OpenSceneGraph/examples/osghangglide/base.cpp

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/* OpenSceneGraph example, osghangglide.
*
* 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.
*/
#include <math.h>
#include <osg/Geode>
#include <osg/Geometry>
#include <osg/Texture2D>
#include <osg/TexEnv>
#include <osg/Depth>
#include <osg/StateSet>
#include <osgDB/ReadFile>
using namespace osg;
Node *makeBase( void )
{
int i, c;
float theta;
float ir = 20.0f;
Vec3Array *coords = new Vec3Array(19);
Vec2Array *tcoords = new Vec2Array(19);
Vec4Array *colors = new Vec4Array(1);
(*colors)[0].set(1.0f,1.0f,1.0f,1.0f);
c = 0;
(*coords)[c].set(0.0f,0.0f,0.0f);
(*tcoords)[c].set(0.0f,0.0f);
for( i = 0; i <= 18; i++ )
{
theta = osg::DegreesToRadians((float)i * 20.0);
(*coords)[c].set(ir * cosf( theta ), ir * sinf( theta ), 0.0f);
(*tcoords)[c].set((*coords)[c][0]/36.0f,(*coords)[c][1]/36.0f);
c++;
}
Geometry *geom = new Geometry;
geom->setVertexArray( coords );
geom->setTexCoordArray( 0, tcoords );
geom->setColorArray( colors, Array::BIND_OVERALL );
geom->addPrimitiveSet( new DrawArrays(PrimitiveSet::TRIANGLE_FAN,0,19) );
Texture2D *tex = new Texture2D;
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/branches/OpenSceneGraph-3.4@15165 16af8721-9629-0410-8352-f15c8da7e697
2015-10-22 22:14:53 +08:00
tex->setImage(osgDB::readRefImageFile("Images/water.rgb"));
tex->setWrap( Texture2D::WRAP_S, Texture2D::REPEAT );
tex->setWrap( Texture2D::WRAP_T, Texture2D::REPEAT );
StateSet *dstate = new StateSet;
dstate->setMode( GL_LIGHTING, StateAttribute::OFF );
dstate->setTextureAttributeAndModes(0, tex, StateAttribute::ON );
dstate->setTextureAttribute(0, new TexEnv );
// clear the depth to the far plane.
osg::Depth* depth = new osg::Depth;
depth->setFunction(osg::Depth::ALWAYS);
depth->setRange(1.0,1.0);
dstate->setAttributeAndModes(depth,StateAttribute::ON );
dstate->setRenderBinDetails(-1,"RenderBin");
geom->setStateSet( dstate );
Geode *geode = new Geode;
geode->addDrawable( geom );
return geode;
}