From cdfdcecd046c494470bfb4cc1de66f6cfca5efec Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 12 Aug 2016 23:38:50 +0300
Subject: [PATCH] Handle clipping in Pipeline and Renderer

---
 source/pipeline.cpp |  9 ++++++++-
 source/pipeline.h   |  4 ++++
 source/renderer.cpp | 35 +++++++++++++++++++++++++++++++++++
 source/renderer.h   |  7 ++++++-
 4 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/source/pipeline.cpp b/source/pipeline.cpp
index bcbbb05f..1833001f 100644
--- a/source/pipeline.cpp
+++ b/source/pipeline.cpp
@@ -178,6 +178,7 @@ void Pipeline::render(Renderer &renderer, const Tag &tag) const
 		Bind bind_depth_test(i->get_depth_test());
 		Bind bind_blend(i->get_blend());
 		renderer.set_lighting(i->get_lighting());
+		renderer.set_clipping(i->get_clipping());
 
 		for(vector<Slot>::const_iterator j=renderables.begin(); j!=renderables.end(); ++j)
 			if(j->passes.empty() || j->passes.count(i->get_tag()))
@@ -241,7 +242,8 @@ Pipeline::Pass::Pass(const Tag &t):
 	tag(t),
 	lighting(0),
 	depth_test(0),
-	blend(0)
+	blend(0),
+	clipping(0)
 { }
 
 void Pipeline::Pass::set_lighting(const Lighting *l)
@@ -259,6 +261,11 @@ void Pipeline::Pass::set_blend(const Blend *b)
 	blend = b;
 }
 
+void Pipeline::Pass::set_clipping(const Clipping *c)
+{
+	clipping =c;
+}
+
 
 Pipeline::Slot::Slot(const Renderable *r):
 	renderable(r)
diff --git a/source/pipeline.h b/source/pipeline.h
index 515ca1a4..2c61a537 100644
--- a/source/pipeline.h
+++ b/source/pipeline.h
@@ -13,6 +13,7 @@ namespace GL {
 
 class Blend;
 class Camera;
+class Clipping;
 class DepthTest;
 class Lighting;
 class PostProcessor;
@@ -49,6 +50,7 @@ public:
 		const Lighting *lighting;
 		const DepthTest *depth_test;
 		const Blend *blend;
+		const Clipping *clipping;
 
 	public:
 		Pass(const Tag &);
@@ -58,9 +60,11 @@ public:
 		void set_lighting(const Lighting *);
 		void set_depth_test(const DepthTest *);
 		void set_blend(const Blend *);
+		void set_clipping(const Clipping *);
 		const Lighting *get_lighting() const { return lighting; }
 		const DepthTest *get_depth_test() const { return depth_test; }
 		const Blend *get_blend() const { return blend; }
+		const Clipping *get_clipping() const { return clipping; }
 	};
 
 private:
diff --git a/source/renderer.cpp b/source/renderer.cpp
index c558757f..6a4c488f 100644
--- a/source/renderer.cpp
+++ b/source/renderer.cpp
@@ -1,6 +1,7 @@
 #include "batch.h"
 #include "buffer.h"
 #include "camera.h"
+#include "clipping.h"
 #include "error.h"
 #include "lighting.h"
 #include "material.h"
@@ -102,6 +103,15 @@ void Renderer::set_lighting(const Lighting *l)
 	changed |= LIGHTING;
 }
 
+void Renderer::set_clipping(const Clipping *c)
+{
+	state->clipping = c;
+	state->clipping_matrix = mtx_stack.top();
+	if(c)
+		c->update_shader_data(standard_shdata, mtx_stack.top());
+	changed |= CLIPPING;
+}
+
 void Renderer::set_shader_program(const Program *p, const ProgramData *d)
 {
 	state->shprog = p;
@@ -144,6 +154,7 @@ void Renderer::pop_state()
 		throw stack_underflow("Renderer::pop_state");
 
 	const Lighting *old_lighting = state->lighting;
+	const Clipping *old_clipping = state->clipping;
 	state_stack.pop_back();
 	state = &state_stack.back();
 	if(shdata_stack.size()>state->shdata_count)
@@ -160,6 +171,12 @@ void Renderer::pop_state()
 			state->lighting->update_shader_data(standard_shdata, state->lighting_matrix);
 		changed |= LIGHTING;
 	}
+	if(state->clipping!=old_clipping)
+	{
+		if(state->clipping)
+			state->clipping->update_shader_data(standard_shdata, state->clipping_matrix);
+		changed |= CLIPPING;
+	}
 }
 
 void Renderer::escape()
@@ -256,6 +273,23 @@ void Renderer::apply_state()
 		}
 	}
 
+	if(changed&CLIPPING)
+	{
+		if(state->clipping)
+		{
+			if(legacy_bindings)
+			{
+				MatrixStack::modelview() = state->clipping_matrix;
+				state->clipping->bind(true);
+				changed = (changed&~CLIPPING)|LEGACY_MATRIX;
+			}
+			else
+				state->clipping->bind(false);
+		}
+		else
+			Clipping::unbind();
+	}
+
 	if(state->shprog)
 	{
 		bool shprog_changed = (state->shprog!=Program::current());
@@ -357,6 +391,7 @@ Renderer::State::State():
 	lowest_effect_texunit(TexUnit::get_n_units()),
 	material(0),
 	lighting(0),
+	clipping(0),
 	shprog(0),
 	shdata_count(0),
 	mesh(0),
diff --git a/source/renderer.h b/source/renderer.h
index 18d3a41a..3d561b4f 100644
--- a/source/renderer.h
+++ b/source/renderer.h
@@ -13,6 +13,7 @@ namespace GL {
 class Batch;
 class Buffer;
 class Camera;
+class Clipping;
 class Material;
 class Mesh;
 class Lighting;
@@ -69,6 +70,8 @@ private:
 		const Material *material;
 		const Lighting *lighting;
 		Matrix lighting_matrix;
+		const Clipping *clipping;
+		Matrix clipping_matrix;
 		const Program *shprog;
 		unsigned shdata_count;
 		const Mesh *mesh;
@@ -95,7 +98,8 @@ private:
 		MODERN_MATRIX = 2,
 		MATRIX = LEGACY_MATRIX|MODERN_MATRIX,
 		LIGHTING = 4,
-		SHADER_DATA = 8
+		CLIPPING = 8,
+		SHADER_DATA = 16
 	};
 
 	MtxStack mtx_stack;
@@ -138,6 +142,7 @@ public:
 	void set_material(const Material *);
 
 	void set_lighting(const Lighting *);
+	void set_clipping(const Clipping *);
 
 	/** Sets the shader program to use.  An initial set of data can be set as
 	well, with the same semantics as add_shader_data. */
-- 
2.45.2