smartglasses/code/Utils.java

package com.yeyupiaoling.teststadiometry;

import android.graphics.Bitmap;
import android.graphics.Matrix;
import android.util.Size;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class Utils {
    private static final String TAG = Utils.class.getName();

    // 获取最优的预览图片大小
    public static Size chooseOptimalSize(final Size[] choices, final int width, final int height) {
        final Size desiredSize = new Size(width, height);

        // Collect the supported resolutions that are at least as big as the preview Surface
        boolean exactSizeFound = false;
        float desiredAspectRatio = width * 1.0f / height; //in landscape perspective
        float bestAspectRatio = 0;
        final List<Size> bigEnough = new ArrayList<Size>();
        for (final Size option : choices) {
            if (option.equals(desiredSize)) {
                // Set the size but don't return yet so that remaining sizes will still be logged.
                exactSizeFound = true;
                break;
            }

            float aspectRatio = option.getWidth() * 1.0f / option.getHeight();
            if (aspectRatio > desiredAspectRatio) continue; //smaller than screen
            //try to find the best aspect ratio which fits in screen
            if (aspectRatio > bestAspectRatio) {
                if (option.getHeight() >= height && option.getWidth() >= width) {
                    bigEnough.clear();
                    bigEnough.add(option);
                    bestAspectRatio = aspectRatio;
                }
            } else if (aspectRatio == bestAspectRatio) {
                if (option.getHeight() >= height && option.getWidth() >= width) {
                    bigEnough.add(option);
                }
            }
        }
        if (exactSizeFound) {
            return desiredSize;
        }

        if (bigEnough.size() > 0) {
            final Size chosenSize = Collections.min(bigEnough, new Comparator<Size>() {
                @Override
                public int compare(Size lhs, Size rhs) {
                    return Long.signum(
                            (long) lhs.getWidth() * lhs.getHeight() - (long) rhs.getWidth() * rhs.getHeight());
                }
            });
            return chosenSize;
        } else {
            return choices[0];
        }
    }

    public static Bitmap rotateBitmap(Bitmap bitmap, int angle) {
        Matrix matrix = new Matrix();
        matrix.postRotate(angle);
        return Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
    }

    public static List<Bitmap> bisectionBitmap(Bitmap bitmap) {
        List<Bitmap> bitmapList = new ArrayList<>();
        Bitmap left = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth() / 2, bitmap.getHeight(), null, true);
        bitmapList.add(left);
        Bitmap right = Bitmap.createBitmap(bitmap, bitmap.getWidth() / 2, 0, bitmap.getWidth() / 2, bitmap.getHeight(), null, true);
        bitmapList.add(right);
        return bitmapList;
    }
}