From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 7 Oct 2016 12:38:09 +0000 (+0300)
Subject: Perform culling in eye space and account for Renderer's matrix
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=0a20dd14a0d1fd027a7d411b4d427bd4252342cc

Perform culling in eye space and account for Renderer's matrix

This allows container renderables to apply intermediate transforms to the
Renderer.  Sometimes it may be inconvenient to propagate every matrix
change down through the hierarchy.
---

diff --git a/source/scene.cpp b/source/scene.cpp
index 7d3c1679..ad9dcd15 100644
--- a/source/scene.cpp
+++ b/source/scene.cpp
@@ -27,26 +27,20 @@ bool Scene::setup_frustum(const Renderer &renderer) const
 	if(!camera)
 		return false;
 
-	const Matrix &matrix = camera->get_object_matrix();
+	culling_matrix = renderer.get_matrix();
 
 	float y = tan(camera->get_field_of_view()/2.0f);
 	float s = sqrt(y*y+1);
-	frustum_edges[0] = matrix*Vector4(0, 1/s, y/s, 0);
-	frustum_edges[1] = matrix*Vector4(0, -1/s, y/s, 0);
+	frustum_edges[0] = Vector4(0, 1/s, y/s, 0);
+	frustum_edges[1] = Vector4(0, -1/s, y/s, 0);
 
 	float x = y*camera->get_aspect();
 	s = sqrt(x*x+1);
-	frustum_edges[2] = matrix*Vector4(1/s, 0, x/s, 0);
-	frustum_edges[3] = matrix*Vector4(-1/s, 0, x/s, 0);
+	frustum_edges[2] = Vector4(1/s, 0, x/s, 0);
+	frustum_edges[3] = Vector4(-1/s, 0, x/s, 0);
 
-	const Vector3 &camera_pos = camera->get_position();
-	Vector4 pos4 = compose(camera_pos, 0.0f);
-	for(unsigned i=0; i<4; ++i)
-		frustum_edges[i].w = -inner_product(frustum_edges[i], pos4);
-
-	const Vector3 &look_dir = camera->get_look_direction();
-	frustum_edges[4] = compose(look_dir, -dot(camera_pos, look_dir)-camera->get_far_clip());
-	frustum_edges[5] = compose(-look_dir, dot(camera_pos, look_dir)+camera->get_near_clip());
+	frustum_edges[4] = Vector4(0, 0, -1, -camera->get_far_clip());
+	frustum_edges[5] = Vector4(0, 0, 1, camera->get_near_clip());
 
 	return true;
 }
@@ -58,7 +52,7 @@ bool Scene::frustum_cull(const Renderable &renderable) const
 	if(!matrix || !bsphere)
 		return false;
 
-	Vector4 center = *matrix*compose(bsphere->get_center(), 1.0f);
+	Vector4 center = culling_matrix*(*matrix*compose(bsphere->get_center(), 1.0f));
 	float radius = bsphere->get_radius();
 
 	for(unsigned i=0; i<6; ++i)
diff --git a/source/scene.h b/source/scene.h
index 27656a59..a04fbc01 100644
--- a/source/scene.h
+++ b/source/scene.h
@@ -3,6 +3,7 @@
 
 #include <list>
 #include <msp/datafile/objectloader.h>
+#include "matrix.h"
 #include "renderable.h"
 #include "vector.h"
 
@@ -28,6 +29,7 @@ public:
 
 protected:
 	std::list<Renderable *> owned_data;
+	mutable Matrix culling_matrix;
 	mutable Vector4 frustum_edges[6];
 
 	Scene() { }