CoordArrows length update fix

examples/coordarrows.cpp

@@ -11,6 +11,12 @@ int main()
     mplot::Visual v(1024, 768, "Coordinate Arrows");
     v.showCoordArrows (true); // Shows the 'scene' coordarrows, that you get in every mplot::Visual
     v.lightingEffects(true);
+    // You can update the coord arrows lengths and thickness scaling factor for the main CoordArrows
+    // if you want to. This updates to the defaults, and so is what you'd get if you left the call
+    // out:
+    v.updateCoordLengths ({ 0.1f, 0.1f, 0.1f }, 1.0f);
+    // This alternative makes the coordinate arrows longer:
+    // v.updateCoordLengths ({ 0.2f, 0.2f, 0.2f }, 1.0f);
 
     // An extra CoordArrows model, with defaults
     sm::vec<float> offset = {};
@@ -19,9 +25,11 @@ int main()
     cavm->finalize();
     v.addVisualModel (cavm);
 
-    sm::vec<float> ux = {1,0,0};
-    sm::vec<float> uy = {0,1,0};
-    sm::vec<float> uz = {0,0,1};
+    // I define some unit vectors here, because it makes the calls to CoordArrows::init easy to
+    // read, but you can also use sm::vec<float>::ux(), etc to get static, constexpr unit vectors
+    constexpr sm::vec<float> ux = {1,0,0};
+    constexpr sm::vec<float> uy = {0,1,0};
+    constexpr sm::vec<float> uz = {0,0,1};
 
     // An CoordArrows model, with non-defaults
     offset[0] += 1.5f;

mplot/VisualBase.h

@@ -397,10 +397,13 @@ namespace mplot
             this->coordArrows->reinit();
         }
 
+        // Update the lengths of the CoordArrows that (usually) appear in the corner of the screen
         void updateCoordLengths (const sm::vec<float, 3>& _lengths, const float _thickness = 1.0f)
         {
             this->coordArrows->lengths = _lengths;
             this->coordArrows->thickness = _thickness;
+            this->coordArrows->clear();
+            this->coordArrows->initAxisLabels();
             this->coordArrows->reinit();
         }