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   void ODGauge::useImageCoords(bool use)
 103   {
 104     if( updateFlag(USE_IMAGE_COORDS, use) && texture )
 105       updateCoordinateFrame();
 106   }
 107
 108   //----------------------------------------------------------------------------
 109   void ODGauge::useStencil(bool use)
 110   {
 111     if( updateFlag(USE_STENCIL, use) && texture )
 112       updateStencil();
 113   }
 114
 115   //----------------------------------------------------------------------------
 116   void ODGauge::useAdditiveBlend(bool use)
 117   {
 118     if( updateFlag(USE_ADDITIVE_BLEND, use) && camera )
 119       updateBlendMode();
 120   }
 121
 122   //----------------------------------------------------------------------------
 123   void ODGauge::setSampling( bool mipmapping,
 124                              int coverage_samples,
 125                              int color_samples )
 126   {
 127     if(    !updateFlag(USE_MIPMAPPING, mipmapping)
 128         && _coverage_samples == coverage_samples
 129         && _color_samples == color_samples )
 130       return;
 131
 132     if( color_samples > coverage_samples )
 133     {
 134       SG_LOG
 135       (
 136         SG_GL,
 137         SG_WARN,
 138         "ODGauge::setSampling: color_samples > coverage_samples not allowed!"
 139       );
 140       color_samples = coverage_samples;
 141     }
 142
 143     _coverage_samples = coverage_samples;
 144     _color_samples = color_samples;
 145
 146     updateSampling();
 147   }
 148
 149   //----------------------------------------------------------------------------
 150   void ODGauge::setRender(bool render)
 151   {
 152     // Only the far camera should trigger this texture to be rendered.
 153     camera->setNodeMask(render ? simgear::BACKGROUND_BIT : 0);
 154   }
 155
 156   //----------------------------------------------------------------------------
 157   bool ODGauge::serviceable(void)
 158   {
 159     return _flags & AVAILABLE;
 160   }
 161
 162   //----------------------------------------------------------------------------
 163   void ODGauge::allocRT(osg::NodeCallback* camera_cull_callback)
 164   {
 165     camera = new osg::Camera;
 166     camera->setDataVariance(osg::Object::DYNAMIC);
 167     camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
 168     camera->setRenderOrder(osg::Camera::PRE_RENDER);
 169     camera->setClearColor(osg::Vec4(0.0f, 0.0f, 0.0f , 0.0f));
 170     camera->setClearStencil(0);
 171     camera->setRenderTargetImplementation( osg::Camera::FRAME_BUFFER_OBJECT,
 172                                                osg::Camera::FRAME_BUFFER );
 173
 174     if( camera_cull_callback )
 175       camera->setCullCallback(camera_cull_callback);
 176
 177     setRender(true);
 178     updateCoordinateFrame();
 179     updateStencil();
 180
 181     osg::StateSet* stateSet = camera->getOrCreateStateSet();
 182     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
 183     stateSet->setMode(GL_CULL_FACE, osg::StateAttribute::OFF);
 184     stateSet->setMode(GL_FOG, osg::StateAttribute::OFF);
 185     stateSet->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
 186     stateSet->setAttributeAndModes(
 187       new osg::PolygonMode( osg::PolygonMode::FRONT_AND_BACK,
 188                             osg::PolygonMode::FILL ),
 189       osg::StateAttribute::ON );
 190     stateSet->setAttributeAndModes(
 191       new osg::AlphaFunc(osg::AlphaFunc::GREATER, 0.001f),
 192       osg::StateAttribute::ON );
 193     stateSet->setAttribute(new osg::ShadeModel(osg::ShadeModel::FLAT));
 194
 195     if( !texture )
 196     {
 197       texture = new osg::Texture2D;
 198       texture->setTextureSize(_size_x, _size_y);
 199       texture->setInternalFormat(GL_RGBA);
 200     }
 201
 202     updateSampling();
 203     updateBlendMode();
 204
 205     if( _system_adapter )
 206       _system_adapter->addCamera(camera.get());
 207
 208     _flags |= AVAILABLE;
 209   }
 210
 211   //----------------------------------------------------------------------------
 212   void ODGauge::reinit()
 213   {
 214     osg::NodeCallback* cull_callback = camera ? camera->getCullCallback() : 0;
 215     clear();
 216     allocRT(cull_callback);
 217   }
 218
 219   //----------------------------------------------------------------------------
 220   void ODGauge::clear()
 221   {
 222     if( camera.valid() && _system_adapter )
 223       _system_adapter->removeCamera(camera.get());
 224     camera.release();
 225     texture.release();
 226
 227     _flags &= ~AVAILABLE;
 228   }
 229
 230   //----------------------------------------------------------------------------
 231   bool ODGauge::updateFlag(Flags flag, bool enable)
 232   {
 233     if( (_flags & flag) == enable )
 234       return false;
 235
 236     _flags ^= flag;
 237     return true;
 238   }
 239
 240   //----------------------------------------------------------------------------
 241   void ODGauge::updateCoordinateFrame()
 242   {
 243     assert( camera );
 244
 245     if( _view_width < 0 )
 246       _view_width = _size_x;
 247     if( _view_height < 0 )
 248       _view_height = _size_y;
 249
 250     camera->setViewport(0, 0, _size_x, _size_y);
 251
 252     if( _flags & USE_IMAGE_COORDS )
 253       camera->setProjectionMatrix(
 254         osg::Matrix::ortho2D(0, _view_width, _view_height, 0)
 255       );
 256     else
 257       camera->setProjectionMatrix(
 258         osg::Matrix::ortho2D( -_view_width/2.,  _view_width/2.,
 259                               -_view_height/2., _view_height/2. )
 260       );
 261   }
 262
 263   //----------------------------------------------------------------------------
 264   void ODGauge::updateStencil()
 265   {
 266     assert( camera );
 267
 268     GLbitfield mask = GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT;
 269
 270     if( _flags & USE_STENCIL )
 271     {
 272       camera->attach( osg::Camera::PACKED_DEPTH_STENCIL_BUFFER,
 273                        GL_DEPTH_STENCIL_EXT );
 274       mask |= GL_STENCIL_BUFFER_BIT;
 275     }
 276     else
 277     {
 278       camera->detach(osg::Camera::PACKED_DEPTH_STENCIL_BUFFER);
 279     }
 280
 281     camera->setClearMask(mask);
 282   }
 283
 284   //----------------------------------------------------------------------------
 285   void ODGauge::updateSampling()
 286   {
 287     assert( camera );
 288     assert( texture );
 289
 290     texture->setFilter(
 291       osg::Texture2D::MIN_FILTER,
 292       (_flags & USE_MIPMAPPING) ? osg::Texture2D::LINEAR_MIPMAP_LINEAR
 293                                 : osg::Texture2D::LINEAR
 294     );
 295     camera->attach(
 296       osg::Camera::COLOR_BUFFER,
 297       texture.get(),
 298       0, 0,
 299       _flags & USE_MIPMAPPING,
 300       _coverage_samples,
 301       _color_samples
 302     );
 303   }
 304
 305   //----------------------------------------------------------------------------
 306   void ODGauge::updateBlendMode()
 307   {
 308     assert( camera );
 309
 310     camera->getOrCreateStateSet()
 311       ->setAttributeAndModes
 312       (
 313         (_flags & USE_ADDITIVE_BLEND)
 314           ? new osg::BlendFunc( osg::BlendFunc::SRC_ALPHA,
 315                                 osg::BlendFunc::ONE_MINUS_SRC_ALPHA,
 316                                 osg::BlendFunc::ONE,
 317                                 osg::BlendFunc::ONE )
 318           : new osg::BlendFunc( osg::BlendFunc::SRC_ALPHA,
 319                                 osg::BlendFunc::ONE_MINUS_SRC_ALPHA )
 320       );
 321   }
 322
 323 } // namespace canvas
 324 } // namespace simgear