*
*/
+#include <algorithm>
+
#include <osgDB/Registry>
#include <osgDB/Input>
#include <osgDB/ParameterOutput>
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
{
- if (!_cloudsprites.size()) return;
+ if (_cloudsprites.empty()) return;
osg::State& state = *renderInfo.getState();
- osg::Matrix vm = state.getModelViewMatrix();
- //TODO: It isn't clear whether this is worth the perf hit ATM.
+ int frameNumber = state.getFrameStamp()->getFrameNumber();
+ unsigned int contextID = state.getContextID();
+ SortData& sortData = _sortData[contextID];
+ Geometry* g = _geometry->asGeometry();
- // 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(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;
+ // 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.
+ osg::Vec3Array* v = dynamic_cast<osg::Vec3Array*>(g->getVertexArray());
+ if ((v->size() > 4) &&
+ (frameNumber - sortData.skip_limit >= sortData.frameSorted)) {
+ Matrix mvp = state.getModelViewMatrix() * state.getProjectionMatrix();
+
+ osg::Vec4Array* c = dynamic_cast<osg::Vec4Array*>(g->getColorArray());
+ osg::Vec2Array* t = dynamic_cast<osg::Vec2Array*>(g->getTexCoordArray(0));
+ Vec3f av[4];
+ Vec4f ac[4];
+ Vec2f at[4];
+
+ // Perform a single pass bubble sort of the array,
+ // keeping track of whether we've had to make any changes
+ bool sorted = true;
+ for (unsigned int i = 4; i < v->size(); i = i + 4) {
+ // The position of the sprite is stored in the colour
+ // array, with the exception of the w() coordinate
+ // which is the z-scaling parameter.
+ Vec4f a = (*c)[i-4];
+ Vec4f aPos = Vec4f(a.x(), a.y(), a.z(), 1.0f) * mvp;
+ Vec4f b = (*c)[i];
+ Vec4f bPos = Vec4f(b.x(), b.y(), b.z(), 1.0f) * mvp;
+
+ if ((aPos.z()/aPos.w()) < (bPos.z()/bPos.w() - 0.0001)) {
+ // a is non-trivially closer than b, so should be rendered
+ // later. Swap them around
+ for (int j = 0; j < 4; j++) {
+ av[j] = (*v)[i+j-4];
+ ac[j] = (*c)[i+j-4];
+ at[j] = (*t)[i+j-4];
+
+ (*v)[i+j -4] = (*v)[i+j];
+ (*c)[i+j -4] = (*c)[i+j];
+ (*t)[i+j -4] = (*t)[i+j];
+
+ (*v)[i+j] = av[j];
+ (*c)[i+j] = ac[j];
+ (*t)[i+j] = at[j];
+ }
+
+ // Indicate that the arrays were not sorted
+ // so we should check them next iteration
+ sorted = false;
+ }
+ }
+
+ if (sorted) {
+ // This cloud is sorted, so no need to re-sort.
+
+ 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
+ sortData.skip_limit += sg_random() * 10;
+ }
+ if (sortData.skip_limit > 500) {
+ // Maximum of every 500 frames (10-20 seconds)
+ sortData.skip_limit = 500 + sg_random() * 10;
+ }
+ } else {
+ sortData.skip_limit = 1;
}
- else
- p = q;
+
+ sortData.frameSorted = frameNumber;
}
-
+
const Extensions* extensions = getExtensions(state.getContextID(),true);
+ GLfloat ua1[3] = { (GLfloat) 1.0f,
+ (GLfloat) shade_factor,
+ (GLfloat) cloud_height };
+ GLfloat ua2[3] = { (GLfloat) bottom_factor,
+ (GLfloat) middle_factor,
+ (GLfloat) top_factor };
+
+ extensions->glVertexAttrib3fv(USR_ATTR_1, ua1 );
+ extensions->glVertexAttrib3fv(USR_ATTR_2, ua2 );
+ _geometry->draw(renderInfo);
+}
- for(CloudSpriteList::const_iterator t = _cloudsprites.begin(); t != _cloudsprites.end(); ++t)
+void CloudShaderGeometry::addSprite(const SGVec3f& p, int tx, int ty,
+ float w, float h, float cull)
+{
+ // Only add the sprite if it is further than the cull distance to all other sprites
+ // except for the center sprite.
+ for (CloudShaderGeometry::CloudSpriteList::iterator iter = _cloudsprites.begin();
+ iter != _cloudsprites.end();
+ ++iter)
{
- extensions->glVertexAttrib1f(TEXTURE_INDEX_X, (GLfloat) (*t)->texture_index_x/varieties_x);
- extensions->glVertexAttrib1f(TEXTURE_INDEX_Y, (GLfloat) (*t)->texture_index_y/varieties_y);
- extensions->glVertexAttrib1f(WIDTH, (GLfloat) (*t)->width);
- extensions->glVertexAttrib1f(HEIGHT, (GLfloat) (*t)->height);
- extensions->glVertexAttrib1f(SHADE, (GLfloat) (*t)->shade);
- glColor4f((*t)->position.x(), (*t)->position.y(), (*t)->position.z(), 1.0);
- _geometry->draw(renderInfo);
+ if ((iter != _cloudsprites.begin()) &&
+ (distSqr(iter->position, p) < cull)) {
+ // Too close - cull it
+ return;
+ }
}
+
+ _cloudsprites.push_back(CloudSprite(p, tx, ty, w, h));
}
-BoundingBox CloudShaderGeometry::computeBound() const
+void CloudShaderGeometry::generateGeometry()
{
- BoundingBox geom_box = _geometry->getBound();
- BoundingBox bb;
- for(CloudSpriteList::const_iterator itr = _cloudsprites.begin();
- itr != _cloudsprites.end();
- ++itr) {
- bb.expandBy(geom_box.corner(0)*(*itr)->width +
- osg::Vec3( (*itr)->position.x(), (*itr)->position.y(), (*itr)->position.z() ));
- bb.expandBy(geom_box.corner(7)*(*itr)->height +
- osg::Vec3( (*itr)->position.x(), (*itr)->position.y(), (*itr)->position.z() ));
+ // Generate a set of geometries as a QuadStrip based on the list of sprites
+ int numsprites = _cloudsprites.size();
+
+ // Create front and back polygons so we don't need to screw around
+ // with two-sided lighting in the shader.
+ osg::ref_ptr<osg::Vec3Array> v = new osg::Vec3Array;
+ osg::ref_ptr<osg::Vec3Array> n = new osg::Vec3Array;
+ osg::ref_ptr<osg::Vec4Array> c = new osg::Vec4Array;
+ osg::ref_ptr<osg::Vec2Array> t = new osg::Vec2Array;
+
+ int idx = 0;
+
+ for (CloudShaderGeometry::CloudSpriteList::iterator iter = _cloudsprites.begin();
+ iter != _cloudsprites.end();
+ ++iter)
+ {
+
+ float cw = 0.5f * iter->width;
+ float ch = 0.5f * iter->height;
+
+ // Create the vertices
+ v->push_back(osg::Vec3(0.0f, -cw, -ch));
+ v->push_back(osg::Vec3(0.0f, cw, -ch));
+ v->push_back(osg::Vec3(0.0f, cw, ch));
+ v->push_back(osg::Vec3(0.0f, -cw, ch));
+
+ // The normals aren't actually used in lighting,
+ // but we set them per vertex as this is more
+ // efficient than an overall binding on some
+ // graphics cards.
+ n->push_back(osg::Vec3(1.0f, -1.0f, -1.0f));
+ n->push_back(osg::Vec3(1.0f, 1.0f, -1.0f));
+ n->push_back(osg::Vec3(1.0f, 1.0f, 1.0f));
+ n->push_back(osg::Vec3(1.0f, -1.0f, 1.0f));
+
+ // Set the texture coords for each vertex
+ // from the texture index, and the number
+ // of textures in the image
+ int x = iter->texture_index_x;
+ int y = iter->texture_index_y;
+
+ t->push_back(osg::Vec2( (float) x / varieties_x, (float) y / varieties_y));
+ t->push_back(osg::Vec2( (float) (x + 1) / varieties_x, (float) y / varieties_y));
+ t->push_back(osg::Vec2( (float) (x + 1) / varieties_x, (float) (y + 1) / varieties_y));
+ t->push_back(osg::Vec2( (float) x / varieties_x, (float) (y + 1) / varieties_y));
+
+ // The color isn't actually use in lighting, but instead to indicate the center of rotation
+ c->push_back(osg::Vec4(iter->position.x(), iter->position.y(), iter->position.z(), zscale));
+ c->push_back(osg::Vec4(iter->position.x(), iter->position.y(), iter->position.z(), zscale));
+ c->push_back(osg::Vec4(iter->position.x(), iter->position.y(), iter->position.z(), zscale));
+ c->push_back(osg::Vec4(iter->position.x(), iter->position.y(), iter->position.z(), zscale));
+
+ idx++;
}
- return bb;
+
+ //Quads now created, add it to the geometry.
+ osg::Geometry* geom = new osg::Geometry;
+ geom->setVertexArray(v);
+ geom->setTexCoordArray(0, t);
+ geom->setNormalArray(n);
+ geom->setNormalBinding(Geometry::BIND_PER_VERTEX);
+ geom->setColorArray(c);
+ geom->setColorBinding(Geometry::BIND_PER_VERTEX);
+ geom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS,0,numsprites*4));
+ _geometry = geom;
}
bool CloudShaderGeometry_readLocalData(Object& obj, Input& fr)
while (!fr.eof() && fr[0].getNoNestedBrackets() > entry) {
SGVec3f v;
int tx, ty;
- float w, h, s;
+ float w, h;
if (fr[0].getFloat(v.x()) && fr[1].getFloat(v.y())
- && fr[2].getFloat(v.z()) && fr[3].getInt(tx) && fr[3].getInt(ty) &&
- fr[4].getFloat(w) && fr[4].getFloat(h)&& fr[4].getFloat(s)) {
+ && fr[2].getFloat(v.z()) && fr[3].getInt(tx) && fr[4].getInt(ty) &&
+ fr[5].getFloat(w) && fr[6].getFloat(h)) {
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));
+ geom._cloudsprites.push_back(CloudShaderGeometry::CloudSprite(v, tx, ty, w, h));
} else {
++fr;
}
}
+ geom.generateGeometry();
}
return iteratorAdvanced;
}
= 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 << 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 << " " << std::endl;
}
fw.moveOut();
fw.indent() << "}" << std::endl;