From 7ad5b81283c39e66ba2ca84314e283f277fc77e0 Mon Sep 17 00:00:00 2001
From: yy1717 <fctom1215@outlook.com>
Date: 星期五, 03 四月 2020 11:39:17 +0800
Subject: [PATCH] 坐标
---
lib/src/main/cpp/Geometry.cpp | 68 ++++++++++++++++++++++++++++++++++
1 files changed, 68 insertions(+), 0 deletions(-)
diff --git a/lib/src/main/cpp/Geometry.cpp b/lib/src/main/cpp/Geometry.cpp
index 01e15cd..0a43ae1 100644
--- a/lib/src/main/cpp/Geometry.cpp
+++ b/lib/src/main/cpp/Geometry.cpp
@@ -10,6 +10,7 @@
#include <jni.h>
#include <malloc.h>
#include <initializer_list>
+#include <cctype>
#include "jni_log.h"
@@ -474,3 +475,70 @@
return p4;
}
+
+/****************************************************************
+ * p3
+ * | 'L'
+ * |
+ * p1------------------>p2
+ * |
+ * | 'R'
+ * p3
+ * @param p1
+ * @param p2
+ * @param L
+ * @param dir
+ * @return
+ */
+PointF Calc3Point(PointF p1, PointF p2, double L, char dir)
+{
+ PointF p3;
+
+ dir = toupper(dir);
+
+ if (dir != 'L' && dir != 'R')
+ dir = 'L';
+
+ if (isEqual(p1.X, p2.X)) {
+ p3.Y = p2.Y;
+ if (p2.Y > p1.Y) {
+ p3.X = p2.X + ((dir == 'L')? -L:L);
+ } else {
+ p3.X = p2.X + ((dir=='L')?L:-L);
+ }
+ return p3;
+ }
+ if (isEqual(p1.Y, p2.Y)) {
+ p3.X = p2.X;
+ if (p2.X > p1.X) {
+ p3.Y = p2.Y + ((dir == 'L')? L:-L);
+ } else {
+ p3.Y = p2.Y + ((dir == 'L')? -L:L);
+ }
+ return p3;
+ }
+
+ double k = (p2.Y - p1.Y) / (p2.X - p1.X);
+ double b = p1.Y - k*p1.X;
+
+ double A = 1 + pow(k, 2);
+ double B = 2*k*(b - p2.Y) - 2*p2.X;
+ double C = pow(b - p2.Y, 2) + pow(p2.X, 2) - pow(L,2);
+
+ double x3, y3;
+
+
+ if (p1.X < p2.X) {
+ x3 = (- B - sqrt(pow(B, 2) - 4*A*C))/(2*A);
+ } else {
+ x3 = (- B + sqrt(pow(B, 2) - 4*A*C))/(2*A);
+ }
+ y3 = k * x3 + b;
+
+ p3.X = x3;
+ p3.Y = y3;
+
+ p3 = rotatePoint(p3, p2, (dir == 'L') ? 270 : 90);
+
+ return p3;
+}
--
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