X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;ds=sidebyside;f=src%2FCockpit%2Fpanel.cxx;h=d20af07af99fd6913890a2ac943f7d2c50f1b642;hb=470292a4341334820681d6d6e2ecc6039b8d6dd6;hp=5f638f44f09a3d19a5a15d07c657421ae88836e8;hpb=f1b1077d930d542014baf54a328b7a233182647a;p=flightgear.git

diff --git a/src/Cockpit/panel.cxx b/src/Cockpit/panel.cxx
index 5f638f44f..d20af07af 100644
--- a/src/Cockpit/panel.cxx
+++ b/src/Cockpit/panel.cxx
@@ -36,12 +36,49 @@
 
 #include <Main/globals.hxx>
 #include <Main/fg_props.hxx>
+#include <Main/viewmgr.hxx>
 #include <Objects/texload.h>
 #include <Time/light.hxx>
 
 #include "hud.hxx"
 #include "panel.hxx"
 
+#define WIN_X 0
+#define WIN_Y 0
+#define WIN_W 1024
+#define WIN_H 768
+
+#if defined( NONE ) && defined( _MSC_VER )
+#  pragma message( "A sloppy coder has defined NONE as a macro!!!" )
+#  undef NONE
+#elif defined( NONE )
+#  pragma warn A sloppy coder has defined NONE as a macro!!!
+#  undef NONE
+#endif
+
+
+
+////////////////////////////////////////////////////////////////////////
+// Local functions.
+////////////////////////////////////////////////////////////////////////
+
+
+/**
+ * Calculate the aspect adjustment for the panel.
+ */
+static float
+get_aspect_adjust (int xsize, int ysize)
+{
+  float ideal_aspect = float(WIN_W) / float(WIN_H);
+  float real_aspect = float(xsize) / float(ysize);
+  return (real_aspect / ideal_aspect);
+}
+
+
+
+////////////////////////////////////////////////////////////////////////
+// Global functions.
+////////////////////////////////////////////////////////////////////////
 
 bool
 fgPanelVisible ()
@@ -65,15 +102,16 @@ FGTextureManager::createTexture (const string &relativePath)
 {
   ssgTexture * texture = _textureMap[relativePath];
   if (texture == 0) {
-    cerr << "Texture " << relativePath << " does not yet exist" << endl;
+    SG_LOG( SG_COCKPIT, SG_DEBUG,
+            "Texture " << relativePath << " does not yet exist" );
     SGPath tpath(globals->get_fg_root());
     tpath.append(relativePath);
     texture = new ssgTexture((char *)tpath.c_str(), false, false);
     _textureMap[relativePath] = texture;
     if (_textureMap[relativePath] == 0) 
-      cerr << "Texture *still* doesn't exist" << endl;
-    cerr << "Created texture " << relativePath
-	 << " handle=" << texture->getHandle() << endl;
+      SG_LOG( SG_COCKPIT, SG_ALERT, "Texture *still* doesn't exist" );
+    SG_LOG( SG_COCKPIT, SG_DEBUG, "Created texture " << relativePath
+            << " handle=" << texture->getHandle() );
   }
 
   return texture;
@@ -130,12 +168,15 @@ static fntRenderer text_renderer;
 /**
  * Constructor.
  */
-FGPanel::FGPanel (int window_x, int window_y, int window_w, int window_h)
+FGPanel::FGPanel ()
   : _mouseDown(false),
     _mouseInstrument(0),
-    _winx(window_x), _winy(window_y), _winw(window_w), _winh(window_h),
-    _width(_winw), _height(int(_winh * 0.5768 + 1)),
-    _x_offset(0), _y_offset(0), _view_height(int(_winh * 0.4232))
+    _width(WIN_W), _height(int(WIN_H * 0.5768 + 1)),
+    _x_offset(0), _y_offset(0), _view_height(int(WIN_H * 0.4232)),
+    _bound(false),
+    _jitter(0.0),
+    _xsize_node(fgGetNode("/sim/startup/xsize", true)),
+    _ysize_node(fgGetNode("/sim/startup/ysize", true))
 {
   setVisibility(fgPanelVisible());
 }
@@ -146,7 +187,8 @@ FGPanel::FGPanel (int window_x, int window_y, int window_w, int window_h)
  */
 FGPanel::~FGPanel ()
 {
-  unbind();
+  if (_bound)
+    unbind();
   for (instrument_list_type::iterator it = _instruments.begin();
        it != _instruments.end();
        it++) {
@@ -183,8 +225,14 @@ void
 FGPanel::bind ()
 {
   fgTie("/sim/panel/visibility", &_visibility);
+  fgSetArchivable("/sim/panel/visibility");
   fgTie("/sim/panel/x-offset", &_x_offset);
+  fgSetArchivable("/sim/panel/x-offset");
   fgTie("/sim/panel/y-offset", &_y_offset);
+  fgSetArchivable("/sim/panel/y-offset");
+  fgTie("/sim/panel/jitter", &_jitter);
+  fgSetArchivable("/sim/panel/jitter");
+  _bound = true;
 }
 
 
@@ -197,6 +245,7 @@ FGPanel::unbind ()
   fgUntie("/sim/panel/visibility");
   fgUntie("/sim/panel/x-offset");
   fgUntie("/sim/panel/y-offset");
+  _bound = false;
 }
 
 
@@ -207,29 +256,68 @@ void
 FGPanel::update ()
 {
 				// Do nothing if the panel isn't visible.
-  if (!fgPanelVisible())
-    return;
+    if ( !fgPanelVisible() ) {
+        return;
+    }
 
 				// If the mouse is down, do something
-  if (_mouseDown) {
-    _mouseDelay--;
-    if (_mouseDelay < 0) {
-      _mouseInstrument->doMouseAction(_mouseButton, _mouseX, _mouseY);
-      _mouseDelay = 2;
+    if (_mouseDown) {
+        _mouseDelay--;
+        if (_mouseDelay < 0) {
+            _mouseInstrument->doMouseAction(_mouseButton, _mouseX, _mouseY);
+            _mouseDelay = 2;
+        }
     }
-  }
 
 				// Now, draw the panel
+    float aspect_adjust = get_aspect_adjust(_xsize_node->getIntValue(),
+                                            _ysize_node->getIntValue());
+    if (aspect_adjust <1.0)
+        update(WIN_X, int(WIN_W * aspect_adjust), WIN_Y, WIN_H);
+    else
+        update(WIN_X, WIN_W, WIN_Y, int(WIN_H / aspect_adjust));
+}
+
+
+void
+FGPanel::update (GLfloat winx, GLfloat winw, GLfloat winy, GLfloat winh)
+{
+				// Calculate accelerations
+				// and jiggle the panel accordingly
+				// The factors and bounds are just
+				// initial guesses; using sqrt smooths
+				// out the spikes.
+  double x_offset = _x_offset;
+  double y_offset = _y_offset;
+
+  if (_jitter != 0.0) {
+    double a_x_pilot = current_aircraft.fdm_state->get_A_X_pilot();
+    double a_y_pilot = current_aircraft.fdm_state->get_A_Y_pilot();
+    double a_z_pilot = current_aircraft.fdm_state->get_A_Z_pilot();
+
+    double a_zx_pilot = a_z_pilot - a_x_pilot;
+    
+    int x_adjust = int(sqrt(fabs(a_y_pilot) * _jitter)) *
+		   (a_y_pilot < 0 ? -1 : 1);
+    int y_adjust = int(sqrt(fabs(a_zx_pilot) * _jitter)) *
+		   (a_zx_pilot < 0 ? -1 : 1);
+
+				// adjustments in screen coordinates
+    x_offset += x_adjust;
+    y_offset += y_adjust;
+  }
+
   glMatrixMode(GL_PROJECTION);
   glPushMatrix();
   glLoadIdentity();
-  gluOrtho2D(_winx, _winx + _winw, _winy, _winy + _winh);
+  gluOrtho2D(winx, winx + winw, winy, winy + winh); /* right side up */
+  // gluOrtho2D(winx + winw, winx, winy + winh, winy); /* up side down */
 
   glMatrixMode(GL_MODELVIEW);
   glPushMatrix();
   glLoadIdentity();
 
-  glTranslated(_x_offset, _y_offset, 0);
+  glTranslated(x_offset, y_offset, 0);
 
 				// Draw the background
   glEnable(GL_TEXTURE_2D);
@@ -244,14 +332,14 @@ FGPanel::update ()
       glColor4f(0.7, 0.2, 0.2, 1.0);
   }
   glBindTexture(GL_TEXTURE_2D, _bg->getHandle());
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+  // glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+  // glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
   glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
   glBegin(GL_POLYGON);
-  glTexCoord2f(0.0, 0.0); glVertex3f(_winx, _winy, 0);
-  glTexCoord2f(1.0, 0.0); glVertex3f(_winx + _width, _winy, 0);
-  glTexCoord2f(1.0, 1.0); glVertex3f(_winx + _width, _winy + _height, 0);
-  glTexCoord2f(0.0, 1.0); glVertex3f(_winx, _winy + _height, 0);
+  glTexCoord2f(0.0, 0.0); glVertex3f(WIN_X, WIN_Y, 0);
+  glTexCoord2f(1.0, 0.0); glVertex3f(WIN_X + _width, WIN_Y, 0);
+  glTexCoord2f(1.0, 1.0); glVertex3f(WIN_X + _width, WIN_Y + _height, 0);
+  glTexCoord2f(0.0, 1.0); glVertex3f(WIN_X, WIN_Y + _height, 0);
   glEnd();
 
 				// Draw the instruments.
@@ -261,7 +349,7 @@ FGPanel::update ()
   for ( ; current != end; current++) {
     FGPanelInstrument * instr = *current;
     glLoadIdentity();
-    glTranslated(_x_offset, _y_offset, 0);
+    glTranslated(x_offset, y_offset, 0);
     glTranslated(instr->getXPos(), instr->getYPos(), 0);
     instr->draw();
   }
@@ -311,7 +399,7 @@ FGPanel::setBackground (ssgTexture * texture)
 void
 FGPanel::setXOffset (int offset)
 {
-  if (offset <= 0 && offset >= -_width + _winw)
+  if (offset <= 0 && offset >= -_width + WIN_W)
     _x_offset = offset;
 }
 
@@ -333,6 +421,10 @@ FGPanel::setYOffset (int offset)
 bool
 FGPanel::doMouseAction (int button, int updown, int x, int y)
 {
+				// FIXME: this same code appears in update()
+  int xsize = _xsize_node->getIntValue();
+  int ysize = _ysize_node->getIntValue();
+  float aspect_adjust = get_aspect_adjust(xsize, ysize);
 
 				// Note a released button and return
   // cerr << "Doing mouse action\n";
@@ -343,9 +435,13 @@ FGPanel::doMouseAction (int button, int updown, int x, int y)
   }
 
 				// Scale for the real window size.
-  x = int(((float)x / fgGetInt("/sim/startup/xsize")) * _winw);
-  y = int(_winh - (((float)y / fgGetInt("/sim/startup/ysize"))
-		   * _winh));
+  if (aspect_adjust < 1.0) {
+    x = int(((float)x / xsize) * WIN_W * aspect_adjust);
+    y = int(WIN_H - ((float(y) / ysize) * WIN_H));
+  } else {
+    x = int(((float)x / xsize) * WIN_W);
+    y = int((WIN_H - ((float(y) / ysize) * WIN_H)) / aspect_adjust);
+  }
 
 				// Adjust for offsets.
   x -= _x_offset;
@@ -386,87 +482,29 @@ FGPanelAction::FGPanelAction ()
 FGPanelAction::FGPanelAction (int button, int x, int y, int w, int h)
   : _button(button), _x(x), _y(y), _w(w), _h(h)
 {
+  for (unsigned int i = 0; i < _bindings.size(); i++)
+    delete _bindings[i];
 }
 
 FGPanelAction::~FGPanelAction ()
 {
 }
 
-
-
-////////////////////////////////////////////////////////////////////////
-// Implementation of FGAdjustAction.
-////////////////////////////////////////////////////////////////////////
-
-FGAdjustAction::FGAdjustAction (int button, int x, int y, int w, int h,
-				SGValue * value, float increment, 
-				float min, float max, bool wrap)
-  : FGPanelAction(button, x, y, w, h),
-    _value(value), _increment(increment), _min(min), _max(max), _wrap(wrap)
-{
-}
-
-FGAdjustAction::~FGAdjustAction ()
-{
-}
-
 void
-FGAdjustAction::doAction ()
-{
-  float val = _value->getFloatValue();
-  val += _increment;
-  if (val < _min) {
-    val = (_wrap ? _max : _min);
-  } else if (val > _max) {
-    val = (_wrap ? _min : _max);
-  }
-  _value->setDoubleValue(val);
-}
-
-
-
-////////////////////////////////////////////////////////////////////////
-// Implementation of FGSwapAction.
-////////////////////////////////////////////////////////////////////////
-
-FGSwapAction::FGSwapAction (int button, int x, int y, int w, int h,
-			    SGValue * value1, SGValue * value2)
-  : FGPanelAction(button, x, y, w, h), _value1(value1), _value2(value2)
-{
-}
-
-FGSwapAction::~FGSwapAction ()
+FGPanelAction::addBinding (FGBinding * binding)
 {
+  _bindings.push_back(binding);
 }
 
 void
-FGSwapAction::doAction ()
+FGPanelAction::doAction ()
 {
-  float val = _value1->getFloatValue();
-  _value1->setDoubleValue(_value2->getFloatValue());
-  _value2->setDoubleValue(val);
-}
-
-
-
-////////////////////////////////////////////////////////////////////////
-// Implementation of FGToggleAction.
-////////////////////////////////////////////////////////////////////////
-
-FGToggleAction::FGToggleAction (int button, int x, int y, int w, int h,
-				SGValue * value)
-  : FGPanelAction(button, x, y, w, h), _value(value)
-{
-}
-
-FGToggleAction::~FGToggleAction ()
-{
-}
-
-void
-FGToggleAction::doAction ()
-{
-  _value->setBoolValue(!(_value->getBoolValue()));
+  if (test()) {
+    int nBindings = _bindings.size();
+    for (int i = 0; i < nBindings; i++) {
+      _bindings[i]->fire();
+    }
+  }
 }
 
 
@@ -476,11 +514,13 @@ FGToggleAction::doAction ()
 ////////////////////////////////////////////////////////////////////////
 
 FGPanelTransformation::FGPanelTransformation ()
+  : table(0)
 {
 }
 
 FGPanelTransformation::~FGPanelTransformation ()
 {
+  delete table;
 }
 
 
@@ -560,12 +600,14 @@ FGPanelInstrument::addAction (FGPanelAction * action)
 bool
 FGPanelInstrument::doMouseAction (int button, int x, int y)
 {
-  action_list_type::iterator it = _actions.begin();
-  action_list_type::iterator last = _actions.end();
-  for ( ; it != last; it++) {
-    if ((*it)->inArea(button, x, y)) {
-      (*it)->doAction();
-      return true;
+  if (test()) {
+    action_list_type::iterator it = _actions.begin();
+    action_list_type::iterator last = _actions.end();
+    for ( ; it != last; it++) {
+      if ((*it)->inArea(button, x, y)) {
+	(*it)->doAction();
+	return true;
+      }
     }
   }
   return false;
@@ -593,11 +635,13 @@ FGLayeredInstrument::~FGLayeredInstrument ()
 void
 FGLayeredInstrument::draw ()
 {
-  for (int i = 0; i < (int)_layers.size(); i++) {
-    glPushMatrix();
-    glTranslatef(0.0, 0.0, (i / 100.0) + 0.1);
-    _layers[i]->draw();
-    glPopMatrix();
+  if (test()) {
+    for (int i = 0; i < (int)_layers.size(); i++) {
+      glPushMatrix();
+      glTranslatef(0.0, 0.0, (i / 100.0) + 0.1);
+      _layers[i]->draw();
+      glPopMatrix();
+    }
   }
 }
 
@@ -658,24 +702,30 @@ FGInstrumentLayer::transform () const
   transformation_list::const_iterator last = _transformations.end();
   while (it != last) {
     FGPanelTransformation *t = *it;
-    float val = (t->value == 0 ? 0.0 : t->value->getFloatValue());
-    if (val < t->min) {
-      val = t->min;
-    } else if (val > t->max) {
-      val = t->max;
-    }
-    val = val * t->factor + t->offset;
-
-    switch (t->type) {
-    case FGPanelTransformation::XSHIFT:
-      glTranslatef(val, 0.0, 0.0);
-      break;
-    case FGPanelTransformation::YSHIFT:
-      glTranslatef(0.0, val, 0.0);
-      break;
-    case FGPanelTransformation::ROTATION:
-      glRotatef(-val, 0.0, 0.0, 1.0);
-      break;
+    if (t->test()) {
+      float val = (t->node == 0 ? 0.0 : t->node->getFloatValue());
+      if (val < t->min) {
+	val = t->min;
+      } else if (val > t->max) {
+	val = t->max;
+      }
+      if(t->table==0) {
+	val = val * t->factor + t->offset;
+      } else {
+	val = t->table->interpolate(val) * t->factor + t->offset;
+      }
+      
+      switch (t->type) {
+      case FGPanelTransformation::XSHIFT:
+	glTranslatef(val, 0.0, 0.0);
+	break;
+      case FGPanelTransformation::YSHIFT:
+	glTranslatef(0.0, val, 0.0);
+	break;
+      case FGPanelTransformation::ROTATION:
+	glRotatef(-val, 0.0, 0.0, 1.0);
+	break;
+      }
     }
     it++;
   }
@@ -688,6 +738,38 @@ FGInstrumentLayer::addTransformation (FGPanelTransformation * transformation)
 }
 
 
+
+////////////////////////////////////////////////////////////////////////
+// Implementation of FGGroupLayer.
+////////////////////////////////////////////////////////////////////////
+
+FGGroupLayer::FGGroupLayer ()
+{
+}
+
+FGGroupLayer::~FGGroupLayer ()
+{
+  for (unsigned int i = 0; i < _layers.size(); i++)
+    delete _layers[i];
+}
+
+void
+FGGroupLayer::draw ()
+{
+  if (test()) {
+    int nLayers = _layers.size();
+    for (int i = 0; i < nLayers; i++)
+      _layers[i]->draw();
+  }
+}
+
+void
+FGGroupLayer::addLayer (FGInstrumentLayer * layer)
+{
+  _layers.push_back(layer);
+}
+
+
 
 ////////////////////////////////////////////////////////////////////////
 // Implementation of FGTexturedLayer.
@@ -709,27 +791,29 @@ FGTexturedLayer::~FGTexturedLayer ()
 void
 FGTexturedLayer::draw ()
 {
-  int w2 = _w / 2;
-  int h2 = _h / 2;
-
-  transform();
-  glBindTexture(GL_TEXTURE_2D, _texture.getTexture()->getHandle());
-  glBegin(GL_POLYGON);
-
+  if (test()) {
+    int w2 = _w / 2;
+    int h2 = _h / 2;
+    
+    transform();
+    glBindTexture(GL_TEXTURE_2D, _texture.getTexture()->getHandle());
+    glBegin(GL_POLYGON);
+    
 				// From Curt: turn on the panel
 				// lights after sundown.
-  if ( cur_light_params.sun_angle * SGD_RADIANS_TO_DEGREES < 95.0 ) {
+    if ( cur_light_params.sun_angle * SGD_RADIANS_TO_DEGREES < 95.0 ) {
       glColor4fv( cur_light_params.scene_diffuse );
-  } else {
+    } else {
       glColor4f(0.7, 0.2, 0.2, 1.0);
-  }
+    }
 
 
-  glTexCoord2f(_texture.getMinX(), _texture.getMinY()); glVertex2f(-w2, -h2);
-  glTexCoord2f(_texture.getMaxX(), _texture.getMinY()); glVertex2f(w2, -h2);
-  glTexCoord2f(_texture.getMaxX(), _texture.getMaxY()); glVertex2f(w2, h2);
-  glTexCoord2f(_texture.getMinX(), _texture.getMaxY()); glVertex2f(-w2, h2);
-  glEnd();
+    glTexCoord2f(_texture.getMinX(), _texture.getMinY()); glVertex2f(-w2, -h2);
+    glTexCoord2f(_texture.getMaxX(), _texture.getMinY()); glVertex2f(w2, -h2);
+    glTexCoord2f(_texture.getMaxX(), _texture.getMaxY()); glVertex2f(w2, h2);
+    glTexCoord2f(_texture.getMinX(), _texture.getMaxY()); glVertex2f(-w2, h2);
+    glEnd();
+  }
 }
 
 
@@ -758,24 +842,26 @@ FGTextLayer::~FGTextLayer ()
 void
 FGTextLayer::draw ()
 {
-  glPushMatrix();
-  glColor4fv(_color);
-  transform();
-  text_renderer.setFont(guiFntHandle);
-  text_renderer.setPointSize(_pointSize);
-  text_renderer.begin();
-  text_renderer.start3f(0, 0, 0);
-
-  _now.stamp();
-  if (_now - _then > 100000) {
-    recalc_value();
-    _then = _now;
-  }
-  text_renderer.puts((char *)(_value.c_str()));
+  if (test()) {
+    glPushMatrix();
+    glColor4fv(_color);
+    transform();
+    text_renderer.setFont(guiFntHandle);
+    text_renderer.setPointSize(_pointSize);
+    text_renderer.begin();
+    text_renderer.start3f(0, 0, 0);
+
+    _now.stamp();
+    if (_now - _then > 100000) {
+      recalc_value();
+      _then = _now;
+    }
+    text_renderer.puts((char *)(_value.c_str()));
 
-  text_renderer.end();
-  glColor4f(1.0, 1.0, 1.0, 1.0);	// FIXME
-  glPopMatrix();
+    text_renderer.end();
+    glColor4f(1.0, 1.0, 1.0, 1.0);	// FIXME
+    glPopMatrix();
+  }
 }
 
 void
@@ -831,7 +917,7 @@ FGTextLayer::Chunk::Chunk (const string &text, const string &fmt)
     _fmt = "%s";
 }
 
-FGTextLayer::Chunk::Chunk (ChunkType type, const SGValue * value,
+FGTextLayer::Chunk::Chunk (ChunkType type, const SGPropertyNode * node,
 			   const string &fmt, float mult)
   : _type(type), _fmt(fmt), _mult(mult)
 {
@@ -841,24 +927,28 @@ FGTextLayer::Chunk::Chunk (ChunkType type, const SGValue * value,
     else
       _fmt = "%.2f";
   }
-  _value = value;
+  _node = node;
 }
 
 const char *
 FGTextLayer::Chunk::getValue () const
 {
-  switch (_type) {
-  case TEXT:
-    sprintf(_buf, _fmt.c_str(), _text.c_str());
+  if (test()) {
+    switch (_type) {
+    case TEXT:
+      sprintf(_buf, _fmt.c_str(), _text.c_str());
+      return _buf;
+    case TEXT_VALUE:
+      sprintf(_buf, _fmt.c_str(), _node->getStringValue().c_str());
+      break;
+    case DOUBLE_VALUE:
+      sprintf(_buf, _fmt.c_str(), _node->getFloatValue() * _mult);
+      break;
+    }
     return _buf;
-  case TEXT_VALUE:
-    sprintf(_buf, _fmt.c_str(), _value->getStringValue().c_str());
-    break;
-  case DOUBLE_VALUE:
-    sprintf(_buf, _fmt.c_str(), _value->getFloatValue() * _mult);
-    break;
+  } else {
+    return "";
   }
-  return _buf;
 }
 
 
@@ -867,10 +957,10 @@ FGTextLayer::Chunk::getValue () const
 // Implementation of FGSwitchLayer.
 ////////////////////////////////////////////////////////////////////////
 
-FGSwitchLayer::FGSwitchLayer (int w, int h, const SGValue * value,
+FGSwitchLayer::FGSwitchLayer (int w, int h, const SGPropertyNode * node,
 			      FGInstrumentLayer * layer1,
 			      FGInstrumentLayer * layer2)
-  : FGInstrumentLayer(w, h), _value(value), _layer1(layer1), _layer2(layer2)
+  : FGInstrumentLayer(w, h), _node(node), _layer1(layer1), _layer2(layer2)
 {
 }
 
@@ -883,11 +973,13 @@ FGSwitchLayer::~FGSwitchLayer ()
 void
 FGSwitchLayer::draw ()
 {
-  transform();
-  if (_value->getBoolValue()) {
-    _layer1->draw();
-  } else {
-    _layer2->draw();
+  if (test()) {
+    transform();
+    if (_node->getBoolValue()) {
+      _layer1->draw();
+    } else {
+      _layer2->draw();
+    }
   }
 }