如何在Openlayers上整合饼图？尝试使用OPenlayer样式圈实现相同，但圆不能转换为半圆，因此不能作为图表放置 请提供合适的例子。
答案 0 :(得分：3)
我建议您在ol3-ext处查看import gab.opencv.*;
import java.nio.*;
import org.opencv.imgproc.Imgproc;
import org.opencv.core.Mat;
import org.opencv.core.CvType;
import org.opencv.core.Core;
OpenCV opencv;
Imgproc imgproc;
PImage canny;
PImage src, out;
Mat one, two;
double a = 20.0;
double b = 10.0;
void setup() {
src = loadImage("cat.jpg");
size( 429, 360);
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
one = new Mat( width, height, CvType.CV_8UC3);
two = new Mat( width, height, CvType.CV_8UC3);
one = toMat(src);
imgproc.pyrMeanShiftFiltering( one, two, a, b);
out = toPImage(two);
}
void draw() {
image(out, 0, 0, width, height);
}
Mat toMat(PImage image) {
int w = image.width;
int h = image.height;
Mat mat = new Mat(h, w, CvType.CV_8UC3);
byte[] data8 = new byte[w*h*4];
int[] data32 = new int[w*h];
arrayCopy(image.pixels, data32);
ByteBuffer bBuf = ByteBuffer.allocate(w*h*4);
IntBuffer iBuf = bBuf.asIntBuffer();
iBuf.put(data32);
bBuf.get(data8);
mat.put(0, 0, data8);
return mat;
}
PImage toPImage(Mat mat) {
int w = mat.width();
int h = mat.height();
PImage image = createImage(w, h, ARGB);
byte[] data8 = new byte[w*h*4];
int[] data32 = new int[w*h];
mat.get(0, 0, data8);
ByteBuffer.wrap(data8).asIntBuffer().get(data32);
arrayCopy(data32, image.pixels);
return image;
}
<强>示例：