from the start... checking in ode-0.9

1 files changed, 50 insertions, 0 deletions

diff --git a/libraries/ode-0.9/OPCODE/OPC_PlanesAABBOverlap.h b/libraries/ode-0.9/OPCODE/OPC_PlanesAABBOverlap.h
new file mode 100644
index 0000000..5d7576e
--- /dev/null
+++ b/libraries/ode-0.9/OPCODE/OPC_PlanesAABBOverlap.h
@@ -0,0 +1,50 @@
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+/**
+ *      Planes-AABB overlap test.
+ *      - original code by Ville Miettinen, from Umbra/dPVS (released on the GD-Algorithms mailing list)
+ *      - almost used "as-is", I even left the comments (hence the frustum-related notes)
+ *
+ *      \param          center                  [in] box center
+ *      \param          extents                 [in] box extents
+ *      \param          out_clip_mask   [out] bitmask for active planes
+ *      \param          in_clip_mask    [in] bitmask for active planes
+ *      \return         TRUE if boxes overlap planes
+ */
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+inline_ BOOL PlanesCollider::PlanesAABBOverlap(const Point& center, const Point& extents, udword& out_clip_mask, udword in_clip_mask)
+{
+        // Stats
+        mNbVolumeBVTests++;
+
+        const Plane* p = mPlanes;
+
+        // Evaluate through all active frustum planes. We determine the relation 
+        // between the AABB and a plane by using the concept of "near" and "far"
+        // vertices originally described by Zhang (and later by Möller). Our
+        // variant here uses 3 fabs ops, 6 muls, 7 adds and two floating point
+        // comparisons per plane. The routine early-exits if the AABB is found
+        // to be outside any of the planes. The loop also constructs a new output
+        // clip mask. Most FPUs have a native single-cycle fabsf() operation.
+
+        udword Mask                             = 1;                    // current mask index (1,2,4,8,..)
+        udword TmpOutClipMask   = 0;                    // initialize output clip mask into empty. 
+
+        while(Mask<=in_clip_mask)                               // keep looping while we have active planes left...
+        {
+                if(in_clip_mask & Mask)                         // if clip plane is active, process it..
+                {               
+                        float NP = extents.x*fabsf(p->n.x) + extents.y*fabsf(p->n.y) + extents.z*fabsf(p->n.z); // ### fabsf could be precomputed
+                        float MP = center.x*p->n.x + center.y*p->n.y + center.z*p->n.z + p->d;
+
+                        if(NP < MP)                                             // near vertex behind the clip plane... 
+                                return FALSE;                           // .. so there is no intersection..
+                        if((-NP) < MP)                                  // near and far vertices on different sides of plane..
+                                TmpOutClipMask |= Mask;         // .. so update the clip mask...
+                }
+                Mask+=Mask;                                                     // mk = (1<<plane)
+                p++;                                                            // advance to next plane
+        }
+
+        out_clip_mask = TmpOutClipMask;                 // copy output value (temp used to resolve aliasing!)
+        return TRUE;                                                    // indicate that AABB intersects frustum
+}