readme

CollisionMesh.h

@@ -0,0 +1,41 @@
+#ifndef COLLISION_MESH_CLASS
+#define COLLISION_MESH_CLASS
+
+#include <vector>
+
+#include <glm/glm.hpp>
+
+#include "Structures.h"
+
+// Triangle soup for triangle by triangle collision, wrapped in a BVH.
+// Triangles live in the body's unit space, so t.GetMatrix() takes them to world space
+// the same way it does for a Mesh. Winding must be counter clockwise seen from outside.
+class CollisionMesh {
+public:
+    CollisionMesh(const std::vector<Triangle>& meshTriangles);
+
+    // The 12 triangles of a unit cube, used for any body without its own mesh
+    static const CollisionMesh& UnitBox();
+
+    const std::vector<Triangle>& GetTriangles() const { return triangles; }
+
+    // Appends the index of every triangle whose BVH leaf could touch tri (same space as the mesh)
+    void Query(const Triangle& tri, std::vector<int>& hits) const;
+
+private:
+    struct Node {
+        glm::vec3 boundsMin;
+        glm::vec3 boundsMax;
+        int left = -1;   // -1 = leaf
+        int right = -1;
+        int start = 0;
+        int count = 0;
+    };
+
+    int Build(int start, int count);
+
+    std::vector<Triangle> triangles;
+    std::vector<Node> nodes;
+};
+
+#endif