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Sort cloud sprites using std::sort, based on projected Z.

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A "cleanup" of cloud sorting.
This commit is contained in:
Tim Moore 2009-01-16 00:37:40 +01:00
parent 25c08e56c2
commit 8b57ed46b1
3 changed files with 115 additions and 98 deletions
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142
simgear/scene/sky/CloudShaderGeometry.cxx
View File

@ -19,6 +19,8 @@
*
*/
#include <algorithm>
#include <osgDB/Registry>
#include <osgDB/Input>
#include <osgDB/ParameterOutput>
@ -31,6 +33,17 @@ using namespace osg;
using namespace osgDB;
using namespace simgear;
namespace
{
struct SpriteComp
{
bool operator() (const CloudShaderGeometry::SortData::SortItem& lhs,
const CloudShaderGeometry::SortData::SortItem& rhs) const
{
return lhs.depth < rhs.depth;
}
};
}
namespace simgear
{
void CloudShaderGeometry::drawImplementation(RenderInfo& renderInfo) const
@ -38,80 +51,93 @@ void CloudShaderGeometry::drawImplementation(RenderInfo& renderInfo) const
if (!_cloudsprites.size()) return;
osg::State& state = *renderInfo.getState();
unsigned int contextID = state.getContextID();
SortData& sortData = _sortData[contextID];
int frameNumber = state.getFrameStamp()->getFrameNumber();
if (!sortData.spriteIdx)
sortData.spriteIdx = new SortData::SortItemList;
if (sortData.spriteIdx->size() < _cloudsprites.size()) {
for (int i = sortData.spriteIdx->size(); i < _cloudsprites.size(); ++i)
sortData.spriteIdx->push_back(SortData::SortItem(i, 0.0f));
sortData.frameSorted = frameNumber - (sortData.skip_limit + 1);
}
// If the cloud is already sorted, then it is likely to still be sorted.
// Therefore we can avoid re-sorting it for a period. If it is still
// sorted after that period, then we can wait for a longer period before
// checking again. In this way, only clouds that are changing regularly
// are sorted.
skip_info->skip_count = (skip_info->skip_count + 1) % skip_info->skip_limit;
if (skip_info->skip_count == 0)
{
osg::Matrix vm = state.getModelViewMatrix();
bool sorted = true;
// Transform the viewing direction, represented by the eye space vector (0,0,-1, 0), into model-space
// (here we simply take the opposite direction and reverse the ordering when sorting)
osg::Vec3f view_dir(vm(0, 2), vm(1, 2), vm(2, 2)); // Caveat: OpenSceneGraph matrices are transposed!
float p = view_dir*_cloudsprites[0]->position.osg();
// Do a single iteration of a bubble sort, sorting
// back to front.
for(unsigned int i = 0; i < _cloudsprites.size() - 1; i++)
{
float q = view_dir*_cloudsprites[i+1]->position.osg();
if (p > q) {
CloudSprite c = *_cloudsprites[i];
*_cloudsprites[i] = *_cloudsprites[i+1];
*_cloudsprites[i+1] = c;
sorted = false;
}
else
p = q;
if (frameNumber - sortData.skip_limit >= sortData.frameSorted) {
Matrix mvp = state.getModelViewMatrix() * state.getProjectionMatrix();
for (SortData::SortItemList::iterator itr = sortData.spriteIdx->begin(),
end = sortData.spriteIdx->end();
itr != end;
++itr) {
Vec4f projPos
= Vec4f(_cloudsprites[itr->idx].position.osg(), 1.0f) * mvp;
itr->depth = projPos.z() / projPos.w();
}
if (sorted)
{
// Already sorted?
if (std::adjacent_find(sortData.spriteIdx->rbegin(),
sortData.spriteIdx->rend(), SpriteComp())
== sortData.spriteIdx->rend()) {
// This cloud is sorted, so no need to re-sort.
skip_info->skip_limit = skip_info->skip_limit * 2;
if (skip_info->skip_limit > 30)
{
sortData.skip_limit = sortData.skip_limit * 2;
if (sortData.skip_limit > 30) {
// Jitter the skip frames to avoid synchronized sorts
// which will cause periodic frame-rate drops
skip_info->skip_limit += sg_random() * 10;
sortData.skip_limit += sg_random() * 10;
}
if (skip_info->skip_limit > 128)
{
if (sortData.skip_limit > 128) {
// Maximum of every 128 frames (2 - 4 seconds)
skip_info->skip_limit = 128 + sg_random() * 10;
sortData.skip_limit = 128 + sg_random() * 10;
}
} else {
std::sort(sortData.spriteIdx->begin(), sortData.spriteIdx->end(),
SpriteComp());
sortData.skip_limit = 1;
}
else
{
// This cloud is unsorted, so we need to sort next frame
skip_info->skip_limit = 1;
}
sortData.frameSorted = frameNumber;
}
const Extensions* extensions = getExtensions(state.getContextID(),true);
for(CloudSpriteList::const_iterator t = _cloudsprites.begin(); t != _cloudsprites.end(); ++t)
{
GLfloat ua1[3] = { (GLfloat) (*t)->texture_index_x/varieties_x, (GLfloat) (*t)->texture_index_y/varieties_y, (*t)->width };
GLfloat ua2[3] = { (GLfloat) (*t)->height, (*t)->shade, (GLfloat) (*t)->cloud_height };
for(SortData::SortItemList::const_iterator itr = sortData.spriteIdx->begin(),
end = sortData.spriteIdx->end();
itr != end;
++itr) {
const CloudSprite& t = _cloudsprites[itr->idx];
GLfloat ua1[3] = { (GLfloat)t.texture_index_x/varieties_x,
(GLfloat)t.texture_index_y/varieties_y,
t.width };
GLfloat ua2[3] = { (GLfloat)t.height,
t.shade,
(GLfloat) t.cloud_height };
extensions->glVertexAttrib3fv(USR_ATTR_1, ua1 );
extensions->glVertexAttrib3fv(USR_ATTR_2, ua2 );
glColor4f((*t)->position.x(), (*t)->position.y(), (*t)->position.z(), 1.0);
glColor4f(t.position.x(), t.position.y(), t.position.z(), 1.0);
_geometry->draw(renderInfo);
}
}
void CloudShaderGeometry::addSprite(SGVec3f& p, int tx, int ty,
float w, float h,
float s, float cull, float cloud_height)
{
// Only add the sprite if it is further than the cull distance to all other sprites
for (CloudShaderGeometry::CloudSpriteList::iterator iter = _cloudsprites.begin();
iter != _cloudsprites.end();
++iter)
{
if (distSqr(iter->position, p) < cull) {
// Too close - cull it
return;
}
}
_cloudsprites.push_back(CloudSprite(p, tx, ty, w, h, s, cloud_height));
}
bool CloudShaderGeometry_readLocalData(Object& obj, Input& fr)
{
bool iteratorAdvanced = false;
@ -143,7 +169,7 @@ bool CloudShaderGeometry_readLocalData(Object& obj, Input& fr)
fr[5].getFloat(w) && fr[6].getFloat(h)&& fr[7].getFloat(s) && fr[8].getFloat(ch)) {
fr += 5;
//SGVec3f* v = new SGVec3f(v.x(), v.y(), v.z());
geom._cloudsprites.push_back(new CloudShaderGeometry::CloudSprite(v, tx, ty, w, h,s,ch));
geom._cloudsprites.push_back(CloudShaderGeometry::CloudSprite(v, tx, ty, w, h,s,ch));
} else {
++fr;
}
@ -165,11 +191,11 @@ bool CloudShaderGeometry_writeLocalData(const Object& obj, Output& fw)
= geom._cloudsprites.begin();
itr != geom._cloudsprites.end();
++itr) {
fw.indent() << (*itr)->position.x() << " " << (*itr)->position.y() << " "
<< (*itr)->position.z() << " " << (*itr)->texture_index_x << " "
<< (*itr)->texture_index_y << " " << (*itr)->width << " "
<< (*itr)->height << " " << (*itr)->shade
<< (*itr)->cloud_height << " "<< std::endl;
fw.indent() << itr->position.x() << " " << itr->position.y() << " "
<< itr->position.z() << " " << itr->texture_index_x << " "
<< itr->texture_index_y << " " << itr->width << " "
<< itr->height << " " << itr->shade
<< itr->cloud_height << " "<< std::endl;
}
fw.moveOut();
fw.indent() << "}" << std::endl;

69
simgear/scene/sky/CloudShaderGeometry.hxx
View File

@ -31,6 +31,7 @@
#include <osg/RenderInfo>
#include <osg/Vec3>
#include <osg/Vec4>
#include <osg/buffered_value>
#include <simgear/math/SGMath.hxx>
#include <simgear/math/sg_random.h>
@ -49,14 +50,12 @@ class CloudShaderGeometry : public osg::Drawable
CloudShaderGeometry()
{
setUseDisplayList(false);
skip_info = new SkipInfo();
}
CloudShaderGeometry(int vx, int vy, float width, float height) :
varieties_x(vx), varieties_y(vy)
{
setUseDisplayList(false);
skip_info = new SkipInfo();
float x = width/2.0f;
float z = height/2.0f;
_bbox.expandBy(-x, -x, -z);
@ -69,14 +68,6 @@ class CloudShaderGeometry : public osg::Drawable
META_Object(flightgear, CloudShaderGeometry);
struct SkipInfo {
SkipInfo() : skip_count(0), skip_limit(1) {}
int skip_count;
int skip_limit;
};
SkipInfo* skip_info;
struct CloudSprite {
CloudSprite(SGVec3f& p, int tx, int ty, float w, float h, float s, float ch) :
position(p), texture_index_x(tx), texture_index_y(ty), width(w), height(h), shade(s), cloud_height(ch)
@ -91,17 +82,17 @@ class CloudShaderGeometry : public osg::Drawable
float cloud_height;
};
typedef std::vector<CloudSprite*> CloudSpriteList;
typedef std::vector<CloudSprite> CloudSpriteList;
CloudSpriteList _cloudsprites;
void insert(CloudSprite* t)
void insert(const CloudSprite& t)
{ _cloudsprites.push_back(t); }
void insert(SGVec3f& p, int tx, int ty, float w, float h, float s, float ch)
{ insert(new CloudSprite(p, tx, ty, w, h, s, ch)); }
{ insert(CloudSprite(p, tx, ty, w, h, s, ch)); }
unsigned getNumCloudSprite() const
{ return _cloudsprites.size(); }
CloudSprite* getCloudSprite(unsigned i) const
CloudSprite& getCloudSprite(unsigned i)
{ return _cloudsprites[i]; }
virtual void drawImplementation(osg::RenderInfo& renderInfo) const;
@ -115,23 +106,8 @@ class CloudShaderGeometry : public osg::Drawable
_geometry = geometry;
}
void addSprite(SGVec3f& p, int tx, int ty, float w, float h, float s, float cull, float cloud_height)
{
// Only add the sprite if it is further than the cull distance to all other sprites
for (CloudShaderGeometry::CloudSpriteList::iterator iter = _cloudsprites.begin();
iter != _cloudsprites.end();
++iter)
{
if (distSqr((*iter)->position, p) < cull)
{
// Too close - cull it
return;
}
}
_cloudsprites.push_back(new CloudSprite(p, tx, ty, w, h, s, cloud_height));
}
void addSprite(SGVec3f& p, int tx, int ty, float w, float h, float s, float cull, float cloud_height);
osg::ref_ptr<osg::Drawable> _geometry;
int varieties_x;
@ -140,15 +116,30 @@ class CloudShaderGeometry : public osg::Drawable
// Bounding box extents.
osg::BoundingBox _bbox;
protected:
struct SortData
{
struct SortItem
{
SortItem(size_t idx_, float depth_) : idx(idx_), depth(depth_) {}
SortItem() : idx(0), depth(0.0f) {}
size_t idx;
float depth;
};
SortData() : frameSorted(0), skip_limit(1), spriteIdx(0) {}
int frameSorted;
int skip_limit;
// This will be sorted by Z distance
typedef std::vector<SortItem> SortItemList;
SortItemList* spriteIdx;
};
protected:
mutable osg::buffered_object<SortData> _sortData;
virtual ~CloudShaderGeometry() {
delete skip_info;
for (unsigned int i = 0; i < _cloudsprites.size(); i++)
{
delete _cloudsprites[i];
}
}
virtual ~CloudShaderGeometry()
{
for (unsigned int i = 0; i < _sortData.size(); ++i)
delete _sortData[i].spriteIdx;
}
};
}

2
simgear/scene/sky/cloudfield.cxx
View File

@ -137,7 +137,7 @@ bool SGCloudField::reposition( const SGVec3f& p, const SGVec3f& up, double lon,
field_transform->setMatrix( LAT*LON*T );
}
field_root->getStateSet()->setRenderBinDetails(asl, "RenderBin");
field_root->getStateSet()->setRenderBinDetails(asl, "DepthSortedBin");
return true;
}