<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="fill_parent"android:layout_height="fill_parent"android:orientation="vertical" ><com.baidu.mapapi.map.TextureMapViewandroid:id="@+id/bmapView"android:layout_width="match_parent"android:layout_height="fill_parent" />
</RelativeLayout>

using Android.App;
using Android.OS;
using Com.Baidu.Mapapi.Map;
using Com.Baidu.Mapapi.Model;
using Android.Graphics;
using Android.Util;
using System.Collections.Generic;
using Javax.Microedition.Khronos.Opengles;
using Java.Nio;
using Android.Opengl;namespace BdMapV371Demos.SrcSdkDemos
{/// <summary>/// 此demo用来展示如何在地图绘制的每帧中再额外绘制一些用户自己的内容/// </summary>[Activity(Label = "@string/demo_name_opengl")]public class Demo24OpenGL : Activity, BaiduMap.IOnMapDrawFrameCallback{// 地图相关private TextureMapView mMapView;private BaiduMap mBaiduMap;private Bitmap bitmap;private LatLng latlng1 = new LatLng(39.97923, 116.357428);private LatLng latlng2 = new LatLng(39.94923, 116.397428);private LatLng latlng3 = new LatLng(39.96923, 116.437428);private IList<LatLng> latLngPolygon;private float[] vertexs;private FloatBuffer vertexBuffer;private int textureId = -1;private readonly string LTAG = "Demo24OpenGL";protected override void OnCreate(Bundle savedInstanceState){base.OnCreate(savedInstanceState);SetContentView(Resource.Layout.demo24_opengl);mMapView = FindViewById<TextureMapView>(Resource.Id.bmapView);mBaiduMap = mMapView.Map;latLngPolygon = new List<LatLng>(){latlng1,latlng2,latlng3};mBaiduMap.SetOnMapDrawFrameCallback(this);bitmap = BitmapFactory.DecodeResource(Resources,Resource.Drawable.ground_overlay);}protected override void OnPause(){mMapView.OnPause();base.OnPause();}protected override void OnResume(){mMapView.OnResume();textureId = -1;base.OnResume();}protected override void OnDestroy(){mMapView.OnDestroy();base.OnDestroy();}public void OnMapDrawFrame(IGL10 gl, MapStatus drawingMapStatus){if (mBaiduMap.Projection != null){calPolylinePoint(drawingMapStatus);drawPolyline(gl, Color.Argb(255, 255, 0, 0), vertexBuffer, 10, 3,drawingMapStatus);drawTexture(gl, bitmap, drawingMapStatus);}}public void calPolylinePoint(MapStatus mspStatus){PointF[] polyPoints = new PointF[latLngPolygon.Count];vertexs = new float[3 * latLngPolygon.Count];int i = 0;foreach (LatLng xy in latLngPolygon){polyPoints[i] = mBaiduMap.Projection.ToOpenGLLocation(xy, mspStatus);vertexs[i * 3] = polyPoints[i].X;vertexs[i * 3 + 1] = polyPoints[i].Y;vertexs[i * 3 + 2] = 0.0f;i++;}for (int j = 0; j < vertexs.Length; j++){Log.Debug(LTAG, "vertexs[" + j + "]: " + vertexs[j]);}vertexBuffer = makeFloatBuffer(vertexs);}private FloatBuffer makeFloatBuffer(float[] fs){ByteBuffer bb = ByteBuffer.AllocateDirect(fs.Length * 4);bb.Order(ByteOrder.NativeOrder());FloatBuffer fb = bb.AsFloatBuffer();fb.Put(fs);fb.Position(0);return fb;}private void drawPolyline(IGL10 gl, int color, FloatBuffer lineVertexBuffer,float lineWidth, int pointSize, MapStatus drawingMapStatus){gl.GlEnable(GL10.GlBlend);gl.GlEnableClientState(GL10.GlVertexArray);gl.GlBlendFunc(GL10.GlSrcAlpha, GL10.GlOneMinusSrcAlpha);float colorA = Color.GetAlphaComponent(color) / 255f;float colorR = Color.GetRedComponent(color) / 255f;float colorG = Color.GetGreenComponent(color) / 255f;float colorB = Color.GetBlueComponent(color) / 255f;gl.GlVertexPointer(3, GL10.GlFloat, 0, lineVertexBuffer);gl.GlColor4f(colorR, colorG, colorB, colorA);gl.GlLineWidth(lineWidth);gl.GlDrawArrays(GL10.GlLineStrip, 0, pointSize);gl.GlDisable(GL10.GlBlend);gl.GlDisableClientState(GL10.GlVertexArray);}/// <summary>/// 使用opengl坐标绘制/// </summary>/// <param name="gl"></param>/// <param name="bitmap"></param>/// <param name="drawingMapStatus"></param>public void drawTexture(IGL10 gl, Bitmap bitmap, MapStatus drawingMapStatus){PointF p1 = mBaiduMap.Projection.ToOpenGLLocation(latlng2,drawingMapStatus);PointF p2 = mBaiduMap.Projection.ToOpenGLLocation(latlng3,drawingMapStatus);ByteBuffer byteBuffer = ByteBuffer.AllocateDirect(4 * 3 * 4);byteBuffer.Order(ByteOrder.NativeOrder());FloatBuffer vertices = byteBuffer.AsFloatBuffer();vertices.Put(new float[] { p1.X, p1.Y, 0.0f, p2.X, p1.Y, 0.0f, p1.X,p2.Y, 0.0f, p2.X, p2.Y, 0.0f });ByteBuffer indicesBuffer = ByteBuffer.AllocateDirect(6 * 2);indicesBuffer.Order(ByteOrder.NativeOrder());ShortBuffer indices = indicesBuffer.AsShortBuffer();indices.Put(new short[] { 0, 1, 2, 1, 2, 3 });ByteBuffer textureBuffer = ByteBuffer.AllocateDirect(4 * 2 * 4);textureBuffer.Order(ByteOrder.NativeOrder());FloatBuffer texture = textureBuffer.AsFloatBuffer();texture.Put(new float[] { 0, 1f, 1f, 1f, 0f, 0f, 1f, 0f });indices.Position(0);vertices.Position(0);texture.Position(0);// 生成纹理if (textureId == -1){int[] textureIds = new int[1];gl.GlGenTextures(1, textureIds, 0);textureId = textureIds[0];Log.Debug(LTAG, "textureId: " + textureId);gl.GlBindTexture(GL10.GlTexture2d, textureId);GLUtils.TexImage2D(GL10.GlTexture2d, 0, bitmap, 0);gl.GlTexParameterf(GL10.GlTexture2d, GL10.GlTextureMinFilter, GL10.GlNearest);gl.GlTexParameterf(GL10.GlTexture2d, GL10.GlTextureMagFilter, GL10.GlNearest);gl.GlBindTexture(GL10.GlTexture2d, 0);}gl.GlEnable(GL10.GlTexture2d);gl.GlEnableClientState(GL10.GlVertexArray);gl.GlEnableClientState(GL10.GlTextureCoordArray);gl.GlEnable(GL10.GlBlend);gl.GlBlendFunc(GL10.GlSrcAlpha, GL10.GlOneMinusSrcAlpha);gl.GlColor4f(1.0f, 1.0f, 1.0f, 1.0f);// 绑定纹理ID
            gl.GlBindTexture(GL10.GlTexture2d, textureId);gl.GlVertexPointer(3, GL10.GlFloat, 0, vertices);gl.GlTexCoordPointer(2, GL10.GlFloat, 0, texture);gl.GlDrawElements(GL10.GlTriangleStrip, 6, GL10.GlUnsignedShort, indices);gl.GlDisable(GL10.GlTexture2d);gl.GlDisableClientState(GL10.GlVertexArray);gl.GlDisableClientState(GL10.GlTextureCoordArray);gl.GlDisable(GL10.GlBlend);}}
}