simgear/canvas/ODGauge.cxx

   1 // Owner Drawn Gauge helper class
   2 //
   3 // Written by Harald JOHNSEN, started May 2005.
   4 //
   5 // Copyright (C) 2005  Harald JOHNSEN
   6 //
   7 // Ported to OSG by Tim Moore - Jun 2007
   8 //
   9 // Heavily modified to be usable for the 2d Canvas by Thomas Geymayer - April 2012
  10 // Supports now multisampling/mipmapping, usage of the stencil buffer and placing
  11 // the texture in the scene by certain filter criteria
  12 //
  13 // This library is free software; you can redistribute it and/or
  14 // modify it under the terms of the GNU Library General Public
  15 // License as published by the Free Software Foundation; either
  16 // version 2 of the License, or (at your option) any later version.
  17 //
  18 // This library is distributed in the hope that it will be useful,
  19 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  21 // Library General Public License for more details.
  22 //
  23 // You should have received a copy of the GNU Library General Public
  24 // License along with this library; if not, write to the Free Software
  25 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA
  26
  27 #ifdef HAVE_CONFIG_H
  28 #  include <simgear_config.h>
  29 #endif
  30
  31 #include "ODGauge.hxx"
  32 #include "CanvasSystemAdapter.hxx"
  33
  34 #include <simgear/debug/logstream.hxx>
  35 #include <simgear/scene/util/RenderConstants.hxx>
  36
  37 #include <osg/Texture2D>
  38 #include <osg/AlphaFunc>
  39 #include <osg/BlendFunc>
  40 #include <osg/Camera>
  41 #include <osg/Matrix>
  42 #include <osg/PolygonMode>
  43 #include <osg/ShadeModel>
  44 #include <osg/StateSet>
  45 #include <osg/FrameBufferObject> // for GL_DEPTH_STENCIL_EXT on Windows
  46
  47 #include <cassert>
  48
  49 namespace simgear
  50 {
  51 namespace canvas
  52 {
  53
  54   //----------------------------------------------------------------------------
  55   ODGauge::ODGauge():
  56     _size_x( -1 ),
  57     _size_y( -1 ),
  58     _view_width( -1 ),
  59     _view_height( -1 ),
  60     _flags(0),
  61     _coverage_samples( 0 ),
  62     _color_samples( 0 )
  63   {
  64
  65   }
  66
  67   //----------------------------------------------------------------------------
  68   ODGauge::~ODGauge()
  69   {
  70     clear();
  71   }
  72
  73   //----------------------------------------------------------------------------
  74   void ODGauge::setSystemAdapter(const SystemAdapterPtr& system_adapter)
  75   {
  76     _system_adapter = system_adapter;
  77   }
  78
  79   //----------------------------------------------------------------------------
  80   void ODGauge::setSize(int size_x, int size_y)
  81   {
  82     _size_x = size_x;
  83     _size_y = size_y < 0 ? size_x : size_y;
  84
  85     if( serviceable() )
  86       reinit();
  87     else if( texture )
  88       texture->setTextureSize(_size_x, _size_y);
  89   }
  90
  91   //----------------------------------------------------------------------------
  92   void ODGauge::setViewSize(int width, int height)
  93   {
  94     _view_width = width;
  95     _view_height = height < 0 ? width : height;
  96
  97     if( camera )
  98       updateCoordinateFrame();
  99   }
 100
 101   //----------------------------------------------------------------------------
 102   osg::Vec2s ODGauge::getViewSize() const
 103   {
 104     return osg::Vec2s(_view_width, _view_height);
 105   }
 106
 107   //----------------------------------------------------------------------------
 108   void ODGauge::useImageCoords(bool use)
 109   {
 110     if( updateFlag(USE_IMAGE_COORDS, use) && texture )
 111       updateCoordinateFrame();
 112   }
 113
 114   //----------------------------------------------------------------------------
 115   void ODGauge::useStencil(bool use)
 116   {
 117     if( updateFlag(USE_STENCIL, use) && texture )
 118       updateStencil();
 119   }
 120
 121   //----------------------------------------------------------------------------
 122   void ODGauge::useAdditiveBlend(bool use)
 123   {
 124     if( updateFlag(USE_ADDITIVE_BLEND, use) && camera )
 125       updateBlendMode();
 126   }
 127
 128   //----------------------------------------------------------------------------
 129   void ODGauge::setSampling( bool mipmapping,
 130                              int coverage_samples,
 131                              int color_samples )
 132   {
 133     if(    !updateFlag(USE_MIPMAPPING, mipmapping)
 134         && _coverage_samples == coverage_samples
 135         && _color_samples == color_samples )
 136       return;
 137
 138     if( color_samples > coverage_samples )
 139     {
 140       SG_LOG
 141       (
 142         SG_GL,
 143         SG_WARN,
 144         "ODGauge::setSampling: color_samples > coverage_samples not allowed!"
 145       );
 146       color_samples = coverage_samples;
 147     }
 148
 149     _coverage_samples = coverage_samples;
 150     _color_samples = color_samples;
 151
 152     updateSampling();
 153   }
 154
 155   //----------------------------------------------------------------------------
 156   void ODGauge::setRender(bool render)
 157   {
 158     // Only the far camera should trigger this texture to be rendered.
 159     camera->setNodeMask(render ? simgear::BACKGROUND_BIT : 0);
 160   }
 161
 162   //----------------------------------------------------------------------------
 163   bool ODGauge::serviceable() const
 164   {
 165     return _flags & AVAILABLE;
 166   }
 167
 168   //----------------------------------------------------------------------------
 169   void ODGauge::allocRT(osg::NodeCallback* camera_cull_callback)
 170   {
 171     camera = new osg::Camera;
 172     camera->setDataVariance(osg::Object::DYNAMIC);
 173     camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
 174     camera->setRenderOrder(osg::Camera::PRE_RENDER);
 175     camera->setClearColor(osg::Vec4(0.0f, 0.0f, 0.0f , 0.0f));
 176     camera->setClearStencil(0);
 177     camera->setRenderTargetImplementation( osg::Camera::FRAME_BUFFER_OBJECT,
 178                                                osg::Camera::FRAME_BUFFER );
 179
 180     if( camera_cull_callback )
 181       camera->setCullCallback(camera_cull_callback);
 182
 183     setRender(true);
 184     updateCoordinateFrame();
 185     updateStencil();
 186
 187     osg::StateSet* stateSet = camera->getOrCreateStateSet();
 188     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
 189     stateSet->setMode(GL_CULL_FACE, osg::StateAttribute::OFF);
 190     stateSet->setMode(GL_FOG, osg::StateAttribute::OFF);
 191     stateSet->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
 192     stateSet->setAttributeAndModes(
 193       new osg::PolygonMode( osg::PolygonMode::FRONT_AND_BACK,
 194                             osg::PolygonMode::FILL ),
 195       osg::StateAttribute::ON );
 196     stateSet->setAttributeAndModes(
 197       new osg::AlphaFunc(osg::AlphaFunc::GREATER, 0.001f),
 198       osg::StateAttribute::ON );
 199     stateSet->setAttribute(new osg::ShadeModel(osg::ShadeModel::FLAT));
 200
 201     if( !texture )
 202     {
 203       texture = new osg::Texture2D;
 204       texture->setTextureSize(_size_x, _size_y);
 205       texture->setInternalFormat(GL_RGBA);
 206     }
 207
 208     updateSampling();
 209     updateBlendMode();
 210
 211     if( _system_adapter )
 212       _system_adapter->addCamera(camera.get());
 213
 214     _flags |= AVAILABLE;
 215   }
 216
 217   //----------------------------------------------------------------------------
 218   void ODGauge::reinit()
 219   {
 220     osg::NodeCallback* cull_callback = camera ? camera->getCullCallback() : 0;
 221     clear();
 222     allocRT(cull_callback);
 223   }
 224
 225   //----------------------------------------------------------------------------
 226   void ODGauge::clear()
 227   {
 228     if( camera.valid() && _system_adapter )
 229       _system_adapter->removeCamera(camera.get());
 230     camera.release();
 231     texture.release();
 232
 233     _flags &= ~AVAILABLE;
 234   }
 235
 236   //----------------------------------------------------------------------------
 237   bool ODGauge::updateFlag(Flags flag, bool enable)
 238   {
 239     if( bool(_flags & flag) == enable )
 240       return false;
 241
 242     _flags ^= flag;
 243     return true;
 244   }
 245
 246   //----------------------------------------------------------------------------
 247   void ODGauge::updateCoordinateFrame()
 248   {
 249     assert( camera );
 250
 251     if( _view_width < 0 )
 252       _view_width = _size_x;
 253     if( _view_height < 0 )
 254       _view_height = _size_y;
 255
 256     camera->setViewport(0, 0, _size_x, _size_y);
 257
 258     if( _flags & USE_IMAGE_COORDS )
 259       camera->setProjectionMatrix(
 260         osg::Matrix::ortho2D(0, _view_width, _view_height, 0)
 261       );
 262     else
 263       camera->setProjectionMatrix(
 264         osg::Matrix::ortho2D( -_view_width/2.,  _view_width/2.,
 265                               -_view_height/2., _view_height/2. )
 266       );
 267   }
 268
 269   //----------------------------------------------------------------------------
 270   void ODGauge::updateStencil()
 271   {
 272     assert( camera );
 273
 274     GLbitfield mask = GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT;
 275
 276     if( _flags & USE_STENCIL )
 277     {
 278       camera->attach( osg::Camera::PACKED_DEPTH_STENCIL_BUFFER,
 279                        GL_DEPTH_STENCIL_EXT );
 280       mask |= GL_STENCIL_BUFFER_BIT;
 281     }
 282     else
 283     {
 284       camera->detach(osg::Camera::PACKED_DEPTH_STENCIL_BUFFER);
 285     }
 286
 287     camera->setClearMask(mask);
 288   }
 289
 290   //----------------------------------------------------------------------------
 291   void ODGauge::updateSampling()
 292   {
 293     assert( camera );
 294     assert( texture );
 295
 296     texture->setFilter(
 297       osg::Texture2D::MIN_FILTER,
 298       (_flags & USE_MIPMAPPING) ? osg::Texture2D::LINEAR_MIPMAP_LINEAR
 299                                 : osg::Texture2D::LINEAR
 300     );
 301     camera->attach(
 302       osg::Camera::COLOR_BUFFER,
 303       texture.get(),
 304       0, 0,
 305       _flags & USE_MIPMAPPING,
 306       _coverage_samples,
 307       _color_samples
 308     );
 309   }
 310
 311   //----------------------------------------------------------------------------
 312   void ODGauge::updateBlendMode()
 313   {
 314     assert( camera );
 315
 316     camera->getOrCreateStateSet()
 317       ->setAttributeAndModes
 318       (
 319         (_flags & USE_ADDITIVE_BLEND)
 320           ? new osg::BlendFunc( osg::BlendFunc::SRC_ALPHA,
 321                                 osg::BlendFunc::ONE_MINUS_SRC_ALPHA,
 322                                 osg::BlendFunc::ONE,
 323                                 osg::BlendFunc::ONE )
 324           : new osg::BlendFunc( osg::BlendFunc::SRC_ALPHA,
 325                                 osg::BlendFunc::ONE_MINUS_SRC_ALPHA )
 326       );
 327   }
 328
 329 } // namespace canvas
 330 } // namespace simgear