Android版谷歌地图绘制performanse问题道路上10.000+覆盖 [英] Android google maps drawing roads performanse issue with 10.000+ overlay
问题描述
我工作的一个项目，该项目是aboot绘制道路和显示有关道路的一些信息。问题是，我使用这么多geopoints（5.000-10.000 +）和绘制线分点，并显示不同颜色的道路，所以地图是太慢了。我做了一些我的配置应用程序，但仍然太慢。
你有关于解决我的问题，并为性能更好的任何想法？
I am working on a project which is aboot drawing roads and displaying some informations about the roads. The issue is that I am using so many geopoints( 5.000-10.000 +) and drawing line points to points and showing the roads with different colors, so the map is too slow. I did some configurations about my application but still too slow. Do you have any idea about solving my problem and being the performance better?
下面是我的code。
for (int t = 0; t < roads.size(); t++) {
for (int i = 0; i < roads.get(t).size() - 1; i++) {
//bounds up-bottom-right-left to draw roads
if (boundBox[0] >= roads.get(t).get(i)
.getLatitudeE6()
&& boundBox[1] >= roads.get(t).get(i)
.getLongitudeE6()
&& boundBox[2] <= roads.get(t).get(i)
.getLatitudeE6()
&& boundBox[3] <= roads.get(t).get(i)
.getLongitudeE6()) {
MyOverlay mOverlay = new MyOverlay();
mOverlay.setColor(Color.GREEN);
mOverlay.setWidth(4);
mOverlay.setPair(roads.get(t).get(i),
roads.get(t).get(i + 1));
mapOverlays.add(mOverlay);
}
}
}
class MyOverlay extends Overlay {
GeoPoint gp1 = new GeoPoint(0, 0);
GeoPoint gp2 = new GeoPoint(0, 0);
int colr=0,width=0;
public MyOverlay() {
}
public void draw(Canvas canvas, MapView mapv, boolean shadow) {
super.draw(canvas, mapv, false);
Paint mPaint = new Paint();
mPaint.setDither(true);
mPaint.setColor(colr);
mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(width);
Point p1 = new Point();
Point p2 = new Point();
Path path = new Path();
Projection projection = mapv.getProjection();
projection.toPixels(gp1, p1);
projection.toPixels(gp2, p2);
path.moveTo((float) p2.x, (float) p2.y);
path.lineTo((float) p1.x, (float) p1.y);
// canvas.drawBitmap(markerBitmap, point.x, point.y, null);
canvas.drawPath(path, mPaint);
//canvas.drawBitmap(bitmap, src, dst, paint);
}
public void setPair(GeoPoint gpone, GeoPoint gptwo) {
gp1 = gpone;
gp2 = gptwo;
}
public void setColor(int clr)
{
colr=clr;
}
public void setWidth(int w)
{
width=w;
}
}
有没有人来解决我的问题？
Is there anyone to solve my issue ?
推荐答案
有几件事情可以做，以提高工作效率。
There are a few things you can do to improve efficiency.
您code的首块可以作出稍微更有效的：
Your first block of code could be made slightly more efficient:
for (int t = 0, size = roads.size(); t < size; t++) { //Avoid calling '.size()' over and over
for (int i = 0; i < roads.get(t).size() - 1; i++) {//Avoid calling '.size()' over and over
final GeoPoint road = roads.get(t).get(i); //Reduce the number of get() calls.
if (boundBox[0] >= road.getLatitudeE6()
&& boundBox[1] >= road.getLongitudeE6()
&& boundBox[2] <= road.getLatitudeE6()
&& boundBox[3] <= road.getLongitudeE6()) {
MyOverlay mOverlay = new MyOverlay();
mOverlay.setColor(Color.GREEN);
mOverlay.setWidth(4);
mOverlay.setPair(road, roads.get(t).get(i + 1));
mapOverlays.add(mOverlay);
}
}
}
但最重要的，最大的性能消耗我可以在你的code看到的是，你分配一个新的渲染对象（油漆，路径，点），每次抽奖（）被调用。这可重构，所以你重复使用相同的油漆如：
But most importantly, the biggest performance drain I can see in your code is that you are allocating a new rendering objects (Paint, Path, Point) every time draw() is called. This can be refactored so you reuse the same Paint instance:
class MyOverlay extends Overlay {
GeoPoint gp1 = new GeoPoint(0, 0);
GeoPoint gp2 = new GeoPoint(0, 0);
Point p1 = new Point();
Point p2 = new Point();
Path path = new Path();
int colr=0,width=0;
public MyOverlay() {
Paint mPaint = new Paint();
mPaint.setDither(true);
mPaint.setColor(colr);
mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(width);
}
public void draw(Canvas canvas, MapView mapv, boolean shadow) {
super.draw(canvas, mapv, false);
path.reset();
Projection projection = mapv.getProjection();
projection.toPixels(gp1, p1);
projection.toPixels(gp2, p2);
path.moveTo((float) p2.x, (float) p2.y);
path.lineTo((float) p1.x, (float) p1.y);
canvas.drawPath(path, mPaint);
}
}
有关更多信息请参见做的和不要的文章在这里部分：的http://android-developers.blogspot.com.au/2011/03/android-30-hardware-acceleration.html.
For more info see the 'Do's and Dont's section of the article here: http://android-developers.blogspot.com.au/2011/03/android-30-hardware-acceleration.html.
从文章的有关观点是：不要创建draw方法渲染对象：一个常见的错误是创建一个新的油漆，或新的路径，每次调用的渲染方法时这是不仅造成浪费，迫使系统更经常地运行GC，它也绕过在硬件管道缓存和优化。的
The relevant point from the article is: "Don't create render objects in draw methods: a common mistake is to create a new Paint, or a new Path, every time a rendering method is invoked. This is not only wasteful, forcing the system to run the GC more often, it also bypasses caches and optimizations in the hardware pipeline."
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