Converting a working VB class to Java - plot

Question

I'm trying to convert a working VB class to Java, but it's giving incorrect results.
This is the VB class:
Public Class Triangle
Public A As PointF
Public B As PointF
Public C As PointF
''' <summary>
'''
''' </summary>
''' <param name="sideA">The length of the known side BC</param>
''' <param name="sideB">The length of the known side AC</param>
''' <param name="sideC">The length of the known side AB</param>
''' <param name="angleA">The internal angle in Radians at vertex A</param>
''' <param name="angleB">The internal angle in Radians at vertex B</param>
''' <param name="angleC">The internal angle in Radians at vertex C</param>
''' <remarks></remarks>
Public Sub New(ByVal sideA As Decimal, ByVal sideB As Decimal, ByVal sideC As Decimal, ByVal angleA As Decimal, ByVal angleB As Decimal, ByVal angleC As Decimal)
Dim bX As Decimal = CDec(Math.Cos(angleA) * sideC)
Dim bY As Decimal = CDec(Math.Sin(angleA) * sideC)
Me.A = PointF.Empty
Me.C = PointF.Add(A, New SizeF(sideB, 0))
Me.B = New PointF(bX, -bY)
If bX < 0 Then
Me.A = PointF.Add(Me.A, New SizeF(-bX, 0))
Me.B = PointF.Add(Me.B, New SizeF(-bX, 0))
Me.C = PointF.Add(Me.C, New SizeF(-bX, 0))
End If
End Sub
Public Sub ScaleToFit(ByVal maxWidthOrHeight As Decimal)
Dim xCoords() As Single = {Me.A.X, Me.B.X, Me.C.X}
Dim OverallWidth As Decimal = CDec(xCoords.Max - xCoords.Min)
Dim OverallHeight As Decimal = CDec(Math.Abs(Me.B.Y)) 'B.Y is negative owing to GDI+ coordinates
Dim scaleFactor As Decimal = If(OverallWidth > OverallHeight, _
maxWidthOrHeight / OverallWidth, _
maxWidthOrHeight / OverallHeight)
Scale(scaleFactor)
centreTriangle(25, 300)
End Sub
Private Sub Scale(ByVal scaleFactor As Decimal)
Me.A = ScalePointF(Me.A, scaleFactor)
Me.B = ScalePointF(Me.B, scaleFactor)
Me.C = ScalePointF(Me.C, scaleFactor)
End Sub
Private Function ScalePointF(ByVal pf As PointF, ByVal factor As Decimal) As PointF
Return New PointF(pf.X * factor, pf.Y * factor)
End Function
Private Sub centreTriangle(ByVal border As Integer, ByVal displaySize As Integer)
If B.Y > A.Y Then B.Y -= ((B.Y - A.Y) * 2)
Dim pts() As PointF = New PointF() {A, B, C}
Dim offset_X As Integer = pts.Min(Function(p) CInt(p.X)) - border
Dim offset_Y As Integer = pts.Max(Function(p) CInt(p.Y)) - (displaySize - border)
A = New PointF(A.X - offset_X, A.Y - offset_Y)
B = New PointF(B.X - offset_X, B.Y - offset_Y)
C = New PointF(C.X - offset_X, C.Y - offset_Y)
End Sub
End Class
This is the triangle the VB class plots:
Triangle plotted with VB class
This is the Java class:
public class Triangle
{
private Point A;
private Point B;
private Point C;
/**
* #return Point A
*/
public Point getA()
{
return this.A;
}
/**
* #return Point B
*/
public Point getB()
{
return this.B;
}
/**
* #return Point C
*/
public Point getC()
{
return this.C;
}
/**
#param sideA The length of the known side BC
#param sideB The length of the known side AC
#param sideC The length of the known side AB
#param angleA The internal angle in Radians at vertex A
#param angleB The internal angle in Radians at vertex B
#param angleC The internal angle in Radians at vertex C
*/
public Triangle(float sideA, float sideB, float sideC, float angleA, float angleB, float angleC)
{
float bX = (float)(Math.cos(angleA) * sideC);
float bY = (float)(Math.sin(angleA) * sideC);
this.A = new Point(0, 0);
this.C = new Point((int)(this.A.getX() + sideB), (int)this.A.getY());
this.B = new Point((int)bX, (int)-bY);
if (bX < 0)
{
this.A = new Point((int)(this.A.getX() - bX), (int)this.A.getY());
this.B = new Point((int)(this.B.getX() - bX), (int)this.B.getY());
this.C = new Point((int)(this.C.getX() - bX), (int)this.C.getY());
}
}
public final void ScaleToFit(float maxWidthOrHeight)
{
float[] xCoords = {(float)this.getA().getX(), (float)this.getB().getX(), (float)this.getC().getX()};
float min = 10000;
float max = -1;
for(int x = 0; x < 3; x++) {
if(xCoords[x] < min) {min = xCoords[x];}
if(xCoords[x] > max) {max = xCoords[x];}
}
float OverallWidth = (float)(max - min);
float OverallHeight = (float)Math.abs(this.getB().getY()); //B.Y is negative owing to Graphics coordinates
float scaleFactor = (float)(OverallWidth > OverallHeight ? maxWidthOrHeight / OverallWidth : maxWidthOrHeight / OverallHeight);
Scale(scaleFactor);
centreTriangle(25, 300);
}
private void Scale(float scaleFactor)
{
this.A = ScalePoint(this.A, scaleFactor);
this.B = ScalePoint(this.B, scaleFactor);
this.C = ScalePoint(this.C, scaleFactor);
}
private Point ScalePoint(Point p, float factor)
{
return new Point((int)(p.getX() * factor), (int)(p.getY() * factor));
}
private void centreTriangle(int border, int displaySize)
{
int y1 = (int)this.A.getY();
int y2 = (int)this.B.getY();
if(y2 > y1) {y2 -= ((y2 - y1) * 2);}
this.B = new Point((int)this.B.getX(), y2);
Point[] pts = new Point[] {this.A, this.B, this.C};
float min = 10000;
float max = -1;
for(int x = 0; x < 3; x++) {
if(pts[x].getX() < min) {min = (float)pts[x].getX();}
if(pts[x].getY() > max) {max = (float)pts[x].getY();}
}
int offset_X = (int)(min - border);
int offset_Y = (int)(max - (displaySize - border));
this.A = new Point((int)(this.A.getX() - offset_X), (int)(this.A.getY() - offset_Y));
this.B = new Point((int)(this.B.getX() - offset_X), (int)(this.B.getY() - offset_Y));
this.C = new Point((int)(this.C.getX() - offset_X), (int)(this.C.getY() - offset_Y));
}
}
This doesn't plot the triangle properly. This is a triangle plotted by the Java class, with the same inputs as the VB class:
Same triangle plotted with Java class

Answer 1

The answer is that converting float values to int was causing a noticeable difference. This is the fixed code...
package html.triangle;
import java.awt.Point;
import javax.swing.JOptionPane;
import html.shared.points.*;
/**
*
* #author Paul Long
*/
public class Triangle
{
private PointF A;
private PointF B;
private PointF C;
/**
* #return Point A
*/
public Point getA()
{
return new Point((int)this.A.getX(), (int)this.A.getY());
}
/**
* #return Point B
*/
public Point getB()
{
return new Point((int)this.B.getX(), (int)this.B.getY());
}
/**
* #return Point C
*/
public Point getC()
{
return new Point((int)this.C.getX(), (int)this.C.getY());
}
/**
#param sideA The length of the known side BC
#param sideB The length of the known side AC
#param sideC The length of the known side AB
#param angleA The internal angle in Radians at vertex A
#param angleB The internal angle in Radians at vertex B
#param angleC The internal angle in Radians at vertex C
*/
public Triangle(float sideA, float sideB, float sideC, float angleA, float angleB, float angleC)
{
float bX = (float)(Math.cos(angleA) * sideC);
float bY = (float)(Math.sin(angleA) * sideC);
this.A = new PointF(0, 0);
this.C = new PointF(this.A.getX() + sideB, this.A.getY());
this.B = new PointF(bX, bY);
if (bX < 0)
{
this.A = new PointF((this.A.getX() + Math.abs(bX)), this.A.getY());
this.B = new PointF((this.B.getX() + Math.abs(bX)), this.B.getY());
this.C = new PointF((this.C.getX() + Math.abs(bX)), this.C.getY());
}
}
public final void ScaleToFit(float maxWidthOrHeight)
{
float[] xCoords = {(float)this.A.getX(), (float)this.B.getX(), (float)this.C.getX()};
float min = 10000;
float max = -1;
for(int x = 0; x < 3; x++) {
if(xCoords[x] < min) {min = xCoords[x];}
if(xCoords[x] > max) {max = xCoords[x];}
}
float OverallWidth = (float)(max - min);
float[] yCoords = {(float)this.A.getY(), (float)this.B.getY(), (float)this.C.getY()};
min = 10000;
max = -1;
for(int x = 0; x < 3; x++) {
if(yCoords[x] < min) {min = yCoords[x];}
if(yCoords[x] > max) {max = yCoords[x];}
}
float OverallHeight = (float)(max - min);
float scaleFactor = (float)(OverallWidth > OverallHeight ? maxWidthOrHeight / OverallWidth : maxWidthOrHeight / OverallHeight);
Scale(scaleFactor);
centreTriangle(25, 300);
}
private void Scale(float scaleFactor)
{
this.A = ScalePoint(this.A, scaleFactor);
this.B = ScalePoint(this.B, scaleFactor);
this.C = ScalePoint(this.C, scaleFactor);
}
private PointF ScalePoint(PointF p, float factor)
{
return new PointF((p.getX() * factor), (p.getY() * factor));
}
private void centreTriangle(int border, int displaySize)
{
int y1 = (int)this.A.getY();
int y2 = (int)this.B.getY();
if(y2 > y1) {y2 -= ((y2 - y1) * 2);}
this.B = new PointF(this.B.getX(), y2);
PointF[] pts = new PointF[] {this.A, this.B, this.C};
float min = 10000;
float max = -1;
for(int x = 0; x < 3; x++) {
if(pts[x].getX() < min) {min = (float)pts[x].getX();}
if(pts[x].getY() > max) {max = (float)pts[x].getY();}
}
int offset_X = (int)(min - border);
int offset_Y = (int)(max - (displaySize - border));
this.A = new PointF((this.A.getX() - offset_X), (this.A.getY() - offset_Y));
this.B = new PointF((this.B.getX() - offset_X), (this.B.getY() - offset_Y));
this.C = new PointF((this.C.getX() - offset_X), (this.C.getY() - offset_Y));
}
}
package html.shared.points;
/**
*
* #author Paul Long
*/
public class PointF
{
private float X;
private float Y;
/**
* #return the X
*/
public float getX()
{
return X;
}
/**
* #return the Y
*/
public float getY()
{
return Y;
}
public PointF(float X, float Y) {
this.X = X;
this.Y = Y;
}
}