From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 15 May 2023 20:44:38 +0000 (+0300)
Subject: Add support for shadows
X-Git-Url: https://git.tdb.fi/?a=commitdiff_plain;h=7bb9a433db1a08b159afe5ef7b12ceb6559993ac;p=libs%2Fgame.git

Add support for shadows
---

diff --git a/source/game/light.cpp b/source/game/light.cpp
index 91db96f..1afa519 100644
--- a/source/game/light.cpp
+++ b/source/game/light.cpp
@@ -7,4 +7,12 @@ Light::Light(Handle<Entity> e, const Setup &s):
 	setup(s)
 { }
 
+unsigned Light::get_shadow_map_size(unsigned base) const
+{
+	if(setup.shadow_detail<0)
+		return base>>-setup.shadow_detail;
+	else
+		return base<<setup.shadow_detail;
+}
+
 } // namespace Msp::Game
diff --git a/source/game/light.h b/source/game/light.h
index f14dc6d..5787db0 100644
--- a/source/game/light.h
+++ b/source/game/light.h
@@ -20,6 +20,8 @@ public:
 
 	LightType get_type() const { return setup.type; }
 	float get_intensity() const { return setup.intensity; }
+	bool casts_shadows() const { return setup.cast_shadows; }
+	unsigned get_shadow_map_size(unsigned) const;
 };
 
 } // namespace Msp::Game
diff --git a/source/game/setups.mgs b/source/game/setups.mgs
index 6cad214..8e62edc 100644
--- a/source/game/setups.mgs
+++ b/source/game/setups.mgs
@@ -28,6 +28,13 @@ component Light
 {
 	field type LightType { default "DIRECTIONAL"; };
 	field intensity float { default "1.0f"; };
+	field cast_shadows bool { default "false"; };
+	field shadow_detail int { default "0"; };
+};
+
+component ShadowTarget
+{
+	field radius float { default "100.0f"; };
 };
 
 component MeshSource
diff --git a/source/game/shadowtarget.cpp b/source/game/shadowtarget.cpp
new file mode 100644
index 0000000..61dd64d
--- /dev/null
+++ b/source/game/shadowtarget.cpp
@@ -0,0 +1,10 @@
+#include "shadowtarget.h"
+
+namespace Msp::Game {
+
+ShadowTarget::ShadowTarget(Handle<Entity> e, const Setup &setup):
+	Component(e),
+	radius(setup.radius)
+{ }
+
+} // namespace Msp::Game
diff --git a/source/game/shadowtarget.h b/source/game/shadowtarget.h
new file mode 100644
index 0000000..a5d7fbd
--- /dev/null
+++ b/source/game/shadowtarget.h
@@ -0,0 +1,25 @@
+#ifndef MSP_GAME_SHADOWTARGET_H_
+#define MSP_GAME_SHADOWTARGET_H_
+
+#include <msp/game/setups.h>
+#include "component.h"
+
+namespace Msp::Game {
+
+class MSPGAME_API ShadowTarget: public Component
+{
+public:
+	using Setup = ShadowTargetSetup;
+
+private:
+	float radius;
+
+public:
+	ShadowTarget(Handle<Entity>, const Setup &);
+
+	float get_radius() const { return radius; }
+};
+
+} // namespace Msp::Game
+
+#endif
diff --git a/source/gameview/lightemitter.cpp b/source/gameview/lightemitter.cpp
index 0f78fe3..8b52b88 100644
--- a/source/gameview/lightemitter.cpp
+++ b/source/gameview/lightemitter.cpp
@@ -28,6 +28,14 @@ void LightEmitter::set_lighting(GL::Lighting *l)
 		lighting->attach(*light);
 }
 
+void LightEmitter::set_shadow_map(GL::ShadowMap *sm, unsigned size, GL::Renderable &caster)
+{
+	if(auto dl = get_if<GL::DirectionalLight>(&storage))
+		sm->add_light(*dl, size, caster);
+	else if(auto pl = get_if<GL::PointLight>(&storage))
+		sm->add_light(*pl, size, caster);
+}
+
 void LightEmitter::set_intensity(float i)
 {
 	light->set_color(GL::Color(i));
diff --git a/source/gameview/lightemitter.h b/source/gameview/lightemitter.h
index d3e2f83..d77cc02 100644
--- a/source/gameview/lightemitter.h
+++ b/source/gameview/lightemitter.h
@@ -7,6 +7,7 @@
 #include <msp/gl/directionallight.h>
 #include <msp/gl/lighting.h>
 #include <msp/gl/pointlight.h>
+#include <msp/gl/shadowmap.h>
 #include "mspgameview_api.h"
 
 namespace Msp::GameView {
@@ -23,6 +24,7 @@ public:
 	~LightEmitter();
 
 	void set_lighting(GL::Lighting *);
+	void set_shadow_map(GL::ShadowMap *, unsigned, GL::Renderable &);
 
 	void set_intensity(float);
 
diff --git a/source/gameview/renderer.cpp b/source/gameview/renderer.cpp
index 8a4c416..b6f78e1 100644
--- a/source/gameview/renderer.cpp
+++ b/source/gameview/renderer.cpp
@@ -2,6 +2,7 @@
 #include <msp/game/entity.h>
 #include <msp/game/light.h>
 #include <msp/game/meshsource.h>
+#include <msp/game/shadowtarget.h>
 #include <msp/game/stage.h>
 #include <msp/game/transform.h>
 #include <msp/gl/colorcurve.h>
@@ -30,6 +31,7 @@ Renderer::Renderer(Game::Stage &s, GL::View &v):
 
 	stage.synthesize_initial_events(event_observer);
 
+	content_slot.set(&scene);
 	view.set_camera(&gl_camera);
 }
 
@@ -65,6 +67,8 @@ void Renderer::component_created(const Game::Events::ComponentCreated &event)
 			re.light_emitter = Game::Owned<LightEmitter>(re.entity, light->get_type());
 			re.light_emitter->set_intensity(light->get_intensity());
 			re.light_emitter->set_lighting(&lighting);
+			if(light->casts_shadows())
+				shadows_changed = true;
 		}
 	}
 }
@@ -85,8 +89,12 @@ void Renderer::component_destroyed(const Game::Events::ComponentDestroyed &event
 	{
 		if(dynamic_handle_cast<Game::MeshSource>(event.component))
 			i->mesh_renderer = nullptr;
-		if(dynamic_handle_cast<Game::Light>(event.component))
+		if(auto light = dynamic_handle_cast<Game::Light>(event.component))
+		{
 			i->light_emitter = nullptr;
+			if(light->casts_shadows())
+				shadows_changed = true;
+		}
 	}
 }
 
@@ -100,7 +108,7 @@ void Renderer::camera_changed(const Game::Events::CameraChanged &event)
 		sequence->set_clear_enabled(true);
 		sequence->set_clear_colors({ GL::Color(0.0f) });
 
-		GL::Sequence::Step &opaque = sequence->add_step(GL::Tag(), scene);
+		GL::Sequence::Step &opaque = sequence->add_step(GL::Tag(), content_slot);
 		opaque.set_depth_test(GL::LEQUAL);
 		opaque.set_lighting(&lighting);
 
@@ -115,6 +123,63 @@ void Renderer::camera_changed(const Game::Events::CameraChanged &event)
 
 void Renderer::tick(Time::TimeDelta)
 {
+	if(shadows_changed)
+	{
+		shadows_changed = false;
+
+		vector<ShadowedLight> lights;
+
+		unsigned total_area = 0;
+		stage.iterate_objects<LightEmitter>([&lights, &total_area, this](LightEmitter &e){
+			if(Game::Handle<Game::Light> light = e.get_entity()->get_component<Game::Light>())
+			{
+				unsigned size = light->get_shadow_map_size(shadow_base_size);;
+				total_area += size*size;
+				lights.emplace_back(&e, size);
+			}
+		});
+
+		unsigned width = 1;
+		while(width*width<total_area)
+			width <<= 1;
+		unsigned height = (width*width>=total_area*2 ? width/2 : width);
+
+		if(lights.empty())
+		{
+			shadow_map = nullptr;
+			content_slot.set(&scene);
+		}
+		else
+		{
+			sort(lights);
+
+			if(!shadow_seq)
+			{
+				shadow_seq = make_unique<GL::Sequence>();
+				shadow_seq->set_clear_enabled(true);
+				GL::Sequence::Step &step = shadow_seq->add_step("shadow", scene);
+				step.set_depth_test(GL::LEQUAL);
+			}
+
+			shadow_map = make_unique<GL::ShadowMap>(width, height, scene, lighting);
+			for(const ShadowedLight &l: lights)
+				l.light->set_shadow_map(shadow_map.get(), l.shadow_size, *shadow_seq);
+
+			content_slot.set(shadow_map.get());
+		}
+	}
+
+	if(shadow_map)
+	{
+		Geometry::BoundingSphere<float, 3> shadow_bounds;
+		stage.iterate_objects<Game::ShadowTarget>([&shadow_bounds](Game::ShadowTarget &s){
+			LinAl::Vector<float, 3> pos = s.get_entity()->get_transform()->get_position();
+			shadow_bounds = shadow_bounds | Geometry::BoundingSphere<float, 3>(pos, s.get_radius());
+		});
+
+		shadow_map->set_target(shadow_bounds.get_center(), shadow_bounds.get_radius());
+	}
+
 	if(active_camera)
 	{
 		Game::Handle<Game::Transform> transform = active_camera->get_entity()->get_transform();
diff --git a/source/gameview/renderer.h b/source/gameview/renderer.h
index 3b39945..c37bc33 100644
--- a/source/gameview/renderer.h
+++ b/source/gameview/renderer.h
@@ -10,7 +10,9 @@
 #include <msp/gl/light.h>
 #include <msp/gl/lighting.h>
 #include <msp/gl/sequence.h>
+#include <msp/gl/shadowmap.h>
 #include <msp/gl/simplescene.h>
+#include <msp/gl/slot.h>
 #include <msp/gl/view.h>
 #include "mspgameview_api.h"
 
@@ -31,14 +33,27 @@ private:
 		RenderedEntity(Game::Handle<Game::Entity>);
 	};
 
+	struct ShadowedLight
+	{
+		LightEmitter *light;
+		unsigned shadow_size;
+
+		bool operator<(const ShadowedLight &other) const { return shadow_size>other.shadow_size; }
+	};
+
 	GL::View &view;
 	Game::EventObserver event_observer;
 	std::vector<RenderedEntity> entities;
 	GL::SimpleScene scene;
 	GL::Lighting lighting;
+	std::unique_ptr<GL::ShadowMap> shadow_map;
+	std::unique_ptr<GL::Sequence> shadow_seq;
 	Game::Handle<Game::Camera> active_camera;
 	GL::Camera gl_camera;
 	std::unique_ptr<GL::Sequence> sequence;
+	GL::Slot content_slot;
+	unsigned shadow_base_size = 4096;
+	bool shadows_changed = false;
 
 public:
 	Renderer(Game::Stage &, GL::View &);