Java的：平滑颜色转变 [英] Java: Smooth Color Transition
问题描述
我试图让健康吧，和什么可能是原始的，它会开始了绿色，失去健康后，你会发现它会变黄，然后是橙色，然后变成红色..或到的东西相对的。
I am trying to make a health bar, and as what might be original, it will start out green, and after losing health you find that it will turn yellow, then orange, then red.. or something relative to that.
我试着用这个链接提供的方法：<一href=\"https://stackoverflow.com/questions/19841477/java-smooth-color-transition\">https://stackoverflow.com/questions/19841477/java-smooth-color-transition
I tried using the method provided in this link: https://stackoverflow.com/questions/19841477/java-smooth-color-transition
从该链接的结果是这样的code，刚刚从价值100测试为0，但它在抛出：IllegalArgumentException 在正常绿色，和我的原因的猜测是它是超过255的值。
The result from that link was this code, just a test from value 100 to 0, but it ended in an IllegalArgumentException at normally Red and Green, and my guess for reason is it being over the value of 255.
Color to = Color.red;
Color base = Color.green;
int red = (int)Math.abs((100 * to.getRed()) + ((1 - 100) * base.getRed()));
int green = (int)Math.abs((100 * to.getGreen()) + ((1 - 100) * base.getGreen()));
int blue = (int)Math.abs((100 * to.getBlue()) + ((1 - 100) * base.getBlue()));
setForeground(new Color(red, green, blue));
它并没有真正的工作，我绝对不知道我怎样才能得到它转换我希望它的方式。
所以，在我的 HealthBar 类，我有一个更新（）法
So within my HealthBar class, I have an update() method
public void update() {
if (getValue() < 10) setForeground(Color.red);
else if (getValue() < 25) setForeground(Color.orange);
else if (getValue() < 60) setForeground(Color.yellow);
else setForeground(Color.green);
}
这code确实在某一点根本转变。
This code does a basic transition at certain points.
我需要创建领域在某些值使用某些的颜色 健康酒吧，所以现在我有这个。
I need to create fields to use certain colors at certain values of the health bar, so now I have this..
if (getValue() < 10) {
Color to = Color.black;
// Color current = getForeground() ?
Color from = Color.red;
// ?
}
我只想用一个例子的最后一位。
I am just going to use an example for the last bit.
所以我知道我将会有一个颜色，我要和一个颜色的是一个基地。我不敢肯定，如果我需要一个颜色电流。我现在看到的问题是过渡的步骤，因为每个转换有不同数额的步骤。
So I know that I am going to have a color that I am going to, and a color that is a base. I am not so sure if I need a color for current. The problem that I see now is for the steps of the transition because each transition has a different amount of steps.
总结和问题结果
我不知道如何实现我在尝试，我只知道可以肯定的是，我需要一个以和基颜色，我提供了一个链接到一个答案，我看见了，但我无法真正弄清楚。随着给出的信息，我怎么能得到它的过渡颜色
？
Summary and Question
I don't know how to achieve what I am attempting, all I know for sure is I need a to and base color, and I provided a link to an answer that I saw, but I couldn't really figure it out. With the information given, how could I get it to transition colors
?
推荐答案
我花了很多时间试图找到/创建为我工作的混合算法，这基本上是我能蹒跚起来。
I spent a lot of time trying to find/create a blending algorithm that worked for me, this is basically what I was able to hobble together.
我用这个方法来生成一个渐变过渡混合多种颜色，作为展示<一个href=\"https://stackoverflow.com/questions/13223065/color-fading-algorithm/13223818#13223818\">here
I've used this approach to generate a gradient transition mixing multiple colors, as demonstrated here
基本上，这种方法允许你设置了一系列的颜色和比例标记，使你获得更大的控制权指向之间的颜色过渡。
Basically, this approach allows you to set up a series of colors and percentage marks so that you gain much greater control over which points the colors transition between.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.text.NumberFormat;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class ColorFading {
public static void main(String[] args) {
new ColorFading();
}
public ColorFading() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new FadePane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class FadePane extends JPanel {
private final float[] fractions = new float[]{0f, 0.5f, 1f};
private final Color[] colors = new Color[]{Color.RED, Color.YELLOW, Color.GREEN};
private float progress = 1f;
private JSlider slider;
public FadePane() {
slider = new JSlider(0, 100);
setLayout(new BorderLayout());
add(slider, BorderLayout.SOUTH);
slider.addChangeListener(new ChangeListener() {
@Override
public void stateChanged(ChangeEvent e) {
progress = ((float)slider.getValue() / 100f);
repaint();
}
});
slider.setValue(100);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
int width = getWidth();
int height = getHeight();
Color startColor = blendColors(fractions, colors, progress);
g2d.setColor(startColor);
g2d.fillRect(0, 0, width, height);
g2d.dispose();
}
}
public static Color blendColors(float[] fractions, Color[] colors, float progress) {
Color color = null;
if (fractions != null) {
if (colors != null) {
if (fractions.length == colors.length) {
int[] indicies = getFractionIndicies(fractions, progress);
float[] range = new float[]{fractions[indicies[0]], fractions[indicies[1]]};
Color[] colorRange = new Color[]{colors[indicies[0]], colors[indicies[1]]};
float max = range[1] - range[0];
float value = progress - range[0];
float weight = value / max;
color = blend(colorRange[0], colorRange[1], 1f - weight);
} else {
throw new IllegalArgumentException("Fractions and colours must have equal number of elements");
}
} else {
throw new IllegalArgumentException("Colours can't be null");
}
} else {
throw new IllegalArgumentException("Fractions can't be null");
}
return color;
}
public static int[] getFractionIndicies(float[] fractions, float progress) {
int[] range = new int[2];
int startPoint = 0;
while (startPoint < fractions.length && fractions[startPoint] <= progress) {
startPoint++;
}
if (startPoint >= fractions.length) {
startPoint = fractions.length - 1;
}
range[0] = startPoint - 1;
range[1] = startPoint;
return range;
}
public static Color blend(Color color1, Color color2, double ratio) {
float r = (float) ratio;
float ir = (float) 1.0 - r;
float rgb1[] = new float[3];
float rgb2[] = new float[3];
color1.getColorComponents(rgb1);
color2.getColorComponents(rgb2);
float red = rgb1[0] * r + rgb2[0] * ir;
float green = rgb1[1] * r + rgb2[1] * ir;
float blue = rgb1[2] * r + rgb2[2] * ir;
if (red < 0) {
red = 0;
} else if (red > 255) {
red = 255;
}
if (green < 0) {
green = 0;
} else if (green > 255) {
green = 255;
}
if (blue < 0) {
blue = 0;
} else if (blue > 255) {
blue = 255;
}
Color color = null;
try {
color = new Color(red, green, blue);
} catch (IllegalArgumentException exp) {
NumberFormat nf = NumberFormat.getNumberInstance();
System.out.println(nf.format(red) + "; " + nf.format(green) + "; " + nf.format(blue));
exp.printStackTrace();
}
return color;
}
}
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