bitmap旋转平移有效的样板代码

作者: 吉凶以情迁 | 来源:发表于2021-08-24 21:09 被阅读0次

bitmap旋转平移有效的样板代码
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旋转平移
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哎、不服老不行了，现在基础都给搞懵逼了。

bitmap旋转90 ，测试是居中旋转的，之前不是距中旋转的代码我有空看看比较下。

    public static Bitmap rotateBitmap(Bitmap origin, float alpha) {
        if (origin == null) {
            return null;
        }
        int width = origin.getWidth();
        int height = origin.getHeight();
        Matrix matrix = new Matrix();
        matrix.setRotate(alpha);
        // 围绕原地进行旋转
        Bitmap newBM = Bitmap.createBitmap(origin, 0, 0, width, height, matrix, false);
        if (newBM.equals(origin)) {
            return newBM;
        }
        origin.recycle();
        return newBM;
    }

平移代码如果设置画笔则能看到移动后被挪开的背景颜色

    /**
     * 平移代码
     * @param origin
     * @param x
     * @param y
     * @return
     */
    public static Bitmap translateBitmap(Bitmap origin, float x,float y) {
//        Bitmap returnBitmap = Bitmap.createBitmap(origin,0,0,origin.getWidth(),origin.getHeight());
        Bitmap returnBitmap = Bitmap.createBitmap(origin.getWidth(),origin.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas=new Canvas(returnBitmap);
//2.设置画笔
//        Paint paint=new Paint();
//        paint.setColor(Color.BLACK);
//        canvas.drawColor(Color.WHITE);
//        paint.setAntiAlias(true);  //消除锯齿
//3.画位图

        Matrix matrix=new Matrix();
        matrix.postTranslate(x, y);
        canvas.drawBitmap(origin,matrix, null);

        return returnBitmap;

平移下面这样写无法平移没有效果的 ,目前没搞懂原因，可能是要进行所谓的其他缩放等操作，百思不得其解，

    public static Bitmap rotateBitmap(Bitmap origin, float x,float y) {
        if (origin == null) {
            return null;
        }
        int width = origin.getWidth();
        int height = origin.getHeight();
        Matrix matrix = new Matrix();
        matrix.postTranslate(x,y);
        // 围绕原地进行旋转
        Bitmap newBM = Bitmap.createBitmap(origin, 0, 0, width, height, matrix, false);
        if (newBM.equals(origin)) {
            return newBM;
        }
        origin.recycle();
        return newBM;
    }

之前可能是即时运行问题现在又可以了


    public static Bitmap adjustPhotoRotation(Bitmap bm, final int orientationDegree) {

        Matrix m = new Matrix();
        m.setRotate(orientationDegree, (float) bm.getWidth() / 2, (float) bm.getHeight() / 2);
        float targetX, targetY;
        if (orientationDegree == 90) {
            targetX = bm.getHeight();
            targetY = 0;
        } else {
            targetX = bm.getHeight();
            targetY = bm.getWidth();
        }

        final float[] values = new float[9];
        m.getValues(values);

        float x1 = values[Matrix.MTRANS_X];
        float y1 = values[Matrix.MTRANS_Y];

        m.postTranslate(targetX - x1, targetY - y1);

        Bitmap bm1 = Bitmap.createBitmap(bm.getHeight(), bm.getWidth(), Bitmap.Config.ARGB_8888);


        Paint paint = new Paint();
        Canvas canvas = new Canvas(bm1);
        canvas.drawBitmap(bm, m, paint);

        return bm1;
    }