1 files changed, 1629 insertions, 0 deletions

diff --git a/src/Collision.cpp b/src/Collision.cpp
new file mode 100644
index 00000000..14b3adcd
--- /dev/null
+++ b/src/Collision.cpp
@@ -0,0 +1,1629 @@
+#include "common.h"
+#include "patcher.h"
+#include "Game.h"
+#include "General.h"
+#include "RenderBuffer.h"
+#include "SurfaceTable.h"
+#include "Collision.h"
+
+enum Direction
+{
+	DIR_X_POS,
+	DIR_X_NEG,
+	DIR_Y_POS,
+	DIR_Y_NEG,
+	DIR_Z_POS,
+	DIR_Z_NEG,
+};
+
+eLevelName &CCollision::ms_collisionInMemory = *(eLevelName*)0x8F6250;
+CLinkList<CColModel*> &CCollision::ms_colModelCache = *(CLinkList<CColModel*>*)0x95CB58;
+
+#if 0
+
+void
+CCollision::Init(void)
+{
+	ms_colModelCache.Init(NUMCOLCACHELINKS);
+	ms_collisionInMemory = LEVEL_NONE;
+}
+
+void
+CCollision::Update(void)
+{
+	CVector pos = FindPlayerCoors();
+	eLevelName level = CTheZones::m_CurrLevel;
+	bool changeLevel = false;
+
+	// hardcode a level if there are no zones
+	if(level == LEVEL_NONE){
+		if(CGame::currLevel == LEVEL_INDUSTRIAL &&
+		   pos.x < 400.0f){
+			level = LEVEL_COMMERCIAL;
+			changeLevel = true;
+		}else if(CGame::currLevel == LEVEL_SUBURBAN &&
+		         pos.x > -450.0f && pos.y < -1400.0f){
+			level = LEVEL_COMMERCIAL;
+			changeLevel = true;
+		}else{
+			if(pos.x > 800.0f){
+				level = LEVEL_INDUSTRIAL;
+				changeLevel = true;
+			}else if(pos.x < -800.0f){
+				level = LEVEL_SUBURBAN;
+				changeLevel = true;
+			}
+		}
+	}
+	if(level != LEVEL_NONE && level != CGame::currLevel){
+		debug("changing level %d -> %d\n", CGame::currLevel, level);
+		CGame::currLevel = level;
+	}
+	if(ms_collisionInMemory != CGame::currLevel)
+		LoadCollisionWhenINeedIt(changeLevel);
+	CStreaming::HaveAllBigBuildingsLoaded(CGame::currLevel);
+}
+
+void
+CCollision::LoadCollisionWhenINeedIt(bool changeLevel)
+{
+	eLevelName level;
+	level = LEVEL_NONE;
+	if(!changeLevel){
+		//assert(0 && "unimplemented");
+	}
+
+	if(level != CGame::currLevel || changeLevel){
+		CTimer::Stop();
+		CStreaming::RemoveIslandsNotUsed(LEVEL_INDUSTRIAL);
+		CStreaming::RemoveIslandsNotUsed(LEVEL_COMMERCIAL);
+		CStreaming::RemoveIslandsNotUsed(LEVEL_SUBURBAN);
+		CStreaming::RemoveBigBuildings(LEVEL_INDUSTRIAL);
+		CStreaming::RemoveBigBuildings(LEVEL_COMMERCIAL);
+		CStreaming::RemoveBigBuildings(LEVEL_SUBURBAN);
+		ms_collisionInMemory = CGame::currLevel;
+		CStreaming::RemoveUnusedBigBuildings(CGame::currLevel);
+		CStreaming::RemoveUnusedBuildings(CGame::currLevel);
+		CStreaming::RequestBigBuildings(CGame::currLevel);
+		CStreaming::LoadAllRequestedModels();
+		CStreaming::HaveAllBigBuildingsLoaded(CGame::currLevel);
+		CTimer::Update();
+	}
+}
+
+#endif
+
+//
+// Test
+//
+
+
+bool
+CCollision::TestSphereSphere(const CColSphere &s1, const CColSphere &s2)
+{
+	float d = s1.radius + s2.radius;
+	return (s1.center - s2.center).MagnitudeSqr() < d*d;
+}
+
+bool
+CCollision::TestSphereBox(const CColSphere &sph, const CColBox &box)
+{
+	if(sph.center.x + sph.radius < box.min.x) return false;
+	if(sph.center.x - sph.radius > box.max.x) return false;
+	if(sph.center.y + sph.radius < box.min.y) return false;
+	if(sph.center.y - sph.radius > box.max.y) return false;
+	if(sph.center.z + sph.radius < box.min.z) return false;
+	if(sph.center.z - sph.radius > box.max.z) return false;
+	return true;
+}
+
+bool
+CCollision::TestLineBox(const CColLine &line, const CColBox &box)
+{
+	float t, x, y, z;
+	// If either line point is in the box, we have a collision
+	if(line.p0.x > box.min.x && line.p0.x < box.max.x &&
+	   line.p0.y > box.min.y && line.p0.y < box.max.y &&
+	   line.p0.z > box.min.z && line.p0.z < box.max.z)
+		return true;
+	if(line.p1.x > box.min.x && line.p1.x < box.max.x &&
+	   line.p1.y > box.min.y && line.p1.y < box.max.y &&
+	   line.p1.z > box.min.z && line.p1.z < box.max.z)
+		return true;
+
+	// check if points are on opposite sides of min x plane
+	if((box.min.x - line.p1.x) * (box.min.x - line.p0.x) < 0.0f){
+		// parameter along line where we intersect
+		t = (box.min.x - line.p0.x) / (line.p1.x - line.p0.x);
+		// y of intersection
+		y = line.p0.y + (line.p1.y - line.p0.y)*t;
+		if(y > box.min.y && y < box.max.y){
+			// z of intersection
+			z = line.p0.z + (line.p1.z - line.p0.z)*t;
+			if(z > box.min.z && z < box.max.z)
+				return true;
+		}
+	}
+
+	// same test with max x plane
+	if((line.p1.x - box.max.x) * (line.p0.x - box.max.x) < 0.0f){
+		t = (line.p0.x - box.max.x) / (line.p0.x - line.p1.x);
+		y = line.p0.y + (line.p1.y - line.p0.y)*t;
+		if(y > box.min.y && y < box.max.y){
+			z = line.p0.z + (line.p1.z - line.p0.z)*t;
+			if(z > box.min.z && z < box.max.z)
+				return true;
+		}
+	}
+
+	// min y plne
+	if((box.min.y - line.p0.y) * (box.min.y - line.p1.y) < 0.0f){
+		t = (box.min.y - line.p0.y) / (line.p1.y - line.p0.y);
+		x = line.p0.x + (line.p1.x - line.p0.x)*t;
+		if(x > box.min.x && x < box.max.x){
+			z = line.p0.z + (line.p1.z - line.p0.z)*t;
+			if(z > box.min.z && z < box.max.z)
+				return true;
+		}
+	}
+
+	// max y plane
+	if((line.p0.y - box.max.y) * (line.p1.y - box.max.y) < 0.0f){
+		t = (line.p0.y - box.max.y) / (line.p0.y - line.p1.y);
+		x = line.p0.x + (line.p1.x - line.p0.x)*t;
+		if(x > box.min.x && x < box.max.x){
+			z = line.p0.z + (line.p1.z - line.p0.z)*t;
+			if(z > box.min.z && z < box.max.z)
+				return true;
+		}
+	}
+
+	// min z plne
+	if((box.min.z - line.p0.z) * (box.min.z - line.p1.z) < 0.0f){
+		t = (box.min.z - line.p0.z) / (line.p1.z - line.p0.z);
+		x = line.p0.x + (line.p1.x - line.p0.x)*t;
+		if(x > box.min.x && x < box.max.x){
+			y = line.p0.y + (line.p1.y - line.p0.y)*t;
+			if(y > box.min.y && y < box.max.y)
+				return true;
+		}
+	}
+
+	// max z plane
+	if((line.p0.z - box.max.z) * (line.p1.z - box.max.z) < 0.0f){
+		t = (line.p0.z - box.max.z) / (line.p0.z - line.p1.z);
+		x = line.p0.x + (line.p1.x - line.p0.x)*t;
+		if(x > box.min.x && x < box.max.x){
+			y = line.p0.y + (line.p1.y - line.p0.y)*t;
+			if(y > box.min.y && y < box.max.y)
+				return true;
+		}
+	}
+	return false;
+}
+
+bool
+CCollision::TestVerticalLineBox(const CColLine &line, const CColBox &box)
+{
+	if(line.p0.x <= box.min.x) return false;
+	if(line.p0.y <= box.min.y) return false;
+	if(line.p0.x >= box.max.x) return false;
+	if(line.p0.y >= box.max.y) return false;
+	if(line.p0.z < line.p1.z){
+		if(line.p0.z > box.max.z) return false;
+		if(line.p1.z < box.min.z) return false;
+	}else{
+		if(line.p1.z > box.max.z) return false;
+		if(line.p0.z < box.min.z) return false;
+	}
+	return true;
+}
+
+bool
+CCollision::TestLineTriangle(const CColLine &line, const CVector *verts, const CColTriangle &tri, const CColTrianglePlane &plane)
+{
+	float t;
+	CVector normal;
+	plane.GetNormal(normal);
+
+	// if points are on the same side, no collision
+	if(plane.CalcPoint(line.p0) * plane.CalcPoint(line.p1) > 0.0f)
+		return false;
+
+	// intersection parameter on line
+	t = -plane.CalcPoint(line.p0) / DotProduct(line.p1 - line.p0, normal);
+	// find point of intersection
+	CVector p = line.p0 + (line.p1-line.p0)*t;
+
+	const CVector &va = verts[tri.a];
+	const CVector &vb = verts[tri.b];
+	const CVector &vc = verts[tri.c];
+	CVector2D vec1, vec2, vec3, vect;
+
+	// We do the test in 2D. With the plane direction we
+	// can figure out how to project the vectors.
+	// normal = (c-a) x (b-a)
+	switch(plane.dir){
+	case DIR_X_POS:
+		vec1.x = va.y; vec1.y = va.z;
+		vec2.x = vc.y; vec2.y = vc.z;
+		vec3.x = vb.y; vec3.y = vb.z;
+		vect.x = p.y; vect.y = p.z;
+		break;
+	case DIR_X_NEG:
+		vec1.x = va.y; vec1.y = va.z;
+		vec2.x = vb.y; vec2.y = vb.z;
+		vec3.x = vc.y; vec3.y = vc.z;
+		vect.x = p.y; vect.y = p.z;
+		break;
+	case DIR_Y_POS:
+		vec1.x = va.z; vec1.y = va.x;
+		vec2.x = vc.z; vec2.y = vc.x;
+		vec3.x = vb.z; vec3.y = vb.x;
+		vect.x = p.z; vect.y = p.x;
+		break;
+	case DIR_Y_NEG:
+		vec1.x = va.z; vec1.y = va.x;
+		vec2.x = vb.z; vec2.y = vb.x;
+		vec3.x = vc.z; vec3.y = vc.x;
+		vect.x = p.z; vect.y = p.x;
+		break;
+	case DIR_Z_POS:
+		vec1.x = va.x; vec1.y = va.y;
+		vec2.x = vc.x; vec2.y = vc.y;
+		vec3.x = vb.x; vec3.y = vb.y;
+		vect.x = p.x; vect.y = p.y;
+		break;
+	case DIR_Z_NEG:
+		vec1.x = va.x; vec1.y = va.y;
+		vec2.x = vb.x; vec2.y = vb.y;
+		vec3.x = vc.x; vec3.y = vc.y;
+		vect.x = p.x; vect.y = p.y;
+		break;
+	default:
+		assert(0);
+	}
+	// This is our triangle:
+	// 3-------2
+	//  \  P  /
+	//   \   /
+	//    \ /
+	//     1
+	// We can use the "2d cross product" to check on which side
+	// a vector is of another. Test is true if point is inside of all edges.
+	if(CrossProduct2D(vec2-vec1, vect-vec1) < 0.0f) return false;
+	if(CrossProduct2D(vec3-vec1, vect-vec1) > 0.0f) return false;
+	if(CrossProduct2D(vec3-vec2, vect-vec2) < 0.0f) return false;
+	return true;
+}
+
+// Test if line segment intersects with sphere.
+// If the first point is inside the sphere this test does not register a collision!
+// The code is reversed from the original code and rather ugly, see Process for a clear version.
+// TODO: actually rewrite this mess
+bool
+CCollision::TestLineSphere(const CColLine &line, const CColSphere &sph)
+{
+	CVector v01 = line.p1 - line.p0;	// vector from p0 to p1
+	CVector v0c = sph.center - line.p0;	// vector from p0 to center
+	float linesq = v01.MagnitudeSqr();
+	// I leave in the strange -2 factors even though they serve no real purpose
+	float projline = -2.0f * DotProduct(v01, v0c);	// project v0c onto line
+	// Square of tangent from p0 multiplied by line length so we can compare with projline.
+	// The length of the tangent would be this: sqrt((c-p0)^2 - r^2).
+	// Negative if p0 is inside the sphere! This breaks the test!
+	float tansq = 4.0f * linesq *
+		(sph.center.MagnitudeSqr() - 2.0f*DotProduct(sph.center, line.p0) + line.p0.MagnitudeSqr() - sph.radius*sph.radius);
+	float diffsq = projline*projline - tansq;
+	// if diffsq < 0 that means the line is a passant, so no intersection
+	if(diffsq < 0.0f)
+		return false;
+	// projline (negative in GTA for some reason) is the point on the line
+	// in the middle of the two intersection points (startin from p0).
+	// sqrt(diffsq) somehow works out to be the distance from that
+	// midpoint to the intersection points.
+	// So subtract that and get rid of the awkward scaling:
+	float f = (-projline - sqrt(diffsq)) / (2.0f*linesq);
+	// f should now be in range [0, 1] for [p0, p1]
+	return f >= 0.0f && f <= 1.0f;
+}
+
+bool
+CCollision::TestSphereTriangle(const CColSphere &sphere,
+	const CVector *verts, const CColTriangle &tri, const CColTrianglePlane &plane)
+{
+	// If sphere and plane don't intersect, no collision
+	if(fabs(plane.CalcPoint(sphere.center)) > sphere.radius)
+		return false;
+
+	const CVector &va = verts[tri.a];
+	const CVector &vb = verts[tri.b];
+	const CVector &vc = verts[tri.c];
+
+	// calculate two orthogonal basis vectors for the triangle
+	CVector vec2 = vb - va;
+	float len = vec2.Magnitude();
+	vec2 = vec2 * (1.0f/len);
+	CVector vec1 = CrossProduct(vec2, plane.normal);
+
+	// We know A has local coordinate [0,0] and B has [0,len].
+	// Now calculate coordinates on triangle for these two vectors:
+	CVector vac = vc - va;
+	CVector vas = sphere.center - va;
+	CVector2D b(0.0f, len);
+	CVector2D c(DotProduct(vec1, vac), DotProduct(vec2, vac));
+	CVector2D s(DotProduct(vec1, vas), DotProduct(vec2, vas));
+
+	// The three triangle lines partition the space into 6 sectors,
+	// find out in which the center lies.
+	int insideAB = CrossProduct2D(s, b) >= 0.0f;
+	int insideAC = CrossProduct2D(c, s) >= 0.0f;
+	int insideBC = CrossProduct2D(s-b, c-b) >= 0.0f;
+
+	int testcase = insideAB + insideAC + insideBC;
+	float dist = 0.0f;
+	if(testcase == 1){
+		// closest to a vertex
+		if(insideAB) dist = (sphere.center - vc).Magnitude();
+		else if(insideAC) dist = (sphere.center - vb).Magnitude();
+		else if(insideBC) dist = (sphere.center - va).Magnitude();
+		else assert(0);
+	}else if(testcase == 2){
+		// closest to an edge
+		if(!insideAB) dist = DistToLine(&va, &vb, &sphere.center);
+		else if(!insideAC) dist = DistToLine(&va, &vc, &sphere.center);
+		else if(!insideBC) dist = DistToLine(&vb, &vc, &sphere.center);
+		else assert(0);
+	}else if(testcase == 3){
+		// center is in triangle
+		return true;
+	}else
+		assert(0);	// front fell off
+
+	return dist < sphere.radius;
+}
+
+bool
+CCollision::TestLineOfSight(CColLine &line, const CMatrix &matrix, CColModel &model, bool ignoreSurf78)
+{
+	static CMatrix matTransform;
+	int i;
+
+	// transform line to model space
+	Invert(matrix, matTransform);
+	CColLine newline(matTransform * line.p0, matTransform * line.p1);
+
+	// If we don't intersect with the bounding box, no chance on the rest
+	if(!TestLineBox(newline, model.boundingBox))
+		return false;
+
+	for(i = 0; i < model.numSpheres; i++)
+		if(!ignoreSurf78 || model.spheres[i].surface != 7 && model.spheres[i].surface != 8)
+			if(TestLineSphere(newline, model.spheres[i]))
+				return true;
+
+	for(i = 0; i < model.numBoxes; i++)
+		if(!ignoreSurf78 || model.boxes[i].surface != 7 && model.boxes[i].surface != 8)
+			if(TestLineBox(newline, model.boxes[i]))
+				return true;
+
+	CalculateTrianglePlanes(&model);
+	for(i = 0; i < model.numTriangles; i++)
+		if(!ignoreSurf78 || model.triangles[i].surface != 7 && model.triangles[i].surface != 8)
+			if(TestLineTriangle(newline, model.vertices, model.triangles[i], model.trianglePlanes[i]))
+				return true;
+
+	return false;
+}
+
+
+//
+// Process
+//
+
+// For Spheres mindist is the squared distance to its center
+// For Lines mindist is between [0,1]
+
+bool
+CCollision::ProcessSphereSphere(const CColSphere &s1, const CColSphere &s2, CColPoint &point, float &mindistsq)
+{
+	CVector dist = s1.center - s2.center;
+	float d = dist.Magnitude() - s2.radius;	// distance from s1's center to s2
+	float dc = d < 0.0f ? 0.0f : d;		// clamp to zero, i.e. if s1's center is inside s2
+	// no collision if sphere is not close enough
+	if(mindistsq <= dc*dc || s1.radius <= dc)
+		return false;
+	dist.Normalise();
+	point.point = s1.center - dist*dc;
+	point.normal = dist;
+	point.surfaceA = s1.surface;
+	point.pieceA = s1.piece;
+	point.surfaceB = s2.surface;
+	point.pieceB = s2.piece;
+	point.depth = s1.radius - d;	// sphere overlap
+	mindistsq = dc*dc;		// collision radius
+	return true;
+}
+
+bool
+CCollision::ProcessSphereBox(const CColSphere &sph, const CColBox &box, CColPoint &point, float &mindistsq)
+{
+	CVector p;
+	CVector dist;
+
+	// GTA's code is too complicated, uses a huge 3x3x3 if statement
+	// we can simplify the structure a lot
+
+	// first make sure we have a collision at all
+	if(sph.center.x + sph.radius < box.min.x) return false;
+	if(sph.center.x - sph.radius > box.max.x) return false;
+	if(sph.center.y + sph.radius < box.min.y) return false;
+	if(sph.center.y - sph.radius > box.max.y) return false;
+	if(sph.center.z + sph.radius < box.min.z) return false;
+	if(sph.center.z - sph.radius > box.max.z) return false;
+
+	// Now find out where the sphere center lies in relation to all the sides
+	int xpos = sph.center.x < box.min.x ? 1 :
+	           sph.center.x > box.max.x ? 2 :
+	           0;
+	int ypos = sph.center.y < box.min.y ? 1 :
+	           sph.center.y > box.max.y ? 2 :
+	           0;
+	int zpos = sph.center.z < box.min.z ? 1 :
+	           sph.center.z > box.max.z ? 2 :
+	           0;
+
+	if(xpos == 0 && ypos == 0 && zpos == 0){
+		// sphere is inside the box
+		p = (box.min + box.max)*0.5f;
+
+		dist = sph.center - p;
+		float lensq = dist.MagnitudeSqr();
+		if(lensq < mindistsq){
+			point.normal = dist * (1.0f/sqrt(lensq));
+			point.point = sph.center - point.normal;
+			point.surfaceA = sph.surface;
+			point.pieceA = sph.piece;
+			point.surfaceB = box.surface;
+			point.pieceB = box.piece;
+
+			// find absolute distance to the closer side in each dimension
+			float dx = dist.x > 0.0f ?
+				box.max.x - sph.center.x :
+				sph.center.x - box.min.x;
+			float dy = dist.y > 0.0f ?
+				box.max.y - sph.center.y :
+				sph.center.y - box.min.y;
+			float dz = dist.z > 0.0f ?
+				box.max.z - sph.center.z :
+				sph.center.z - box.min.z;
+			// collision depth is maximum of that:
+			if(dx > dy && dx > dz)
+				point.depth = dx;
+			else if(dy > dz)
+				point.depth = dy;
+			else
+				point.depth = dz;
+			return true;
+		}
+	}else{
+		// sphere is outside.
+		// closest point on box:
+		p.x = xpos == 1 ? box.min.x :
+		      xpos == 2 ? box.max.x :
+		      sph.center.x;
+		p.y = ypos == 1 ? box.min.y :
+		      ypos == 2 ? box.max.y :
+		      sph.center.y;
+		p.z = zpos == 1 ? box.min.z :
+		      zpos == 2 ? box.max.z :
+		      sph.center.z;
+
+		dist = sph.center - p;
+		float lensq = dist.MagnitudeSqr();
+		if(lensq < mindistsq){
+			float len = sqrt(lensq);
+			point.point = p;
+			point.normal = dist * (1.0f/len);
+			point.surfaceA = sph.surface;
+			point.pieceA = sph.piece;
+			point.surfaceB = box.surface;
+			point.pieceB = box.piece;
+			point.depth = sph.radius - len;
+			mindistsq = lensq;
+			return true;
+		}
+	}
+	return false;
+}
+
+bool
+CCollision::ProcessLineBox(const CColLine &line, const CColBox &box, CColPoint &point, float &mindist)
+{
+	float mint, t, x, y, z;
+	CVector normal;
+	CVector p;
+
+	mint = 1.0f;
+	// check if points are on opposite sides of min x plane
+	if((box.min.x - line.p1.x) * (box.min.x - line.p0.x) < 0.0f){
+		// parameter along line where we intersect
+		t = (box.min.x - line.p0.x) / (line.p1.x - line.p0.x);
+		// y of intersection
+		y = line.p0.y + (line.p1.y - line.p0.y)*t;
+		if(y > box.min.y && y < box.max.y){
+			// z of intersection
+			z = line.p0.z + (line.p1.z - line.p0.z)*t;
+			if(z > box.min.z && z < box.max.z)
+				if(t < mint){
+					mint = t;
+					p = CVector(box.min.x, y, z);
+					normal = CVector(-1.0f, 0.0f, 0.0f);
+				}
+		}
+	}
+
+	// max x plane
+	if((line.p1.x - box.max.x) * (line.p0.x - box.max.x) < 0.0f){
+		t = (line.p0.x - box.max.x) / (line.p0.x - line.p1.x);
+		y = line.p0.y + (line.p1.y - line.p0.y)*t;
+		if(y > box.min.y && y < box.max.y){
+			z = line.p0.z + (line.p1.z - line.p0.z)*t;
+			if(z > box.min.z && z < box.max.z)
+				if(t < mint){
+					mint = t;
+					p = CVector(box.max.x, y, z);
+					normal = CVector(1.0f, 0.0f, 0.0f);
+				}
+		}
+	}
+
+	// min y plne
+	if((box.min.y - line.p0.y) * (box.min.y - line.p1.y) < 0.0f){
+		t = (box.min.y - line.p0.y) / (line.p1.y - line.p0.y);
+		x = line.p0.x + (line.p1.x - line.p0.x)*t;
+		if(x > box.min.x && x < box.max.x){
+			z = line.p0.z + (line.p1.z - line.p0.z)*t;
+			if(z > box.min.z && z < box.max.z)
+				if(t < mint){
+					mint = t;
+					p = CVector(x, box.min.y, z);
+					normal = CVector(0.0f, -1.0f, 0.0f);
+				}
+		}
+	}
+
+	// max y plane
+	if((line.p0.y - box.max.y) * (line.p1.y - box.max.y) < 0.0f){
+		t = (line.p0.y - box.max.y) / (line.p0.y - line.p1.y);
+		x = line.p0.x + (line.p1.x - line.p0.x)*t;
+		if(x > box.min.x && x < box.max.x){
+			z = line.p0.z + (line.p1.z - line.p0.z)*t;
+			if(z > box.min.z && z < box.max.z)
+				if(t < mint){
+					mint = t;
+					p = CVector(x, box.max.y, z);
+					normal = CVector(0.0f, 1.0f, 0.0f);
+				}
+		}
+	}
+
+	// min z plne
+	if((box.min.z - line.p0.z) * (box.min.z - line.p1.z) < 0.0f){
+		t = (box.min.z - line.p0.z) / (line.p1.z - line.p0.z);
+		x = line.p0.x + (line.p1.x - line.p0.x)*t;
+		if(x > box.min.x && x < box.max.x){
+			y = line.p0.y + (line.p1.y - line.p0.y)*t;
+			if(y > box.min.y && y < box.max.y)
+				if(t < mint){
+					mint = t;
+					p = CVector(x, y, box.min.z);
+					normal = CVector(0.0f, 0.0f, -1.0f);
+				}
+		}
+	}
+
+	// max z plane
+	if((line.p0.z - box.max.z) * (line.p1.z - box.max.z) < 0.0f){
+		t = (line.p0.z - box.max.z) / (line.p0.z - line.p1.z);
+		x = line.p0.x + (line.p1.x - line.p0.x)*t;
+		if(x > box.min.x && x < box.max.x){
+			y = line.p0.y + (line.p1.y - line.p0.y)*t;
+			if(y > box.min.y && y < box.max.y)
+				if(t < mint){
+					mint = t;
+					p = CVector(x, y, box.max.z);
+					normal = CVector(0.0f, 0.0f, 1.0f);
+				}
+		}
+	}
+
+	if(mint >= mindist)
+		return false;
+
+	point.point = p;
+	point.normal = normal;
+	point.surfaceA = 0;
+	point.pieceA = 0;
+	point.surfaceB = box.surface;
+	point.pieceB = box.piece;
+	mindist = mint;
+
+	return true;
+}
+
+// If line.p0 lies inside sphere, no collision is registered.
+bool
+CCollision::ProcessLineSphere(const CColLine &line, const CColSphere &sphere, CColPoint &point, float &mindist)
+{
+	CVector v01 = line.p1 - line.p0;
+	CVector v0c = sphere.center - line.p0;
+	float linesq = v01.MagnitudeSqr();
+	// project v0c onto v01, scaled by |v01| this is the midpoint of the two intersections
+	float projline = DotProduct(v01, v0c);
+	// tangent of p0 to sphere, scaled by linesq just like projline^2
+	float tansq = (v0c.MagnitudeSqr() - sphere.radius*sphere.radius) * linesq;
+	// this works out to be the square of the distance between the midpoint and the intersections
+	float diffsq = projline*projline - tansq;
+	// no intersection
+	if(diffsq < 0.0f)
+		return false;
+	// point of first intersection, in range [0,1] between p0 and p1
+	float t = (projline - sqrt(diffsq)) / linesq;
+	// if not on line or beyond mindist, no intersection
+	if(t < 0.0f || t > 1.0f || t >= mindist)
+		return false;
+	point.point = line.p0 + v01*t;
+	point.normal = point.point - sphere.center;
+	point.normal.Normalise();
+	point.surfaceA = 0;
+	point.pieceA = 0;
+	point.surfaceB = sphere.surface;
+	point.pieceB = sphere.piece;
+	mindist = t;
+	return true;
+}
+
+bool
+CCollision::ProcessVerticalLineTriangle(const CColLine &line,
+	const CVector *verts, const CColTriangle &tri, const CColTrianglePlane &plane,
+	CColPoint &point, float &mindist, CStoredCollPoly *poly)
+{
+	float t;
+	CVector normal;
+
+	const CVector &p0 = line.p0;
+	const CVector &va = verts[tri.a];
+	const CVector &vb = verts[tri.b];
+	const CVector &vc = verts[tri.c];
+
+	// early out bound rect test
+	if(p0.x < va.x && p0.x < vb.x && p0.x < vc.x) return false;
+	if(p0.x > va.x && p0.x > vb.x && p0.x > vc.x) return false;
+	if(p0.y < va.y && p0.y < vb.y && p0.y < vc.y) return false;
+	if(p0.y > va.y && p0.y > vb.y && p0.y > vc.y) return false;
+
+	plane.GetNormal(normal);
+	// if points are on the same side, no collision
+	if(plane.CalcPoint(p0) * plane.CalcPoint(line.p1) > 0.0f)
+		return false;
+
+	// intersection parameter on line
+	float h = (line.p1 - p0).z;
+	t = -plane.CalcPoint(p0) / (h * normal.z);
+	// early out if we're beyond the mindist
+	if(t >= mindist)
+		return false;
+	CVector p(p0.x, p0.y, p0.z + h*t);
+
+	CVector2D vec1, vec2, vec3, vect;
+	switch(plane.dir){
+	case DIR_X_POS:
+		vec1.x = va.y; vec1.y = va.z;
+		vec2.x = vc.y; vec2.y = vc.z;
+		vec3.x = vb.y; vec3.y = vb.z;
+		vect.x = p.y; vect.y = p.z;
+		break;
+	case DIR_X_NEG:
+		vec1.x = va.y; vec1.y = va.z;
+		vec2.x = vb.y; vec2.y = vb.z;
+		vec3.x = vc.y; vec3.y = vc.z;
+		vect.x = p.y; vect.y = p.z;
+		break;
+	case DIR_Y_POS:
+		vec1.x = va.z; vec1.y = va.x;
+		vec2.x = vc.z; vec2.y = vc.x;
+		vec3.x = vb.z; vec3.y = vb.x;
+		vect.x = p.z; vect.y = p.x;
+		break;
+	case DIR_Y_NEG:
+		vec1.x = va.z; vec1.y = va.x;
+		vec2.x = vb.z; vec2.y = vb.x;
+		vec3.x = vc.z; vec3.y = vc.x;
+		vect.x = p.z; vect.y = p.x;
+		break;
+	case DIR_Z_POS:
+		vec1.x = va.x; vec1.y = va.y;
+		vec2.x = vc.x; vec2.y = vc.y;
+		vec3.x = vb.x; vec3.y = vb.y;
+		vect.x = p.x; vect.y = p.y;
+		break;
+	case DIR_Z_NEG:
+		vec1.x = va.x; vec1.y = va.y;
+		vec2.x = vb.x; vec2.y = vb.y;
+		vec3.x = vc.x; vec3.y = vc.y;
+		vect.x = p.x; vect.y = p.y;
+		break;
+	default:
+		assert(0);
+	}
+	if(CrossProduct2D(vec2-vec1, vect-vec1) < 0.0f) return false;
+	if(CrossProduct2D(vec3-vec1, vect-vec1) > 0.0f) return false;
+	if(CrossProduct2D(vec3-vec2, vect-vec2) < 0.0f) return false;
+	point.point = p;
+	point.normal = normal;
+	point.surfaceA = 0;
+	point.pieceA = 0;
+	point.surfaceB = tri.surface;
+	point.pieceB = 0;
+	if(poly){
+		poly->verts[0] = va;
+		poly->verts[1] = vb;
+		poly->verts[2] = vc;
+		poly->valid = true;
+	}
+	mindist = t;
+	return true;
+}
+
+bool
+CCollision::ProcessLineTriangle(const CColLine &line ,
+	const CVector *verts, const CColTriangle &tri, const CColTrianglePlane &plane,
+	CColPoint &point, float &mindist)
+{
+	float t;
+	CVector normal;
+	plane.GetNormal(normal);
+
+	// if points are on the same side, no collision
+	if(plane.CalcPoint(line.p0) * plane.CalcPoint(line.p1) > 0.0f)
+		return false;
+
+	// intersection parameter on line
+	t = -plane.CalcPoint(line.p0) / DotProduct(line.p1 - line.p0, normal);
+	// early out if we're beyond the mindist
+	if(t >= mindist)
+		return false;
+	// find point of intersection
+	CVector p = line.p0 + (line.p1-line.p0)*t;
+
+	const CVector &va = verts[tri.a];
+	const CVector &vb = verts[tri.b];
+	const CVector &vc = verts[tri.c];
+	CVector2D vec1, vec2, vec3, vect;
+
+	switch(plane.dir){
+	case DIR_X_POS:
+		vec1.x = va.y; vec1.y = va.z;
+		vec2.x = vc.y; vec2.y = vc.z;
+		vec3.x = vb.y; vec3.y = vb.z;
+		vect.x = p.y; vect.y = p.z;
+		break;
+	case DIR_X_NEG:
+		vec1.x = va.y; vec1.y = va.z;
+		vec2.x = vb.y; vec2.y = vb.z;
+		vec3.x = vc.y; vec3.y = vc.z;
+		vect.x = p.y; vect.y = p.z;
+		break;
+	case DIR_Y_POS:
+		vec1.x = va.z; vec1.y = va.x;
+		vec2.x = vc.z; vec2.y = vc.x;
+		vec3.x = vb.z; vec3.y = vb.x;
+		vect.x = p.z; vect.y = p.x;
+		break;
+	case DIR_Y_NEG:
+		vec1.x = va.z; vec1.y = va.x;
+		vec2.x = vb.z; vec2.y = vb.x;
+		vec3.x = vc.z; vec3.y = vc.x;
+		vect.x = p.z; vect.y = p.x;
+		break;
+	case DIR_Z_POS:
+		vec1.x = va.x; vec1.y = va.y;
+		vec2.x = vc.x; vec2.y = vc.y;
+		vec3.x = vb.x; vec3.y = vb.y;
+		vect.x = p.x; vect.y = p.y;
+		break;
+	case DIR_Z_NEG:
+		vec1.x = va.x; vec1.y = va.y;
+		vec2.x = vb.x; vec2.y = vb.y;
+		vec3.x = vc.x; vec3.y = vc.y;
+		vect.x = p.x; vect.y = p.y;
+		break;
+	default:
+		assert(0);
+	}
+	if(CrossProduct2D(vec2-vec1, vect-vec1) < 0.0f) return false;
+	if(CrossProduct2D(vec3-vec1, vect-vec1) > 0.0f) return false;
+	if(CrossProduct2D(vec3-vec2, vect-vec2) < 0.0f) return false;
+	point.point = p;
+	point.normal = normal;
+	point.surfaceA = 0;
+	point.pieceA = 0;
+	point.surfaceB = tri.surface;
+	point.pieceB = 0;
+	mindist = t;
+	return true;
+}
+
+bool
+CCollision::ProcessSphereTriangle(const CColSphere &sphere,
+	const CVector *verts, const CColTriangle &tri, const CColTrianglePlane &plane,
+	CColPoint &point, float &mindistsq)
+{
+	// If sphere and plane don't intersect, no collision
+	float planedist = plane.CalcPoint(sphere.center);
+	float distsq = planedist*planedist;
+	if(fabs(planedist) > sphere.radius || distsq > mindistsq)
+		return false;
+
+	const CVector &va = verts[tri.a];
+	const CVector &vb = verts[tri.b];
+	const CVector &vc = verts[tri.c];
+
+	// calculate two orthogonal basis vectors for the triangle
+	CVector normal;
+	plane.GetNormal(normal);
+	CVector vec2 = vb - va;
+	float len = vec2.Magnitude();
+	vec2 = vec2 * (1.0f/len);
+	CVector vec1 = CrossProduct(vec2, normal);
+
+	// We know A has local coordinate [0,0] and B has [0,len].
+	// Now calculate coordinates on triangle for these two vectors:
+	CVector vac = vc - va;
+	CVector vas = sphere.center - va;
+	CVector2D b(0.0f, len);
+	CVector2D c(DotProduct(vec1, vac), DotProduct(vec2, vac));
+	CVector2D s(DotProduct(vec1, vas), DotProduct(vec2, vas));
+
+	// The three triangle lines partition the space into 6 sectors,
+	// find out in which the center lies.
+	int insideAB = CrossProduct2D(s, b) >= 0.0f;
+	int insideAC = CrossProduct2D(c, s) >= 0.0f;
+	int insideBC = CrossProduct2D(s-b, c-b) >= 0.0f;
+
+	int testcase = insideAB + insideAC + insideBC;
+	float dist = 0.0f;
+	CVector p;
+	if(testcase == 1){
+		// closest to a vertex
+		if(insideAB) p = vc;
+		else if(insideAC) p = vb;
+		else if(insideBC) p = va;
+		else assert(0);
+		dist = (sphere.center - p).Magnitude();
+	}else if(testcase == 2){
+		// closest to an edge
+		if(!insideAB) dist = DistToLine(&va, &vb, &sphere.center, p);
+		else if(!insideAC) dist = DistToLine(&va, &vc, &sphere.center, p);
+		else if(!insideBC) dist = DistToLine(&vb, &vc, &sphere.center, p);
+		else assert(0);
+	}else if(testcase == 3){
+		// center is in triangle
+		dist = fabs(planedist);
+		p = sphere.center - normal*planedist;
+	}else
+		assert(0);	// front fell off
+
+	if(dist >= sphere.radius || dist*dist >= mindistsq)
+		return false;
+
+	point.point = p;
+	point.normal = sphere.center - p;
+	point.normal.Normalise();
+	point.surfaceA = sphere.surface;
+	point.pieceA = sphere.piece;
+	point.surfaceB = tri.surface;
+	point.pieceB = 0;
+	point.depth = sphere.radius - dist;
+	mindistsq = dist*dist;
+	return true;
+}
+
+bool
+CCollision::ProcessLineOfSight(const CColLine &line,
+	const CMatrix &matrix, CColModel &model,
+	CColPoint &point, float &mindist, bool ignoreSurf78)
+{
+	static CMatrix matTransform;
+	int i;
+
+	// transform line to model space
+	Invert(matrix, matTransform);
+	CColLine newline(matTransform * line.p0, matTransform * line.p1);
+
+	// If we don't intersect with the bounding box, no chance on the rest
+	if(!TestLineBox(newline, model.boundingBox))
+		return false;
+
+	float coldist = mindist;
+	for(i = 0; i < model.numSpheres; i++)
+		if(!ignoreSurf78 || model.spheres[i].surface != 7 && model.spheres[i].surface != 8)
+			ProcessLineSphere(newline, model.spheres[i], point, coldist);
+
+	for(i = 0; i < model.numBoxes; i++)
+		if(!ignoreSurf78 || model.boxes[i].surface != 7 && model.boxes[i].surface != 8)
+			ProcessLineBox(newline, model.boxes[i], point, coldist);
+
+	CalculateTrianglePlanes(&model);
+	for(i = 0; i < model.numTriangles; i++)
+		if(!ignoreSurf78 || model.triangles[i].surface != 7 && model.triangles[i].surface != 8)
+			ProcessLineTriangle(newline, model.vertices, model.triangles[i], model.trianglePlanes[i], point, coldist);
+
+	if(coldist < mindist){
+		point.point = matrix * point.point;
+		point.normal = Multiply3x3(matrix, point.normal);
+		mindist = coldist;
+		return true;
+	}
+	return false;
+}
+
+bool
+CCollision::ProcessVerticalLine(const CColLine &line,
+	const CMatrix &matrix, CColModel &model,
+	CColPoint &point, float &mindist, bool ignoreSurf78, CStoredCollPoly *poly)
+{
+	static CStoredCollPoly TempStoredPoly;
+	int i;
+
+	// transform line to model space
+	// Why does the game seem to do this differently than above?
+	CColLine newline(MultiplyInverse(matrix, line.p0), MultiplyInverse(matrix, line.p1));
+	newline.p1.x = newline.p0.x;
+	newline.p1.y = newline.p0.y;
+
+	if(!TestVerticalLineBox(newline, model.boundingBox))
+		return false;
+
+	float coldist = mindist;
+	for(i = 0; i < model.numSpheres; i++)
+		if(!ignoreSurf78 || model.spheres[i].surface != 7 && model.spheres[i].surface != 8)
+			ProcessLineSphere(newline, model.spheres[i], point, coldist);
+
+	for(i = 0; i < model.numBoxes; i++)
+		if(!ignoreSurf78 || model.boxes[i].surface != 7 && model.boxes[i].surface != 8)
+			ProcessLineBox(newline, model.boxes[i], point, coldist);
+
+	CalculateTrianglePlanes(&model);
+	TempStoredPoly.valid = false;
+	for(i = 0; i < model.numTriangles; i++)
+		if(!ignoreSurf78 || model.triangles[i].surface != 7 && model.triangles[i].surface != 8)
+			ProcessVerticalLineTriangle(newline, model.vertices, model.triangles[i], model.trianglePlanes[i], point, coldist, &TempStoredPoly);
+
+	if(coldist < mindist){
+		point.point = matrix * point.point;
+		point.normal = Multiply3x3(matrix, point.normal);
+		if(poly && TempStoredPoly.valid){
+			*poly = TempStoredPoly;
+			poly->verts[0] = matrix * poly->verts[0];
+			poly->verts[1] = matrix * poly->verts[1];
+			poly->verts[2] = matrix * poly->verts[2];
+		}
+		mindist = coldist;
+		return true;
+	}
+	return false;
+}
+
+enum {
+	MAXNUMSPHERES = 128,
+	MAXNUMBOXES = 32,
+	MAXNUMLINES = 16,
+	MAXNUMTRIS = 600
+};
+
+// This checks model A's spheres and lines against model B's spheres, boxes and triangles.
+// Returns the number of A's spheres that collide.
+// Returned ColPoints are in world space.
+// NB: lines do not seem to be supported very well, use with caution
+int32
+CCollision::ProcessColModels(const CMatrix &matrixA, CColModel &modelA,
+	const CMatrix &matrixB, CColModel &modelB,
+	CColPoint *spherepoints, CColPoint *linepoints, float *linedists)
+{
+	static int aSphereIndicesA[MAXNUMSPHERES];
+	static int aLineIndicesA[MAXNUMLINES];
+	static int aSphereIndicesB[MAXNUMSPHERES];
+	static int aBoxIndicesB[MAXNUMBOXES];
+	static int aTriangleIndicesB[MAXNUMTRIS];
+	static bool aCollided[MAXNUMLINES];
+	static CColSphere aSpheresA[MAXNUMSPHERES];
+	static CColLine aLinesA[MAXNUMLINES];
+	static CMatrix matAB, matBA;
+	CColSphere s;
+	int i, j;
+
+	assert(modelA.numSpheres <= MAXNUMSPHERES);
+	assert(modelA.numLines <= MAXNUMLINES);
+
+	// From model A space to model B space
+	matAB = Invert(matrixB, matAB) * matrixA;
+
+	CColSphere bsphereAB;	// bounding sphere of A in B space
+	bsphereAB.Set(modelA.boundingSphere.radius, matAB * modelA.boundingSphere.center);
+	if(!TestSphereBox(bsphereAB, modelB.boundingBox))
+		return 0;
+	// B to A space
+	matBA = Invert(matrixA, matBA) * matrixB;
+
+	// transform modelA's spheres and lines to B space
+	for(i = 0; i < modelA.numSpheres; i++){
+		CColSphere &s = modelA.spheres[i];
+		aSpheresA[i].Set(s.radius, matAB * s.center, s.surface, s.piece);
+	}
+	for(i = 0; i < modelA.numLines; i++)
+		aLinesA[i].Set(matAB * modelA.lines[i].p0, matAB * modelA.lines[i].p1);
+
+	// Test them against model B's bounding volumes
+	int numSpheresA = 0;
+	int numLinesA = 0;
+	for(i = 0; i < modelA.numSpheres; i++)
+		if(TestSphereBox(aSpheresA[i], modelB.boundingBox))
+			aSphereIndicesA[numSpheresA++] = i;
+	// no actual check???
+	for(i = 0; i < modelA.numLines; i++)
+		aLineIndicesA[numLinesA++] = i;
+	// No collision
+	if(numSpheresA == 0 && numLinesA == 0)
+		return 0;
+
+	// Check model B against A's bounding volumes
+	int numSpheresB = 0;
+	int numBoxesB = 0;
+	int numTrianglesB = 0;
+	for(i = 0; i < modelB.numSpheres; i++){
+		s.Set(modelB.spheres[i].radius, matBA * modelB.spheres[i].center);
+		if(TestSphereBox(s, modelA.boundingBox))
+			aSphereIndicesB[numSpheresB++] = i;
+	}
+	for(i = 0; i < modelB.numBoxes; i++)
+		if(TestSphereBox(bsphereAB, modelB.boxes[i]))
+			aBoxIndicesB[numBoxesB++] = i;
+	CalculateTrianglePlanes(&modelB);
+	for(i = 0; i < modelB.numTriangles; i++)
+		if(TestSphereTriangle(bsphereAB, modelB.vertices, modelB.triangles[i], modelB.trianglePlanes[i]))
+			aTriangleIndicesB[numTrianglesB++] = i;
+	assert(numSpheresB <= MAXNUMSPHERES);
+	assert(numBoxesB <= MAXNUMBOXES);
+	assert(numTrianglesB <= MAXNUMTRIS);
+	// No collision
+	if(numSpheresB == 0 && numBoxesB == 0 && numTrianglesB == 0)
+		return 0;
+
+	// We now have the collision volumes in A and B that are worth processing.
+
+	// Process A's spheres against B's collision volumes
+	int numCollisions = 0;
+	for(i = 0; i < numSpheresA; i++){
+		float coldist = 1.0e24f;
+		bool hasCollided = false;
+
+		for(j = 0; j < numSpheresB; j++)
+			hasCollided |= ProcessSphereSphere(
+				aSpheresA[aSphereIndicesA[i]],
+				modelB.spheres[aSphereIndicesB[j]],
+				spherepoints[numCollisions], coldist);
+		for(j = 0; j < numBoxesB; j++)
+			hasCollided |= ProcessSphereBox(
+				aSpheresA[aSphereIndicesA[i]],
+				modelB.boxes[aBoxIndicesB[j]],
+				spherepoints[numCollisions], coldist);
+		for(j = 0; j < numTrianglesB; j++)
+			hasCollided |= ProcessSphereTriangle(
+				aSpheresA[aSphereIndicesA[i]],
+				modelB.vertices,
+				modelB.triangles[aTriangleIndicesB[j]],
+				modelB.trianglePlanes[aTriangleIndicesB[j]],
+				spherepoints[numCollisions], coldist);
+		if(hasCollided)
+			numCollisions++;
+	}
+	for(i = 0; i < numCollisions; i++){
+		spherepoints[i].point = matrixB * spherepoints[i].point;
+		spherepoints[i].normal = Multiply3x3(matrixB, spherepoints[i].normal);
+	}
+
+	// And the same thing for the lines in A
+	for(i = 0; i < numLinesA; i++){
+		aCollided[i] = false;
+
+		for(j = 0; j < numSpheresB; j++)
+			aCollided[i] |= ProcessLineSphere(
+				aLinesA[aLineIndicesA[i]],
+				modelB.spheres[aSphereIndicesB[j]],
+				linepoints[aLineIndicesA[i]],
+				linedists[aLineIndicesA[i]]);
+		for(j = 0; j < numBoxesB; j++)
+			aCollided[i] |= ProcessLineBox(
+				aLinesA[aLineIndicesA[i]],
+				modelB.boxes[aBoxIndicesB[j]],
+				linepoints[aLineIndicesA[i]],
+				linedists[aLineIndicesA[i]]);
+		for(j = 0; j < numTrianglesB; j++)
+			aCollided[i] |= ProcessLineTriangle(
+				aLinesA[aLineIndicesA[i]],
+				modelB.vertices,
+				modelB.triangles[aTriangleIndicesB[j]],
+				modelB.trianglePlanes[aTriangleIndicesB[j]],
+				linepoints[aLineIndicesA[i]],
+				linedists[aLineIndicesA[i]]);
+	}
+	for(i = 0; i < numLinesA; i++)
+		if(aCollided[i]){
+			j = aLineIndicesA[i];
+			linepoints[j].point = matrixB * linepoints[j].point;
+			linepoints[j].normal = Multiply3x3(matrixB, linepoints[j].normal);
+		}
+
+	return numCollisions;	// sphere collisions
+}
+
+
+//
+// Misc
+//
+
+float
+CCollision::DistToLine(const CVector *l0, const CVector *l1, const CVector *point)
+{
+	float lensq = (*l1 - *l0).MagnitudeSqr();
+	float dot = DotProduct(*point - *l0, *l1 - *l0);
+	// Between 0 and len we're above the line.
+	// if not, calculate distance to endpoint
+	if(dot <= 0.0f)
+		return (*point - *l0).Magnitude();
+	if(dot >= lensq)
+		return (*point - *l1).Magnitude();
+	// distance to line
+	return sqrt((*point - *l0).MagnitudeSqr() - dot*dot/lensq);
+}
+
+// same as above but also return the point on the line
+float
+CCollision::DistToLine(const CVector *l0, const CVector *l1, const CVector *point, CVector &closest)
+{
+	float lensq = (*l1 - *l0).MagnitudeSqr();
+	float dot = DotProduct(*point - *l0, *l1 - *l0);
+	// find out which point we're closest to
+	if(dot <= 0.0f)
+		closest = *l0;
+	else if(dot >= lensq)
+		closest = *l1;
+	else
+		closest = *l0 + (*l1 - *l0)*(dot/lensq);
+	// this is the distance
+	return (*point - closest).Magnitude();
+}
+
+void
+CCollision::CalculateTrianglePlanes(CColModel *model)
+{
+	if(model->numTriangles == 0)
+		return;
+
+	CLink<CColModel*> *lptr;
+	if(model->trianglePlanes){
+		// re-insert at front so it's not removed again soon
+		lptr = model->GetLinkPtr();
+		lptr->Remove();
+		ms_colModelCache.head.Insert(lptr);
+	}else{
+		assert(model);
+		lptr = ms_colModelCache.Insert(model);
+		if(lptr == nil){
+			// make room if we have to, remove last in list
+			lptr = ms_colModelCache.tail.prev;
+			assert(lptr);
+			assert(lptr->item);
+			lptr->item->RemoveTrianglePlanes();
+			ms_colModelCache.Remove(lptr);
+			// now this cannot fail
+			lptr = ms_colModelCache.Insert(model);
+			assert(lptr);
+		}
+		model->CalculateTrianglePlanes();
+		model->SetLinkPtr(lptr);
+	}
+}
+
+void
+CCollision::DrawColModel(const CMatrix &mat, const CColModel &colModel)
+{
+}
+
+void
+CCollision::DrawColModel_Coloured(const CMatrix &mat, const CColModel &colModel, int32 id)
+{
+	int i;
+	int s;
+	float f;
+	CVector verts[8];
+	CVector min, max;
+	int r, g, b;
+	RwImVertexIndex *iptr;
+	RwIm3DVertex *vptr;
+
+	RenderBuffer::ClearRenderBuffer();
+	RwRenderStateSet(rwRENDERSTATEZWRITEENABLE, (void*)TRUE);
+	RwRenderStateSet(rwRENDERSTATEVERTEXALPHAENABLE, (void*)TRUE);
+	RwRenderStateSet(rwRENDERSTATESRCBLEND, (void*)rwBLENDSRCALPHA);
+	RwRenderStateSet(rwRENDERSTATEDESTBLEND, (void*)rwBLENDINVSRCALPHA);
+	RwRenderStateSet(rwRENDERSTATETEXTURERASTER, nil);
+
+	for(i = 0; i < colModel.numTriangles; i++){
+		colModel.GetTrianglePoint(verts[0], colModel.triangles[i].a);
+		colModel.GetTrianglePoint(verts[1], colModel.triangles[i].b);
+		colModel.GetTrianglePoint(verts[2], colModel.triangles[i].c);
+		verts[0] = mat * verts[0];
+		verts[1] = mat * verts[1];
+		verts[2] = mat * verts[2];
+
+		// TODO: surface
+		r = 255;
+		g = 128;
+		b = 0;
+
+		s = colModel.triangles[i].surface;
+		f = (s & 0xF)/32.0f + 0.5f;
+		switch(CSurfaceTable::GetAdhesionGroup(s)){
+		case ADHESIVE_RUBBER:
+			r = f * 255.0f;
+			g = 0;
+			b = 0;
+			break;
+		case ADHESIVE_HARD:
+			r = f*255.0f;
+			g = f*255.0f;
+			b = f*128.0f;
+			break;
+		case ADHESIVE_ROAD:
+			r = f*128.0f;
+			g = f*128.0f;
+			b = f*128.0f;
+			break;
+		case ADHESIVE_LOOSE:
+			r = 0;
+			g = f * 255.0f;
+			b = 0;
+			break;
+		case ADHESIVE_WET:
+			r = 0;
+			g = 0;
+			b = f * 255.0f;
+			break;
+		default:
+			// this doesn't make much sense
+			r *= f;
+			g *= f;
+			b *= f;
+		}
+
+		// TODO: make some surface types flicker?
+
+		if(s > SURFACE_32){
+			r = CGeneral::GetRandomNumber();
+			g = CGeneral::GetRandomNumber();
+			b = CGeneral::GetRandomNumber();
+			printf("Illegal surfacetype:%d on MI:%d\n", s, id);
+		}
+
+		RenderBuffer::StartStoring(6, 3, &iptr, &vptr);
+		RwIm3DVertexSetRGBA(&vptr[0], r, g, b, 255);
+		RwIm3DVertexSetRGBA(&vptr[1], r, g, b, 255);
+		RwIm3DVertexSetRGBA(&vptr[2], r, g, b, 255);
+		RwIm3DVertexSetU(&vptr[0], 0.0f);
+		RwIm3DVertexSetV(&vptr[0], 0.0f);
+		RwIm3DVertexSetU(&vptr[1], 0.0f);
+		RwIm3DVertexSetV(&vptr[1], 1.0f);
+		RwIm3DVertexSetU(&vptr[2], 1.0f);
+		RwIm3DVertexSetV(&vptr[2], 1.0f);
+		RwIm3DVertexSetPos(&vptr[0], verts[0].x, verts[0].y, verts[0].z);
+		RwIm3DVertexSetPos(&vptr[1], verts[1].x, verts[1].y, verts[1].z);
+		RwIm3DVertexSetPos(&vptr[2], verts[2].x, verts[2].y, verts[2].z);
+		iptr[0] = 0; iptr[1] = 1; iptr[2] = 2;
+		iptr[3] = 0; iptr[4] = 2; iptr[5] = 1;
+		RenderBuffer::StopStoring();
+	}
+
+	for(i = 0; i < colModel.numBoxes; i++){
+		min = colModel.boxes[i].min;
+		max = colModel.boxes[i].max;
+
+		verts[0] = mat * CVector(min.x, min.y, min.z);
+		verts[1] = mat * CVector(min.x, min.y, max.z);
+		verts[2] = mat * CVector(min.x, max.y, min.z);
+		verts[3] = mat * CVector(min.x, max.y, max.z);
+		verts[4] = mat * CVector(max.x, min.y, min.z);
+		verts[5] = mat * CVector(max.x, min.y, max.z);
+		verts[6] = mat * CVector(max.x, max.y, min.z);
+		verts[7] = mat * CVector(max.x, max.y, max.z);
+
+		s = colModel.boxes[i].surface;
+		f = (s & 0xF)/32.0f + 0.5f;
+		switch(CSurfaceTable::GetAdhesionGroup(s)){
+		case ADHESIVE_RUBBER:
+			r = f * 255.0f;
+			g = 0;
+			b = 0;
+			break;
+		case ADHESIVE_HARD:
+			r = f*255.0f;
+			g = f*255.0f;
+			b = f*128.0f;
+			break;
+		case ADHESIVE_ROAD:
+			r = f*128.0f;
+			g = f*128.0f;
+			b = f*128.0f;
+			break;
+		case ADHESIVE_LOOSE:
+			r = 0;
+			g = f * 255.0f;
+			b = 0;
+			break;
+		case ADHESIVE_WET:
+			r = 0;
+			g = 0;
+			b = f * 255.0f;
+			break;
+		default:
+			// this doesn't make much sense
+			r *= f;
+			g *= f;
+			b *= f;
+		}
+
+		// TODO: make some surface types flicker?
+
+		RenderBuffer::StartStoring(36, 8, &iptr, &vptr);
+		RwIm3DVertexSetRGBA(&vptr[0], r, g, b, 255);
+		RwIm3DVertexSetRGBA(&vptr[1], r, g, b, 255);
+		RwIm3DVertexSetRGBA(&vptr[2], r, g, b, 255);
+		RwIm3DVertexSetRGBA(&vptr[3], r, g, b, 255);
+		RwIm3DVertexSetRGBA(&vptr[4], r, g, b, 255);
+		RwIm3DVertexSetRGBA(&vptr[5], r, g, b, 255);
+		RwIm3DVertexSetRGBA(&vptr[6], r, g, b, 255);
+		RwIm3DVertexSetRGBA(&vptr[7], r, g, b, 255);
+		RwIm3DVertexSetU(&vptr[0], 0.0f);
+		RwIm3DVertexSetV(&vptr[0], 0.0f);
+		RwIm3DVertexSetU(&vptr[1], 0.0f);
+		RwIm3DVertexSetV(&vptr[1], 1.0f);
+		RwIm3DVertexSetU(&vptr[2], 1.0f);
+		RwIm3DVertexSetV(&vptr[2], 1.0f);
+		RwIm3DVertexSetU(&vptr[3], 0.0f);
+		RwIm3DVertexSetV(&vptr[3], 0.0f);
+		RwIm3DVertexSetU(&vptr[4], 0.0f);
+		RwIm3DVertexSetV(&vptr[4], 1.0f);
+		RwIm3DVertexSetU(&vptr[5], 1.0f);
+		RwIm3DVertexSetV(&vptr[5], 1.0f);
+		RwIm3DVertexSetU(&vptr[6], 0.0f);
+		RwIm3DVertexSetV(&vptr[6], 1.0f);
+		RwIm3DVertexSetU(&vptr[7], 1.0f);
+		RwIm3DVertexSetV(&vptr[7], 1.0f);
+		RwIm3DVertexSetPos(&vptr[0], verts[0].x, verts[0].y, verts[0].z);
+		RwIm3DVertexSetPos(&vptr[1], verts[1].x, verts[1].y, verts[1].z);
+		RwIm3DVertexSetPos(&vptr[2], verts[2].x, verts[2].y, verts[2].z);
+		RwIm3DVertexSetPos(&vptr[3], verts[3].x, verts[3].y, verts[3].z);
+		RwIm3DVertexSetPos(&vptr[4], verts[4].x, verts[4].y, verts[4].z);
+		RwIm3DVertexSetPos(&vptr[5], verts[5].x, verts[5].y, verts[5].z);
+		RwIm3DVertexSetPos(&vptr[6], verts[6].x, verts[6].y, verts[6].z);
+		RwIm3DVertexSetPos(&vptr[7], verts[7].x, verts[7].y, verts[7].z);
+		iptr[0] = 0; iptr[1] = 1; iptr[2] = 2;
+		iptr[3] = 1; iptr[4] = 3; iptr[5] = 2;
+		iptr[6] = 1; iptr[7] = 5; iptr[8] = 7;
+		iptr[9] = 1; iptr[10] = 7; iptr[11] = 3;
+		iptr[12] = 2; iptr[13] = 3; iptr[14] = 7;
+		iptr[15] = 2; iptr[16] = 7; iptr[17] = 6;
+		iptr[18] = 0; iptr[19] = 5; iptr[20] = 1;
+		iptr[21] = 0; iptr[22] = 4; iptr[23] = 5;
+		iptr[24] = 0; iptr[25] = 2; iptr[26] = 4;
+		iptr[27] = 2; iptr[28] = 6; iptr[29] = 4;
+		iptr[30] = 4; iptr[31] = 6; iptr[32] = 7;
+		iptr[33] = 4; iptr[34] = 7; iptr[35] = 5;
+		RenderBuffer::StopStoring();
+	}
+ 
+	RenderBuffer::RenderStuffInBuffer();
+	RwRenderStateSet(rwRENDERSTATESRCBLEND, (void*)rwBLENDSRCALPHA);
+	RwRenderStateSet(rwRENDERSTATEDESTBLEND, (void*)rwBLENDINVSRCALPHA);
+	RwRenderStateSet(rwRENDERSTATEVERTEXALPHAENABLE, (void*)FALSE);
+	RwRenderStateSet(rwRENDERSTATEZWRITEENABLE, (void*)TRUE);
+	RwRenderStateSet(rwRENDERSTATEZTESTENABLE, (void*)TRUE);
+}
+
+
+/*
+ * ColModel code
+ */
+
+void
+CColSphere::Set(float radius, const CVector &center, uint8 surf, uint8 piece)
+{
+	this->radius = radius;
+	this->center = center;
+	this->surface = surf;
+	this->piece = piece;
+}
+
+void
+CColBox::Set(const CVector &min, const CVector &max, uint8 surf, uint8 piece)
+{
+	this->min = min;
+	this->max = max;
+	this->surface = surf;
+	this->piece = piece;
+}
+
+void
+CColLine::Set(const CVector &p0, const CVector &p1)
+{
+	this->p0 = p0;
+	this->p1 = p1;
+}
+
+void
+CColTriangle::Set(const CVector *, int a, int b, int c, uint8 surf, uint8 piece)
+{
+	this->a = a;
+	this->b = b;
+	this->c = c;
+	this->surface = surf;
+}
+
+void
+CColTrianglePlane::Set(const CVector *v, CColTriangle &tri)
+{
+	const CVector &va = v[tri.a];
+	const CVector &vb = v[tri.b];
+	const CVector &vc = v[tri.c];
+
+	normal = CrossProduct(vc-va, vb-va);
+	normal.Normalise();
+	dist = DotProduct(normal, va);
+	CVector an(fabs(normal.x), fabs(normal.y), fabs(normal.z));
+	// find out largest component and its direction
+	if(an.x > an.y && an.x > an.z)
+		dir = normal.x < 0.0f ? DIR_X_NEG : DIR_X_POS;
+	else if(an.y > an.z)
+		dir = normal.y < 0.0f ? DIR_Y_NEG : DIR_Y_POS;
+	else
+		dir = normal.z < 0.0f ? DIR_Z_NEG : DIR_Z_POS;
+}
+
+CColModel::CColModel(void)
+{
+	numSpheres = 0;
+	spheres = nil;
+	numLines = 0;
+	lines = nil;
+	numBoxes = 0;
+	boxes = nil;
+	numTriangles = 0;
+	vertices = nil;
+	triangles = nil;
+	trianglePlanes = nil;
+	level = CGame::currLevel;
+	ownsCollisionVolumes = true;
+}
+
+CColModel::~CColModel(void)
+{
+	RemoveCollisionVolumes();
+	RemoveTrianglePlanes();
+}
+
+void
+CColModel::RemoveCollisionVolumes(void)
+{
+	if(ownsCollisionVolumes){
+		RwFree(spheres);
+		RwFree(lines);
+		RwFree(boxes);
+		RwFree(vertices);
+		RwFree(triangles);
+	}
+	numSpheres = 0;
+	numLines = 0;
+	numBoxes = 0;
+	numTriangles = 0;
+	spheres = nil;
+	lines = nil;
+	boxes = nil;
+	vertices = nil;
+	triangles = nil;
+}
+
+void
+CColModel::CalculateTrianglePlanes(void)
+{
+	// HACK: allocate space for one more element to stuff the link pointer into
+	trianglePlanes = (CColTrianglePlane*)RwMalloc(sizeof(CColTrianglePlane) * (numTriangles+1));
+	for(int i = 0; i < numTriangles; i++)
+		trianglePlanes[i].Set(vertices, triangles[i]);
+}
+
+void
+CColModel::RemoveTrianglePlanes(void)
+{
+	RwFree(trianglePlanes);
+	trianglePlanes = nil;
+}
+
+void
+CColModel::SetLinkPtr(CLink<CColModel*> *lptr)
+{
+	assert(trianglePlanes);
+	*(CLink<CColModel*>**)ALIGNPTR(&trianglePlanes[numTriangles]) = lptr;
+}
+
+CLink<CColModel*>*
+CColModel::GetLinkPtr(void)
+{
+	assert(trianglePlanes);
+	return *(CLink<CColModel*>**)ALIGNPTR(&trianglePlanes[numTriangles]);
+}
+
+void
+CColModel::GetTrianglePoint(CVector &v, int i) const
+{
+	v = vertices[i];
+}
+
+STARTPATCHES
+	InjectHook(0x4B9C30, (CMatrix& (*)(const CMatrix &src, CMatrix &dst))Invert, PATCH_JUMP);
+
+	InjectHook(0x40BB70, CCollision::TestSphereBox, PATCH_JUMP);
+	InjectHook(0x40E130, CCollision::TestLineBox, PATCH_JUMP);
+	InjectHook(0x40E5C0, CCollision::TestVerticalLineBox, PATCH_JUMP);
+	InjectHook(0x40EC10, CCollision::TestLineTriangle, PATCH_JUMP);
+	InjectHook(0x40DAA0, CCollision::TestLineSphere, PATCH_JUMP);
+	InjectHook(0x40C580, CCollision::TestSphereTriangle, PATCH_JUMP);
+	InjectHook(0x40F720, CCollision::TestLineOfSight, PATCH_JUMP);
+
+	InjectHook(0x40B9F0, CCollision::ProcessSphereSphere, PATCH_JUMP);
+	InjectHook(0x40BC00, CCollision::ProcessSphereBox, PATCH_JUMP);
+	InjectHook(0x40E670, CCollision::ProcessLineBox, PATCH_JUMP);
+	InjectHook(0x40DE80, CCollision::ProcessLineSphere, PATCH_JUMP);
+	InjectHook(0x40FB50, CCollision::ProcessVerticalLineTriangle, PATCH_JUMP);
+	InjectHook(0x40F140, CCollision::ProcessLineTriangle, PATCH_JUMP);
+	InjectHook(0x40CE30, CCollision::ProcessSphereTriangle, PATCH_JUMP);
+
+	InjectHook(0x40F910, CCollision::ProcessLineOfSight, PATCH_JUMP);
+	InjectHook(0x410120, CCollision::ProcessVerticalLine, PATCH_JUMP);
+	InjectHook(0x410BE0, CCollision::ProcessColModels, PATCH_JUMP);
+
+	InjectHook(0x40B960, CCollision::CalculateTrianglePlanes, PATCH_JUMP);
+	InjectHook(0x411640, &CLink<CColModel*>::Remove, PATCH_JUMP);
+	InjectHook(0x411620, &CLink<CColModel*>::Insert, PATCH_JUMP);
+	InjectHook(0x4115C0, &CLinkList<CColModel*>::Insert, PATCH_JUMP);
+	InjectHook(0x411600, &CLinkList<CColModel*>::Remove, PATCH_JUMP);
+//	InjectHook(0x411530, &CLinkList<CColModel*>::Init, PATCH_JUMP);
+
+	InjectHook(0x411E40, (void (CColSphere::*)(float, const CVector&, uint8, uint8))&CColSphere::Set, PATCH_JUMP);
+	InjectHook(0x40B2A0, &CColBox::Set, PATCH_JUMP);
+	InjectHook(0x40B320, &CColLine::ctor, PATCH_JUMP);
+	InjectHook(0x40B350, &CColLine::Set, PATCH_JUMP);
+	InjectHook(0x411E70, &CColTriangle::Set, PATCH_JUMP);
+
+	InjectHook(0x411EA0, &CColTrianglePlane::Set, PATCH_JUMP);
+	InjectHook(0x412140, &CColTrianglePlane::GetNormal, PATCH_JUMP);
+
+	InjectHook(0x411680, &CColModel::ctor, PATCH_JUMP);
+	InjectHook(0x4116E0, &CColModel::dtor, PATCH_JUMP);
+	InjectHook(0x411D80, &CColModel::RemoveCollisionVolumes, PATCH_JUMP);
+	InjectHook(0x411CB0, &CColModel::CalculateTrianglePlanes, PATCH_JUMP);
+	InjectHook(0x411D10, &CColModel::RemoveTrianglePlanes, PATCH_JUMP);
+	InjectHook(0x411D40, &CColModel::SetLinkPtr, PATCH_JUMP);
+	InjectHook(0x411D60, &CColModel::GetLinkPtr, PATCH_JUMP);
+ENDPATCHES