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OpenSceneGraph/examples/osgtessellate/osgtessellate.cpp
Robert Osfield dd996a3289 Introduced CMake option OSG_PROVIDE_READFILE option that defaults to ON, but when switched to OFF disables the building of the osgDB::read*File() methods, 
forcing users to use osgDB::readRef*File() methods.  The later is preferable as it closes a potential threading bug when using paging databases in conjunction
with the osgDB::Registry Object Cache.  This threading bug occurs when one thread gets an object from the Cache via an osgDB::read*File() call where only
a pointer to the object is passed back, so taking a reference to the object is delayed till it gets reassigned to a ref_ptr<>, but at the same time another
thread calls a flush of the Object Cache deleting this object as it's referenceCount is now zero.  Using osgDB::readREf*File() makes sure the a ref_ptr<> is
passed back and the referenceCount never goes to zero.

To ensure the OSG builds when OSG_PROVIDE_READFILE is to OFF the many cases of osgDB::read*File() usage had to be replaced with a ref_ptr<> osgDB::readRef*File()
usage.  The avoid this change causing lots of other client code to be rewritten to handle the use of ref_ptr<> in place of C pointer I introduced a serious of
templte methods in various class to adapt ref_ptr<> to the underly C pointer to be passed to old OSG API's, example of this is found in include/osg/Group:

    bool addChild(Node* child); // old method which can only be used with a Node*

    tempalte<class T> bool addChild(const osg::ref_ptr<T>& child) { return addChild(child.get()); } // adapter template method

These changes together cover 149 modified files, so it's a large submission. This extent of changes are warrent to make use of the Object Cache
and multi-threaded loaded more robust.



git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@15164 16af8721-9629-0410-8352-f15c8da7e697
2015-10-22 13:42:19 +00:00

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/* OpenSceneGraph example, osgtessellate.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* 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 PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/* osgTessellator
* - this Tessellator is an extension of the basic one - rather than tessellating
* individual polygons, we tessellate the entire geode with multiple contours.
* allows for overlapping contours etc.
* the Tessellator has new member fuinctions
setTessellationType(osgUtil::Tessellator::TESS_TYPE_xxx);
tscx->setBoundaryOnly(bool);
tscx->setWindingType( osgUtil::Tessellator::TESS_WINDING_xxx);
* for winding rules: See the red book chap 13.
*/
#include <osgDB/ReadFile>
#include <osgUtil/Optimizer>
#include <osgViewer/Viewer>
#include <osg/Projection>
#include <osg/MatrixTransform>
#include <osgText/Text>
#include <osgUtil/Tessellator> // to tessellate multiple contours
class tessellateDemoGeometry : public osg::Geometry, public osgUtil::Tessellator {
// We add the Tessellator to the geometry because we want to access the
// tessellatable contours again; you can apply a Tessellator to a Geometry
// to produce exactly a required tessellation once only, and then
// the contours could be discarded since the geometry does not need to be retessellated.
public:
tessellateDemoGeometry() {};
protected:
virtual ~tessellateDemoGeometry() {};
};
osg::Geometry *makePolsTwo (void)
{
// an example of using current geometry contours to create next tessellation
// this polygon disappears once the contour rules make no polygons.
tessellateDemoGeometry *gtess= new tessellateDemoGeometry;
int i;
osg::Vec3Array *coords = new osg::Vec3Array;
osg::Vec3Array *nrms = new osg::Vec3Array;
osg::Vec2Array *tcs = new osg::Vec2Array;
osg::Vec3 nrm(0,-1,0);
static GLdouble quadstrip[8][3] =
{ { 1900.0, 1130.0, 0.0 },
{ 2100.0, 1130.0, 0.0 },
{ 1900.0, 1350.0, 0.0 },
{ 1950.0, 1350.0, 0.0 },
{ 1900.0, 1550.0, 0.0 },
{ 2000.0, 1550.0, 0.0 },
{ 1900.0, 1750.0, 0.0 },
{ 2400.0, 1750.0, 0.0 } };
static GLdouble innerquadstrip[8][3] =
{ { 2000.0, 1230.0, 0.0 },
{ 2050.0, 1230.0, 0.0 },
{ 1920.0, 1350.0, 0.0 },
{ 1940.0, 1350.0, 0.0 },
{ 1920.0, 1550.0, 0.0 },
{ 1980.0, 1550.0, 0.0 },
{ 2000.0, 1650.0, 0.0 },
{ 2400.0, 1650.0, 0.0 } };
// add one large quadstrip
for (i = 0; i < 8; i++)
{
coords->push_back(osg::Vec3(quadstrip[i][0],quadstrip[i][2],quadstrip[i][1]));
tcs->push_back(osg::Vec2(quadstrip[i][0],quadstrip[i][1])/200.0);
nrms->push_back(nrm);
}
for (i = 0; i < 8; i++) {
coords->push_back(osg::Vec3(innerquadstrip[i][0],innerquadstrip[i][2],innerquadstrip[i][1]));
tcs->push_back(osg::Vec2(innerquadstrip[i][0],innerquadstrip[i][1])/200.0);
nrms->push_back(nrm);
}
gtess->setVertexArray(coords);
gtess->setNormalArray(nrms, osg::Array::BIND_PER_VERTEX);
gtess->setTexCoordArray(0,tcs);
// demonstrate that the Tessellator makes textured tessellations
osg::StateSet* stateset = new osg::StateSet();
osg::ref_ptr<osg::Image> image = osgDB::readRefImageFile("Cubemap_snow/posy.jpg");
if (image)
{
osg::Texture2D* texture = new osg::Texture2D;
texture->setImage(image);
texture->setWrap(osg::Texture2D::WRAP_S, osg::Texture2D::REPEAT);
texture->setWrap(osg::Texture2D::WRAP_T, osg::Texture2D::REPEAT);
stateset->setTextureAttributeAndModes(0,texture,osg::StateAttribute::ON);
}
gtess->setStateSet( stateset );
int nstart=0;
// The derived class tessellateDemoGeometry retains the original contours for re-use.
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::TRIANGLE_STRIP,nstart,8));nstart+=8;
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::TRIANGLE_STRIP,nstart,8));nstart+=8;
gtess->setTessellationType(osgUtil::Tessellator::TESS_TYPE_GEOMETRY);
gtess->setBoundaryOnly(true);
gtess->setWindingType( osgUtil::Tessellator::TESS_WINDING_ABS_GEQ_TWO); // so that first change in wind type makes the commonest tessellation - ODD.
return gtess;
}
osg::Geometry *makeSideWall (const float xpos)
{
// demonstrate making a rectangular 'wall' with 2 holes in it.
osg::Geometry *gtess= new osg::Geometry;
int i;
osg::Vec3Array *coords = new osg::Vec3Array;
osg::Vec3Array *nrms = new osg::Vec3Array;
osg::Vec2Array *tcs = new osg::Vec2Array;
osg::Vec3 nrm(-1,0,0);
// front wall
static GLdouble wall[4][2] =
{ { 1130.0, 0.0 },
{ 1130.0, 300.0 } ,
{ 1340.0,300.0 },
{ 1340.0,0.0 } };
gtess->setVertexArray(coords);
gtess->setNormalArray(nrms, osg::Array::BIND_PER_VERTEX);
gtess->setTexCoordArray(0,tcs);
for (i = 0; i < 4; i++) {
coords->push_back(osg::Vec3(xpos,wall[i][1],wall[i][0]));
tcs->push_back(osg::Vec2(wall[i][1],wall[i][0])/100.0);
nrms->push_back(nrm);
}
int nstart=0;
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS,nstart,4));nstart+=4;
for (i = 0; i < 24; i++) { // make an ellipse hole
float y=150+50*cos(i*2*osg::PI/24.0);
float z=1300+30* sin(i*2*osg::PI/24.0);
coords->push_back(osg::Vec3(xpos,y,z));
tcs->push_back(osg::Vec2(y,z)/100.0);
nrms->push_back(nrm);
}
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::POLYGON,nstart,24));nstart+=24;
for (i = 0; i < 5; i++) { // make a pentagonal hole
float y=150+50*cos(i*2*osg::PI/5.0);
float z=1200+40* sin(i*2*osg::PI/5.0);
coords->push_back(osg::Vec3(xpos,y,z));
tcs->push_back(osg::Vec2(y,z)/100.0);
nrms->push_back(nrm);
}
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::POLYGON,nstart,5));nstart+=5;
// demonstrate that the Tessellator makes textured tessellations
osg::StateSet* stateset = new osg::StateSet();
osg::ref_ptr<osg::Image> image = osgDB::readRefImageFile("Cubemap_snow/posx.jpg");
if (image)
{
osg::Texture2D* texture = new osg::Texture2D;
texture->setImage(image);
texture->setWrap(osg::Texture2D::WRAP_S, osg::Texture2D::REPEAT);
texture->setWrap(osg::Texture2D::WRAP_T, osg::Texture2D::REPEAT);
stateset->setTextureAttributeAndModes(0,texture,osg::StateAttribute::ON);
}
gtess->setStateSet( stateset );
osg::ref_ptr<osgUtil::Tessellator> tscx=new osgUtil::Tessellator; // the v1.2 multi-contour Tessellator.
// we use the geometry primitives to describe the contours which are tessellated.
// Winding odd means leave hole in surface where there are 2,4,6... contours circling the point.
tscx->setTessellationType(osgUtil::Tessellator::TESS_TYPE_GEOMETRY);
tscx->setBoundaryOnly(false);
tscx->setWindingType( osgUtil::Tessellator::TESS_WINDING_ODD); // so that first change in wind type makes the commonest tessellation - ODD.
tscx->retessellatePolygons(*gtess);
return gtess;
}
osg::Geometry *makeFrontWall (const float zpos) {
// an example of using one tessellation to make a 'house' wall
// describe the wall as a pentagon, then door & 4 windows are further contours
// tessellate the set of contours to make a 'house wall' from the Boolean-like operations.
int nstart=0; // counts vertices used for the geometry primitives
osg::Geometry *gtess= new osg::Geometry;
int i;
osg::Vec3Array *coords = new osg::Vec3Array;
osg::Vec3Array *nrms = new osg::Vec3Array;
osg::Vec2Array *tcs = new osg::Vec2Array;
osg::Vec3 nrm(0,-1,0);
// front wall
static GLdouble wall[5][2] =
{ { 2200.0, 1130.0 },
{ 2600.0, 1130.0 },
{ 2600.0, 1340.0 },
{ 2400.0, 1440.0 },
{ 2200.0, 1340.0 } };
static GLdouble door[4][2] =
{ { 2360.0, 1130.0 },
{ 2440.0, 1130.0 },
{ 2440.0, 1230.0 },
{ 2360.0, 1230.0 } };
static GLdouble windows[16][2] =
{ { 2240.0, 1180.0 },
{ 2330.0, 1180.0 },
{ 2330.0, 1220.0 },
{ 2240.0, 1220.0 },
{ 2460.0, 1180.0 },
{ 2560.0, 1180.0 },
{ 2560.0, 1220.0 },
{ 2460.0, 1220.0 },
{ 2240.0, 1280.0 },
{ 2330.0, 1280.0 },
{ 2330.0, 1320.0 },
{ 2240.0, 1320.0 },
{ 2460.0, 1280.0 },
{ 2560.0, 1280.0 },
{ 2560.0, 1320.0 },
{ 2460.0, 1320.0 } };
gtess->setVertexArray(coords);
gtess->setNormalArray(nrms, osg::Array::BIND_PER_VERTEX);
gtess->setTexCoordArray(0,tcs);
// add one large pentagon -the wall
for (i = 0; i < 5; i++) {
coords->push_back(osg::Vec3(wall[i][0],zpos,wall[i][1]));
tcs->push_back(osg::Vec2(wall[i][0],wall[i][1])/100.0);
nrms->push_back(nrm);
}
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::POLYGON,nstart,5));nstart+=5;
// add first hole, a door
for (i = 0; i < 4; i++) {
coords->push_back(osg::Vec3(door[i][0],zpos,door[i][1]));
tcs->push_back(osg::Vec2(door[i][0],door[i][1])/100.0);
nrms->push_back(nrm);
}
// and windows
for (i = 0; i < 16; i++) {
coords->push_back(osg::Vec3(windows[i][0],zpos,windows[i][1]));
tcs->push_back(osg::Vec2(windows[i][0],windows[i][1])/100.0);
nrms->push_back(nrm);
}
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS,nstart,20));nstart+=20;
// demonstrate that the Tessellator makes textured tessellations
osg::StateSet* stateset = new osg::StateSet();
osg::ref_ptr<osg::Image> image = osgDB::readRefImageFile("Cubemap_snow/posy.jpg");
if (image)
{
osg::Texture2D* texture = new osg::Texture2D;
texture->setImage(image);
texture->setWrap(osg::Texture2D::WRAP_S, osg::Texture2D::REPEAT);
texture->setWrap(osg::Texture2D::WRAP_T, osg::Texture2D::REPEAT);
stateset->setTextureAttributeAndModes(0,texture,osg::StateAttribute::ON);
}
gtess->setStateSet( stateset );
// We use a Tessellator to produce the tessellation required once only
// and the contours are discarded.
osg::ref_ptr<osgUtil::Tessellator> tscx=new osgUtil::Tessellator; // the v1.2 multi-contour Tessellator.
tscx->setTessellationType(osgUtil::Tessellator::TESS_TYPE_GEOMETRY);
tscx->setBoundaryOnly(false);
tscx->setWindingType( osgUtil::Tessellator::TESS_WINDING_ODD); // so that first change in wind type makes the commonest tessellation - ODD.
tscx->retessellatePolygons(*gtess);
return gtess;
}
osg::Geode *makeHouse (void) {
osg::Geode *gd = new osg::Geode;
gd->addDrawable(makeFrontWall(0.0));
gd->addDrawable(makeFrontWall(300.0));
gd->addDrawable(makeSideWall(2200.0));
gd->addDrawable(makeSideWall(2600.0));
return gd;
}
osg::Geometry *makePols (void) {
tessellateDemoGeometry *gtess= new tessellateDemoGeometry;
int i;
osg::Vec3Array *coords = new osg::Vec3Array;
osg::Vec3Array *nrms = new osg::Vec3Array;
osg::Vec2Array *tcs = new osg::Vec2Array;
osg::Vec3 nrm(0,-1,0);
// coordinates from red book code but shifted by 1000 & 2000 for alternate Tessellatory things.
static GLdouble rects[12][3] =
{ { 50.0, 50.0, 0.0 },
{ 300.0, 50.0, 0.0 },
{ 300.0, 300.0, 0.0 },
{ 50.0, 300.0, 0.0 },
{ 100.0, 100.0, 0.0 },
{ 250.0, 100.0, 0.0 },
{ 250.0, 250.0, 0.0 },
{ 100.0, 250.0, 0.0 },
{ 150.0, 150.0, 0.0 },
{ 200.0, 150.0, 0.0 },
{ 200.0, 200.0, 0.0 },
{ 150.0, 200.0, 0.0 } };
static GLdouble rectsMidanti[12][3] = // the centre 2 contours are traversed opposite order to outer contour.
{ { 1050.0, 50.0, 0.0 },
{ 1300.0, 50.0, 0.0 },
{ 1300.0, 300.0, 0.0 },
{ 1050.0, 300.0, 0.0 },
{ 1250.0, 100.0, 0.0 },
{ 1100.0, 100.0, 0.0 },
{ 1100.0, 250.0, 0.0 },
{ 1250.0, 250.0, 0.0 },
{ 1200.0, 150.0, 0.0 },
{ 1150.0, 150.0, 0.0 },
{ 1150.0, 200.0, 0.0 },
{ 1200.0, 200.0, 0.0 } };
static GLdouble spiral[16][3] = // shift by 1000; nb the order of vertices is reversed from that of the red book
{ { 3400.0, 250.0, 0.0 },
{ 3400.0, 50.0, 0.0 },
{ 3050.0, 50.0, 0.0 },
{ 3050.0, 400.0, 0.0 },
{ 3350.0, 400.0, 0.0 },
{ 3350.0, 100.0, 0.0 },
{ 3100.0, 100.0, 0.0 },
{ 3100.0, 350.0, 0.0 },
{ 3300.0, 350.0, 0.0 },
{ 3300.0, 150.0, 0.0 },
{ 3150.0, 150.0, 0.0 },
{ 3150.0, 300.0, 0.0 },
{ 3250.0, 300.0, 0.0 },
{ 3250.0, 200.0, 0.0 },
{ 3200.0, 200.0, 0.0 },
{ 3200.0, 250.0, 0.0 }
};
static GLdouble quad1[4][3] = // shift by 2000 for next 3 things
{ { 2050.0, 150.0, 0.0 },
{ 2350.0, 150.0, 0.0 },
{ 2350.0, 200.0, 0.0 },
{ 2050.0, 200.0, 0.0 }
};
static GLdouble quad2[4][3] =
{ { 2100.0, 100.0, 0.0 },
{ 2300.0, 100.0, 0.0 },
{ 2300.0, 350.0, 0.0 },
{ 2100.0, 350.0, 0.0 }
};
static GLdouble tri[3][3] =
{ { 2200.0, 50.0, 0.0 },
{ 2250.0, 300.0, 0.0 },
{ 2150.0, 300.0, 0.0 }
};
static GLdouble quad3[4][3] =
{ { 100.0, 1100.0, 0.0 },
{ 1300.0, 1100.0, 0.0 },
{ 1300.0, 2350.0, 0.0 },
{ 100.0, 2350.0, 0.0}
};
static GLdouble quadstrip[8][3] =
{ { 900.0, 1130.0, 0.0 },
{ 1100.0, 1130.0, 0.0 },
{ 900.0, 1350.0, 0.0 },
{ 950.0, 1350.0, 0.0 },
{ 900.0, 1550.0, 0.0 },
{ 1000.0, 1550.0, 0.0 },
{ 900.0, 1750.0, 0.0 },
{ 1400.0, 1750.0, 0.0 }
};
for (i = 0; i < 12; i++) {
coords->push_back(osg::Vec3(rects[i][0],rects[i][2],rects[i][1]));
tcs->push_back(osg::Vec2(rects[i][0],rects[i][1])/200.0);
nrms->push_back(nrm);
}
for (i = 0; i < 12; i++) {
coords->push_back(osg::Vec3(rectsMidanti[i][0],rectsMidanti[i][2],rectsMidanti[i][1]));
tcs->push_back(osg::Vec2(rectsMidanti[i][0],rectsMidanti[i][1])/200.0);
nrms->push_back(nrm);
}
for (i = 0; i < 16; i++) { // and reverse spiral to make same as that of red book ch 11
coords->push_back(osg::Vec3(spiral[15-i][0],spiral[15-i][2],spiral[15-i][1]));
tcs->push_back(osg::Vec2(spiral[15-i][0],spiral[15-i][1])/200.0);
nrms->push_back(nrm);
}
for (i = 0; i < 4; i++) {
coords->push_back(osg::Vec3(quad1[i][0],quad1[i][2],quad1[i][1]));
tcs->push_back(osg::Vec2(quad1[i][0],quad1[i][1])/200.0);
nrms->push_back(nrm);
}
for (i = 0; i < 4; i++) {
coords->push_back(osg::Vec3(quad2[i][0],quad2[i][2],quad2[i][1]));
tcs->push_back(osg::Vec2(quad2[i][0],quad2[i][1])/200.0);
nrms->push_back(nrm);
}
for (i = 0; i < 3; i++) {
coords->push_back(osg::Vec3(tri[i][0],tri[i][2],tri[i][1]));
tcs->push_back(osg::Vec2(tri[i][0],tri[i][1])/200.0);
nrms->push_back(nrm);
}
// add one large quad with multiple holes
for (i = 0; i < 4; i++) {
coords->push_back(osg::Vec3(quad3[i][0],quad3[i][2],quad3[i][1]));
tcs->push_back(osg::Vec2(quad3[i][0],quad3[i][1])/200.0);
nrms->push_back(nrm);
}
{
osg::Vec3 centre(300,0,1500);
for (i = 0; i < 18; i++) {
osg::Vec3 rim=centre+osg::Vec3(-cos(osg::DegreesToRadians((float)i*20.0)),0.0,sin(osg::DegreesToRadians((float)i*20.0)))*150.0;
coords->push_back(rim);
tcs->push_back(osg::Vec2(rim.x(),rim.z())/200.0);
nrms->push_back(nrm);
}
}
{
osg::Vec3 centre(400,0,1800);
for (i = 0; i < 18; i++) {
osg::Vec3 rim=centre+osg::Vec3(-cos(osg::DegreesToRadians((float)i*15.0)),0.0,sin(osg::DegreesToRadians((float)i*15.0)))*250.0;
coords->push_back(rim);
tcs->push_back(osg::Vec2(rim.x(),rim.z())/200.0);
nrms->push_back(nrm);
}
}
{
osg::Vec3 centre(600,0,1400);
for (i = 0; i < 18; i++) {
osg::Vec3 rim=centre+osg::Vec3(-cos(osg::DegreesToRadians((float)i*12.0)),0.0,sin(osg::DegreesToRadians((float)i*12.0)))*250.0;
coords->push_back(rim);
tcs->push_back(osg::Vec2(rim.x(),rim.z())/200.0);
nrms->push_back(nrm);
}
}
// add one large quadstrip
for (i = 0; i < 8; i++) {
coords->push_back(osg::Vec3(quadstrip[i][0],quadstrip[i][2],quadstrip[i][1]));
tcs->push_back(osg::Vec2(quadstrip[i][0],quadstrip[i][1])/200.0);
nrms->push_back(nrm);
}
gtess->setVertexArray(coords);
gtess->setNormalArray(nrms, osg::Array::BIND_PER_VERTEX);
gtess->setTexCoordArray(0,tcs);
// demonstrate that the Tessellator makes textured tessellations
osg::StateSet* stateset = new osg::StateSet();
osg::ref_ptr<osg::Image> image = osgDB::readRefImageFile("Cubemap_snow/posz.jpg");
if (image)
{
osg::Texture2D* texture = new osg::Texture2D;
texture->setImage(image);
texture->setWrap(osg::Texture2D::WRAP_S, osg::Texture2D::REPEAT);
texture->setWrap(osg::Texture2D::WRAP_T, osg::Texture2D::REPEAT);
stateset->setTextureAttributeAndModes(0,texture,osg::StateAttribute::ON);
}
gtess->setStateSet( stateset );
int nstart=0;
// the contours accepoted are polygons; quads & tris. Trifans can bve added later.
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS,nstart,12));nstart+=12;
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS,nstart,12));nstart+=12;
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::POLYGON,nstart,16));nstart+=16;
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS,nstart,4));nstart+=4;
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS,nstart,4));nstart+=4;
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::TRIANGLES,nstart,3));nstart+=3;
// A rectabngle with multiple holes
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::LINE_LOOP,nstart,4));nstart+=4;
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::TRIANGLE_FAN,nstart,18));nstart+=18;
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::POLYGON,nstart,18));nstart+=18;
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::POLYGON,nstart,18));nstart+=18;
// test for quad strip
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::TRIANGLE_STRIP,nstart,8));nstart+=8;
// We need to access the tessellatable contours again to demonstrate all types of tessellation.
// I could add the Tessellator to the geometry as userdata, but here
// I use the derived tessellateDemoGeometry to hold both the drawable geode and the original contours.
gtess->setTessellationType(osgUtil::Tessellator::TESS_TYPE_GEOMETRY);
gtess->setBoundaryOnly(true);
gtess->setWindingType( osgUtil::Tessellator::TESS_WINDING_ABS_GEQ_TWO); // so that first change in wind type makes the commonest tessellation - ODD.
return gtess;
}
osg::Node* createHUD()
{ // add a string reporting the type of winding rule tessellation applied
osg::Geode* geode = new osg::Geode();
std::string timesFont("fonts/arial.ttf");
// turn lighting off for the text and disable depth test to ensure its always ontop.
osg::StateSet* stateset = geode->getOrCreateStateSet();
stateset->setMode(GL_LIGHTING,osg::StateAttribute::OFF);
// Disable depth test, and make sure that the hud is drawn after everything
// else so that it always appears ontop.
stateset->setMode(GL_DEPTH_TEST,osg::StateAttribute::OFF);
stateset->setRenderBinDetails(11,"RenderBin");
osg::Vec3 position(150.0f,900.0f,0.0f);
osg::Vec3 delta(0.0f,-30.0f,0.0f);
{
osgText::Text* text = new osgText::Text;
geode->addDrawable( text );
text->setFont(timesFont);
text->setPosition(position);
text->setText("Tessellation example - no tessellation (use 'W' wireframe to visualise)");
text->setColor(osg::Vec4(1.0,1.0,0.8,1.0));
position += delta;
}
{
osgText::Text* text = new osgText::Text;
geode->addDrawable( text );
text->setFont(timesFont);
text->setPosition(position);
text->setText("Press 'n' to use an alternative tessellation.");
}
// create the hud.
osg::MatrixTransform* modelview_abs = new osg::MatrixTransform;
modelview_abs->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
modelview_abs->setMatrix(osg::Matrix::identity());
modelview_abs->addChild(geode);
osg::Projection* projection = new osg::Projection;
projection->setMatrix(osg::Matrix::ortho2D(0,1280,0,1024));
projection->addChild(modelview_abs);
return projection;
}
osg::Group *makeTessellateExample (void) {
osg::Group *grp=new osg::Group;
osg::Geode *gd=new osg::Geode;
gd->addDrawable(makePols());
gd->addDrawable(makePolsTwo());
grp->addChild(gd);
grp->addChild(makeHouse());
return grp;
}
class setTessellateVisitor : public osg::NodeVisitor
{ // searches a loaded model tree for tessellatable geometries.
// used with any database model which has a renderGroup (Geode) named 'tessellate'
// or you can force a type of tess with special names or a sub-class of Geode could have extra information
// of course you can use any name to detect what is to be tessellated!
// all the polygons within the specific node are deemed to be contours, so
// any tessellation can be requested.
public:
setTessellateVisitor():osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN) {
}
virtual void apply(osg::Geode& geode) {
if (geode.getName().compare(0,9,"tessellate")==0) {
for(unsigned int i=0;i<geode.getNumDrawables();++i)
{
osg::Geometry* geom = dynamic_cast<osg::Geometry*>(geode.getDrawable(i));
if (geom) {
osg::ref_ptr<osgUtil::Tessellator> tscx=new osgUtil::Tessellator();
if (tscx.valid()) {
tscx->setTessellationType(osgUtil::Tessellator::TESS_TYPE_GEOMETRY);
if (geode.getName()== "tessellate") {
// add a Tessellator so that this geom is retessellated when N is pressed
tscx->setBoundaryOnly(true);
tscx->setWindingType( osgUtil::Tessellator::TESS_WINDING_ABS_GEQ_TWO); // so that first change in wind type makes the commonest tessellation - ODD.
geom->setUserData(tscx.get());
} else if (geode.getName()== "tessellate odd") {
// OR you can just apply the Tessellator once only, using these different types
tscx->setWindingType( osgUtil::Tessellator::TESS_WINDING_ODD); // commonest tessellation - ODD.
tscx->retessellatePolygons(*geom);
} else if (geode.getName()== "tessellate odd bound") {
tscx->setBoundaryOnly(true);
tscx->setWindingType( osgUtil::Tessellator::TESS_WINDING_ODD); // tessellation - ODD, only show boundary.
tscx->retessellatePolygons(*geom);
} else if (geode.getName()== "tessellate positive") {
tscx->setWindingType( osgUtil::Tessellator::TESS_WINDING_POSITIVE); // tessellation - pos.
tscx->retessellatePolygons(*geom);
} else if (geode.getName()== "tessellate positive bound") {
tscx->setBoundaryOnly(true);
tscx->setWindingType( osgUtil::Tessellator::TESS_WINDING_POSITIVE);
tscx->retessellatePolygons(*geom);
} else if (geode.getName()== "tessellate negative") {
tscx->setWindingType( osgUtil::Tessellator::TESS_WINDING_NEGATIVE);
tscx->retessellatePolygons(*geom);
} else if (geode.getName()== "tessellate negative bound") {
tscx->setBoundaryOnly(true);
tscx->setWindingType( osgUtil::Tessellator::TESS_WINDING_NEGATIVE);
tscx->retessellatePolygons(*geom);
} else if (geode.getName()== "tessellate nonzero") {
tscx->setWindingType( osgUtil::Tessellator::TESS_WINDING_NONZERO);
tscx->retessellatePolygons(*geom);
} else if (geode.getName()== "tessellate nonzero bound") {
tscx->setBoundaryOnly(true);
tscx->setWindingType( osgUtil::Tessellator::TESS_WINDING_NONZERO);
tscx->retessellatePolygons(*geom);
} else if (geode.getName()== "tessellate geq2") {
tscx->setWindingType( osgUtil::Tessellator::TESS_WINDING_ABS_GEQ_TWO);
tscx->retessellatePolygons(*geom);
} else if (geode.getName()== "tessellate geq2 bound") {
tscx->setBoundaryOnly(true);
tscx->setWindingType( osgUtil::Tessellator::TESS_WINDING_ABS_GEQ_TWO);
tscx->retessellatePolygons(*geom);
}
}
}
}
}
}
};
class cxTessellateVisitor : public osg::NodeVisitor
{ // special to this demo, traverses SG and finds nodes which have been tessellated
// for test/demo purposes these nodes are of type tessellateDemoGeometry
// but you could store the Tessellator as UserData or however you like.
// the Tessellator holds copies of the original contours used in the tessellation
// In this visitor, I reuse the contours to make a different type of tessellation.
public:
cxTessellateVisitor():osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN) {
}
virtual void apply(osg::Geode& geode) {
for(unsigned int i=0;i<geode.getNumDrawables();++i)
{
tessellateDemoGeometry *geom=dynamic_cast<tessellateDemoGeometry*>(geode.getDrawable(i));
if (geom) {
if (!geom->getBoundaryOnly()) { // turn on bounds only
// NB this shows only the true boundary of the curves, no internal edges
geom->setBoundaryOnly(true);
} else { // change to next type of tessellation...
geom->setBoundaryOnly(false);
switch (geom->getWindingType()) {
case osgUtil::Tessellator::TESS_WINDING_ODD:
geom->setWindingType(osgUtil::Tessellator::TESS_WINDING_NONZERO);
break;
case osgUtil::Tessellator::TESS_WINDING_NONZERO:
geom->setWindingType( osgUtil::Tessellator::TESS_WINDING_POSITIVE);
break;
case osgUtil::Tessellator::TESS_WINDING_POSITIVE:
geom->setWindingType( osgUtil::Tessellator::TESS_WINDING_NEGATIVE);
break;
case osgUtil::Tessellator::TESS_WINDING_NEGATIVE:
geom->setWindingType( osgUtil::Tessellator::TESS_WINDING_ABS_GEQ_TWO);
break;
case osgUtil::Tessellator::TESS_WINDING_ABS_GEQ_TWO:
geom->setWindingType( osgUtil::Tessellator::TESS_WINDING_ODD);
break;
}
}
switch (geom->getWindingType()) { // a text to be added to the scene.
case osgUtil::Tessellator::TESS_WINDING_ODD:
str="TESS_WINDING_ODD";
break;
case osgUtil::Tessellator::TESS_WINDING_NONZERO:
str="TESS_WINDING_NONZERO";
break;
case osgUtil::Tessellator::TESS_WINDING_POSITIVE:
str="TESS_WINDING_POSITIVE";
break;
case osgUtil::Tessellator::TESS_WINDING_NEGATIVE:
str="TESS_WINDING_NEGATIVE";
break;
case osgUtil::Tessellator::TESS_WINDING_ABS_GEQ_TWO:
str="TESS_WINDING_ABS_GEQ_TWO";
break;
}
if (geom->getBoundaryOnly()) str += " Boundary";
geom->retessellatePolygons(*geom);
}
osgText::Text* txt = dynamic_cast<osgText::Text*>(geode.getDrawable(i));
if (txt) {
const osg::Vec4& ct=txt->getColor(); // pick the text to be changed by its color
if (ct.z()<0.9) {
txt->setText(str.c_str());
}
}
}
traverse(geode);
}
std::string str; // a label for on screen display
};
class KeyboardEventHandler : public osgGA::GUIEventHandler
{ // extra event handler traps 'n' key to re-tessellate any tessellated geodes.
public:
KeyboardEventHandler(osg::Node *nd):
_scene(nd) {}
virtual bool handle(const osgGA::GUIEventAdapter& ea,osgGA::GUIActionAdapter&)
{
switch(ea.getEventType())
{
case(osgGA::GUIEventAdapter::KEYDOWN):
{
if (_scene && ea.getKey()=='n')
{
// re-tessellate the scene graph.
// the same contours are re-tessellated using a new method. Old contours
// & tessellation type are held internally in the derived Geode class tessellateDemoGeometry.
cxTessellateVisitor tsv;
_scene->accept(tsv);
return true;
}
break;
}
default:
break;
}
return false;
}
osg::Node *_scene;
};
int main( int argc, char **argv )
{
// use an ArgumentParser object to manage the program arguments.
osg::ArgumentParser arguments(&argc,argv);
// construct the viewer.
osgViewer::Viewer viewer;
// read the scene from the list of file specified commandline args.
osg::ref_ptr<osg::Node> loadedModel = osgDB::readRefNodeFiles(arguments);
// if no model has been successfully loaded report failure.
if (!loadedModel)
{
loadedModel=makeTessellateExample();
} else { // if there is a loaded model:
// tessellate by searching for geode called tessellate & tessellate it
setTessellateVisitor tsv;
loadedModel->accept(tsv);
}
// create the hud.
osg::Group *gload= dynamic_cast<osg::Group *> (loadedModel.get());
gload->addChild(createHUD());
osgUtil::Optimizer optimizer;
optimizer.optimize(loadedModel.get() );
// set the scene to render
viewer.setSceneData(loadedModel.get());
// add event handler for keyboard 'n' to retessellate
viewer.addEventHandler(new KeyboardEventHandler(loadedModel.get()));
return viewer.run();
}
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