added FitToScreen()

modules/gfx/pymod/__init__.py

@@ -45,3 +45,81 @@ LIGHTPURPLE=LIGHTMAGENTA
 ORANGE=Color(1.0,0.5,0.0)
 DARKORANGE=Color(0.5,0.25,0.0)
 LIGHTORANGE=Color(1.0,0.75,0.5)
+
+
+
+def FitToScreen(gfx_ent, width=None, height=None, margin=0.01):
+  """
+  Setup camera such that it is centered on the graphical entity and the entity 
+  fits the entire viewport. The longest axes of the entity are aligned along 
+  the x- and y- axes of the screen.
+  
+  :param gfx_ent: The graphical entity
+  :type gfx_ent: str or :class:`Entity`
+  
+  
+  """
+  from ost import geom
+  import math
+  def _XYZ(view, axes):
+    """
+    returns the vectors in x, y and z direction respectively. The smallest 
+    vector is in z, then y, and the largest along x.
+    """
+    rows=[axes.GetRow(i) for i in range(3)]
+    lengths=[]
+    for axe in rows:
+      min_proj=geom.Dot(axe, view.atoms[0].pos)
+      max_proj=min_proj
+      for atom in view.atoms[1:]:
+        proj=geom.Dot(axe, atom.pos)
+        min_proj=min(proj, min_proj)
+        max_proj=max(proj, max_proj)
+      lengths.append(max_proj-min_proj)
+    def cmp_x(rhs, lhs):
+      return cmp(lhs[1], rhs[1])
+    sorted_axes=sorted(zip(rows, lengths), cmp_x)
+    return [r*l for r,l in sorted_axes]
+  scene=Scene()
+  if not isinstance(gfx_ent, Entity):
+    gfx_ent=scene[str(gfx_ent)]
+  width=width and width or scene.viewport.width
+  height=height and height or scene.viewport.height
+  atom_positions=geom.Vec3List([atom.pos for atom in gfx_ent.view.atoms])
+  axes=atom_positions.principal_axes
+  sorted_axes=_XYZ(gfx_ent.view, axes)
+  x_bigger_than_y=geom.Length(sorted_axes[0])>geom.Length(sorted_axes[1])
+  if x_bigger_than_y:
+    if width>height:    
+      x_axes=geom.Normalize(sorted_axes[0])
+      y_axes=geom.Normalize(sorted_axes[1])
+    else:
+      x_axes=geom.Normalize(sorted_axes[1])
+      y_axes=geom.Normalize(sorted_axes[0])
+  else:
+    if width>height:    
+      x_axes=geom.Normalize(sorted_axes[1])
+      y_axes=geom.Normalize(sorted_axes[0])
+    else:
+      x_axes=geom.Normalize(sorted_axes[0])
+      y_axes=geom.Normalize(sorted_axes[1])
+  z_axes=geom.Normalize(geom.Cross(x_axes, y_axes))
+  rotation=geom.Mat3(x_axes[0], x_axes[1], x_axes[2],
+                     y_axes[0], y_axes[1], y_axes[2],
+                     z_axes[0], z_axes[1], z_axes[2])
+  rtc=geom.Mat4(rotation)
+  
+  center=gfx_ent.center
+  aspect=float(width)/float(height)
+  factor_y=1.0/math.tan(math.radians(scene.fov))
+  factor_x=factor_y/aspect
+  z_off=geom.Length(sorted_axes[2])*0.5
+  rtc[0,3]=center[0]
+  rtc[1,3]=center[1]
+  rtc[2,3]=center[2]
+  rtc[3,0]=0
+  rtc[3,1]=0
+  rtc[3,2]=-(max(factor_x*(1+margin)*geom.Length(sorted_axes[0]), 
+                factor_y*(1+margin)*geom.Length(sorted_axes[1]))+z_off)
+  scene.SetRTC(rtc)
+

modules/gfx/pymod/export_scene.cc

@@ -67,7 +67,14 @@ void export_Scene()
   void (Scene::*remove2)(const String&) = &Scene::Remove;
   void (Scene::*center_on1)(const String&) = &Scene::CenterOn;
   void (Scene::*center_on2)(const GfxObjP&) = &Scene::CenterOn;
-
+  
+  class_<Viewport>("Viewport", init<>())
+    .def_readwrite("x", &Viewport::x)
+    .def_readwrite("y", &Viewport::y)
+    .def_readwrite("width", &Viewport::width)
+    .def_readwrite("height", &Viewport::height)
+  ;
+  
   class_<Scene, boost::noncopyable>("SceneSingleton",no_init)
     .def("Add", &Scene::Add, 
          scene_add_overloads())
@@ -77,6 +84,7 @@ void export_Scene()
     .def("AutoslabMax",&Scene::AutoslabMax)
     .def("Remove", remove1)
     .def("Remove", remove2)
+    .add_property("viewport", &Scene::GetViewport)
     .def("RequestRedraw", &Scene::RequestRedraw)
     .def("SetCenter",&Scene::SetCenter)
     .def("GetCenter",&Scene::GetCenter)
@@ -118,15 +126,15 @@ void export_Scene()
                   &Scene::SetFogFarOffset)
     .def("GetRTC",&Scene::GetRTC)
     .def("SetRTC",&Scene::SetRTC)
-	.add_property("rtc",&Scene::GetRTC,&Scene::SetRTC)
-	.def("GetTransform",&Scene::GetTransform)
-	.def("SetTransform",&Scene::SetTransform)
-	.add_property("transform", &Scene::GetTransform, &Scene::SetTransform)
-	.def("SetSelectionMode",&Scene::SetSelectionMode)
-	.def("GetSelectionMode",&Scene::GetSelectionMode)
-	.add_property("smode",
-	             &Scene::GetSelectionMode,
-	             &Scene::SetSelectionMode)
+    .add_property("rtc",&Scene::GetRTC,&Scene::SetRTC)
+    .def("GetTransform",&Scene::GetTransform)
+    .def("SetTransform",&Scene::SetTransform)
+    .add_property("transform", &Scene::GetTransform, &Scene::SetTransform)
+    .def("SetSelectionMode",&Scene::SetSelectionMode)
+    .def("GetSelectionMode",&Scene::GetSelectionMode)
+    .add_property("smode",
+                 &Scene::GetSelectionMode,
+                 &Scene::SetSelectionMode)
     .def("Stereo",&Scene::Stereo)
     .def("SetStereoInverted",&Scene::SetStereoInverted)
     .def("SetStereoView",&Scene::SetStereoView)