我试图用Java制作一些形状。我创建了两个有两种不同颜色的矩形,但我想创建一个星形,我找不到有用的资源来帮助我这样做。
这是我的代码:
import java.awt.*;
import javax.swing.*;
public class shapes extends JPanel{
@Override
public void paintComponent(Graphics GPHCS){
super.paintComponent(GPHCS);
GPHCS.setColor(Color.BLUE);
GPHCS.fillRect(25,25,100,30);
GPHCS.setColor(Color.GRAY);
GPHCS.fillRect(25,65,100,30);
GPHCS.setColor(new Color(190,81,215));
GPHCS.drawString("This is my text", 25, 120);
}
}
答案 0 :(得分:8)
您可以尝试使用多边形和一些基本数学:
int midX = 500;
int midY = 340;
int radius[] = {118,40,90,40};
int nPoints = 16;
int[] X = new int[nPoints];
int[] Y = new int[nPoints];
for (double current=0.0; current<nPoints; current++)
{
int i = (int) current;
double x = Math.cos(current*((2*Math.PI)/max))*radius[i % 4];
double y = Math.sin(current*((2*Math.PI)/max))*radius[i % 4];
X[i] = (int) x+midX;
Y[i] = (int) y+midY;
}
g.setColor(Color.WHITE);
g.fillPolygon(X, Y, nPoints);
答案 1 :(得分:4)
您也可以使用现有的课程,例如http://java-sl.com/shapes.html为正多边形和恒星。
答案 2 :(得分:2)
Polygon
类可以被视为自Java 1.0以来一直存在的遗留类,但在新代码中几乎不能再使用了。在单独的数组中指定x / y坐标的奇怪方法,更重要的是,它仅支持 int[]
数组这一事实限制了它的应用领域。虽然它实现了Shape
接口,但是此接口有更多现代实现可用于表示多边形。在大多数情况下,将多边形描述为Path2D
更容易,更灵活。可以创建Path2D p = new Path2D.Double();
,然后执行一系列moveTo
和lineTo
调用,以生成所需的形状。
以下程序显示了Path2D
类如何用于生成星形。最重要的方法是createStar
方法。这是非常通用的。收到
如果需要,可以使用更简单的方法 - 与下面代码中的createDefaultStar
示例一样。
该程序显示不同的星星,绘制为线条,并填充不同的颜色和径向渐变颜料,例如:
完整的程序为MCVE:
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.RadialGradientPaint;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.geom.Path2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class DrawStarShape
{
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
@Override
public void run()
{
createAndShowGUI();
}
});
}
private static void createAndShowGUI()
{
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.getContentPane().add(new DrawStarShapePanel());
f.setSize(600, 600);
f.setLocationRelativeTo(null);
f.setVisible(true);
}
}
class DrawStarShapePanel extends JPanel
{
@Override
protected void paintComponent(Graphics gr)
{
super.paintComponent(gr);
Graphics2D g = (Graphics2D) gr;
g.setColor(Color.WHITE);
g.fillRect(0, 0, getWidth(), getHeight());
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g.setColor(Color.BLACK);
g.draw(createDefaultStar(50, 200, 200));
g.setPaint(Color.RED);
g.fill(createStar(400, 400, 40, 60, 10, 0));
g.setPaint(new RadialGradientPaint(
new Point(400, 200), 60, new float[] { 0, 1 },
new Color[] { Color.RED, Color.YELLOW }));
g.fill(createStar(400, 200, 20, 60, 8, 0));
g.setPaint(new RadialGradientPaint(
new Point(200, 400), 50, new float[] { 0, 0.3f, 1 },
new Color[] { Color.RED, Color.YELLOW, Color.ORANGE }));
g.fill(createStar(200, 400, 40, 50, 20, 0));
}
private static Shape createDefaultStar(double radius, double centerX,
double centerY)
{
return createStar(centerX, centerY, radius, radius * 2.63, 5,
Math.toRadians(-18));
}
private static Shape createStar(double centerX, double centerY,
double innerRadius, double outerRadius, int numRays,
double startAngleRad)
{
Path2D path = new Path2D.Double();
double deltaAngleRad = Math.PI / numRays;
for (int i = 0; i < numRays * 2; i++)
{
double angleRad = startAngleRad + i * deltaAngleRad;
double ca = Math.cos(angleRad);
double sa = Math.sin(angleRad);
double relX = ca;
double relY = sa;
if ((i & 1) == 0)
{
relX *= outerRadius;
relY *= outerRadius;
}
else
{
relX *= innerRadius;
relY *= innerRadius;
}
if (i == 0)
{
path.moveTo(centerX + relX, centerY + relY);
}
else
{
path.lineTo(centerX + relX, centerY + relY);
}
}
path.closePath();
return path;
}
}
答案 3 :(得分:0)
我有2种方法。
1)
public static Bitmap drawStar(int W, int H, int color, boolean andRing)
{
Path path = new Path();
Bitmap output = Bitmap.createBitmap(W, H, Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
paint.setColor(color);
float midW ,min ,fat ,half ,radius;
if(andRing)
{
midW = W / 2;
min = Math.min(W, H);
half = min / 2;
midW = midW - half;
fat = min / 17;
radius = half - fat;
paint.setStrokeWidth(fat);
paint.setStyle(Paint.Style.STROKE);
canvas.drawCircle(midW + half, half, radius, paint);
path.reset();
paint.setStyle(Paint.Style.FILL);
path.moveTo( half * 0.5f, half * 0.84f);
path.lineTo( half * 1.5f, half * 0.84f);
path.lineTo( half * 0.68f, half * 1.45f);
path.lineTo( half * 1.0f, half * 0.5f);
path.lineTo( half * 1.32f, half * 1.45f);
path.lineTo( half * 0.5f, half * 0.84f);
}
else
{
min = Math.min(W, H);
half = min/2;
path.reset();
paint.setStyle(Paint.Style.FILL);
path.moveTo( half * 0.1f , half * 0.65f);
path.lineTo( half * 1.9f , half * 0.65f);
path.lineTo( half * 0.40f , half * 1.65f);
path.lineTo( half , 0 );
path.lineTo( half * 1.60f, half * 1.65f);
path.lineTo( half * 0.1f, half * 0.65f);
}
canvas.drawPath(path, paint);
return output;
}
2)
public static Bitmap drawStar(int W,int H,int spikes,int innerRadius,int outerRadius, int backColor,boolean border, int borderColor)
{
if(W < 10)
W = 10;
if(H < 10)
H = 10;
if(spikes < 5)
spikes = 5;
int smallL = W;
if(H < W)
smallL = H;
if(outerRadius > smallL/2)
outerRadius = smallL/2;
if(innerRadius < 5)
innerRadius = 5;
if(border)
{
outerRadius -=2;
innerRadius -=2;
}
Path path = new Path();
Bitmap output = Bitmap.createBitmap(W, H, Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
paint.setColor(backColor);
int cx = W/2;
int cy = H/2;
double rot = Math.PI / 2 * 3;
float x,y;
double step = Math.PI / spikes;
path.moveTo(cx, cy - outerRadius);
for (int i = 0; i < spikes; i++)
{
x = (float) (cx + Math.cos(rot) * outerRadius);
y = (float) (cy + Math.sin(rot) * outerRadius);
path.lineTo(x, y);
rot += step;
x = (float) (cx + Math.cos(rot) * innerRadius);
y = (float) (cy + Math.sin(rot) * innerRadius);
path.lineTo(x, y);
rot += step;
}
path.lineTo(cx, cy - outerRadius);
path.close();
canvas.drawPath(path, paint);
if(border)
{
paint.setStyle(Style.STROKE);
paint.setStrokeWidth(2);
paint.setColor(borderColor);
canvas.drawPath(path, paint);
}
return output;
}