Graphics2D的圆形表 [英] Graphics2D circular table
问题描述
我想建立一个用户界面的RGBike POV：
http://www.instructables.com/id/RGBike-POV-Open-项目/
该方案将在网格的形式显示一个自行车轮。用户可以点击
到单一的广场和改变这些颜色。
我想建立该applet在java中。我被困在以正确的方式绘制车轮。
我需要有一种每个矩形阵列，以色彩后出口。
最好的事情是制定一种圆形表。绘制每个形状
用的Graphics2D让每个作为单个对象将是一个想法，太。但是，这将
大约860单的形状，有点太多由油漆每次更新它们（）。
I'm trying to build a User Interface for the RGBike POV: http://www.instructables.com/id/RGBike-POV-Open-project/ The program will display a bike wheel in form of a grid. The user can click onto the single squares and changes the colour of these. I want to build this applet in java. I'm stuck at drawing the wheel in the right way. I need to have a sort of array of every rectangle, to export the colour later. The best thing would be to draw a sort of circular table. Drawing each shape With graphics2D to have each as a single object would be an idea, too. But that would be around 860 single shapes, little bit too much to update them every time by paint().
说着POV做过这样的用户界面，为他们的项目已经：
http://www.ladyada.net/make/spokepov/software.html
但是，只有他们的老python脚本是开源的。
感谢您的帮助家伙！
Spoke POV has done such a user Interface for their project already: http://www.ladyada.net/make/spokepov/software.html But only their old python script is open source. Thanks for your help Guys!
推荐答案
很感激，我有previously产生了过去段形;）
Be VERY grateful that I have previously generate a "segment" shape in the past ;)
这基本上是单独生成每个段（做一些时髦的翻译转化为现实的空间），并保持它可以检查，看看是否鼠标落在那里范围内形状的缓存。
This basically generates each segment individually (does some funky translation into real space) and maintains a cache of shapes which can be checked to see if the mouse falls within there bounds.
这是相当低效的，但我觉得你的想法。
This is rather inefficient, but I think you get the idea.
我还应该注意的是，我没有后备缓冲器麻烦。并不是说，它可以使用一个，我刚才离开了，没有它...
I should also be noted, that I didn't bother with a backing buffer. Not to say it could use one, I just got away without it...
public class TestSpoke {
public static void main(String[] args) {
new TestSpoke();
}
public TestSpoke() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public static class TestPane extends JPanel {
public static final int CIRCLE_COUNT = 16;
public static final int SEGMENT_COUNT = 80;
private Map<Integer, List<Shape>> mapWheel;
private Map<Point, Color> mapColors;
public TestPane() {
mapColors = new HashMap<>(CIRCLE_COUNT * SEGMENT_COUNT);
addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent e) {
Map<Integer, List<Shape>> mapWheel = getWheel();
for (Integer circle : mapWheel.keySet()) {
List<Shape> segments = mapWheel.get(circle);
for (int index = 0; index < segments.size(); index++) {
Shape segment = segments.get(index);
if (segment.contains(e.getPoint())) {
mapColors.put(new Point(circle, index), Color.RED);
repaint();
break;
}
}
}
}
});
}
@Override
public void invalidate() {
mapWheel = null;
super.invalidate();
}
protected float getRadius() {
return Math.min(getWidth(), getHeight());
}
/**
* This builds a wheel (if required) made of segments.
* @return
*/
protected Map<Integer, List<Shape>> getWheel() {
if (mapWheel == null) {
mapWheel = new HashMap<>(CIRCLE_COUNT);
// The current radius
float radius = getRadius();
// The radius of each individual circle...
float circleRadius = radius / CIRCLE_COUNT;
// The range of each segment
float extent = 360f / SEGMENT_COUNT;
for (int circle = 0; circle < CIRCLE_COUNT; circle++) {
float startAngle = 0;
List<Shape> segments = new ArrayList<>(SEGMENT_COUNT);
mapWheel.put(circle, segments);
// Calculate the "translation" to place each segement in the
// center of the screen
float innerRadius = circleRadius * circle;
float x = (getWidth() - innerRadius) / 2;
float y = (getHeight() - innerRadius) / 2;
for (int seg = 0; seg < SEGMENT_COUNT; seg++) {
// Generate a Segment shape
Segment segment = new Segment(circleRadius * circle, circleRadius, startAngle, extent);
startAngle += extent;
// We translate the segment to the screen space
// This will make it faster to paint and check for mouse clicks
PathIterator pi = segment.getPathIterator(AffineTransform.getTranslateInstance(x, y));
Path2D path = new Path2D.Float();
path.append(pi, true);
segments.add(path);
}
}
}
return mapWheel;
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
Map<Integer, List<Shape>> mapWheel = getWheel();
for (Integer circle : mapWheel.keySet()) {
List<Shape> segments = mapWheel.get(circle);
for (int index = 0; index < segments.size(); index++) {
Shape segment = segments.get(index);
Color color = mapColors.get(new Point(circle, index));
if (color != null) {
g2d.setColor(color);
g2d.fill(segment);
}
g2d.setColor(Color.BLACK);
g2d.draw(segment);
}
}
g2d.dispose();
}
@Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
public static class Segment extends Path2D.Float {
public Segment(float radius, float thickness, float extent) {
this(radius, thickness, 0f, extent);
}
public Segment(float radius, float thickness, float startAngle, float extent) {
// Basically, we want to draw the outter edge from a to b angle,
// draw the connecting line from the outter to the inner,
// draw the inner from b to a angel and
// draw the connecting line from the inner to out the outter
// We want to span about 30 degrees, with a small gap...
// I want the gap to be a factor of the radius
Arc2D.Float outter = new Arc2D.Float(0, 0, radius, radius, startAngle, extent, Arc2D.OPEN);
Arc2D.Float inner = new Arc2D.Float(thickness / 2f, thickness / 2f, radius - thickness, radius - thickness, startAngle + extent, -extent, Arc2D.OPEN);
append(outter, true);
float angel = startAngle + extent;
Point2D p1 = getPointOnEdge(angel, radius);
Point2D p2 = getPointOnEdge(angel, radius - thickness);
// We need to adjust in for the change in the radius
p2.setLocation(p2.getX() + (thickness / 2f), p2.getY() + (thickness / 2f));
lineTo(p2.getX(), p2.getY());
append(inner, true);
angel = startAngle;
p1 = getPointOnEdge(angel, radius);
p2 = getPointOnEdge(angel, radius - thickness);
p2.setLocation(p2.getX() + (thickness / 2f), p2.getY() + (thickness / 2f));
lineTo(p1.getX(), p1.getY());
closePath();
}
public Point2D getPointOnEdge(float angel, float radius) {
angel -= 90;
float x = radius / 2f;
float y = radius / 2f;
double rads = Math.toRadians((angel + 90));
// This determins the length of tick as calculate from the center of
// the circle. The original code from which this derived allowed
// for a varible length line from the center of the cirlce, we
// actually want the opposite, so we calculate the outter limit first
float fullLength = (radius / 2f);
// Calculate the outter point of the line
float xPosy = (float) (x + Math.cos(rads) * fullLength);
float yPosy = (float) (y - Math.sin(rads) * fullLength);
return new Point2D.Float(xPosy, yPosy);
}
}
}
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