定位坐标进行转换

app/src/main/cpp/PhoneDevice.cpp

@@ -7,6 +7,7 @@
 #include "ncnn/yolov5ncnn.h"
 #include "GPIOControl.h"
 #include "CvText.h"
+#include "PositionHelper.h"
 
 #include <opencv2/opencv.hpp>
 #include <opencv2/core.hpp>
@@ -38,6 +39,7 @@ extern bool GetJniEnv(JavaVM *vm, JNIEnv **env, bool& didAttachThread);
 // are normalized to eight bits.
 static const int kMaxChannelValue = 262143;
 
+
 static long getFreeMemoryImpl(const char* const sums[], const size_t sumsLen[], size_t num)
 {
     int fd = open("/proc/meminfo", O_RDONLY | O_CLOEXEC);
@@ -1914,6 +1916,10 @@ void CPhoneDevice::UpdatePosition(double lon, double lat, double radius, time_t
 {
     if (m_listener != NULL)
     {
+        if (shouldConvertPosition(lat, lon))
+        {
+            transformPosition(lat, lon);
+        }
         return m_listener->OnPositionDataArrived(lon, lat, radius, ts);
     }
 }

app/src/main/cpp/PositionHelper.h

@@ -0,0 +1,57 @@
+#ifndef __POSITION_HELPER_H__
+#define __POSITION_HELPER_H__
+
+#include <cmath>
+#define _USE_MATH_DEFINES
+
+inline double transformLat(double x, double y)
+{
+	double ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * std::sqrt(std::abs(x));
+	ret += (20.0 * std::sin(6.0 * x * M_PI) + 20.0 * std::sin(2.0 * x * M_PI)) * 2.0 / 3.0;
+	ret += (20.0 * std::sin(y * M_PI) + 40.0 * std::sin(y / 3.0 * M_PI)) * 2.0 / 3.0;
+	ret += (160.0 * std::sin(y / 12.0 * M_PI) + 320 * std::sin(y * M_PI / 30.0)) * 2.0 / 3.0;
+	return ret;
+}
+
+inline double transformLng(double x, double y)
+{
+	double ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * std::sqrt(std::abs(x));
+	ret += (20.0 * std::sin(6.0 * x * M_PI) + 20.0 * std::sin(2.0 * x * M_PI)) * 2.0 / 3.0;
+	ret += (20.0 * std::sin(x * M_PI) + 40.0 * std::sin(x / 3.0 * M_PI)) * 2.0 / 3.0;
+	ret += (150.0 * std::sin(x / 12.0 * M_PI) + 300.0 * std::sin(x / 30.0 * M_PI)) * 2.0 / 3.0;
+	return ret;
+}
+
+inline void transformPosition(double& lat, double& lng)
+{
+    // 卫星椭球坐标投影到平面地图坐标系的投影因子
+#define AXIS 6378245.0
+    // 椭球的偏心率(a^2 - b^2) / a^2
+#define OFFSET 0.00669342162296594323
+	double dLat = transformLat(lng - 105.0, lat - 35.0);
+	double dLon = transformLng(lng - 105.0, lat - 35.0);
+	double radLat = lat / 180.0 * M_PI;
+	double magic = std::sin(radLat);
+	magic = 1 - OFFSET * magic * magic;
+	double sqrtMagic = std::sqrt(magic);
+	dLat = (dLat * 180.0) / ((AXIS * (1 - OFFSET)) / (magic * sqrtMagic) * M_PI);
+	dLon = (dLon * 180.0) / (AXIS / sqrtMagic * std::cos(radLat) * M_PI);
+	lat = dLat;
+	lng = dLon;
+}
+
+inline bool shouldConvertPosition(double lat, double lon)
+{
+	if (lon < 72.004 || lon > 137.8347)
+	{
+		return false;
+	}
+	if (lat < 0.8293 || lat > 55.8271)
+	{
+		return false;
+	}
+	return true;
+}
+
+
+#endif // __POSITION_HELPER_H__