Custom boxy nodes (stairs, slabs) and collision changes

1 files changed, 387 insertions, 139 deletions

diff --git a/src/collision.cpp b/src/collision.cpp
index f8db42d26..09a7df7c2 100644
--- a/src/collision.cpp
+++ b/src/collision.cpp
@@ -22,32 +22,249 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "map.h"
 #include "nodedef.h"
 #include "gamedef.h"
+#include "log.h"
+#include <vector>
+#include "util/timetaker.h"
+#include "main.h" // g_profiler
+#include "profiler.h"
+
+// Helper function:
+// Checks for collision of a moving aabbox with a static aabbox
+// Returns -1 if no collision, 0 if X collision, 1 if Y collision, 2 if Z collision
+// The time after which the collision occurs is stored in dtime.
+int axisAlignedCollision(
+		const aabb3f &staticbox, const aabb3f &movingbox,
+		const v3f &speed, f32 d, f32 &dtime)
+{
+	//TimeTaker tt("axisAlignedCollision");
+
+	f32 xsize = (staticbox.MaxEdge.X - staticbox.MinEdge.X);
+	f32 ysize = (staticbox.MaxEdge.Y - staticbox.MinEdge.Y);
+	f32 zsize = (staticbox.MaxEdge.Z - staticbox.MinEdge.Z);
+
+	aabb3f relbox(
+			movingbox.MinEdge.X - staticbox.MinEdge.X,
+			movingbox.MinEdge.Y - staticbox.MinEdge.Y,
+			movingbox.MinEdge.Z - staticbox.MinEdge.Z,
+			movingbox.MaxEdge.X - staticbox.MinEdge.X,
+			movingbox.MaxEdge.Y - staticbox.MinEdge.Y,
+			movingbox.MaxEdge.Z - staticbox.MinEdge.Z
+	);
+
+	if(speed.X > 0) // Check for collision with X- plane
+	{
+		if(relbox.MaxEdge.X <= d)
+		{
+			dtime = - relbox.MaxEdge.X / speed.X;
+			if((relbox.MinEdge.Y + speed.Y * dtime < ysize) &&
+					(relbox.MaxEdge.Y + speed.Y * dtime > 0) &&
+					(relbox.MinEdge.Z + speed.Z * dtime < zsize) &&
+					(relbox.MaxEdge.Z + speed.Z * dtime > 0))
+				return 0;
+		}
+		else if(relbox.MinEdge.X > xsize)
+		{
+			return -1;
+		}
+	}
+	else if(speed.X < 0) // Check for collision with X+ plane
+	{
+		if(relbox.MinEdge.X >= xsize - d)
+		{
+			dtime = (xsize - relbox.MinEdge.X) / speed.X;
+			if((relbox.MinEdge.Y + speed.Y * dtime < ysize) &&
+					(relbox.MaxEdge.Y + speed.Y * dtime > 0) &&
+					(relbox.MinEdge.Z + speed.Z * dtime < zsize) &&
+					(relbox.MaxEdge.Z + speed.Z * dtime > 0))
+				return 0;
+		}
+		else if(relbox.MaxEdge.X < 0)
+		{
+			return -1;
+		}
+	}
+
+	// NO else if here
+
+	if(speed.Y > 0) // Check for collision with Y- plane
+	{
+		if(relbox.MaxEdge.Y <= d)
+		{
+			dtime = - relbox.MaxEdge.Y / speed.Y;
+			if((relbox.MinEdge.X + speed.X * dtime < xsize) &&
+					(relbox.MaxEdge.X + speed.X * dtime > 0) &&
+					(relbox.MinEdge.Z + speed.Z * dtime < zsize) &&
+					(relbox.MaxEdge.Z + speed.Z * dtime > 0))
+				return 1;
+		}
+		else if(relbox.MinEdge.Y > ysize)
+		{
+			return -1;
+		}
+	}
+	else if(speed.Y < 0) // Check for collision with Y+ plane
+	{
+		if(relbox.MinEdge.Y >= ysize - d)
+		{
+			dtime = (ysize - relbox.MinEdge.Y) / speed.Y;
+			if((relbox.MinEdge.X + speed.X * dtime < xsize) &&
+					(relbox.MaxEdge.X + speed.X * dtime > 0) &&
+					(relbox.MinEdge.Z + speed.Z * dtime < zsize) &&
+					(relbox.MaxEdge.Z + speed.Z * dtime > 0))
+				return 1;
+		}
+		else if(relbox.MaxEdge.Y < 0)
+		{
+			return -1;
+		}
+	}
+
+	// NO else if here
+
+	if(speed.Z > 0) // Check for collision with Z- plane
+	{
+		if(relbox.MaxEdge.Z <= d)
+		{
+			dtime = - relbox.MaxEdge.Z / speed.Z;
+			if((relbox.MinEdge.X + speed.X * dtime < xsize) &&
+					(relbox.MaxEdge.X + speed.X * dtime > 0) &&
+					(relbox.MinEdge.Y + speed.Y * dtime < ysize) &&
+					(relbox.MaxEdge.Y + speed.Y * dtime > 0))
+				return 2;
+		}
+		//else if(relbox.MinEdge.Z > zsize)
+		//{
+		//	return -1;
+		//}
+	}
+	else if(speed.Z < 0) // Check for collision with Z+ plane
+	{
+		if(relbox.MinEdge.Z >= zsize - d)
+		{
+			dtime = (zsize - relbox.MinEdge.Z) / speed.Z;
+			if((relbox.MinEdge.X + speed.X * dtime < xsize) &&
+					(relbox.MaxEdge.X + speed.X * dtime > 0) &&
+					(relbox.MinEdge.Y + speed.Y * dtime < ysize) &&
+					(relbox.MaxEdge.Y + speed.Y * dtime > 0))
+				return 2;
+		}
+		//else if(relbox.MaxEdge.Z < 0)
+		//{
+		//	return -1;
+		//}
+	}
+
+	return -1;
+}
+
+// Helper function:
+// Checks if moving the movingbox up by the given distance would hit a ceiling.
+bool wouldCollideWithCeiling(
+		const std::vector<aabb3f> &staticboxes,
+		const aabb3f &movingbox,
+		f32 y_increase, f32 d)
+{
+	//TimeTaker tt("wouldCollideWithCeiling");
+
+	assert(y_increase >= 0);
+
+	for(std::vector<aabb3f>::const_iterator
+			i = staticboxes.begin();
+			i != staticboxes.end(); i++)
+	{
+		const aabb3f& staticbox = *i;
+		if((movingbox.MaxEdge.Y - d <= staticbox.MinEdge.Y) &&
+				(movingbox.MaxEdge.Y + y_increase > staticbox.MinEdge.Y) &&
+				(movingbox.MinEdge.X < staticbox.MaxEdge.X) &&
+				(movingbox.MaxEdge.X > staticbox.MinEdge.X) &&
+				(movingbox.MinEdge.Z < staticbox.MaxEdge.Z) &&
+				(movingbox.MaxEdge.Z > staticbox.MinEdge.Z))
+			return true;
+	}
+
+	return false;
+}
+
 
 collisionMoveResult collisionMoveSimple(Map *map, IGameDef *gamedef,
-		f32 pos_max_d, const core::aabbox3d<f32> &box_0,
-		f32 dtime, v3f &pos_f, v3f &speed_f)
+		f32 pos_max_d, const aabb3f &box_0,
+		f32 stepheight, f32 dtime,
+		v3f &pos_f, v3f &speed_f, v3f &accel_f)
 {
+	//TimeTaker tt("collisionMoveSimple");
+    ScopeProfiler sp(g_profiler, "collisionMoveSimple avg", SPT_AVG);
+
 	collisionMoveResult result;
 
-	// If there is no speed, there are no collisions
+	/*
+		Calculate new velocity
+	*/
+	speed_f += accel_f * dtime;
+
+    // If there is no speed, there are no collisions
 	if(speed_f.getLength() == 0)
 		return result;
 
-	v3f oldpos_f = pos_f;
-	v3s16 oldpos_i = floatToInt(oldpos_f, BS);
-
 	/*
-		Calculate new position
+		Collect node boxes in movement range
 	*/
-	pos_f += speed_f * dtime;
+	std::vector<aabb3f> cboxes;
+	std::vector<bool> is_unloaded;
+	std::vector<bool> is_step_up;
+	{
+	//TimeTaker tt2("collisionMoveSimple collect boxes");
+    ScopeProfiler sp(g_profiler, "collisionMoveSimple collect boxes avg", SPT_AVG);
+
+	v3s16 oldpos_i = floatToInt(pos_f, BS);
+	v3s16 newpos_i = floatToInt(pos_f + speed_f * dtime, BS);
+	s16 min_x = MYMIN(oldpos_i.X, newpos_i.X) + (box_0.MinEdge.X / BS) - 1;
+	s16 min_y = MYMIN(oldpos_i.Y, newpos_i.Y) + (box_0.MinEdge.Y / BS) - 1;
+	s16 min_z = MYMIN(oldpos_i.Z, newpos_i.Z) + (box_0.MinEdge.Z / BS) - 1;
+	s16 max_x = MYMAX(oldpos_i.X, newpos_i.X) + (box_0.MaxEdge.X / BS) + 1;
+	s16 max_y = MYMAX(oldpos_i.Y, newpos_i.Y) + (box_0.MaxEdge.Y / BS) + 1;
+	s16 max_z = MYMAX(oldpos_i.Z, newpos_i.Z) + (box_0.MaxEdge.Z / BS) + 1;
+
+	for(s16 x = min_x; x <= max_x; x++)
+	for(s16 y = min_y; y <= max_y; y++)
+	for(s16 z = min_z; z <= max_z; z++)
+	{
+		try{
+			// Object collides into walkable nodes
+			MapNode n = map->getNode(v3s16(x,y,z));
+			if(gamedef->getNodeDefManager()->get(n).walkable == false)
+				continue;
+
+			std::vector<aabb3f> nodeboxes = n.getNodeBoxes(gamedef->ndef());
+			for(std::vector<aabb3f>::iterator
+					i = nodeboxes.begin();
+					i != nodeboxes.end(); i++)
+			{
+				aabb3f box = *i;
+				box.MinEdge += v3f(x, y, z)*BS;
+				box.MaxEdge += v3f(x, y, z)*BS;
+				cboxes.push_back(box);
+				is_unloaded.push_back(false);
+				is_step_up.push_back(false);
+			}
+		}
+		catch(InvalidPositionException &e)
+		{
+			// Collide with unloaded nodes
+			aabb3f box = getNodeBox(v3s16(x,y,z), BS);
+			cboxes.push_back(box);
+			is_unloaded.push_back(true);
+			is_step_up.push_back(false);
+		}
+	}
+	} // tt2
+
+	assert(cboxes.size() == is_unloaded.size());
+	assert(cboxes.size() == is_step_up.size());
 
 	/*
 		Collision detection
 	*/
-	
-	// position in nodes
-	v3s16 pos_i = floatToInt(pos_f, BS);
-	
+
 	/*
 		Collision uncertainty radius
 		Make it a bit larger than the maximum distance of movement
@@ -58,49 +275,129 @@ collisionMoveResult collisionMoveSimple(Map *map, IGameDef *gamedef,
 
 	// This should always apply, otherwise there are glitches
 	assert(d > pos_max_d);
-	
-	/*
-		Calculate collision box
-	*/
-	core::aabbox3d<f32> box = box_0;
-	box.MaxEdge += pos_f;
-	box.MinEdge += pos_f;
-	core::aabbox3d<f32> oldbox = box_0;
-	oldbox.MaxEdge += oldpos_f;
-	oldbox.MinEdge += oldpos_f;
 
-	/*
-		If the object lies on a walkable node, this is set to true.
-	*/
-	result.touching_ground = false;
-	
-	/*
-		Go through every node around the object
-	*/
-	s16 min_x = (box_0.MinEdge.X / BS) - 2;
-	s16 min_y = (box_0.MinEdge.Y / BS) - 2;
-	s16 min_z = (box_0.MinEdge.Z / BS) - 2;
-	s16 max_x = (box_0.MaxEdge.X / BS) + 1;
-	s16 max_y = (box_0.MaxEdge.Y / BS) + 1;
-	s16 max_z = (box_0.MaxEdge.Z / BS) + 1;
-	for(s16 y = oldpos_i.Y + min_y; y <= oldpos_i.Y + max_y; y++)
-	for(s16 z = oldpos_i.Z + min_z; z <= oldpos_i.Z + max_z; z++)
-	for(s16 x = oldpos_i.X + min_x; x <= oldpos_i.X + max_x; x++)
+	int loopcount = 0;
+
+	while(dtime > BS*1e-10)
 	{
-		try{
-			// Object collides into walkable nodes
-			MapNode n = map->getNode(v3s16(x,y,z));
-			if(gamedef->getNodeDefManager()->get(n).walkable == false)
+		//TimeTaker tt3("collisionMoveSimple dtime loop");
+        ScopeProfiler sp(g_profiler, "collisionMoveSimple dtime loop avg", SPT_AVG);
+
+		// Avoid infinite loop
+		loopcount++;
+		if(loopcount >= 100)
+		{
+			infostream<<"collisionMoveSimple: WARNING: Loop count exceeded, aborting to avoid infiniite loop"<<std::endl;
+			dtime = 0;
+			break;
+		}
+
+		aabb3f movingbox = box_0;
+		movingbox.MinEdge += pos_f;
+		movingbox.MaxEdge += pos_f;
+
+		int nearest_collided = -1;
+		f32 nearest_dtime = dtime;
+		u32 nearest_boxindex = -1;
+
+		/*
+			Go through every nodebox, find nearest collision
+		*/
+		for(u32 boxindex = 0; boxindex < cboxes.size(); boxindex++)
+		{
+			// Ignore if already stepped up this nodebox.
+			if(is_step_up[boxindex])
+				continue;
+
+			// Find nearest collision of the two boxes (raytracing-like)
+			f32 dtime_tmp;
+			int collided = axisAlignedCollision(
+					cboxes[boxindex], movingbox, speed_f, d, dtime_tmp);
+
+			if(collided == -1 || dtime_tmp >= nearest_dtime)
 				continue;
+
+			nearest_dtime = dtime_tmp;
+			nearest_collided = collided;
+			nearest_boxindex = boxindex;
 		}
-		catch(InvalidPositionException &e)
+
+		if(nearest_collided == -1)
 		{
-			// Doing nothing here will block the object from
-			// walking over map borders
+			// No collision with any collision box.
+			pos_f += speed_f * dtime;
+			dtime = 0;  // Set to 0 to avoid "infinite" loop due to small FP numbers
 		}
+		else
+		{
+			// Otherwise, a collision occurred.
+
+			const aabb3f& cbox = cboxes[nearest_boxindex];
+
+			// Check for stairs.
+			bool step_up = (nearest_collided != 1) && // must not be Y direction
+					(movingbox.MinEdge.Y < cbox.MaxEdge.Y) &&
+					(movingbox.MinEdge.Y + stepheight > cbox.MaxEdge.Y) &&
+					(!wouldCollideWithCeiling(cboxes, movingbox,
+							cbox.MaxEdge.Y - movingbox.MinEdge.Y,
+							d));
+
+			// Move to the point of collision and reduce dtime by nearest_dtime
+			if(nearest_dtime < 0)
+			{
+				// Handle negative nearest_dtime (can be caused by the d allowance)
+				if(!step_up)
+				{
+					if(nearest_collided == 0)
+						pos_f.X += speed_f.X * nearest_dtime;
+					if(nearest_collided == 1)
+						pos_f.Y += speed_f.Y * nearest_dtime;
+					if(nearest_collided == 2)
+						pos_f.Z += speed_f.Z * nearest_dtime;
+				}
+			}
+			else
+			{
+				pos_f += speed_f * nearest_dtime;
+				dtime -= nearest_dtime;
+			}
+
+			// Set the speed component that caused the collision to zero
+			if(step_up)
+			{
+				// Special case: Handle stairs
+				is_step_up[nearest_boxindex] = true;
+			}
+			else if(nearest_collided == 0) // X
+			{
+				speed_f.X = 0;
+				result.collides = true;
+				result.collides_xz = true;
+			}
+			else if(nearest_collided == 1) // Y
+			{
+				speed_f.Y = 0;
+				result.collides = true;
+			}
+			else if(nearest_collided == 2) // Z
+			{
+				speed_f.Z = 0;
+				result.collides = true;
+				result.collides_xz = true;
+			}
+		}
+	}
+
+	/*
+		Final touches: Check if standing on ground, step up stairs.
+	*/
+	aabb3f box = box_0;
+	box.MinEdge += pos_f;
+	box.MaxEdge += pos_f;
+	for(u32 boxindex = 0; boxindex < cboxes.size(); boxindex++)
+	{
+		const aabb3f& cbox = cboxes[boxindex];
 
-		core::aabbox3d<f32> nodebox = getNodeBox(v3s16(x,y,z), BS);
-		
 		/*
 			See if the object is touching ground.
 
@@ -111,112 +408,50 @@ collisionMoveResult collisionMoveSimple(Map *map, IGameDef *gamedef,
 			Use 0.15*BS so that it is easier to get on a node.
 		*/
 		if(
-				//fabs(nodebox.MaxEdge.Y-box.MinEdge.Y) < d
-				fabs(nodebox.MaxEdge.Y-box.MinEdge.Y) < 0.15*BS
-				&& nodebox.MaxEdge.X-d > box.MinEdge.X
-				&& nodebox.MinEdge.X+d < box.MaxEdge.X
-				&& nodebox.MaxEdge.Z-d > box.MinEdge.Z
-				&& nodebox.MinEdge.Z+d < box.MaxEdge.Z
+				cbox.MaxEdge.X-d > box.MinEdge.X &&
+				cbox.MinEdge.X+d < box.MaxEdge.X &&
+				cbox.MaxEdge.Z-d > box.MinEdge.Z &&
+				cbox.MinEdge.Z+d < box.MaxEdge.Z
 		){
-			result.touching_ground = true;
-		}
-		
-		// If object doesn't intersect with node, ignore node.
-		if(box.intersectsWithBox(nodebox) == false)
-			continue;
-		
-		/*
-			Go through every axis
-		*/
-		v3f dirs[3] = {
-			v3f(0,0,1), // back-front
-			v3f(0,1,0), // top-bottom
-			v3f(1,0,0), // right-left
-		};
-		for(u16 i=0; i<3; i++)
-		{
-			/*
-				Calculate values along the axis
-			*/
-			f32 nodemax = nodebox.MaxEdge.dotProduct(dirs[i]);
-			f32 nodemin = nodebox.MinEdge.dotProduct(dirs[i]);
-			f32 objectmax = box.MaxEdge.dotProduct(dirs[i]);
-			f32 objectmin = box.MinEdge.dotProduct(dirs[i]);
-			f32 objectmax_old = oldbox.MaxEdge.dotProduct(dirs[i]);
-			f32 objectmin_old = oldbox.MinEdge.dotProduct(dirs[i]);
-			
-			/*
-				Check collision for the axis.
-				Collision happens when object is going through a surface.
-			*/
-			bool negative_axis_collides =
-				(nodemax > objectmin && nodemax <= objectmin_old + d
-					&& speed_f.dotProduct(dirs[i]) < 0);
-			bool positive_axis_collides =
-				(nodemin < objectmax && nodemin >= objectmax_old - d
-					&& speed_f.dotProduct(dirs[i]) > 0);
-			bool main_axis_collides =
-					negative_axis_collides || positive_axis_collides;
-			
-			/*
-				Check overlap of object and node in other axes
-			*/
-			bool other_axes_overlap = true;
-			for(u16 j=0; j<3; j++)
+			if(is_step_up[boxindex])
 			{
-				if(j == i)
-					continue;
-				f32 nodemax = nodebox.MaxEdge.dotProduct(dirs[j]);
-				f32 nodemin = nodebox.MinEdge.dotProduct(dirs[j]);
-				f32 objectmax = box.MaxEdge.dotProduct(dirs[j]);
-				f32 objectmin = box.MinEdge.dotProduct(dirs[j]);
-				if(!(nodemax - d > objectmin && nodemin + d < objectmax))
-				{
-					other_axes_overlap = false;
-					break;
-				}
+				pos_f.Y += (cbox.MaxEdge.Y - box.MinEdge.Y);
+				box = box_0;
+				box.MinEdge += pos_f;
+				box.MaxEdge += pos_f;
 			}
-			
-			/*
-				If this is a collision, revert the pos_f in the main
-				direction.
-			*/
-			if(other_axes_overlap && main_axis_collides)
+			if(fabs(cbox.MaxEdge.Y-box.MinEdge.Y) < 0.15*BS)
 			{
-				speed_f -= speed_f.dotProduct(dirs[i]) * dirs[i];
-				pos_f -= pos_f.dotProduct(dirs[i]) * dirs[i];
-				pos_f += oldpos_f.dotProduct(dirs[i]) * dirs[i];
-				result.collides = true;
+				result.touching_ground = true;
+				if(is_unloaded[boxindex])
+					result.standing_on_unloaded = true;
 			}
-		
 		}
-	} // xyz
-	
+	}
+
 	return result;
 }
 
+#if 0
+// This doesn't seem to work and isn't used
 collisionMoveResult collisionMovePrecise(Map *map, IGameDef *gamedef,
-		f32 pos_max_d, const core::aabbox3d<f32> &box_0,
-		f32 dtime, v3f &pos_f, v3f &speed_f)
+		f32 pos_max_d, const aabb3f &box_0,
+		f32 stepheight, f32 dtime,
+		v3f &pos_f, v3f &speed_f, v3f &accel_f)
 {
-	collisionMoveResult final_result;
+	//TimeTaker tt("collisionMovePrecise");
+    ScopeProfiler sp(g_profiler, "collisionMovePrecise avg", SPT_AVG);
 	
+	collisionMoveResult final_result;
+
 	// If there is no speed, there are no collisions
 	if(speed_f.getLength() == 0)
 		return final_result;
 
-	// Maximum time increment (for collision detection etc)
-	// time = distance / speed
-	f32 dtime_max_increment = pos_max_d / speed_f.getLength();
-	
-	// Maximum time increment is 10ms or lower
-	if(dtime_max_increment > 0.01)
-		dtime_max_increment = 0.01;
-	
 	// Don't allow overly huge dtime
 	if(dtime > 2.0)
 		dtime = 2.0;
-	
+
 	f32 dtime_downcount = dtime;
 
 	u32 loopcount = 0;
@@ -224,6 +459,16 @@ collisionMoveResult collisionMovePrecise(Map *map, IGameDef *gamedef,
 	{
 		loopcount++;
 
+		// Maximum time increment (for collision detection etc)
+		// time = distance / speed
+		f32 dtime_max_increment = 1.0;
+		if(speed_f.getLength() != 0)
+			dtime_max_increment = pos_max_d / speed_f.getLength();
+
+		// Maximum time increment is 10ms or lower
+		if(dtime_max_increment > 0.01)
+			dtime_max_increment = 0.01;
+
 		f32 dtime_part;
 		if(dtime_downcount > dtime_max_increment)
 		{
@@ -242,17 +487,20 @@ collisionMoveResult collisionMovePrecise(Map *map, IGameDef *gamedef,
 		}
 
 		collisionMoveResult result = collisionMoveSimple(map, gamedef,
-				pos_max_d, box_0, dtime_part, pos_f, speed_f);
+				pos_max_d, box_0, stepheight, dtime_part,
+				pos_f, speed_f, accel_f);
 
 		if(result.touching_ground)
 			final_result.touching_ground = true;
 		if(result.collides)
 			final_result.collides = true;
+		if(result.collides_xz)
+			final_result.collides_xz = true;
+		if(result.standing_on_unloaded)
+			final_result.standing_on_unloaded = true;
 	}
 	while(dtime_downcount > 0.001);
-		
 
 	return final_result;
 }
-
-
+#endif