Convert coordination of face point to screen rect that will be draw on canvas - Android Graphics

Android examples for Graphics:Canvas

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Description

Convert coordination of face point to screen rect that will be draw on canvas

Demo Code


//package com.java2s;
import android.graphics.Matrix;
import android.graphics.Point;

import java.util.LinkedList;
import java.util.List;

public class Main {
    /** Convert coordination of face point to screen rect that will be draw on canvas<br> */
    public static List<Point> convertFacePoint(boolean frontCamera,
            float displayOrientation, float viewWidth, float viewHeight,
            Point... points) {//from  w  ww . j a  va2  s  .co m
        Matrix matrix = createConvertMatrix(frontCamera,
                displayOrientation, viewWidth, viewHeight);
        float[] pts = new float[points.length * 2];
        for (int i = 0; i < points.length; ++i) {
            pts[i * 2] = points[i].x;
            pts[i * 2 + 1] = points[i].y;
        }
        matrix.mapPoints(pts);
        List<Point> result = new LinkedList<>();
        for (int j = 0; j < pts.length; j += 2) {
            result.add(new Point((int) pts[j], (int) pts[j + 1]));
        }
        return result;
    }

    private static Matrix createConvertMatrix(boolean frontCamera,
            float displayOrientation, float viewWidth, float viewHeight) {
        Matrix matrix = new Matrix();
        boolean mirror = frontCamera;
        matrix.setScale(mirror ? -1 : 1, 1);
        matrix.postRotate(displayOrientation);
        matrix.postScale(viewWidth / 2000f, viewHeight / 2000f);
        matrix.postTranslate(viewWidth / 2f, viewHeight / 2f);
        return matrix;
    }
}

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