Actual working springy rectangle

2 files changed, 11 insertions, 0 deletions

diff --git a/shared_cpp/mathlib.cpp b/shared_cpp/mathlib.cpp
index 17f9f84..2e92aa8 100644
--- a/shared_cpp/mathlib.cpp
+++ b/shared_cpp/mathlib.cpp
@@ -80,6 +80,16 @@ Vector2 Vector2::rotate(float angle) {
     };
 }
 
+Vector2 Vector2::rotateAround(float angle, const Vector2& other) {
+    Vector2 point = { x - other.x, y - other.y };
+    point = {
+        point.x * cosf(angle) - point.y * sinf(angle),
+        point.x * sinf(angle) + point.y * cosf(angle)
+    };
+    point = point + other;
+    return point;
+}
+
 void Vector2::printDebug(const char* name) {
     printf("%s=Vector2(%f, %f)\n", name, x, y);
 }
diff --git a/shared_cpp/mathlib.h b/shared_cpp/mathlib.h
index 9722f4f..f89addc 100644
--- a/shared_cpp/mathlib.h
+++ b/shared_cpp/mathlib.h
@@ -53,6 +53,7 @@ struct Vector2 {
     Vector2 negate();
     Vector2 getPerp();
     Vector2 rotate(float angle);
+    Vector2 rotateAround(float angle, const Vector2& other);
     float determinant(Vector2 other);
     
     void printDebug(const char* name);