumAreas = 0.0;
double sumVolumesX = 0.0;
double sumVolumesY = 0.0;
double sumX;
double sumY;
double deltaX;
double deltaY;
LocationOJ prevLoc = (LocationOJ) this.get(size - 1);
for (int i = 0; i < size; i++) {
sumX = ((LocationOJ) this.get(i)).getX() + prevLoc.getX();
sumY = ((LocationOJ) this.get(i)).getY() + prevLoc.getY();
deltaX = ((LocationOJ) this.get(i)).getX() - prevLoc.getX();
deltaY = ((LocationOJ) this.get(i)).getY() - prevLoc.getY();
sumVolumesX = sumVolumesX + sumX * sumX * deltaY; // Eq 3. p 489
sumVolumesY = sumVolumesY + sumY * sumY * deltaX; // Eq 3. p 489
sumAreas = sumAreas + sumX * deltaY; // Eq 4. p 490}
prevLoc = (LocationOJ) this.get(i);
}
return Math.abs(sumAreas / 2);
}
/** No operation so far */
public void clearZ() {
if (true) {
return;
}
for (int index = 0; index < this.size(); index++) {
LocationOJ loc = (LocationOJ) get(index);
loc.z = 0;
this.set(index, loc);
}
}
/**
* Four 2D points are used to define two lines p1-p2 and p3-p4. Returns the crosspoint of the two
* lines, or NaN if they are parallel. Result is a 3D point, with z being set to NaN.
*/
public LocationOJ calcCrossPoint(
double p1h,
double p1v,
double p2h,
double p2v,
double p3h,
double p3v,
double p4h,
double p4v) {
double a1 = 0;
double a2 = 0.0;
double b1 = 0;
double b2 = 0;
double dx1;
double dx2;
LocationOJ result = new LocationOJ(nan, nan, nan);
dx1 = (p2h - p1h);
dx2 = p4h - p3h;
if (dx1 == 0 && dx2 == 0) {
return result;
}
if (dx1 != 0.0) {
a1 = (p2v - p1v) / dx1;
b1 = p1v - p1h * a1;
}
if (dx2 != 0.0) {
a2 = (p4v - p3v) / dx2;
b2 = p3v - p3h * a2;
}
if (dx1 != 0.0 && dx2 != 0.0) {
if (a1 == a2) {
return result; // lines are parallel
} else {
result.x = (float) (-(b1 - b2) / (a1 - a2));
result.y = (float) (a1 * result.x + b1); // changed to float 17.4.2010
result.z = (float) nan;
}
}
if (dx1 == 0.0) {
result.x = (float) p1h;
result.y = (float) (a2 * result.x + b2);
}
if (dx2 == 0) {
result.x = (float) p3h;
result.y = (float) (a1 * result.x + b1);
}
return result;
}
/**
* Performs a geometric calculation from the top of the vertex stack, or the entire vertex stack.
* For example if algorithm is "orientation", the top two entries are regarded as two points on a
* line, whose orientation is put into class variable orientation.
*
* @param algorithm
*/
public void calc(String algorithm) {
algorithm = algorithm.toLowerCase();
if (!threeD) { // set all z to zero //15.5.2009
clearZ();
}
LocationOJ aa;
LocationOJ bb;
LocationOJ cc;
LocationOJ dd;
boolean isRelPPath = algorithm.equalsIgnoreCase("relPartialPath");
boolean isPerimeter = algorithm.equalsIgnoreCase("perimeter");
boolean isTotalPath = algorithm.equalsIgnoreCase("totalPath");
boolean isAbsPPath = algorithm.equalsIgnoreCase("partialPath");
boolean isCrossPt = algorithm.equalsIgnoreCase("crosspoint");
boolean isOuterCircle = algorithm.equalsIgnoreCase("outerCircle");
boolean isInnerCircle = algorithm.equalsIgnoreCase("innerCircle");
boolean isDeviation = algorithm.equalsIgnoreCase("deviation");
boolean isHeight = algorithm.equalsIgnoreCase("height");
boolean isArea = algorithm.equalsIgnoreCase("area");
boolean isAngle = algorithm.equalsIgnoreCase("angle");
boolean isOrientation = algorithm.equalsIgnoreCase("orientation");
boolean isPartialPosition = algorithm.startsWith("partialposition");
TriangleOJ tri = new TriangleOJ();
if (isOrientation) {
if (size() < 2) {
return;
}
double x1 = ((LocationOJ) get(size() - 2)).getX();
double y1 = ((LocationOJ) get(size() - 2)).getY();
double x2 = ((LocationOJ) get(size() - 1)).getX();
double y2 = ((LocationOJ) get(size() - 1)).getY();
orientation = Math.atan2(y2 - y1, x2 - x1) * 180.0 / Math.PI;
return;
}
if (isDeviation || isAngle) {
if (size() < 3) {
return;
}
double x0 = ((LocationOJ) get(size() - 3)).getX();
double y0 = ((LocationOJ) get(size() - 3)).getY();
double x1 = ((LocationOJ) get(size() - 2)).getX();
double y1 = ((LocationOJ) get(size() - 2)).getY();
double x2 = ((LocationOJ) get(size() - 1)).getX();
double y2 = ((LocationOJ) get(size() - 1)).getY();
double angle1 = Math.atan2(y1 - y0, x1 - x0) - Math.atan2(y2 - y1, x2 - x1);
angle1 *= 180.0 / Math.PI;
angle = 180 - Math.abs(angle1);
angle1 = -angle1; // clockwise is positive, ccw is negative
while (angle1 <= -180.0) {
angle1 += 360;
}
while (angle1 > 180.0) {
angle1 -= 360;
}
// scalarResult[0] = angle;
deviation = angle1;
return;
}
if (isHeight) {
aa = (LocationOJ) get(0);
bb = (LocationOJ) get(1);
cc = (LocationOJ) get(2);
tri.calcTriangle(aa, cc, bb);
height = tri.hc;
return;
}
if (isRelPPath || isAbsPPath) {
cc = (LocationOJ) peek(); // point to be projected is on the top of stack
int maxIndex = this.size() - 2;
for (int index = 0; index < maxIndex; index++) {
aa = (LocationOJ) get(index);
bb = (LocationOJ) get(index + 1);
tri.calcTriangle(aa, bb, cc, vertexScale, index);
}
partialPath = tri.getMinCcaAccu();
totalLength = tri.getCcAccu();
minSpark = tri.getMinSpark();
signedMinSpark = tri.getSignedMinSpark(); // 19.8.2010
relPartialPath = partialPath / totalLength;
leftEdge = tri.getLeftEdge();
rightEdge = tri.getRightEdge();
impactX = tri.getImpactX();
impactY = tri.getImpactY();
return;
}
if (isTotalPath || isPerimeter || isPartialPosition) {
double subLength = 0;
double pPosX = nan;
double pPosY = nan;
double fraction = 0;
int passes = 1;
if (isPartialPosition) {
passes = 2;
String subStr = algorithm.replace('%', ' ');
int index = subStr.indexOf(" ");
subStr = subStr.substring(index);
fraction = Double.parseDouble(subStr);
if (algorithm.contains("%")) {
fraction *= 0.01;
}
if (fraction < 0) {
fraction = 0;
}
if (fraction > 1) {
fraction = 1;
}
}
for (int pass = 1; pass <= passes; pass++) {
if (pass == 2) {
subLength = fraction * totalLength;
}
double len = 0;
int maxIndex = this.size();
for (int index = 0; index < maxIndex; index++) {
aa = (LocationOJ) get(index);
if (index < maxIndex - 1) {
bb = (LocationOJ) get(index + 1);
} else {
bb = (LocationOJ) get(0);
}
if (index < maxIndex - 1 || isPerimeter) {
double thisSegment = Math.sqrt(sqr(aa.x - bb.x) + sqr(aa.y - bb.y) + sqr(aa.z - bb.z));
len = len + thisSegment;
if (pass == 2) {
double delta = len - subLength;
if (delta >= 0 && Double.isNaN(pPosX)) {
pPosX = bb.x - delta / thisSegment * (bb.x - aa.x);
pPosY = bb.y - delta / thisSegment * (bb.y - aa.y);
}
}
}
}
if (isPerimeter) {
perimeter = len;
}
if (isTotalPath || isPartialPosition) {
totalLength = len;
}
if (isPartialPosition) {
partialPositionX = pPosX;
partialPositionY = pPosY;
}
}
return;
}
if (isCrossPt) {
aa = (LocationOJ) get(0);
bb = (LocationOJ) get(1);
cc = (LocationOJ) get(2);
dd = (LocationOJ) get(3);
crossPoint =
calcCrossPoint(
aa.getX(), aa.getY(), bb.getX(), bb.getY(), cc.getX(), cc.getY(), dd.getX(),
dd.getY());
return;
}
if (isArea) {
area = calcArea();
return;
}
if (isInnerCircle || isOuterCircle) {
double Ax = ((LocationOJ) get(0)).getX();
double Ay = ((LocationOJ) get(0)).getY();
double Bx = ((LocationOJ) get(1)).getX();
double By = ((LocationOJ) get(1)).getY();
double Cx = ((LocationOJ) get(2)).getX();
double Cy = ((LocationOJ) get(2)).getY();
if (isOuterCircle) {
double midABx = (Bx + Ax) / 2;
double midABy = (By + Ay) / 2;
double midCBx = (Cx + Bx) / 2;
double midCBy = (Cy + By) / 2;
double dropABx = midABx + By - Ay;
double dropABy = midABy - (Bx - Ax);
double dropCBx = midCBx + Cy - By;
double dropCBy = midCBy - (Cx - Bx);
// vertexResult[0] = calcCrossPoint(midABx, midABy, dropABx, dropABy, midCBx, midCBy,
// dropCBx, dropCBy);
outerCircleCenter =
calcCrossPoint(midABx, midABy, dropABx, dropABy, midCBx, midCBy, dropCBx, dropCBy);
outerCircleCenterX = outerCircleCenter.x;
outerCircleCenterY = outerCircleCenter.y;
double dx = outerCircleCenter.x - Ax;
double dy = outerCircleCenter.y - Ay;
// scalarResult[0] = Math.sqrt(dx * dx + dy * dy);
outerCircleRadius = Math.sqrt(dx * dx + dy * dy);
}
/*
* A (0)
* / \
* sideC / \sideB
* / m \
* / \
* B(1)-------C(2)
* sideA
**/
if (isInnerCircle) {
double sideC = Math.sqrt(sqr(Bx - Ax) + sqr(By - Ay));
double sideB = Math.sqrt(sqr(Cx - Ax) + sqr(Cy - Ay));
double sideA = Math.sqrt(sqr(Cx - Bx) + sqr(Cy - By));
// divide angle C:
double bSissorAx = Cx + (Ax - Cx) * sideA / sideB;
double bSissorAy = Cy + (Ay - Cy) * sideA / sideB;
double angleDividerCx = (Bx + bSissorAx) / 2;
double angleDividerCy = (By + bSissorAy) / 2;
// divide angle B:
double cSissorAx = Bx + (Ax - Bx) * sideA / sideC;
double cSissorAy = By + (Ay - By) * sideA / sideC;
double angleDividerBx = (Cx + cSissorAx) / 2;
double angleDividerBy = (Cy + cSissorAy) / 2;
innerCircleCenter =
calcCrossPoint(
Cx, Cy, angleDividerCx, angleDividerCy, Bx, By, angleDividerBx, angleDividerBy);
// vertexResult[0] = innerCircleCenter;
innerCircleCenterX = innerCircleCenter.x;
innerCircleCenterY = innerCircleCenter.y;
double mx = innerCircleCenterX; // midpoint of inner circle
double my = innerCircleCenterY;
double sideBM = Math.sqrt(sqr(Bx - mx) + sqr(By - my));
double sideCM = Math.sqrt(sqr(Cx - mx) + sqr(Cy - my));
double s = (sideA + sideBM + sideCM) / 2; // half perimeter
double area1 = Math.sqrt(s * (s - sideA) * (s - sideBM) * (s - sideCM));
double rad = area1 / sideA * 2;
innerCircleRadius = rad;
}
return;
}
}