Add a Scene type that sorts its renderables by depth

diff --git a/source/scene.h b/source/scene.h
index e3aa1fabb2cd5829e6567b706712b1580192b991..fbc57a80e46e396b4128b31d6f86c5562c2b86ab 100644 (file)
--- a/source/scene.h
+++ b/source/scene.h
@@ -10,7 +10,7 @@ class Culler;
 
 /**
 Scenes are containers for other Renderables.  This is a base class that can't
-be instantiated.  At the moment the available Scene types are SimpleScene,
+be instantiated.  Examples of available Scene types are SimpleScene,
 InstancedScene and OrderedScene.
 */
 class Scene: public Renderable

diff --git a/source/simplescene.h b/source/simplescene.h
index be86285bba84b21ea25f98aad1d3f51954a165b1..deba4d5f8877b872aa6d3be5dcc5cb7eecf7c0e1 100644 (file)
--- a/source/simplescene.h
+++ b/source/simplescene.h
@@ -12,7 +12,7 @@ The simplest possible Scene.  Rendering order is unspecified.
 */
 class SimpleScene: public Scene
 {
-private:
+protected:
        typedef std::set<const Renderable *> RenderableSet;
 
        RenderableSet renderables;

diff --git a/source/zsortedscene.cpp b/source/zsortedscene.cpp
new file mode 100644 (file)
index 0000000..da406b7
--- /dev/null
+++ b/source/zsortedscene.cpp
@@ -0,0 +1,67 @@
+#include "camera.h"
+#include "renderer.h"
+#include "zsortedscene.h"
+
+using namespace std;
+
+namespace Msp {
+namespace GL {
+
+ZSortedScene::ZSortedScene():
+       order(BACK_TO_FRONT),
+       reference(FURTHEST)
+{ }
+
+void ZSortedScene::set_order(SortOrder o)
+{
+       order = o;
+}
+
+void ZSortedScene::set_reference(DepthReference r)
+{
+       reference = r;
+}
+
+void ZSortedScene::render(Renderer &renderer, const Tag &tag) const
+{
+       const Camera *camera = renderer.get_camera();
+       if(!camera)
+               return SimpleScene::render(renderer, tag);
+
+       const Matrix &view_matrix = camera->get_matrix();
+
+       std::vector<DepthRenderable> sorted_renderables;
+       sorted_renderables.reserve(renderables.size());
+
+       float radius_factor = 1.0f-reference;
+       float sign = order*2.0f-1.0f;
+
+       setup_cullers(renderer);
+       for(RenderableSet::const_iterator i=renderables.begin(); i!=renderables.end(); ++i)
+               if(!cull(renderer, **i))
+               {
+                       float z = 0;
+                       if(const Matrix *model_matrix = (*i)->get_matrix())
+                       {
+                               if(const Geometry::BoundingSphere<float, 3> *bsphere = (*i)->get_bounding_sphere())
+                                       z = (view_matrix**model_matrix*Vector4(bsphere->get_center(), 1.0f)).z+bsphere->get_radius()*radius_factor;
+                               else
+                                       z = (view_matrix**model_matrix*Vector4(0.0f, 0.0f, 0.0f, 1.0f)).z;
+                       }
+                       sorted_renderables.push_back(DepthRenderable(z*sign, *i));
+               }
+
+       sort(sorted_renderables.begin(), sorted_renderables.end());
+
+       for(vector<DepthRenderable>::const_iterator i=sorted_renderables.begin(); i!=sorted_renderables.end(); ++i)
+               i->renderable->render(renderer, tag);
+}
+
+
+ZSortedScene::DepthRenderable::DepthRenderable(float d, const Renderable *r):
+       depth(d),
+       renderable(r)
+{ }
+
+} // namespace GL
+} // namespace Msp

diff --git a/source/zsortedscene.h b/source/zsortedscene.h
new file mode 100644 (file)
index 0000000..f9f6f7e
--- /dev/null
+++ b/source/zsortedscene.h
@@ -0,0 +1,57 @@
+#ifndef MSP_GL_ZSORTEDSCENE_H_
+#define MSP_GL_ZSORTEDSCENE_H_
+
+#include "simplescene.h"
+
+namespace Msp {
+namespace GL {
+
+enum SortOrder
+{
+       FRONT_TO_BACK,
+       BACK_TO_FRONT
+};
+
+enum DepthReference
+{
+       CLOSEST,
+       CENTER,
+       FURTHEST
+};
+
+/**
+Sorts renderables by their distance from the camera before rendering.  Requires
+renderables to have a matrix.
+*/
+class ZSortedScene: public SimpleScene
+{
+private:
+       struct DepthRenderable
+       {
+               float depth;
+               const Renderable *renderable;
+
+               DepthRenderable(float, const Renderable *);
+
+               bool operator<(const DepthRenderable &o) const { return depth<o.depth; }
+       };
+
+       SortOrder order;
+       DepthReference reference;
+
+public:
+       ZSortedScene();
+
+       /// Sets the sort order.  Default is back to front.
+       void set_order(SortOrder);
+
+       /// Sets the reference point for sorting.  Default is furthest from camera.
+       void set_reference(DepthReference);
+
+       virtual void render(Renderer &, const Tag &) const;
+};
+
+} // namespace GL
+} // namespace Msp
+
+#endif