Files
OpenSpace/modules/globebrowsing/globes/chunknode.cpp
2016-05-02 11:13:41 -04:00

249 lines
9.2 KiB
C++

/*****************************************************************************************
* *
* OpenSpace *
* *
* Copyright (c) 2014-2016 *
* *
* Permission is hereby granted, free of charge, to any person obtaining a copy of this *
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* The above copyright notice and this permission notice shall be included in all copies *
* or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, *
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A *
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#include <modules/globebrowsing/globes/chunknode.h>
#include <ghoul/misc/assert.h>
#include <openspace/engine/wrapper/windowwrapper.h>
#include <openspace/engine/openspaceengine.h>
#include <modules/globebrowsing/globes/chunklodglobe.h>
#include <modules/globebrowsing/rendering/frustumculler.h>
namespace {
const std::string _loggerCat = "ChunkNode";
}
namespace openspace {
int ChunkNode::instanceCount = 0;
int ChunkNode::renderedPatches = 0;
ChunkNode::ChunkNode(ChunkLodGlobe& owner, const GeodeticPatch& patch, ChunkNode* parent)
: _owner(owner)
, _patch(patch)
, _parent(parent)
, _isVisible(true)
{
_children[0] = nullptr;
_children[1] = nullptr;
_children[2] = nullptr;
_children[3] = nullptr;
instanceCount++;
}
ChunkNode::~ChunkNode() {
instanceCount--;
}
bool ChunkNode::isRoot() const {
return _parent == nullptr;
}
bool ChunkNode::isLeaf() const {
return _children[0] == nullptr;
}
void ChunkNode::render(const RenderData& data, ChunkIndex traverseData) {
ghoul_assert(isRoot(), "this method should only be invoked on root");
//LDEBUG("-------------");
internalUpdateChunkTree(data, traverseData);
internalRender(data, traverseData);
}
// Returns true or false wether this node can be merge or not
bool ChunkNode::internalUpdateChunkTree(const RenderData& data, ChunkIndex& traverseData) {
using namespace glm;
Geodetic2 center = _patch.center();
//LDEBUG("x: " << patch.x << " y: " << patch.y << " level: " << patch.level << " lat: " << center.lat << " lon: " << center.lon);
if (isLeaf()) {
int desiredLevel = calculateDesiredLevelAndUpdateIsVisible(data, traverseData);
desiredLevel = glm::clamp(desiredLevel, _owner.minSplitDepth, _owner.maxSplitDepth);
if (desiredLevel > traverseData.level) {
split();
}
else if(desiredLevel < traverseData.level){
return true; // request a merge from parent
}
return false;
}
else {
int requestedMergeMask = 0;
std::vector<ChunkIndex> childIndices = traverseData.childIndices();
for (int i = 0; i < 4; ++i) {
if (_children[i]->internalUpdateChunkTree(data, childIndices[i])) {
requestedMergeMask |= (1 << i);
}
}
// check if all children requested merge
if (requestedMergeMask == 0xf) {
merge();
// re-run this method on this, now that this is a leaf node
return internalUpdateChunkTree(data, traverseData);
}
return false;
}
}
void ChunkNode::internalRender(const RenderData& data, ChunkIndex& traverseData) {
if (isLeaf()) {
if (_isVisible) {
GeodeticTileIndex ti = { traverseData.x, traverseData.y, traverseData.level };
LatLonPatchRenderer& patchRenderer = _owner.getPatchRenderer();
patchRenderer.renderPatch(_patch, data, _owner.ellipsoid(), ti);
//patchRenderer.renderPatch(_patch, data, _owner.ellipsoid());
ChunkNode::renderedPatches++;
}
}
else {
std::vector<ChunkIndex> childIndices = traverseData.childIndices();
for (int i = 0; i < 4; ++i) {
_children[i]->internalRender(data, childIndices[i]);
}
}
}
int ChunkNode::calculateDesiredLevelAndUpdateIsVisible(
const RenderData& data,
const ChunkIndex& traverseData) {
_isVisible = true;
Vec3 globePosition = data.position.dvec3();
Vec3 patchPosition =
globePosition +
_owner.ellipsoid().geodetic2ToCartesian(_patch.center());
Vec3 cameraPosition = data.camera.position().dvec3();
Vec3 cameraDirection = Vec3(data.camera.viewDirection());
Vec3 cameraToChunk = patchPosition - cameraPosition;
// if camera points at same direction as latlon patch normal,
// we see the back side and dont have to split it
//Scalar cosNormalCameraDirection = glm::dot(patchNormal, cameraDirection);
Vec3 globeToCamera = cameraPosition - globePosition;
Geodetic2 cameraPositionOnGlobe =
_owner.ellipsoid().cartesianToGeodetic2(globeToCamera);
Geodetic2 closestPatchPoint = _patch.closestPoint(cameraPositionOnGlobe);
Vec3 normalOfClosestPatchPoint =
_owner.ellipsoid().geodeticSurfaceNormal(closestPatchPoint);
Scalar cosPatchNormalNormalizedGlobeToCamera =
glm::dot(normalOfClosestPatchPoint, glm::normalize(globeToCamera));
//LDEBUG(cosPatchNormalCameraDirection);
// Get the minimum radius from the ellipsoid. The closer the ellipsoid is to a
// sphere, the better this will make the splitting. Using the minimum radius to
// be safe. This means that if the ellipsoid has high difference between radii,
// splitting might accur even though it is not needed.
Scalar minimumGlobeRadius = _owner.ellipsoid().minimumRadius();
double cosAngleToHorizon = minimumGlobeRadius / glm::length(globeToCamera);
if (cosPatchNormalNormalizedGlobeToCamera < cosAngleToHorizon) {
_isVisible = false;
return traverseData.level - 1;
}
// Do frustrum culling
FrustumCuller& culler = _owner.getFrustumCuller();
if (!culler.isVisible(data, _patch, _owner.ellipsoid())) {
_isVisible = false;
return traverseData.level - 1;
}
// Calculate desired level based on distance
Scalar distance = glm::length(cameraToChunk);
_owner.minDistToCamera = fmin(_owner.minDistToCamera, distance);
Scalar scaleFactor = 100 * minimumGlobeRadius;
Scalar projectedScaleFactor = scaleFactor / distance;
int desiredLevel = floor( log2(projectedScaleFactor) );
return desiredLevel;
}
void ChunkNode::split(int depth) {
if (depth > 0 && isLeaf()) {
// Defining short handles for center, halfSize and quarterSize
const Geodetic2& c = _patch.center();
const Geodetic2& hs = _patch.halfSize();
Geodetic2 qs = Geodetic2(0.5 * hs.lat, 0.5 * hs.lon);
// Subdivide bounds
GeodeticPatch nwBounds = GeodeticPatch(Geodetic2(c.lat + qs.lat, c.lon - qs.lon), qs);
GeodeticPatch neBounds = GeodeticPatch(Geodetic2(c.lat + qs.lat, c.lon + qs.lon), qs);
GeodeticPatch swBounds = GeodeticPatch(Geodetic2(c.lat - qs.lat, c.lon - qs.lon), qs);
GeodeticPatch seBounds = GeodeticPatch(Geodetic2(c.lat - qs.lat, c.lon + qs.lon), qs);
// Create new chunk nodes
_children[Quad::NORTH_WEST] = std::unique_ptr<ChunkNode>(new ChunkNode(_owner, nwBounds, this));
_children[Quad::SOUTH_WEST] = std::unique_ptr<ChunkNode>(new ChunkNode(_owner, swBounds, this));
_children[Quad::NORTH_EAST] = std::unique_ptr<ChunkNode>(new ChunkNode(_owner, neBounds, this));
_children[Quad::SOUTH_EAST] = std::unique_ptr<ChunkNode>(new ChunkNode(_owner, seBounds, this));
}
if (depth - 1 > 0) {
for (int i = 0; i < 4; ++i) {
_children[i]->split(depth - 1);
}
}
}
void ChunkNode::merge() {
for (int i = 0; i < 4; ++i) {
if (_children[i] != nullptr) {
_children[i]->merge();
}
_children[i] = nullptr;
}
}
const ChunkNode& ChunkNode::getChild(Quad quad) const {
return *_children[quad];
}
} // namespace openspace