"overzoom"tileoverlay谷歌地图

Question

我有一个问题,我正在尝试为其构建自定义解决方案.我很挣扎,也许我能够让它发挥作用,但也许已经有了另一个解决方案.

我的客户有一个后端来获取磁贴,但它只会在缩放级别8之前.之后,不会显示任何磁贴.

为了制作更多细节瓷砖,我过去使用过/sf/answers/2568740401/.从较高的缩放级别获取4个图块并将其构造为1.

但是现在,我必须从较低的缩放级别获取磁贴,并且需要将其炸毁.我一直试图以上述为基础,但尚未成功.如果有人知道不同的方法,我会非常感激.

或者,也许可以让谷歌地图保持缩放而不需要超过一定水平的新图层？我的意思是,它在缩放级别之间已经做到了

Answer 1

以该解决方案(通过组合4瓦更高的缩放级别为1)由@RadekJ增强瓷砖的分辨率这里作为参考,我就开始工作了相反的:以更低的缩放级别,在4个部分,并用砍碎它可以从中构建更高的缩放级别.

假设您获得的最大缩放级别为8,但您希望能够通过炸毁这些切片将其缩小到9,10等.

每次放大时,瓷砖除以2.因此,以缩放级别9为例,我从缩放级别8中取出瓷砖并将其切割成4个.然后我确定了在9级请求的磁贴所需的"象限".

接下来,我使用递归来获得更高级别的缩放级别.我对结果非常满意.

设置DRAW_DEBUG_DATA为true如果您想要查看其中的图块x,y并将其zoom level绘制在其中.

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;

import com.google.android.gms.maps.model.Tile;
import com.google.android.gms.maps.model.TileProvider;

import java.io.ByteArrayOutputStream;

public class OverZoomTileProvider implements TileProvider {

    public static final int MAX_ZOOM = 8;

    private static final boolean DRAW_DEBUG_DATA = false;

    private static final int TILE_SIZE = 256;
    private static final int HALF_TILE_SIZE = TILE_SIZE / 2;

    private Paint tilePainter = new Paint();

    // these will only be used when DRAW_DEBUG_DATA is true
    private Paint debugRectPaint;
    private Paint debugTextPaint;

    private TileProvider mTileProvider;

    public OverZoomTileProvider(TileProvider tileProvider) {
        mTileProvider = tileProvider;

        if (DRAW_DEBUG_DATA) {
            debugRectPaint = new Paint();
            debugRectPaint.setColor(Color.RED);
            debugRectPaint.setStrokeWidth(1);
            debugRectPaint.setStyle(Paint.Style.STROKE);

            debugTextPaint = new Paint();
            debugTextPaint.setColor(Color.WHITE);
            debugTextPaint.setStyle(Paint.Style.FILL);
            debugTextPaint.setColor(Color.BLACK);
            debugTextPaint.setTextSize(20);
        }
    }

    @Override
    public Tile getTile(int x, int y, int zoom) {
        Bitmap image = Bitmap.createBitmap(TILE_SIZE, TILE_SIZE,
                Bitmap.Config.ARGB_8888);
        image.eraseColor(Color.TRANSPARENT);

        Canvas canvas = new Canvas(image);
        drawTile(canvas, zoom, x, y);

        byte[] data = bitmapToByteArray(image);
        image.recycle();

        return new Tile(TILE_SIZE, TILE_SIZE, data);
    }

    private void drawTile(Canvas canvas, int zoom, int x, int y) {

        Bitmap bitmap = getTileAsBitmap(x, y, zoom);

        if (bitmap != null) {
            canvas.drawBitmap(bitmap, 0, 0, tilePainter);
            bitmap.recycle();
        }

        if (DRAW_DEBUG_DATA) {
            canvas.drawRect(0, 0, canvas.getWidth(), canvas.getHeight(), debugRectPaint);
            canvas.drawText("" + x + ", " + x + " (" + zoom + ")", 128, 128, debugTextPaint);
        }
    }

    private Bitmap getTileAsBitmap(int x, int y, int zoom) {
        if (zoom <= MAX_ZOOM) {
            Tile tile = mTileProvider.getTile(x, y, zoom);

            if (tile == NO_TILE) {
                return null;
            }

            return BitmapFactory.decodeByteArray(tile.data, 0, tile.data.length);
        }


        boolean leftColumn = x % 2 == 0;
        boolean topRow = y % 2 == 0;

        Bitmap bitmap = getTileAsBitmap(x / 2, y / 2, zoom - 1);

        int quadrant;
        if (leftColumn && topRow) {
            quadrant = 1;
        } else if (!leftColumn && topRow) {
            quadrant = 2;
        } else if (leftColumn) {
            quadrant = 3;
        } else {
            quadrant = 4;
        }

        switch (quadrant) {
            case 1:
                bitmap = Bitmap.createBitmap(bitmap, 0, 0, HALF_TILE_SIZE, HALF_TILE_SIZE);
                break;
            case 2:
                bitmap = Bitmap.createBitmap(bitmap, HALF_TILE_SIZE, 0, HALF_TILE_SIZE, HALF_TILE_SIZE);
                break;
            case 3:
                bitmap = Bitmap.createBitmap(bitmap, 0, HALF_TILE_SIZE, HALF_TILE_SIZE, HALF_TILE_SIZE);
                break;
            case 4:
                bitmap = Bitmap.createBitmap(bitmap, HALF_TILE_SIZE, HALF_TILE_SIZE, HALF_TILE_SIZE, HALF_TILE_SIZE);
                break;
        }

        return Bitmap.createScaledBitmap(bitmap, TILE_SIZE, TILE_SIZE, false);
    }

    private static byte[] bitmapToByteArray(Bitmap bm) {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        bm.compress(Bitmap.CompressFormat.PNG, 100, bos);

        byte[] data = bos.toByteArray();
        try {
            bos.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return data;
    }
}