Port of SNOW-643 : Water flicker at high altitude. This doesn't fix the low altitude flicker though (STORM-306)

1 files changed, 277 insertions, 76 deletions

diff --git a/indra/newview/llworld.cpp b/indra/newview/llworld.cpp
index 5760d04a08..8731c9e1a7 100644
--- a/indra/newview/llworld.cpp
+++ b/indra/newview/llworld.cpp
@@ -55,6 +55,11 @@
 #include "pipeline.h"
 #include "llappviewer.h"		// for do_disconnect()
 
+#include <deque>
+#include <queue>
+#include <map>
+#include <cstring>
+
 //
 // Globals
 //
@@ -834,10 +839,69 @@ F32 LLWorld::getLandFarClip() const
 
 void LLWorld::setLandFarClip(const F32 far_clip)
 {
+	static S32 const rwidth = (S32)REGION_WIDTH_U32;
+	S32 const n1 = (llceil(mLandFarClip) - 1) / rwidth;
+	S32 const n2 = (llceil(far_clip) - 1) / rwidth;
+	bool need_water_objects_update = n1 != n2;
+
 	mLandFarClip = far_clip;
+
+	if (need_water_objects_update)
+	{
+		updateWaterObjects();
+	}
 }
 
+// Some region that we're connected to, but not the one we're in, gave us
+// a (possibly) new water height. Update it in our local copy.
+void LLWorld::waterHeightRegionInfo(std::string const& sim_name, F32 water_height)
+{
+	for (region_list_t::iterator iter = mRegionList.begin(); iter != mRegionList.end(); ++iter)
+	{
+		if ((*iter)->getName() == sim_name)
+		{
+			(*iter)->setWaterHeight(water_height);
+			break;
+		}
+	}
+}
 
+// There are three types of water objects:
+// Region water objects: the water in a region.
+// Hole water objects: water in the void but within current draw distance.
+// Edge water objects: the water outside the draw distance, up till the horizon.
+//
+// For example:
+//
+// -----------------------horizon-------------------------
+// |                 |                 |                 |
+// |  Edge Water     |                 |                 |
+// |                 |                 |                 |
+// |                 |                 |                 |
+// |                 |                 |                 |
+// |                 |                 |                 |
+// |                 |      rwidth     |                 |
+// |                 |     <----->     |                 |
+// -------------------------------------------------------
+// |                 |Hole |other|     |                 |
+// |                 |Water|reg. |     |                 |
+// |                 |-----------------|                 |
+// |                 |other|cur. |<--> |                 |
+// |                 |reg. | reg.|  \__|_ draw distance  |
+// |                 |-----------------|                 |
+// |                 |     |     |<--->|                 |
+// |                 |     |     |  \__|_ range          |
+// -------------------------------------------------------
+// |                 |<----width------>|<--horizon ext.->|
+// |                 |                 |                 |
+// |                 |                 |                 |
+// |                 |                 |                 |
+// |                 |                 |                 |
+// |                 |                 |                 |
+// |                 |                 |                 |
+// |                 |                 |                 |
+// -------------------------------------------------------
+//
 void LLWorld::updateWaterObjects()
 {
 	if (!gAgent.getRegion())
@@ -850,128 +914,265 @@ void LLWorld::updateWaterObjects()
 		return;
 	}
 
-	// First, determine the min and max "box" of water objects
-	S32 min_x = 0;
-	S32 min_y = 0;
-	S32 max_x = 0;
-	S32 max_y = 0;
+	// Region width in meters.
+	S32 const rwidth = (S32)REGION_WIDTH_U32;
+
+	// The distance we might see into the void
+	// when standing on the edge of a region, in meters.
+	S32 const draw_distance = llceil(mLandFarClip);
+
+	// We can only have "holes" in the water (where there no region) if we
+	// can have existing regions around it. Taking into account that this
+	// code is only executed when we enter a region, and not when we walk
+	// around in it, we (only) need to take into account regions that fall
+	// within the draw_distance.
+	//
+	// Set 'range' to draw_distance, rounded up to the nearest multiple of rwidth.
+	S32 const nsims = (draw_distance + rwidth - 1) / rwidth;
+	S32 const range = nsims * rwidth;
+
+	// Get South-West corner of current region.
+	LLViewerRegion const* regionp = gAgent.getRegion();
 	U32 region_x, region_y;
-
-	S32 rwidth = 256;
-
-	// We only want to fill in water for stuff that's near us, say, within 256 or 512m
-	S32 range = LLViewerCamera::getInstance()->getFar() > 256.f ? 512 : 256;
-
-	LLViewerRegion* regionp = gAgent.getRegion();
 	from_region_handle(regionp->getHandle(), &region_x, &region_y);
 
-	min_x = (S32)region_x - range;
-	min_y = (S32)region_y - range;
-	max_x = (S32)region_x + range;
-	max_y = (S32)region_y + range;
+	// The min. and max. coordinates of the South-West corners of the Hole water objects.
+	S32 const min_x = (S32)region_x - range;
+	S32 const min_y = (S32)region_y - range;
+	S32 const max_x = (S32)region_x + range;
+	S32 const max_y = (S32)region_y + range;
+
+	// Attempt to determine a sensible water height for all the
+	// Hole Water objects.
+	//
+	// It make little sense to try to guess what the best water
+	// height should be when that isn't completely obvious: if it's
+	// impossible to satisfy every region's water height without
+	// getting a jump in the water height.
+	//
+	// In order to keep the reasoning simple, we assume something
+	// logical as a group of connected regions, where the coastline
+	// is at the outer edge. Anything more complex that would "break"
+	// under such an assumption would probably break anyway (would
+	// depend on terrain editing and existing mega prims, say, if
+	// anything would make sense at all).
+	//
+	// So, what we do is find all connected regions within the
+	// draw distance that border void, and then pick the lowest
+	// water height of those (coast) regions.
+	S32 const n = 2 * nsims + 1;
+	S32 const origin = nsims + nsims * n;
+	std::vector<F32> water_heights(n * n);
+	std::vector<U8> checked(n * n, 0);		// index = nx + ny * n + origin;
+	U8 const region_bit = 1;
+	U8 const hole_bit = 2;
+	U8 const bordering_hole_bit = 4;
+	U8 const bordering_edge_bit = 8;
+	// Use the legacy waterheight for the Edge water in the case
+	// that we don't find any Hole water at all.
+	F32 water_height = DEFAULT_WATER_HEIGHT;
+	int max_count = 0;
+	LL_DEBUGS("WaterHeight") << "Current region: " << regionp->getName() << "; water height: " << regionp->getWaterHeight() << " m." << LL_ENDL;
+	std::map<S32, int> water_height_counts;
+	typedef std::queue<std::pair<S32, S32>, std::deque<std::pair<S32, S32> > > nxny_pairs_type;
+	nxny_pairs_type nxny_pairs;
+	nxny_pairs.push(nxny_pairs_type::value_type(0, 0));
+	water_heights[origin] = regionp->getWaterHeight();
+	checked[origin] = region_bit;
+	// For debugging purposes.
+	int number_of_connected_regions = 1;
+	int uninitialized_regions = 0;
+	int bordering_hole = 0;
+	int bordering_edge = 0;
+	while(!nxny_pairs.empty())
+	{
+		S32 const nx = nxny_pairs.front().first;
+		S32 const ny = nxny_pairs.front().second;
+		LL_DEBUGS("WaterHeight") << "nx,ny = " << nx << "," << ny << LL_ENDL;
+		S32 const index = nx + ny * n + origin;
+		nxny_pairs.pop();
+		for (S32 dir = 0; dir < 4; ++dir)
+		{
+			S32 const cnx = nx + gDirAxes[dir][0];
+			S32 const cny = ny + gDirAxes[dir][1];
+			LL_DEBUGS("WaterHeight") << "dir = " << dir << "; cnx,cny = " << cnx << "," << cny << LL_ENDL;
+			S32 const cindex = cnx + cny * n + origin;
+			bool is_hole = false;
+			bool is_edge = false;
+			LLViewerRegion* new_region_found = NULL;
+			if (cnx < -nsims || cnx > nsims ||
+			    cny < -nsims || cny > nsims)
+			{
+				LL_DEBUGS("WaterHeight") << "  Edge Water!" << LL_ENDL;
+				// Bumped into Edge water object.
+				is_edge = true;
+			}
+			else if (checked[cindex])
+			{
+				LL_DEBUGS("WaterHeight") << "  Already checked before!" << LL_ENDL;
+				// Already checked.
+				is_hole = (checked[cindex] & hole_bit);
+			}
+			else
+			{
+				S32 x = (S32)region_x + cnx * rwidth;
+				S32 y = (S32)region_y + cny * rwidth;
+				U64 region_handle = to_region_handle(x, y);
+				new_region_found = getRegionFromHandle(region_handle);
+				is_hole = !new_region_found;
+				checked[cindex] = is_hole ? hole_bit : region_bit;
+			}
+			if (is_hole)
+			{
+				// This was a region that borders at least one 'hole'.
+				// Count the found coastline.
+				F32 new_water_height = water_heights[index];
+				LL_DEBUGS("WaterHeight") << "  This is void; counting coastline with water height of " << new_water_height << LL_ENDL;
+				S32 new_water_height_cm = llround(new_water_height * 100);
+				int count = (water_height_counts[new_water_height_cm] += 1);
+				// Just use the lowest water height: this is mainly about the horizon water,
+				// and whatever we do, we don't want it to be possible to look under the water
+				// when looking in the distance: it is better to make a step downwards in water
+				// height when going away from the avie than a step upwards. However, since
+				// everyone is used to DEFAULT_WATER_HEIGHT, don't allow a single region
+				// to drag the water level below DEFAULT_WATER_HEIGHT on it's own.
+				if (bordering_hole == 0 ||			// First time we get here.
+				    (new_water_height >= DEFAULT_WATER_HEIGHT &&
+					 new_water_height < water_height) ||
+				    (new_water_height < DEFAULT_WATER_HEIGHT &&
+					 count > max_count)
+				   )
+				{
+					water_height = new_water_height;
+				}
+				if (count > max_count)
+				{
+					max_count = count;
+				}
+				if (!(checked[index] & bordering_hole_bit))
+				{
+					checked[index] |= bordering_hole_bit;
+					++bordering_hole;
+				}
+			}
+			else if (is_edge && !(checked[index] & bordering_edge_bit))
+			{
+				checked[index] |= bordering_edge_bit;
+				++bordering_edge;
+			}
+			if (!new_region_found)
+			{
+				// Dead end, there is no region here.
+				continue;
+			}
+			// Found a new connected region.
+			++number_of_connected_regions;
+			if (new_region_found->getName().empty())
+			{
+				// Uninitialized LLViewerRegion, don't use it's water height.
+				LL_DEBUGS("WaterHeight") << "  Uninitialized region." << LL_ENDL;
+				++uninitialized_regions;
+				continue;
+			}
+			nxny_pairs.push(nxny_pairs_type::value_type(cnx, cny));
+			water_heights[cindex] = new_region_found->getWaterHeight();
+			LL_DEBUGS("WaterHeight") << "  Found a new region (name: " << new_region_found->getName() << "; water height: " << water_heights[cindex] << " m)!" << LL_ENDL;
+		}
+	}
+	llinfos << "Number of connected regions: " << number_of_connected_regions << " (" << uninitialized_regions <<
+		" uninitialized); number of regions bordering Hole water: " << bordering_hole <<
+		"; number of regions bordering Edge water: " << bordering_edge << llendl;
+	llinfos << "Coastline count (height, count): ";
+	bool first = true;
+	for (std::map<S32, int>::iterator iter = water_height_counts.begin(); iter != water_height_counts.end(); ++iter)
+	{
+		if (!first) llcont << ", ";
+		llcont << "(" << (iter->first / 100.f) << ", " << iter->second << ")";
+		first = false;
+	}
+	llcont << llendl;
+	llinfos << "Water height used for Hole and Edge water objects: " << water_height << llendl;
 
-	F32 height = 0.f;
-	
-	for (region_list_t::iterator iter = mRegionList.begin();
-		 iter != mRegionList.end(); ++iter)
+	// Update all Region water objects.
+	for (region_list_t::iterator iter = mRegionList.begin(); iter != mRegionList.end(); ++iter)
 	{
 		LLViewerRegion* regionp = *iter;
 		LLVOWater* waterp = regionp->getLand().getWaterObj();
-		height += regionp->getWaterHeight();
 		if (waterp)
 		{
 			gObjectList.updateActive(waterp);
 		}
 	}
 
+	// Clean up all existing Hole water objects.
 	for (std::list<LLVOWater*>::iterator iter = mHoleWaterObjects.begin();
-		 iter != mHoleWaterObjects.end(); ++ iter)
+		 iter != mHoleWaterObjects.end(); ++iter)
 	{
 		LLVOWater* waterp = *iter;
 		gObjectList.killObject(waterp);
 	}
 	mHoleWaterObjects.clear();
 
-	// Now, get a list of the holes
-	S32 x, y;
-	for (x = min_x; x <= max_x; x += rwidth)
+	// Let the Edge and Hole water boxes be 1024 meter high so that they
+	// are never too small to be drawn (A LL_VO_*_WATER box has water
+	// rendered on it's bottom surface only), and put their bottom at
+	// the current regions water height.
+	F32 const box_height = 1024;
+	F32 const water_center_z = water_height + box_height / 2;
+
+	// Create new Hole water objects within 'range' where there is no region.
+	for (S32 x = min_x; x <= max_x; x += rwidth)
 	{
-		for (y = min_y; y <= max_y; y += rwidth)
+		for (S32 y = min_y; y <= max_y; y += rwidth)
 		{
 			U64 region_handle = to_region_handle(x, y);
 			if (!getRegionFromHandle(region_handle))
 			{
-				LLVOWater* waterp = (LLVOWater *)gObjectList.createObjectViewer(LLViewerObject::LL_VO_WATER, gAgent.getRegion());
+				LLVOWater* waterp = (LLVOWater*)gObjectList.createObjectViewer(LLViewerObject::LL_VO_VOID_WATER, gAgent.getRegion());
 				waterp->setUseTexture(FALSE);
-				waterp->setPositionGlobal(LLVector3d(x + rwidth/2,
-													 y + rwidth/2,
-													 256.f+DEFAULT_WATER_HEIGHT));
-				waterp->setScale(LLVector3((F32)rwidth, (F32)rwidth, 512.f));
+				waterp->setPositionGlobal(LLVector3d(x + rwidth / 2, y + rwidth / 2, water_center_z));
+				waterp->setScale(LLVector3((F32)rwidth, (F32)rwidth, box_height));
 				gPipeline.createObject(waterp);
 				mHoleWaterObjects.push_back(waterp);
 			}
 		}
 	}
 
-	// Update edge water objects
-	S32 wx, wy;
-	S32 center_x, center_y;
-	wx = (max_x - min_x) + rwidth;
-	wy = (max_y - min_y) + rwidth;
-	center_x = min_x + (wx >> 1);
-	center_y = min_y + (wy >> 1);
-
-	S32 add_boundary[4] = {
-		512 - (max_x - region_x),
-		512 - (max_y - region_y),
-		512 - (region_x - min_x),
-		512 - (region_y - min_y) };
+	// Center of the region.
+	S32 const center_x = region_x + rwidth / 2;
+	S32 const center_y = region_y + rwidth / 2;
+	// Width of the area with Hole water objects.
+	S32 const width = rwidth + 2 * range;
+	S32 const horizon_extend = 2048 + 512 - range;	// Legacy value.
+	// The overlap is needed to get rid of sky pixels being visible between the
+	// Edge and Hole water object at greater distances (due to floating point
+	// round off errors).
+	S32 const edge_hole_overlap = 1;		// Twice the actual overlap.
 		
-	S32 dir;
-	for (dir = 0; dir < 8; dir++)
+	for (S32 dir = 0; dir < 8; ++dir)
 	{
-		S32 dim[2] = { 0 };
-		switch (gDirAxes[dir][0])
-		{
-		case -1: dim[0] = add_boundary[2]; break;
-		case  0: dim[0] = wx; break;
-		default: dim[0] = add_boundary[0]; break;
-		}
-		switch (gDirAxes[dir][1])
-		{
-		case -1: dim[1] = add_boundary[3]; break;
-		case  0: dim[1] = wy; break;
-		default: dim[1] = add_boundary[1]; break;
-		}
+		// Size of the Edge water objects.
+		S32 const dim_x = (gDirAxes[dir][0] == 0) ? width : (horizon_extend + edge_hole_overlap);
+		S32 const dim_y = (gDirAxes[dir][1] == 0) ? width : (horizon_extend + edge_hole_overlap);
+		// And their position.
+		S32 const water_center_x = center_x + (width + horizon_extend) / 2 * gDirAxes[dir][0];
+		S32 const water_center_y = center_y + (width + horizon_extend) / 2 * gDirAxes[dir][1];
 
-		// Resize and reshape the water objects
-		const S32 water_center_x = center_x + llround((wx + dim[0]) * 0.5f * gDirAxes[dir][0]);
-		const S32 water_center_y = center_y + llround((wy + dim[1]) * 0.5f * gDirAxes[dir][1]);
-		
 		LLVOWater* waterp = mEdgeWaterObjects[dir];
 		if (!waterp || waterp->isDead())
 		{
 			// The edge water objects can be dead because they're attached to the region that the
 			// agent was in when they were originally created.
-			mEdgeWaterObjects[dir] = (LLVOWater *)gObjectList.createObjectViewer(LLViewerObject::LL_VO_WATER,
-																				 gAgent.getRegion());
+			mEdgeWaterObjects[dir] = (LLVOWater *)gObjectList.createObjectViewer(LLViewerObject::LL_VO_VOID_WATER, gAgent.getRegion());
 			waterp = mEdgeWaterObjects[dir];
 			waterp->setUseTexture(FALSE);
-			waterp->setIsEdgePatch(TRUE);
+			waterp->setIsEdgePatch(TRUE);		// Mark that this is edge water and not hole water.
 			gPipeline.createObject(waterp);
 		}
 
 		waterp->setRegion(gAgent.getRegion());
-		LLVector3d water_pos(water_center_x, water_center_y, 
-			DEFAULT_WATER_HEIGHT+256.f);
-		LLVector3 water_scale((F32) dim[0], (F32) dim[1], 512.f);
-
-		//stretch out to horizon
-		water_scale.mV[0] += fabsf(2048.f * gDirAxes[dir][0]);
-		water_scale.mV[1] += fabsf(2048.f * gDirAxes[dir][1]);
-
-		water_pos.mdV[0] += 1024.f * gDirAxes[dir][0];
-		water_pos.mdV[1] += 1024.f * gDirAxes[dir][1];
+		LLVector3d water_pos(water_center_x, water_center_y, water_center_z);
+		LLVector3 water_scale((F32) dim_x, (F32) dim_y, box_height);
 
 		waterp->setPositionGlobal(water_pos);
 		waterp->setScale(water_scale);