Fix: Make CBillboardSceneNode bounding-box large enough to fit the billboard inside.

It still won't work yet for scaled boundingboxes (or parents being scaled).
But at least it's now large enough for typical unscaled boundingboxes.
Before it was always too small - even for the simplest quadratic billboard case seen without rotation.
Now it's always a bit too large, but that's way less of a problem (collisions still work and culling simply happens a bit less often, but not too often which is way worse)

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@6431 dfc29bdd-3216-0410-991c-e03cc46cb475

diff --git a/source/Irrlicht/CBillboardSceneNode.cpp b/source/Irrlicht/CBillboardSceneNode.cpp
index da90c3a15774a409e3344827f53e90fcd0df4108..c1776d4d13d9bfdb65f679952c20a030087be519 100644 (file)
--- a/source/Irrlicht/CBillboardSceneNode.cpp
+++ b/source/Irrlicht/CBillboardSceneNode.cpp
@@ -141,7 +141,7 @@ void CBillboardSceneNode::updateMesh(const irr::scene::ICameraSceneNode* camera)
 //! returns the axis aligned bounding box of this node\r
 const core::aabbox3d<f32>& CBillboardSceneNode::getBoundingBox() const\r
 {\r
-       // Really wrong when scaled.\r
+       // Really wrong when scaled (as the node does not scale it's vertices - maybe it should?)\r
        return BBoxSafe;\r
 }\r
 \r
@@ -162,9 +162,9 @@ void CBillboardSceneNode::setSize(const core::dimension2d<f32>& size)
        if (core::equals(Size.Height, 0.0f))\r
                Size.Height = 1.0f;\r
 \r
-       const f32 avg = (Size.Width + Size.Height)/6;\r
-       BBoxSafe.MinEdge.set(-avg,-avg,-avg);\r
-       BBoxSafe.MaxEdge.set(avg,avg,avg);\r
+       const f32 extent = 0.5f*sqrt(Size.Width*Size.Width + Size.Height*Size.Height);\r
+       BBoxSafe.MinEdge.set(-extent,-extent,-extent);\r
+       BBoxSafe.MaxEdge.set(extent,extent,extent);\r
 }\r
 \r
 \r
@@ -182,9 +182,9 @@ void CBillboardSceneNode::setSize(f32 height, f32 bottomEdgeWidth, f32 topEdgeWi
                TopEdgeWidth = 1.0f;\r
        }\r
 \r
-       const f32 avg = (core::max_(Size.Width,TopEdgeWidth) + Size.Height)/6;\r
-       BBoxSafe.MinEdge.set(-avg,-avg,-avg);\r
-       BBoxSafe.MaxEdge.set(avg,avg,avg);\r
+       const f32 extent = 0.5f*sqrt(Size.Width*Size.Width + Size.Height*Size.Height);\r
+       BBoxSafe.MinEdge.set(-extent,-extent,-extent);\r
+       BBoxSafe.MaxEdge.set(extent,extent,extent);\r
 }\r
 \r
 \r