[raymath] Hotfix for Vector2Angle() and Vector2LineAngle() (#3396)

* Hotfix for Vector2LineAngle(), should probably be reviewed along with the rest of raylib angle functions to determine what coordinate system we want.

* Hotfix for Vector2LineAngle(), should probably be reviewed along with the rest of raylib angle functions to determine what coordinate system we want.

* [raymath] Hotfix for Vector2Angle and corresponding example

* [raymath] Hotfix for Vector2Angle and corresponding example

---------

Co-authored-by: Ray <[email protected]>

examples/others/raymath_vector_angle.c

@@ -44,7 +44,7 @@ int main(void)
         //----------------------------------------------------------------------------------
         float startangle;
 
-        if (angleMode == 0) startangle = -Vector2LineAngle(v0, v1)*RAD2DEG;
+        if (angleMode == 0) startangle = Vector2LineAngle(v0, v1)*RAD2DEG;
         if (angleMode == 1) startangle = 0.0f; 
 
         v2 = GetMousePosition();
@@ -81,8 +81,8 @@ int main(void)
                 
                 DrawLineEx(v0, v1, 2.0f, BLACK);
                 DrawLineEx(v0, v2, 2.0f, RED);
-                
-                DrawCircleSector(v0, 40.0f, startangle, startangle - angle, 32, Fade(GREEN, 0.6f));
+
+                DrawCircleSector(v0, 40.0f, startangle, startangle + angle, 32, Fade(GREEN, 0.6f));
             }
             else if (angleMode == 1)
             {
@@ -90,8 +90,8 @@ int main(void)
                 
                 DrawLine(0, screenHeight/2, screenWidth, screenHeight/2, LIGHTGRAY);
                 DrawLineEx(v0, v2, 2.0f, RED);
-                
-                DrawCircleSector(v0, 40.0f, startangle, startangle - angle, 32, Fade(GREEN, 0.6f));
+
+                DrawCircleSector(v0, 40.0f, startangle, startangle + angle, 32, Fade(GREEN, 0.6f));
             }
             
             DrawText("v0", v0.x, v0.y, 10, DARKGRAY);

src/raymath.h

@@ -324,8 +324,7 @@ RMAPI float Vector2Angle(Vector2 v1, Vector2 v2)
     float dot = v1.x*v2.x + v1.y*v2.y;
     float det = v1.x*v2.y - v1.y*v2.x;
 
-    // TODO(10/9/2023): Currently angles move clockwise, determine if this is wanted behavior
-    result = -atan2f(det, dot);
+    result = atan2f(det, dot);
 
     return result;
 }