Add AABB tree collision structure to the doom level mesh for threadsafe trace calls for the sprite light

src/CMakeLists.txt

@@ -1101,6 +1101,7 @@ set (PCH_SOURCES
 	common/rendering/hwrenderer/data/hw_aabbtree.cpp
 	common/rendering/hwrenderer/data/hw_shadowmap.cpp
 	common/rendering/hwrenderer/data/hw_shaderpatcher.cpp
+	common/rendering/hwrenderer/data/hw_collision.cpp
 	common/rendering/hwrenderer/postprocessing/hw_postprocessshader.cpp
 	common/rendering/hwrenderer/postprocessing/hw_postprocess.cpp
 	common/rendering/hwrenderer/postprocessing/hw_postprocess_cvars.cpp

src/common/rendering/hwrenderer/data/hw_collision.cpp

@@ -0,0 +1,819 @@
+/*
+**  Level mesh collision detection
+**  Copyright (c) 2018 Magnus Norddahl
+**
+**  This software is provided 'as-is', without any express or implied
+**  warranty.  In no event will the authors be held liable for any damages
+**  arising from the use of this software.
+**
+**  Permission is granted to anyone to use this software for any purpose,
+**  including commercial applications, and to alter it and redistribute it
+**  freely, subject to the following restrictions:
+**
+**  1. The origin of this software must not be misrepresented; you must not
+**     claim that you wrote the original software. If you use this software
+**     in a product, an acknowledgment in the product documentation would be
+**     appreciated but is not required.
+**  2. Altered source versions must be plainly marked as such, and must not be
+**     misrepresented as being the original software.
+**  3. This notice may not be removed or altered from any source distribution.
+**
+*/
+
+#include "hw_collision.h"
+#include <algorithm>
+#include <functional>
+#include <cfloat>
+#ifndef NO_SSE
+#include <immintrin.h>
+#endif
+
+TriangleMeshShape::TriangleMeshShape(const FVector3 *vertices, int num_vertices, const unsigned int *elements, int num_elements)
+	: vertices(vertices), num_vertices(num_vertices), elements(elements), num_elements(num_elements)
+{
+	int num_triangles = num_elements / 3;
+	if (num_triangles <= 0)
+		return;
+
+	std::vector<int> triangles;
+	std::vector<FVector3> centroids;
+	triangles.reserve(num_triangles);
+	centroids.reserve(num_triangles);
+	for (int i = 0; i < num_triangles; i++)
+	{
+		triangles.push_back(i);
+
+		int element_index = i * 3;
+		FVector3 centroid = (vertices[elements[element_index + 0]] + vertices[elements[element_index + 1]] + vertices[elements[element_index + 2]]) * (1.0f / 3.0f);
+		centroids.push_back(centroid);
+	}
+
+	std::vector<int> work_buffer(num_triangles * 2);
+
+	root = subdivide(&triangles[0], (int)triangles.size(), &centroids[0], &work_buffer[0]);
+}
+
+float TriangleMeshShape::sweep(TriangleMeshShape *shape1, SphereShape *shape2, const FVector3 &target)
+{
+	return sweep(shape1, shape2, shape1->root, target);
+}
+
+bool TriangleMeshShape::find_any_hit(TriangleMeshShape *shape1, TriangleMeshShape *shape2)
+{
+	return find_any_hit(shape1, shape2, shape1->root, shape2->root);
+}
+
+bool TriangleMeshShape::find_any_hit(TriangleMeshShape *shape1, SphereShape *shape2)
+{
+	return find_any_hit(shape1, shape2, shape1->root);
+}
+
+std::vector<int> TriangleMeshShape::find_all_hits(TriangleMeshShape* shape1, SphereShape* shape2)
+{
+	std::vector<int> hits;
+	find_all_hits(shape1, shape2, shape1->root, hits);
+	return hits;
+}
+
+bool TriangleMeshShape::find_any_hit(TriangleMeshShape *shape, const FVector3 &ray_start, const FVector3 &ray_end)
+{
+	return find_any_hit(shape, RayBBox(ray_start, ray_end), shape->root);
+}
+
+TraceHit TriangleMeshShape::find_first_hit(TriangleMeshShape *shape, const FVector3 &ray_start, const FVector3 &ray_end)
+{
+	TraceHit hit;
+
+	// Perform segmented tracing to keep the ray AABB box smaller
+
+	FVector3 ray_dir = ray_end - ray_start;
+	float tracedist = (float)ray_dir.Length();
+	float segmentlen = std::max(100.0f, tracedist / 20.0f);
+	for (float t = 0.0f; t < tracedist; t += segmentlen)
+	{
+		float segstart = t / tracedist;
+		float segend = std::min(t + segmentlen, tracedist) / tracedist;
+
+		find_first_hit(shape, RayBBox(ray_start + ray_dir * segstart, ray_start + ray_dir * segend), shape->root, &hit);
+		if (hit.fraction < 1.0f)
+		{
+			hit.fraction = segstart * (1.0f - hit.fraction) + segend * hit.fraction;
+			break;
+		}
+	}
+
+	return hit;
+}
+
+float TriangleMeshShape::sweep(TriangleMeshShape *shape1, SphereShape *shape2, int a, const FVector3 &target)
+{
+	if (sweep_overlap_bv_sphere(shape1, shape2, a, target))
+	{
+		if (shape1->is_leaf(a))
+		{
+			return sweep_intersect_triangle_sphere(shape1, shape2, a, target);
+		}
+		else
+		{
+			return std::min(sweep(shape1, shape2, shape1->nodes[a].left, target), sweep(shape1, shape2, shape1->nodes[a].right, target));
+		}
+	}
+	return 1.0f;
+}
+
+bool TriangleMeshShape::find_any_hit(TriangleMeshShape *shape1, SphereShape *shape2, int a)
+{
+	if (overlap_bv_sphere(shape1, shape2, a))
+	{
+		if (shape1->is_leaf(a))
+		{
+			return overlap_triangle_sphere(shape1, shape2, a);
+		}
+		else
+		{
+			if (find_any_hit(shape1, shape2, shape1->nodes[a].left))
+				return true;
+			else
+				return find_any_hit(shape1, shape2, shape1->nodes[a].right);
+		}
+	}
+	return false;
+}
+
+void TriangleMeshShape::find_all_hits(TriangleMeshShape* shape1, SphereShape* shape2, int a, std::vector<int>& hits)
+{
+	if (overlap_bv_sphere(shape1, shape2, a))
+	{
+		if (shape1->is_leaf(a))
+		{
+			if (overlap_triangle_sphere(shape1, shape2, a))
+			{
+				hits.push_back(shape1->nodes[a].element_index / 3);
+			}
+		}
+		else
+		{
+			find_all_hits(shape1, shape2, shape1->nodes[a].left, hits);
+			find_all_hits(shape1, shape2, shape1->nodes[a].right, hits);
+		}
+	}
+}
+
+bool TriangleMeshShape::find_any_hit(TriangleMeshShape *shape1, TriangleMeshShape *shape2, int a, int b)
+{
+	bool leaf_a = shape1->is_leaf(a);
+	bool leaf_b = shape2->is_leaf(b);
+	if (leaf_a && leaf_b)
+	{
+		return overlap_triangle_triangle(shape1, shape2, a, b);
+	}
+	else if (!leaf_a && !leaf_b)
+	{
+		if (overlap_bv(shape1, shape2, a, b))
+		{
+			if (shape1->volume(a) > shape2->volume(b))
+			{
+				if (find_any_hit(shape1, shape2, shape1->nodes[a].left, b))
+					return true;
+				else
+					return find_any_hit(shape1, shape2, shape1->nodes[a].right, b);
+			}
+			else
+			{
+				if (find_any_hit(shape1, shape2, a, shape2->nodes[b].left))
+					return true;
+				else
+					return find_any_hit(shape1, shape2, a, shape2->nodes[b].right);
+			}
+		}
+		return false;
+	}
+	else if (leaf_a)
+	{
+		if (overlap_bv_triangle(shape2, shape1, b, a))
+		{
+			if (find_any_hit(shape1, shape2, a, shape2->nodes[b].left))
+				return true;
+			else
+				return find_any_hit(shape1, shape2, a, shape2->nodes[b].right);
+		}
+		return false;
+	}
+	else
+	{
+		if (overlap_bv_triangle(shape1, shape2, a, b))
+		{
+			if (find_any_hit(shape1, shape2, shape1->nodes[a].left, b))
+				return true;
+			else
+				return find_any_hit(shape1, shape2, shape1->nodes[a].right, b);
+		}
+		return false;
+	}
+}
+
+bool TriangleMeshShape::find_any_hit(TriangleMeshShape *shape, const RayBBox &ray, int a)
+{
+	if (overlap_bv_ray(shape, ray, a))
+	{
+		if (shape->is_leaf(a))
+		{
+			float baryB, baryC;
+			return intersect_triangle_ray(shape, ray, a, baryB, baryC) < 1.0f;
+		}
+		else
+		{
+			if (find_any_hit(shape, ray, shape->nodes[a].left))
+				return true;
+			else
+				return find_any_hit(shape, ray, shape->nodes[a].right);
+		}
+	}
+	return false;
+}
+
+void TriangleMeshShape::find_first_hit(TriangleMeshShape *shape, const RayBBox &ray, int a, TraceHit *hit)
+{
+	if (overlap_bv_ray(shape, ray, a))
+	{
+		if (shape->is_leaf(a))
+		{
+			float baryB, baryC;
+			float t = intersect_triangle_ray(shape, ray, a, baryB, baryC);
+			if (t < hit->fraction)
+			{
+				hit->fraction = t;
+				hit->triangle = shape->nodes[a].element_index / 3;
+				hit->b = baryB;
+				hit->c = baryC;
+			}
+		}
+		else
+		{
+			find_first_hit(shape, ray, shape->nodes[a].left, hit);
+			find_first_hit(shape, ray, shape->nodes[a].right, hit);
+		}
+	}
+}
+
+bool TriangleMeshShape::overlap_bv_ray(TriangleMeshShape *shape, const RayBBox &ray, int a)
+{
+	return IntersectionTest::ray_aabb(ray, shape->nodes[a].aabb) == IntersectionTest::overlap;
+}
+
+float TriangleMeshShape::intersect_triangle_ray(TriangleMeshShape *shape, const RayBBox &ray, int a, float &barycentricB, float &barycentricC)
+{
+	const int start_element = shape->nodes[a].element_index;
+
+	FVector3 p[3] =
+	{
+		shape->vertices[shape->elements[start_element]],
+		shape->vertices[shape->elements[start_element + 1]],
+		shape->vertices[shape->elements[start_element + 2]]
+	};
+
+	// Moeller–Trumbore ray-triangle intersection algorithm:
+
+	FVector3 D = ray.end - ray.start;
+
+	// Find vectors for two edges sharing p[0]
+	FVector3 e1 = p[1] - p[0];
+	FVector3 e2 = p[2] - p[0];
+
+	// Begin calculating determinant - also used to calculate u parameter
+	FVector3 P = D ^ e2; // cross(D, e2);
+	float det = e1 | P; // dot(e1, P);
+
+	// Backface check
+	//if (det < 0.0f)
+	//	return 1.0f;
+
+	// If determinant is near zero, ray lies in plane of triangle
+	if (det > -FLT_EPSILON && det < FLT_EPSILON)
+		return 1.0f;
+
+	float inv_det = 1.0f / det;
+
+	// Calculate distance from p[0] to ray origin
+	FVector3 T = ray.start - p[0];
+
+	// Calculate u parameter and test bound
+	float u = (T | P) * inv_det; // dot(T, P) * inv_det;
+
+	// Check if the intersection lies outside of the triangle
+	if (u < 0.f || u > 1.f)
+		return 1.0f;
+
+	// Prepare to test v parameter
+	FVector3 Q = T ^ e1; // cross(T, e1);
+
+	// Calculate V parameter and test bound
+	float v = (D | Q) * inv_det; // dot(D, Q) * inv_det;
+
+	// The intersection lies outside of the triangle
+	if (v < 0.f || u + v  > 1.f)
+		return 1.0f;
+
+	float t = (e2 | Q) * inv_det; //dot(e2, Q) * inv_det;
+	if (t <= FLT_EPSILON)
+		return 1.0f;
+
+	// Return hit location on triangle in barycentric coordinates
+	barycentricB = u;
+	barycentricC = v;
+	
+	return t;
+}
+
+bool TriangleMeshShape::sweep_overlap_bv_sphere(TriangleMeshShape *shape1, SphereShape *shape2, int a, const FVector3 &target)
+{
+	// Convert to ray test by expanding the AABB:
+
+	CollisionBBox aabb = shape1->nodes[a].aabb;
+	aabb.Extents.X += shape2->radius;
+	aabb.Extents.Y += shape2->radius;
+	aabb.Extents.Z += shape2->radius;
+
+	return IntersectionTest::ray_aabb(RayBBox(shape2->center, target), aabb) == IntersectionTest::overlap;
+}
+
+float TriangleMeshShape::sweep_intersect_triangle_sphere(TriangleMeshShape *shape1, SphereShape *shape2, int a, const FVector3 &target)
+{
+	const int start_element = shape1->nodes[a].element_index;
+
+	FVector3 p[3] =
+	{
+		shape1->vertices[shape1->elements[start_element]],
+		shape1->vertices[shape1->elements[start_element + 1]],
+		shape1->vertices[shape1->elements[start_element + 2]]
+	};
+
+	FVector3 c = shape2->center;
+	FVector3 e = target;
+	float r = shape2->radius;
+
+	// Dynamic intersection test between a ray and the minkowski sum of the sphere and polygon:
+
+	FVector3 n = ((p[1] - p[0]) ^ (p[2] - p[0])).Unit(); // normalize(cross(p[1] - p[0], p[2] - p[0]));
+	FVector4 plane(n, -(n | p[0])); // plane(n, -dot(n, p[0]));
+
+	// Step 1: Plane intersect test
+
+	float sc = (plane | FVector4(c, 1.0f)); // dot(plane, FVector4(c, 1.0f));
+	float se = (plane | FVector4(e, 1.0f)); // dot(plane, FVector4(e, 1.0f));
+	bool same_side = sc * se > 0.0f;
+
+	if (same_side && std::abs(sc) > r && std::abs(se) > r)
+		return 1.0f;
+
+	// Step 1a: Check if point is in polygon (using crossing ray test in 2d)
+	{
+		float t = (sc - r) / (sc - se);
+
+		FVector3 vt = c + (e - c) * t;
+
+		FVector3 u0 = p[1] - p[0];
+		FVector3 u1 = p[2] - p[0];
+
+		FVector2 v_2d[3] =
+		{
+			FVector2(0.0f, 0.0f),
+			FVector2((u0 | u0), 0.0f), // FVector2(dot(u0, u0), 0.0f),
+			FVector2(0.0f, (u1 | u1)) // FVector2(0.0f, dot(u1, u1))
+		};
+
+		FVector2 point((u0 | vt), (u1 | vt)); // point(dot(u0, vt), dot(u1, vt));
+
+		bool inside = false;
+		FVector2 e0 = v_2d[2];
+		bool y0 = e0.Y >= point.Y;
+		for (int i = 0; i < 3; i++)
+		{
+			FVector2 e1 = v_2d[i];
+			bool y1 = e1.Y >= point.Y;
+
+			if (y0 != y1 && ((e1.Y - point.Y) * (e0.X - e1.X) >= (e1.X - point.X) * (e0.Y - e1.Y)) == y1)
+				inside = !inside;
+
+			y0 = y1;
+			e0 = e1;
+		}
+
+		if (inside)
+			return t;
+	}
+
+	// Step 2: Edge intersect test
+
+	FVector3 ke[3] =
+	{
+		p[1] - p[0],
+		p[2] - p[1],
+		p[0] - p[2],
+	};
+
+	FVector3 kg[3] =
+	{
+		p[0] - c,
+		p[1] - c,
+		p[2] - c,
+	};
+
+	FVector3 ks = e - c;
+
+	float kgg[3];
+	float kgs[3];
+	float kss[3];
+
+	for (int i = 0; i < 3; i++)
+	{
+		float kee = (ke[i] | ke[i]); // dot(ke[i], ke[i]);
+		float keg = (ke[i] | kg[i]); // dot(ke[i], kg[i]);
+		float kes = (ke[i] | ks); // dot(ke[i], ks);
+		kgg[i] = (kg[i] | kg[i]); // dot(kg[i], kg[i]);
+		kgs[i] = (kg[i] | ks); // dot(kg[i], ks);
+		kss[i] = (ks | ks); // dot(ks, ks);
+
+		float aa = kee * kss[i] - kes * kes;
+		float bb = 2 * (keg * kes - kee * kgs[i]);
+		float cc = kee * (kgg[i] - r * r) - keg * keg;
+
+		float sign = (bb >= 0.0f) ? 1.0f : -1.0f;
+		float q = -0.5f * (bb + sign * std::sqrt(bb * bb - 4 * aa * cc));
+		float t0 = q / aa;
+		float t1 = cc / q;
+
+		float t;
+		if (t0 < 0.0f || t0 > 1.0f)
+			t = t1;
+		else if (t1 < 0.0f || t1 > 1.0f)
+			t = t0;
+		else
+			t = std::min(t0, t1);
+
+		if (t >= 0.0f && t <= 1.0f)
+		{
+			FVector3 ct = c + ks * t;
+			float d = ((ct - p[i]) | ke[i]); // dot(ct - p[i], ke[i]);
+			if (d >= 0.0f && d <= kee)
+				return t;
+		}
+	}
+
+	// Step 3: Point intersect test
+
+	for (int i = 0; i < 3; i++)
+	{
+		float aa = kss[i];
+		float bb = -2.0f * kgs[i];
+		float cc = kgg[i] - r * r;
+
+		float sign = (bb >= 0.0f) ? 1.0f : -1.0f;
+		float q = -0.5f * (bb + sign * std::sqrt(bb * bb - 4 * aa * cc));
+		float t0 = q / aa;
+		float t1 = cc / q;
+
+		float t;
+		if (t0 < 0.0f || t0 > 1.0f)
+			t = t1;
+		else if (t1 < 0.0f || t1 > 1.0f)
+			t = t0;
+		else
+			t = std::min(t0, t1);
+
+		if (t >= 0.0f && t <= 1.0f)
+			return t;
+	}
+
+	return 1.0f;
+}
+
+bool TriangleMeshShape::overlap_bv(TriangleMeshShape *shape1, TriangleMeshShape *shape2, int a, int b)
+{
+	return IntersectionTest::aabb(shape1->nodes[a].aabb, shape2->nodes[b].aabb) == IntersectionTest::overlap;
+}
+
+bool TriangleMeshShape::overlap_bv_triangle(TriangleMeshShape *shape1, TriangleMeshShape *shape2, int a, int b)
+{
+	return false;
+}
+
+bool TriangleMeshShape::overlap_bv_sphere(TriangleMeshShape *shape1, SphereShape *shape2, int a)
+{
+	return IntersectionTest::sphere_aabb(shape2->center, shape2->radius, shape1->nodes[a].aabb) == IntersectionTest::overlap;
+}
+
+bool TriangleMeshShape::overlap_triangle_triangle(TriangleMeshShape *shape1, TriangleMeshShape *shape2, int a, int b)
+{
+	return false;
+}
+
+bool TriangleMeshShape::overlap_triangle_sphere(TriangleMeshShape *shape1, SphereShape *shape2, int shape1_node_index)
+{
+	// http://realtimecollisiondetection.net/blog/?p=103
+
+	int element_index = shape1->nodes[shape1_node_index].element_index;
+
+	FVector3 P = shape2->center;
+	FVector3 A = shape1->vertices[shape1->elements[element_index]] - P;
+	FVector3 B = shape1->vertices[shape1->elements[element_index + 1]] - P;
+	FVector3 C = shape1->vertices[shape1->elements[element_index + 2]] - P;
+	float r = shape2->radius;
+	float rr = r * r;
+
+	// Testing if sphere lies outside the triangle plane
+	FVector3 V = ((B - A) ^ (C - A)); // cross(B - A, C - A);
+	float d = A | V; // dot(A, V);
+	float e = V | V; // dot(V, V);
+	bool sep1 = d * d > rr * e;
+
+	// Testing if sphere lies outside a triangle vertex
+	float aa = A | A; // dot(A, A);
+	float ab = A | B; // dot(A, B);
+	float ac = A | C; // dot(A, C);
+	float bb = B | B; // dot(B, B);
+	float bc = B | C; // dot(B, C);
+	float cc = C | C; // dot(C, C);
+	bool sep2 = (aa > rr) && (ab > aa) && (ac > aa);
+	bool sep3 = (bb > rr) && (ab > bb) && (bc > bb);
+	bool sep4 = (cc > rr) && (ac > cc) && (bc > cc);
+
+	// Testing if sphere lies outside a triangle edge
+	FVector3 AB = B - A;
+	FVector3 BC = C - B;
+	FVector3 CA = A - C;
+	float d1 = ab - aa;
+	float d2 = bc - bb;
+	float d3 = ac - cc;
+	float e1 = (AB | AB); // dot(AB, AB)
+	float e2 = (BC | BC); // dot(BC, BC)
+	float e3 = (CA | CA); // dot(CA, CA)
+	FVector3 Q1 = A * e1 - AB * d1;
+	FVector3 Q2 = B * e2 - BC * d2;
+	FVector3 Q3 = C * e3 - CA * d3;
+	FVector3 QC = C * e1 - Q1;
+	FVector3 QA = A * e2 - Q2;
+	FVector3 QB = B * e3 - Q3;
+	bool sep5 = ((Q1 | Q1) > rr * e1 * e1) && ((Q1 | QC) > 0.0f); // (dot(Q1, Q1) > rr * e1 * e1) && (dot(Q1, QC) > 0.0f);
+	bool sep6 = ((Q2 | Q2) > rr * e2 * e2) && ((Q2 | QA) > 0.0f); // (dot(Q2, Q2) > rr * e2 * e2) && (dot(Q2, QA) > 0.0f);
+	bool sep7 = ((Q3 | Q3) > rr * e3 * e3) && ((Q3 | QB) > 0.0f); // (dot(Q3, Q3) > rr * e3 * e3) && (dot(Q3, QB) > 0.0f);
+
+	bool separated = sep1 || sep2 || sep3 || sep4 || sep5 || sep6 || sep7;
+	return (!separated);
+}
+
+bool TriangleMeshShape::is_leaf(int node_index)
+{
+	return nodes[node_index].element_index != -1;
+}
+
+float TriangleMeshShape::volume(int node_index)
+{
+	const FVector3 &extents = nodes[node_index].aabb.Extents;
+	return extents.X * extents.Y * extents.Z;
+}
+
+int TriangleMeshShape::get_min_depth() const
+{
+	std::function<int(int, int)> visit;
+	visit = [&](int level, int node_index) -> int {
+		const Node &node = nodes[node_index];
+		if (node.element_index == -1)
+			return std::min(visit(level + 1, node.left), visit(level + 1, node.right));
+		else
+			return level;
+	};
+	return visit(1, root);
+}
+
+int TriangleMeshShape::get_max_depth() const
+{
+	std::function<int(int, int)> visit;
+	visit = [&](int level, int node_index) -> int {
+		const Node &node = nodes[node_index];
+		if (node.element_index == -1)
+			return std::max(visit(level + 1, node.left), visit(level + 1, node.right));
+		else
+			return level;
+	};
+	return visit(1, root);
+}
+
+float TriangleMeshShape::get_average_depth() const
+{
+	std::function<float(int, int)> visit;
+	visit = [&](int level, int node_index) -> float {
+		const Node &node = nodes[node_index];
+		if (node.element_index == -1)
+			return visit(level + 1, node.left) + visit(level + 1, node.right);
+		else
+			return (float)level;
+	};
+	float depth_sum = visit(1, root);
+	int leaf_count = (num_elements / 3);
+	return depth_sum / leaf_count;
+}
+
+float TriangleMeshShape::get_balanced_depth() const
+{
+	return std::log2((float)(num_elements / 3));
+}
+
+int TriangleMeshShape::subdivide(int *triangles, int num_triangles, const FVector3 *centroids, int *work_buffer)
+{
+	if (num_triangles == 0)
+		return -1;
+
+	// Find bounding box and median of the triangle centroids
+	FVector3 median;
+	FVector3 min, max;
+	min = vertices[elements[triangles[0] * 3]];
+	max = min;
+	for (int i = 0; i < num_triangles; i++)
+	{
+		int element_index = triangles[i] * 3;
+		for (int j = 0; j < 3; j++)
+		{
+			const FVector3 &vertex = vertices[elements[element_index + j]];
+
+			min.X = std::min(min.X, vertex.X);
+			min.Y = std::min(min.Y, vertex.Y);
+			min.Z = std::min(min.Z, vertex.Z);
+
+			max.X = std::max(max.X, vertex.X);
+			max.Y = std::max(max.Y, vertex.Y);
+			max.Z = std::max(max.Z, vertex.Z);
+		}
+
+		median += centroids[triangles[i]];
+	}
+	median /= (float)num_triangles;
+
+	if (num_triangles == 1) // Leaf node
+	{
+		nodes.push_back(Node(min, max, triangles[0] * 3));
+		return (int)nodes.size() - 1;
+	}
+
+	// Find the longest axis
+	float axis_lengths[3] =
+	{
+		max.X - min.X,
+		max.Y - min.Y,
+		max.Z - min.Z
+	};
+
+	int axis_order[3] = { 0, 1, 2 };
+	std::sort(axis_order, axis_order + 3, [&](int a, int b) { return axis_lengths[a] > axis_lengths[b]; });
+
+	// Try split at longest axis, then if that fails the next longest, and then the remaining one
+	int left_count, right_count;
+	FVector3 axis;
+	for (int attempt = 0; attempt < 3; attempt++)
+	{
+		// Find the split plane for axis
+		switch (axis_order[attempt])
+		{
+		default:
+		case 0: axis = FVector3(1.0f, 0.0f, 0.0f); break;
+		case 1: axis = FVector3(0.0f, 1.0f, 0.0f); break;
+		case 2: axis = FVector3(0.0f, 0.0f, 1.0f); break;
+		}
+		FVector4 plane(axis, -(median | axis)); // plane(axis, -dot(median, axis));
+
+		// Split triangles into two
+		left_count = 0;
+		right_count = 0;
+		for (int i = 0; i < num_triangles; i++)
+		{
+			int triangle = triangles[i];
+			int element_index = triangle * 3;
+
+			float side = (FVector4(centroids[triangles[i]], 1.0f) | plane); // dot(FVector4(centroids[triangles[i]], 1.0f), plane);
+			if (side >= 0.0f)
+			{
+				work_buffer[left_count] = triangle;
+				left_count++;
+			}
+			else
+			{
+				work_buffer[num_triangles + right_count] = triangle;
+				right_count++;
+			}
+		}
+
+		if (left_count != 0 && right_count != 0)
+			break;
+	}
+
+	// Check if something went wrong when splitting and do a random split instead
+	if (left_count == 0 || right_count == 0)
+	{
+		left_count = num_triangles / 2;
+		right_count = num_triangles - left_count;
+	}
+	else
+	{
+		// Move result back into triangles list:
+		for (int i = 0; i < left_count; i++)
+			triangles[i] = work_buffer[i];
+		for (int i = 0; i < right_count; i++)
+			triangles[i + left_count] = work_buffer[num_triangles + i];
+	}
+
+	// Create child nodes:
+	int left_index = -1;
+	int right_index = -1;
+	if (left_count > 0)
+		left_index = subdivide(triangles, left_count, centroids, work_buffer);
+	if (right_count > 0)
+		right_index = subdivide(triangles + left_count, right_count, centroids, work_buffer);
+
+	nodes.push_back(Node(min, max, left_index, right_index));
+	return (int)nodes.size() - 1;
+}
+
+/////////////////////////////////////////////////////////////////////////////
+
+IntersectionTest::OverlapResult IntersectionTest::sphere_aabb(const FVector3 &center, float radius, const CollisionBBox &aabb)
+{
+	FVector3 a = aabb.min - center;
+	FVector3 b = center - aabb.max;
+	a.X = std::max(a.X, 0.0f);
+	a.Y = std::max(a.Y, 0.0f);
+	a.Z = std::max(a.Z, 0.0f);
+	b.X = std::max(b.X, 0.0f);
+	b.Y = std::max(b.Y, 0.0f);
+	b.Z = std::max(b.Z, 0.0f);
+	FVector3 e = a + b;
+	float d = (e | e); // dot(e, e);
+	if (d > radius * radius)
+		return disjoint;
+	else
+		return overlap;
+}
+
+IntersectionTest::OverlapResult IntersectionTest::aabb(const CollisionBBox& a, const CollisionBBox& b)
+{
+	if (a.min.X > b.max.X || b.min.X > a.max.X ||
+		a.min.Y > b.max.Y || b.min.Y > a.max.Y ||
+		a.min.Z > b.max.Z || b.min.Z > a.max.Z)
+	{
+		return disjoint;
+	}
+	else
+	{
+		return overlap;
+	}
+}
+
+static const uint32_t clearsignbitmask[] = { 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff };
+
+IntersectionTest::OverlapResult IntersectionTest::ray_aabb(const RayBBox &ray, const CollisionBBox &aabb)
+{
+#ifndef NO_SSE
+
+	__m128 v = _mm_loadu_ps(&ray.v.X);
+	__m128 w = _mm_loadu_ps(&ray.w.X);
+	__m128 h = _mm_loadu_ps(&aabb.Extents.X);
+	__m128 c = _mm_sub_ps(_mm_loadu_ps(&ray.c.X), _mm_loadu_ps(&aabb.Center.X));
+
+	__m128 clearsignbit = _mm_loadu_ps(reinterpret_cast<const float*>(clearsignbitmask));
+
+	__m128 abs_c = _mm_and_ps(c, clearsignbit);
+	int mask = _mm_movemask_ps(_mm_cmpgt_ps(abs_c, _mm_add_ps(v, h)));
+	if (mask & 7)
+		return disjoint;
+
+	__m128 c1 = _mm_shuffle_ps(c, c, _MM_SHUFFLE(3, 0, 0, 1)); // c.Y, c.X, c.X
+	__m128 c2 = _mm_shuffle_ps(c, c, _MM_SHUFFLE(3, 1, 2, 2)); // c.Z, c.Z, c.Y
+	__m128 w1 = _mm_shuffle_ps(w, w, _MM_SHUFFLE(3, 1, 2, 2)); // w.Z, w.Z, w.Y
+	__m128 w2 = _mm_shuffle_ps(w, w, _MM_SHUFFLE(3, 0, 0, 1)); // w.Y, w.X, w.X
+	__m128 lhs = _mm_and_ps(_mm_sub_ps(_mm_mul_ps(c1, w1), _mm_mul_ps(c2, w2)), clearsignbit);
+
+	__m128 h1 = _mm_shuffle_ps(h, h, _MM_SHUFFLE(3, 0, 0, 1)); // h.Y, h.X, h.X
+	__m128 h2 = _mm_shuffle_ps(h, h, _MM_SHUFFLE(3, 1, 2, 2)); // h.Z, h.Z, h.Y
+	__m128 v1 = _mm_shuffle_ps(v, v, _MM_SHUFFLE(3, 1, 2, 2)); // v.Z, v.Z, v.Y
+	__m128 v2 = _mm_shuffle_ps(v, v, _MM_SHUFFLE(3, 0, 0, 1)); // v.Y, v.X, v.X
+	__m128 rhs = _mm_add_ps(_mm_mul_ps(h1, v1), _mm_mul_ps(h2, v2));
+
+	mask = _mm_movemask_ps(_mm_cmpgt_ps(lhs, rhs));
+	return (mask & 7) ? disjoint : overlap;
+
+#else
+	const FVector3 &v = ray.v;
+	const FVector3 &w = ray.w;
+	const FVector3 &h = aabb.Extents;
+	auto c = ray.c - aabb.Center;
+
+	if (std::abs(c.X) > v.X + h.X || std::abs(c.Y) > v.Y + h.Y || std::abs(c.Z) > v.Z + h.Z)
+		return disjoint;
+
+	if (std::abs(c.Y * w.Z - c.Z * w.Y) > h.Y * v.Z + h.Z * v.Y ||
+		std::abs(c.X * w.Z - c.Z * w.X) > h.X * v.Z + h.Z * v.X ||
+		std::abs(c.X * w.Y - c.Y * w.X) > h.X * v.Y + h.Y * v.X)
+		return disjoint;
+
+	return overlap;
+#endif
+}

src/common/rendering/hwrenderer/data/hw_collision.h

@@ -0,0 +1,179 @@
+/*
+**  Level mesh collision detection
+**  Copyright (c) 2018 Magnus Norddahl
+**
+**  This software is provided 'as-is', without any express or implied
+**  warranty.  In no event will the authors be held liable for any damages
+**  arising from the use of this software.
+**
+**  Permission is granted to anyone to use this software for any purpose,
+**  including commercial applications, and to alter it and redistribute it
+**  freely, subject to the following restrictions:
+**
+**  1. The origin of this software must not be misrepresented; you must not
+**     claim that you wrote the original software. If you use this software
+**     in a product, an acknowledgment in the product documentation would be
+**     appreciated but is not required.
+**  2. Altered source versions must be plainly marked as such, and must not be
+**     misrepresented as being the original software.
+**  3. This notice may not be removed or altered from any source distribution.
+**
+*/
+
+#pragma once
+
+#include "common/utility/vectors.h"
+#include <vector>
+#include <cmath>
+
+class SphereShape
+{
+public:
+	SphereShape() { }
+	SphereShape(const FVector3 &center, float radius) : center(center), radius(radius) { }
+
+	FVector3 center;
+	float radius = 0.0f;
+};
+
+struct TraceHit
+{
+	float fraction = 1.0f;
+	int triangle = -1;
+	float b = 0.0f;
+	float c = 0.0f;
+};
+
+class CollisionBBox
+{
+public:
+	CollisionBBox() = default;
+
+	CollisionBBox(const FVector3 &aabb_min, const FVector3 &aabb_max)
+	{
+		min = aabb_min;
+		max = aabb_max;
+		auto halfmin = aabb_min * 0.5f;
+		auto halfmax = aabb_max * 0.5f;
+		Center = halfmax + halfmin;
+		Extents = halfmax - halfmin;
+	}
+
+	FVector3 min;
+	FVector3 max;
+	FVector3 Center;
+	FVector3 Extents;
+	float ssePadding = 0.0f; // Needed to safely load Extents directly into a sse register
+};
+
+class RayBBox
+{
+public:
+	RayBBox(const FVector3 &ray_start, const FVector3 &ray_end) : start(ray_start), end(ray_end)
+	{
+		c = (ray_start + ray_end) * 0.5f;
+		w = ray_end - c;
+		v.X = std::abs(w.X);
+		v.Y = std::abs(w.Y);
+		v.Z = std::abs(w.Z);
+	}
+
+	FVector3 start, end;
+	FVector3 c, w, v;
+	float ssePadding = 0.0f; // Needed to safely load v directly into a sse register
+};
+
+class TriangleMeshShape
+{
+public:
+	TriangleMeshShape(const FVector3 *vertices, int num_vertices, const unsigned int *elements, int num_elements);
+
+	int get_min_depth() const;
+	int get_max_depth() const;
+	float get_average_depth() const;
+	float get_balanced_depth() const;
+
+	const CollisionBBox &get_bbox() const { return nodes[root].aabb; }
+
+	static float sweep(TriangleMeshShape *shape1, SphereShape *shape2, const FVector3 &target);
+
+	static bool find_any_hit(TriangleMeshShape *shape1, TriangleMeshShape *shape2);
+	static bool find_any_hit(TriangleMeshShape *shape1, SphereShape *shape2);
+	static bool find_any_hit(TriangleMeshShape *shape, const FVector3 &ray_start, const FVector3 &ray_end);
+
+	static std::vector<int> find_all_hits(TriangleMeshShape* shape1, SphereShape* shape2);
+
+	static TraceHit find_first_hit(TriangleMeshShape *shape, const FVector3 &ray_start, const FVector3 &ray_end);
+
+	struct Node
+	{
+		Node() = default;
+		Node(const FVector3 &aabb_min, const FVector3 &aabb_max, int element_index) : aabb(aabb_min, aabb_max), element_index(element_index) { }
+		Node(const FVector3 &aabb_min, const FVector3 &aabb_max, int left, int right) : aabb(aabb_min, aabb_max), left(left), right(right) { }
+
+		CollisionBBox aabb;
+		int left = -1;
+		int right = -1;
+		int element_index = -1;
+	};
+
+	const std::vector<Node>& get_nodes() const { return nodes; }
+	int get_root() const { return root; }
+
+private:
+	const FVector3 *vertices = nullptr;
+	const int num_vertices = 0;
+	const unsigned int *elements = nullptr;
+	int num_elements = 0;
+
+	std::vector<Node> nodes;
+	int root = -1;
+
+	static float sweep(TriangleMeshShape *shape1, SphereShape *shape2, int a, const FVector3 &target);
+
+	static bool find_any_hit(TriangleMeshShape *shape1, TriangleMeshShape *shape2, int a, int b);
+	static bool find_any_hit(TriangleMeshShape *shape1, SphereShape *shape2, int a);
+	static bool find_any_hit(TriangleMeshShape *shape1, const RayBBox &ray, int a);
+
+	static void find_all_hits(TriangleMeshShape* shape1, SphereShape* shape2, int a, std::vector<int>& hits);
+
+	static void find_first_hit(TriangleMeshShape *shape1, const RayBBox &ray, int a, TraceHit *hit);
+
+	inline static bool overlap_bv_ray(TriangleMeshShape *shape, const RayBBox &ray, int a);
+	inline static float intersect_triangle_ray(TriangleMeshShape *shape, const RayBBox &ray, int a, float &barycentricB, float &barycentricC);
+
+	inline static bool sweep_overlap_bv_sphere(TriangleMeshShape *shape1, SphereShape *shape2, int a, const FVector3 &target);
+	inline static float sweep_intersect_triangle_sphere(TriangleMeshShape *shape1, SphereShape *shape2, int a, const FVector3 &target);
+
+	inline static bool overlap_bv(TriangleMeshShape *shape1, TriangleMeshShape *shape2, int a, int b);
+	inline static bool overlap_bv_triangle(TriangleMeshShape *shape1, TriangleMeshShape *shape2, int a, int b);
+	inline static bool overlap_bv_sphere(TriangleMeshShape *shape1, SphereShape *shape2, int a);
+	inline static bool overlap_triangle_triangle(TriangleMeshShape *shape1, TriangleMeshShape *shape2, int a, int b);
+	inline static bool overlap_triangle_sphere(TriangleMeshShape *shape1, SphereShape *shape2, int a);
+
+	inline bool is_leaf(int node_index);
+	inline float volume(int node_index);
+
+	int subdivide(int *triangles, int num_triangles, const FVector3 *centroids, int *work_buffer);
+};
+
+class IntersectionTest
+{
+public:
+	enum Result
+	{
+		outside,
+		inside,
+		intersecting,
+	};
+
+	enum OverlapResult
+	{
+		disjoint,
+		overlap
+	};
+
+	static OverlapResult sphere_aabb(const FVector3 &center, float radius, const CollisionBBox &aabb);
+	static OverlapResult aabb(const CollisionBBox &a, const CollisionBBox &b);
+	static OverlapResult ray_aabb(const RayBBox &ray, const CollisionBBox &box);
+};

src/common/rendering/hwrenderer/data/hw_levelmesh.h

@@ -3,6 +3,7 @@
 
 #include "tarray.h"
 #include "vectors.h"
+#include "hw_collision.h"
 
 namespace hwrenderer
 {
@@ -16,6 +17,14 @@ public:
 	TArray<int> MeshUVIndex;
 	TArray<uint32_t> MeshElements;
 	TArray<int> MeshSurfaces;
+
+	std::unique_ptr<TriangleMeshShape> Collision;
+
+	bool Trace(const FVector3& start, FVector3 direction, float maxDist)
+	{
+		FVector3 end = start + direction * std::max(maxDist - 10.0f, 0.0f);
+		return !TriangleMeshShape::find_any_hit(Collision.get(), start, end);
+	}
 };
 
 } // namespace

src/maploader/maploader.cpp

@@ -3331,8 +3331,8 @@ void MapLoader::LoadLightmap(MapData *map)
 	Level->LMTextureCount = 0;
 	Level->LMTextureSize = 0;
 
-	if (!Args->CheckParm("-enablelightmaps"))
+	//if (!Args->CheckParm("-enablelightmaps"))
-		return;		// this feature is still too early WIP to allow general access
+	//	return;		// this feature is still too early WIP to allow general access
 
 	if (!map->Size(ML_LIGHTMAP))
 		return;

src/rendering/hwrenderer/doom_levelmesh.cpp

@@ -56,6 +56,8 @@ DoomLevelMesh::DoomLevelMesh(FLevelLocals &doomMap)
 			}
 		}
 	}
+
+	Collision = std::make_unique<TriangleMeshShape>(MeshVertices.Data(), MeshVertices.Size(), MeshElements.Data(), MeshElements.Size());
 }
 
 void DoomLevelMesh::CreateSideSurfaces(FLevelLocals &doomMap, side_t *side)

src/rendering/hwrenderer/scene/hw_spritelight.cpp

@@ -49,11 +49,14 @@ T smoothstep(const T edge0, const T edge1, const T x)
 static bool TraceLightVisbility(FLightNode* node, const FVector3& L, float dist)
 {
 	FDynamicLight* light = node->lightsource;
-	if (!light->Trace())
+	if (!light->Trace() || !level.levelMesh)
 		return true;
 
-	FTraceResults results;
+	// Note: this is not thread safe (modifies validcount and calls other setup functions)
-	return !Trace(light->Pos, light->Sector, DVector3(-L.X, -L.Y, -L.Z), dist, 0, ML_BLOCKING, nullptr, results);
+	// FTraceResults results;
+	// return !Trace(light->Pos, light->Sector, DVector3(-L.X, -L.Y, -L.Z), dist, 0, ML_BLOCKING, nullptr, results);
+
+	return level.levelMesh->Trace(FVector3((float)light->Pos.X, (float)light->Pos.Y, (float)light->Pos.Z), FVector3(-L.X, -L.Y, -L.Z), dist);
 }
 
 //==========================================================================