序
本文主要簡(jiǎn)述一下如何使用BufferedImage進(jìn)行漸變色操作坠敷。
GradientPaint
java/awt/GradientPaint.java
public class GradientPaint implements Paint {
Point2D.Float p1;
Point2D.Float p2;
Color color1;
Color color2;
boolean cyclic;
//......
}
這個(gè)是生成漸變色的關(guān)鍵類现使，當(dāng)然也有其他的漸變類季希，比如
java/awt/LinearGradientPaint.java
實(shí)例
public static BufferedImage drawGradient(BufferedImage srcImg,
int startX, int startY,
int endX, int endY,
Color colorFrom, Color colorTo,
float opacity) {
BufferedImage dstImg = new BufferedImage(srcImg.getWidth(), srcImg.getHeight(), BufferedImage.TYPE_INT_RGB);
GradientPaint grad = new GradientPaint(startX, startY, colorFrom, endX, endY, colorTo); //從左上到右下漸變;
Graphics2D g2 = (Graphics2D) dstImg.getGraphics();
g2.setPaint(grad);
g2.fillRect(startX, startY, endX, endY);
g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, opacity));
g2.drawImage(srcImg, 0, 0, srcImg.getWidth(), srcImg.getHeight(), null);
g2.dispose();
return dstImg;
}
原理就是先使用GradientPaint畫一個(gè)漸變色的矩形项栏，然后將原圖使用一定透明度覆蓋上去女蜈，這樣就看出漸變澜共。
不足之后的話怜跑，就是漸變顏色會(huì)偏淡样勃。
