From 90a26a1740d5843b60d07d9c39d8567bfed5189c Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Tue, 11 Jan 2011 20:03:37 +0000
Subject: [PATCH] Better tracking of Renderer matrix changes Make
 MatrixStack::top() const

---
 source/matrix.cpp   |  2 +-
 source/matrix.h     |  4 ++--
 source/renderer.cpp | 22 ++++++++++++++--------
 source/renderer.h   | 15 +++++++++++++--
 4 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/source/matrix.cpp b/source/matrix.cpp
index 4c3a7ee6..caa728d0 100644
--- a/source/matrix.cpp
+++ b/source/matrix.cpp
@@ -294,7 +294,7 @@ MatrixStack::MatrixStack():
 	matrices.push_back(Matrix());
 }
 
-const Matrix &MatrixStack::top()
+const Matrix &MatrixStack::top() const
 {
 	return matrices.back();
 }
diff --git a/source/matrix.h b/source/matrix.h
index 42e70c98..1782dc66 100644
--- a/source/matrix.h
+++ b/source/matrix.h
@@ -98,13 +98,13 @@ private:
 public:
 	MatrixStack();
 
-	const Matrix &top();
+	const Matrix &top() const;
 	void load(const Matrix &);
 	void multiply(const Matrix &);
 	void push();
 	void pop();
 private:
-	void update();
+	virtual void update();
 
 public:
 	MatrixStack &operator=(const Matrix &);
diff --git a/source/renderer.cpp b/source/renderer.cpp
index 71a7dedf..bfd446e9 100644
--- a/source/renderer.cpp
+++ b/source/renderer.cpp
@@ -23,6 +23,7 @@ namespace Msp {
 namespace GL {
 
 Renderer::Renderer(const Camera *c):
+	mtx_stack(*this),
 	mtx_changed(false),
 	camera(c),
 	state_stack(1),
@@ -36,10 +37,10 @@ Renderer::Renderer(const Camera *c):
 	{
 		MatrixStack::projection().push();
 		camera->apply();
-		mtx_stack = camera->get_matrix();
+		mtx_stack.load(camera->get_matrix());
 	}
 	else
-		mtx_stack = MatrixStack::modelview().top();
+		mtx_stack.load(MatrixStack::modelview().top());
 }
 
 Renderer::~Renderer()
@@ -55,12 +56,6 @@ Renderer::~Renderer()
 	Buffer::unbind_from(ELEMENT_ARRAY_BUFFER);
 }
 
-MatrixStack &Renderer::matrix_stack()
-{
-	mtx_changed = true;
-	return mtx_stack;
-}
-
 void Renderer::set_texture(const Texture *t)
 {
 	state->texture = t;
@@ -121,6 +116,7 @@ void Renderer::pop_state()
 	state_stack.pop_back();
 	state = &state_stack.back();
 	mtx_stack.pop();
+	mtx_changed = true;
 }
 
 void Renderer::escape()
@@ -192,5 +188,15 @@ Renderer::State::State():
 	shprog(0)
 { }
 
+
+Renderer::MtxStack::MtxStack(Renderer &r):
+	renderer(r)
+{ }
+
+void Renderer::MtxStack::update()
+{
+	renderer.mtx_changed = true;
+}
+
 } // namespace GL
 } // namespace Msp
diff --git a/source/renderer.h b/source/renderer.h
index c06c17e9..8dbe779f 100644
--- a/source/renderer.h
+++ b/source/renderer.h
@@ -56,7 +56,18 @@ private:
 		State();
 	};
 
-	MatrixStack mtx_stack;
+	class MtxStack: public MatrixStack
+	{
+	private:
+		Renderer &renderer;
+
+	public:
+		MtxStack(Renderer &);
+	private:	
+		virtual void update();
+	};
+
+	MtxStack mtx_stack;
 	bool mtx_changed;
 	const Camera *camera;
 	std::list<State> state_stack;
@@ -69,7 +80,7 @@ public:
 	Renderer(const Camera *);
 	~Renderer();
 
-	MatrixStack &matrix_stack();
+	MatrixStack &matrix_stack() { return mtx_stack; }
 
 	const Camera *get_camera() const { return camera; }
 
-- 
2.43.0