raze/source/common/rendering/hwrenderer/data/hw_aabbtree.h
2021-03-18 10:23:53 +01:00

83 lines
2.8 KiB
C++

#pragma once
#include "tarray.h"
#include "vectors.h"
namespace hwrenderer
{
// Node in a binary AABB tree
struct AABBTreeNode
{
AABBTreeNode(const FVector2 &aabb_min, const FVector2 &aabb_max, int line_index) : aabb_left(aabb_min.X), aabb_top(aabb_min.Y), aabb_right(aabb_max.X), aabb_bottom(aabb_max.Y), left_node(-1), right_node(-1), line_index(line_index) { }
AABBTreeNode(const FVector2 &aabb_min, const FVector2 &aabb_max, int left, int right) : aabb_left(aabb_min.X), aabb_top(aabb_min.Y), aabb_right(aabb_max.X), aabb_bottom(aabb_max.Y), left_node(left), right_node(right), line_index(-1) { }
// Axis aligned bounding box for the node
float aabb_left, aabb_top;
float aabb_right, aabb_bottom;
// Child node indices
int left_node;
int right_node;
// AABBTreeLine index if it is a leaf node. Index is -1 if it is not.
int line_index;
// Padding to keep 16-byte length (this structure is uploaded to the GPU)
int padding;
};
// Line segment for leaf nodes in an AABB tree
struct AABBTreeLine
{
float x, y;
float dx, dy;
};
class LevelAABBTree
{
protected:
// Nodes in the AABB tree. Last node is the root node.
TArray<AABBTreeNode> nodes;
// Line segments for the leaf nodes in the tree.
TArray<AABBTreeLine> treelines;
int dynamicStartNode = 0;
int dynamicStartLine = 0;
public:
// Shoot a ray from ray_start to ray_end and return the closest hit as a fractional value between 0 and 1. Returns 1 if no line was hit.
double RayTest(const DVector3 &ray_start, const DVector3 &ray_end);
const void *Nodes() const { return nodes.Data(); }
const void *Lines() const { return treelines.Data(); }
size_t NodesSize() const { return nodes.Size() * sizeof(AABBTreeNode); }
size_t LinesSize() const { return treelines.Size() * sizeof(AABBTreeLine); }
unsigned int NodesCount() const { return nodes.Size(); }
const void *DynamicNodes() const { return nodes.Data() + dynamicStartNode; }
const void *DynamicLines() const { return treelines.Data() + dynamicStartLine; }
size_t DynamicNodesSize() const { return (nodes.Size() - dynamicStartNode) * sizeof(AABBTreeNode); }
size_t DynamicLinesSize() const { return (treelines.Size() - dynamicStartLine) * sizeof(AABBTreeLine); }
size_t DynamicNodesOffset() const { return dynamicStartNode * sizeof(AABBTreeNode); }
size_t DynamicLinesOffset() const { return dynamicStartLine * sizeof(AABBTreeLine); }
virtual bool Update() = 0;
virtual ~LevelAABBTree() = default;
protected:
TArray<int> FindNodePath(unsigned int line, unsigned int node);
// Test if a ray overlaps an AABB node or not
bool OverlapRayAABB(const DVector2 &ray_start2d, const DVector2 &ray_end2d, const AABBTreeNode &node);
// Intersection test between a ray and a line segment
double IntersectRayLine(const DVector2 &ray_start, const DVector2 &ray_end, int line_index, const DVector2 &raydelta, double rayd, double raydist2);
};
} // namespace