Android Image 倒影

最新推荐文章于 2021-05-28 21:02:14 发布

yuxiaohui78

最新推荐文章于 2021-05-28 21:02:14 发布

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本文介绍了一种使用Android平台的Bitmap和Canvas类创建带有底部反射效果的图片的方法。通过翻转原始图片的一部分并添加渐变透明效果实现反射。

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public static Bitmap createReflectedImage(Bitmap originalImage) {

// The gap we want between the reflection and the original image
final int reflectionGap = 4;
int width = originalImage.getWidth();
int height = originalImage.getHeight();
// This will not scale but will flip on the Y axis
Matrix matrix = new Matrix();
matrix.preScale(1, -1);
// Create a Bitmap with the flip matrix applied to it.
// We only want the bottom half of the image
Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0, height / 2, width,
height / 2, matrix, false);
// Create a new bitmap with same width but taller to fit reflection
Bitmap bitmapWithReflection = Bitmap.createBitmap(width, (height + height / 2),
Config.ARGB_8888);
// Create a new Canvas with the bitmap that's big enough for
// the image plus gap plus reflection
Canvas canvas = new Canvas(bitmapWithReflection);
// Draw in the original image
canvas.drawBitmap(originalImage, 0, 0, null);
// Draw in the gap
Paint defaultPaint = new Paint();
canvas.drawRect(0, height, width, height + reflectionGap, defaultPaint);
// Draw in the reflection
canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);
// Create a shader that is a linear gradient that covers the reflection
Paint paint = new Paint();
LinearGradient shader = new LinearGradient(0, originalImage.getHeight(), 0,
bitmapWithReflection.getHeight() + reflectionGap, 0x70ffffff, 0x00ffffff,
TileMode.CLAMP);
// Set the paint to use this shader (linear gradient)
paint.setShader(shader);
// Set the Transfer mode to be porter duff and destination in
paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
// Draw a rectangle using the paint with our linear gradient
canvas.drawRect(0, height, width, bitmapWithReflection.getHeight() + reflectionGap, paint);
return bitmapWithReflection;
}

From: http://www.linuxidc.com/Linux/2011-10/44928.htm