From: Mikko Rasa <tdb@tdb.fi>
Date: Tue, 17 Aug 2021 21:39:41 +0000 (+0300)
Subject: Refactor winding-based culling
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=fe9836f2d8d7abb0480582c544611a5b248310cc;p=libs%2Fgl.git

Refactor winding-based culling
---

diff --git a/source/core/cullface.cpp b/source/core/cullface.cpp
new file mode 100644
index 00000000..b1839504
--- /dev/null
+++ b/source/core/cullface.cpp
@@ -0,0 +1,32 @@
+#include <msp/strings/format.h>
+#include "cullface.h"
+
+namespace Msp {
+namespace GL {
+
+void operator>>(const LexicalConverter &conv, FaceWinding &winding)
+{
+	if(conv.get()=="NON_MANIFOLD")
+		winding = NON_MANIFOLD;
+	else if(conv.get()=="CLOCKWISE")
+		winding = CLOCKWISE;
+	else if(conv.get()=="COUNTERCLOCKWISE")
+		winding = COUNTERCLOCKWISE;
+	else
+		throw lexical_error(format("conversion of '%s' to FaceWinding", conv.get()));
+}
+
+void operator>>(const LexicalConverter &conv, CullMode &cull)
+{
+	if(conv.get()=="NO_CULL")
+		cull = NO_CULL;
+	else if(conv.get()=="CULL_FRONT")
+		cull = CULL_FRONT;
+	else if(conv.get()=="CULL_BACK")
+		cull = CULL_BACK;
+	else
+		throw lexical_error(format("conversion of '%s' to CullMode", conv.get()));
+}
+
+} // namespace GL
+} // namespace Msp
diff --git a/source/core/cullface.h b/source/core/cullface.h
new file mode 100644
index 00000000..fd90ef20
--- /dev/null
+++ b/source/core/cullface.h
@@ -0,0 +1,29 @@
+#ifndef MSP_GL_CULLFACE_H_
+#define MSP_GL_CULLFACE_H_
+
+#include <msp/strings/lexicalcast.h>
+
+namespace Msp {
+namespace GL {
+
+enum FaceWinding
+{
+	NON_MANIFOLD,
+	CLOCKWISE,
+	COUNTERCLOCKWISE
+};
+
+enum CullMode
+{
+	NO_CULL,
+	CULL_FRONT,
+	CULL_BACK
+};
+
+void operator>>(const LexicalConverter &, FaceWinding &);
+void operator>>(const LexicalConverter &, CullMode &);
+
+} // namespace GL
+} // namespace Msp
+
+#endif
diff --git a/source/core/mesh.cpp b/source/core/mesh.cpp
index 492f416d..4414a90e 100644
--- a/source/core/mesh.cpp
+++ b/source/core/mesh.cpp
@@ -31,7 +31,7 @@ void Mesh::init(ResourceManager *rm)
 	ibuf = 0;
 	dirty = 0;
 	disallow_rendering = false;
-	winding = 0;
+	face_winding = NON_MANIFOLD;
 
 	if(rm)
 		set_manager(rm);
@@ -149,9 +149,9 @@ void Mesh::add_batch(const Batch &b)
 	check_buffers(INDEX_BUFFER);
 }
 
-void Mesh::set_winding(const WindingTest *w)
+void Mesh::set_winding(FaceWinding w)
 {
-	winding = w;
+	face_winding = w;
 }
 
 void Mesh::draw(Renderer &renderer) const
@@ -183,7 +183,7 @@ void Mesh::draw(Renderer &renderer, const VertexSetup *vs, unsigned count) const
 		resize_buffers();
 
 	renderer.set_vertex_setup(vs ? vs : &vtx_setup);
-	renderer.set_winding_test(winding);
+	renderer.set_front_face(face_winding);
 
 	if(!count)
 	{
@@ -256,7 +256,7 @@ Mesh::Loader::Loader(Mesh &m, bool g):
 	add("storage",  &Loader::storage);
 	add("vertices", &Loader::vertices);
 	add("vertices", &Loader::vertices_with_format);
-	add("winding",  &Loader::winding);
+	add("winding",  &Mesh::face_winding);
 }
 
 void Mesh::Loader::storage(const vector<VertexAttribute> &a)
@@ -290,14 +290,6 @@ void Mesh::Loader::batch(PrimitiveType p)
 	obj.add_batch(btc);
 }
 
-void Mesh::Loader::winding(FaceWinding w)
-{
-	if(w==CLOCKWISE)
-		obj.winding = &WindingTest::clockwise();
-	else if(w==COUNTERCLOCKWISE)
-		obj.winding = &WindingTest::counterclockwise();
-}
-
 
 Mesh::AsyncLoader::AsyncLoader(Mesh &m, IO::Seekable &i):
 	mesh(m),
diff --git a/source/core/mesh.h b/source/core/mesh.h
index 66516267..57ffce47 100644
--- a/source/core/mesh.h
+++ b/source/core/mesh.h
@@ -3,10 +3,10 @@
 
 #include <msp/datafile/objectloader.h>
 #include "batch.h"
+#include "cullface.h"
 #include "resource.h"
 #include "vertexarray.h"
 #include "vertexsetup.h"
-#include "windingtest.h"
 
 namespace Msp {
 namespace GL {
@@ -36,7 +36,6 @@ public:
 		void vertices();
 		void vertices_with_format(const std::vector<VertexAttribute> &);
 		void batch(PrimitiveType);
-		void winding(FaceWinding);
 	};
 
 private:
@@ -70,7 +69,7 @@ private:
 	VertexSetup vtx_setup;
 	mutable unsigned short dirty;
 	bool disallow_rendering;
-	const WindingTest *winding;
+	FaceWinding face_winding;
 	std::string debug_name;
 
 public:
@@ -97,7 +96,7 @@ public:
 	void add_batch(const Batch &b);
 	const std::vector<Batch> &get_batches() const { return batches; }
 
-	void set_winding(const WindingTest *);
+	void set_winding(FaceWinding);
 
 	void draw(Renderer &) const;
 	void draw_instanced(Renderer &, const VertexSetup &, unsigned) const;
diff --git a/source/core/pipelinestate.cpp b/source/core/pipelinestate.cpp
index a3b9e640..cfeed9ab 100644
--- a/source/core/pipelinestate.cpp
+++ b/source/core/pipelinestate.cpp
@@ -12,7 +12,6 @@
 #include "texture.h"
 #include "uniformblock.h"
 #include "vertexsetup.h"
-#include "windingtest.h"
 
 using namespace std;
 
@@ -25,7 +24,8 @@ vector<int> PipelineState::bound_tex_targets;
 PipelineState::PipelineState():
 	shprog(0),
 	vertex_setup(0),
-	winding_test(0),
+	front_face(COUNTERCLOCKWISE),
+	face_cull(NO_CULL),
 	enabled_clip_planes(0),
 	changes(0)
 {
@@ -57,12 +57,21 @@ void PipelineState::set_vertex_setup(const VertexSetup *s)
 	}
 }
 
-void PipelineState::set_winding_test(const WindingTest *w)
+void PipelineState::set_front_face(FaceWinding w)
 {
-	if(w!=winding_test)
+	if(w!=front_face)
 	{
-		winding_test = w;
-		changes |= WINDING_TEST;
+		front_face = w;
+		changes |= FACE_CULL;
+	}
+}
+
+void PipelineState::set_face_cull(CullMode c)
+{
+	if(c!=face_cull)
+	{
+		face_cull = c;
+		changes |= FACE_CULL;
 	}
 }
 
@@ -132,12 +141,14 @@ void PipelineState::apply(unsigned mask) const
 			vertex_setup->refresh();
 	}
 
-	if(mask&WINDING_TEST)
+	if(mask&FACE_CULL)
 	{
-		if(winding_test)
+		glFrontFace(front_face==CLOCKWISE ? GL_CW : GL_CCW);
+
+		if(face_cull!=NO_CULL)
 		{
 			glEnable(GL_CULL_FACE);
-			glFrontFace(winding_test->get_winding());
+			glCullFace(face_cull==CULL_FRONT ? GL_FRONT : GL_BACK);
 		}
 		else
 			glDisable(GL_CULL_FACE);
diff --git a/source/core/pipelinestate.h b/source/core/pipelinestate.h
index 8d1d1aaa..55d96485 100644
--- a/source/core/pipelinestate.h
+++ b/source/core/pipelinestate.h
@@ -3,6 +3,7 @@
 
 #include <vector>
 #include <msp/core/noncopyable.h>
+#include "cullface.h"
 
 namespace Msp {
 namespace GL {
@@ -42,7 +43,7 @@ private:
 	{
 		SHPROG = 1,
 		VERTEX_SETUP = 2,
-		WINDING_TEST = 4,
+		FACE_CULL = 4,
 		CLIP_PLANES = 8,
 		TEXTURES = 16,
 		UNIFORMS = 32
@@ -50,7 +51,8 @@ private:
 
 	const Program *shprog;
 	const VertexSetup *vertex_setup;
-	const WindingTest *winding_test;
+	FaceWinding front_face;
+	CullMode face_cull;
 	unsigned enabled_clip_planes;
 	std::vector<BoundTexture> textures;
 	std::vector<BoundUniformBlock> uniform_blocks;
@@ -65,7 +67,8 @@ public:
 
 	void set_shader_program(const Program *);
 	void set_vertex_setup(const VertexSetup *);
-	void set_winding_test(const WindingTest *);
+	void set_front_face(FaceWinding);
+	void set_face_cull(CullMode);
 	void set_enabled_clip_planes(unsigned);
 	void set_texture(unsigned, const Texture *, const Sampler *);
 	void set_uniforms(const DefaultUniformBlock *);
@@ -76,7 +79,8 @@ public:
 
 	const Program *get_shader_program() const { return shprog; }
 	const VertexSetup *get_vertex_setup() const { return vertex_setup; }
-	const WindingTest *get_winding_test() const { return winding_test; }
+	FaceWinding get_front_face() const { return front_face; }
+	CullMode get_face_cull() const { return face_cull; }
 
 	void apply() const;
 private:
diff --git a/source/core/windingtest.cpp b/source/core/windingtest.cpp
deleted file mode 100644
index 0b8218ad..00000000
--- a/source/core/windingtest.cpp
+++ /dev/null
@@ -1,61 +0,0 @@
-#include <msp/strings/format.h>
-#include "windingtest.h"
-
-namespace Msp {
-namespace GL {
-
-void operator>>(const LexicalConverter &conv, FaceWinding &winding)
-{
-	if(conv.get()=="CLOCKWISE")
-		winding = CLOCKWISE;
-	else if(conv.get()=="COUNTERCLOCKWISE")
-		winding = COUNTERCLOCKWISE;
-	else
-		throw lexical_error(format("conversion of '%s' to FaceWinding", conv.get()));
-}
-
-WindingTest::WindingTest():
-	winding(COUNTERCLOCKWISE)
-{ }
-
-WindingTest::WindingTest(FaceWinding w):
-	winding(w)
-{ }
-
-void WindingTest::bind() const
-{
-	if(set_current(this))
-	{
-		glEnable(GL_CULL_FACE);
-		glFrontFace(winding);
-	}
-}
-
-void WindingTest::unbind()
-{
-	if(set_current(0))
-		glDisable(GL_CULL_FACE);
-}
-
-const WindingTest &WindingTest::get_reverse() const
-{
-	if(winding==CLOCKWISE)
-		return counterclockwise();
-	else
-		return clockwise();
-}
-
-const WindingTest &WindingTest::clockwise()
-{
-	static WindingTest test(CLOCKWISE);
-	return test;
-}
-
-const WindingTest &WindingTest::counterclockwise()
-{
-	static WindingTest test(COUNTERCLOCKWISE);
-	return test;
-}
-
-} // namespace GL
-} // namespace Msp
diff --git a/source/core/windingtest.h b/source/core/windingtest.h
deleted file mode 100644
index ff5b417d..00000000
--- a/source/core/windingtest.h
+++ /dev/null
@@ -1,47 +0,0 @@
-#ifndef MSP_GL_WINDINGTEST_H_
-#define MSP_GL_WINDINGTEST_H_
-
-#include <msp/strings/lexicalcast.h>
-#include "bindable.h"
-#include "gl.h"
-
-namespace Msp {
-namespace GL {
-
-enum FaceWinding
-{
-	CLOCKWISE = GL_CW,
-	COUNTERCLOCKWISE = GL_CCW
-};
-
-void operator>>(const LexicalConverter &, FaceWinding &);
-
-/**
-Tests the winding of polygons.  If the order of vertices on screen does not
-match the winding, the polygon is not rendered.
-*/
-class WindingTest: public Bindable<WindingTest>
-{
-private:
-	FaceWinding winding;
-
-public:
-	WindingTest();
-	WindingTest(FaceWinding);
-
-	FaceWinding get_winding() const { return winding; }
-
-	void bind() const;
-
-	static void unbind();
-
-	const WindingTest &get_reverse() const;
-
-	static const WindingTest &clockwise();
-	static const WindingTest &counterclockwise();
-};
-
-} // namespace GL
-} // namespace Msp
-
-#endif
diff --git a/source/materials/renderpass.cpp b/source/materials/renderpass.cpp
index 70143e96..9a7ceef7 100644
--- a/source/materials/renderpass.cpp
+++ b/source/materials/renderpass.cpp
@@ -21,7 +21,7 @@ RenderPass::RenderPass():
 	shprog_from_material(false),
 	shdata(0),
 	material(0),
-	back_faces(false),
+	face_cull(CULL_BACK),
 	receive_shadows(false),
 	image_based_lighting(false)
 { }
@@ -124,9 +124,9 @@ int RenderPass::get_texture_index(const string &n) const
 	return (shprog && i!=textures.end() ? shprog->get_uniform_binding(i->tag) : -1);
 }
 
-void RenderPass::set_back_faces(bool bf)
+void RenderPass::set_face_cull(CullMode fc)
 {
-	back_faces = bf;
+	face_cull = fc;
 }
 
 void RenderPass::set_receive_shadows(bool rs)
@@ -141,7 +141,7 @@ void RenderPass::apply(Renderer &renderer) const
 	renderer.set_shader_program(shprog, shdata.get());
 	if(material)
 		renderer.add_shader_data(material->get_shader_data());
-	renderer.set_reverse_winding(back_faces);
+	renderer.set_face_cull(face_cull);
 }
 
 void RenderPass::set_debug_name(const string &name)
@@ -171,12 +171,12 @@ RenderPass::Loader::Loader(RenderPass &p, Collection &c):
 
 void RenderPass::Loader::init_actions()
 {
+	add("face_cull", &RenderPass::face_cull);
 	add("shader",   &Loader::shader);
 	add("image_based_lighting", &RenderPass::image_based_lighting);
 	add("material", &Loader::material_inline);
 	add("material", &Loader::material);
 	add("material_slot", &RenderPass::material_slot);
-	add("back_faces",&RenderPass::back_faces);
 	add("receive_shadows", &RenderPass::receive_shadows);
 	add("texture", &Loader::texture);
 	add("uniforms", &Loader::uniforms);
diff --git a/source/materials/renderpass.h b/source/materials/renderpass.h
index d5587c25..94cc2ed9 100644
--- a/source/materials/renderpass.h
+++ b/source/materials/renderpass.h
@@ -3,6 +3,7 @@
 
 #include <msp/core/refptr.h>
 #include <msp/datafile/objectloader.h>
+#include "cullface.h"
 #include "material.h"
 
 namespace Msp {
@@ -83,7 +84,7 @@ private:
 	const Material *material;
 	std::string material_slot;
 	std::vector<TextureSlot> textures;
-	bool back_faces;
+	CullMode face_cull;
 	bool receive_shadows;
 	bool image_based_lighting;
 
@@ -106,8 +107,8 @@ public:
 	Tag get_texture_tag(const std::string &) const;
 	DEPRECATED void set_texture(unsigned, const Texture *, const Sampler * = 0);
 	DEPRECATED int get_texture_index(const std::string &) const;
-	void set_back_faces(bool);
-	bool get_back_faces() const { return back_faces; }
+	void set_face_cull(CullMode);
+	CullMode get_face_cull() const { return face_cull; }
 	void set_receive_shadows(bool);
 	bool get_receive_shadows() const { return receive_shadows; }
 	void set_image_based_lighting(bool);
diff --git a/source/render/renderer.cpp b/source/render/renderer.cpp
index 4acf3ded..29db9923 100644
--- a/source/render/renderer.cpp
+++ b/source/render/renderer.cpp
@@ -15,7 +15,6 @@
 #include "texture.h"
 #include "vertexarray.h"
 #include "vertexsetup.h"
-#include "windingtest.h"
 
 using namespace std;
 
@@ -152,14 +151,14 @@ void Renderer::set_vertex_setup(const VertexSetup *vs)
 	state->vertex_setup = vs;
 }
 
-void Renderer::set_winding_test(const WindingTest *w)
+void Renderer::set_front_face(FaceWinding winding)
 {
-	state->winding_test = w;
+	state->front_face = winding;
 }
 
-void Renderer::set_reverse_winding(bool r)
+void Renderer::set_face_cull(CullMode cull)
 {
-	state->reverse_winding = r;
+	state->face_cull = cull;
 }
 
 void Renderer::set_object_lod_bias(unsigned b)
@@ -252,7 +251,8 @@ void Renderer::apply_state()
 	}
 	pipeline_state.set_vertex_setup(state->vertex_setup);
 
-	pipeline_state.set_winding_test((state->winding_test && state->reverse_winding) ? &state->winding_test->get_reverse() : state->winding_test);
+	pipeline_state.set_front_face(state->front_face);
+	pipeline_state.set_face_cull(state->face_cull);
 	pipeline_state.set_enabled_clip_planes(state->clipping ? (1<<state->clipping->get_n_planes())-1 : 0);
 
 	if(state->texture_count<texture_stack.size())
@@ -308,8 +308,8 @@ Renderer::State::State():
 	shprog(0),
 	shdata_count(0),
 	vertex_setup(0),
-	winding_test(0),
-	reverse_winding(false),
+	front_face(NON_MANIFOLD),
+	face_cull(NO_CULL),
 	object_lod_bias(0)
 { }
 
diff --git a/source/render/renderer.h b/source/render/renderer.h
index 5f069197..ee48b910 100644
--- a/source/render/renderer.h
+++ b/source/render/renderer.h
@@ -93,8 +93,8 @@ private:
 		const Program *shprog;
 		unsigned shdata_count;
 		const VertexSetup *vertex_setup;
-		const WindingTest *winding_test;
-		bool reverse_winding;
+		FaceWinding front_face;
+		CullMode face_cull;
 		unsigned object_lod_bias;
 
 		State();
@@ -157,8 +157,8 @@ private:
 
 public:
 	void set_vertex_setup(const VertexSetup *);
-	void set_winding_test(const WindingTest *);
-	void set_reverse_winding(bool);
+	void set_front_face(FaceWinding);
+	void set_face_cull(CullMode);
 
 	void set_object_lod_bias(unsigned);
 	unsigned get_object_lod_bias() const { return state->object_lod_bias; }