Merge branch 'animation-rework'

[libs/gl.git] / source / renderable.h

diff --git a/source/renderable.h b/source/renderable.h
index 3432a87ee77ed4db3c72600061127bef767c768d..6e1505ca5a728c0ac1b012eb797cf00c84321ff4 100644 (file)
--- a/source/renderable.h
+++ b/source/renderable.h
@@ -2,6 +2,7 @@
 #define MSP_GL_RENDERABLE_H_
 
 #include <string>
+#include <msp/geometry/boundingsphere.h>
 #include "tag.h"
 
 namespace Msp {
@@ -11,11 +12,18 @@ class Matrix;
 class Renderer;
 
 /**
-Base class for renderable objects.  All Renderables must support rendering with
-a Renderer, and may optionally provide support for standalone rendering.
-
-The render methods take a Tag to identify a render pass.  It is most commonly
-used together with Techniques and Pipelines to implement multipass rendering.
+Base class for renderable objects.  Rendering is performed with the help of a
+Renderer object.
+
+The render method takes a Tag to identify a render pass.  It can be used with
+a Technique to select alternative rendering methods, such as simplified shaders
+for a depth-only shadow pass.
+
+The setup_frame and finish_frame methods provide a mechanism for performing
+once-per-frame operations.  This is most useful for effects, which may need to
+do auxiliary rendering.  With complex rendering hierarchies, these methods may
+be called multiple times for one frame, but it's guaranteed that no rendering
+will occur before a setup_frame call or after a finish_frame call.
 */
 class Renderable
 {
@@ -29,15 +37,22 @@ public:
        virtual long get_instance_key() const { return 0; }
 
        /** Returns the model matrix of the Renderable.  Null is returned if no such
-       matrix exists. */
+       matrix exists.  The matrix should be in world space for some effects to work
+       correctly. */
        virtual const Matrix *get_matrix() const { return 0; }
 
-       /** Renders the renderable without a renderer.  This can be convenient in
-       some simple cases, but most renderables don't need to implement this
-       method. */
-       virtual void render(const Tag & = Tag()) const;
+       /** Returns a bounding sphere that completely encloses the Renderable.  The
+       bounding sphere is expressed in the renderable's coordinates.  Null is
+       returned if the bounding sphere cannot be determined. */
+       virtual const Geometry::BoundingSphere<float, 3> *get_bounding_sphere() const { return 0; }
+
+       /** Called when starting to render a new frame. */
+       virtual void setup_frame(Renderer &) { }
+
+       /** Called when a complete frame has been rendered. */
+       virtual void finish_frame() { }
 
-       /** Renders the renderable.  Implementors should take care to return the
+       /** Renders the Renderable.  Implementors should take care to return the
        renderer to the state it was in, for example by using Renderer::Push. */
        virtual void render(Renderer &, const Tag & = Tag()) const = 0;
 };