Initial commit of the shadow map generator and shadows render interface

Lots of hard coding, buggy in places, far from great, but the basics
work.

19 files changed, 220 insertions, 0 deletions

diff --git a/game/terrain.cpp b/game/terrain.cpp
index 31f7fb1..f798254 100644
--- a/game/terrain.cpp
+++ b/game/terrain.cpp
@@ -7,6 +7,7 @@
 #include <cstddef>
 #include <filesystem>
 #include <gfx/gl/sceneShader.h>
+#include <gfx/gl/shadowMapper.h>
 #include <gfx/image.h>
 #include <gfx/models/mesh.h>
 #include <gfx/models/vertex.hpp>
@@ -93,3 +94,10 @@ Terrain::render(const SceneShader & shader) const
 	water->bind();
 	meshes.apply(&Mesh::Draw);
 }
+
+void
+Terrain::shadows(const ShadowMapper & shadowMapper) const
+{
+	shadowMapper.fixedPoint.use();
+	meshes.apply(&Mesh::Draw);
+}
diff --git a/game/terrain.h b/game/terrain.h
index 70f947c..879d173 100644
--- a/game/terrain.h
+++ b/game/terrain.h
@@ -16,6 +16,7 @@ public:
 	explicit Terrain(std::shared_ptr<GeoData>);
 
 	void render(const SceneShader & shader) const override;
+	void shadows(const ShadowMapper &) const override;
 
 	void tick(TickDuration) override;
 	float waveCycle {0.F};
diff --git a/game/vehicles/railVehicle.cpp b/game/vehicles/railVehicle.cpp
index 0cf4e72..bcde68f 100644
--- a/game/vehicles/railVehicle.cpp
+++ b/game/vehicles/railVehicle.cpp
@@ -18,6 +18,12 @@ RailVehicle::render(const SceneShader & shader) const
 }
 
 void
+RailVehicle::shadows(const ShadowMapper & shadowMapper) const
+{
+	rvClass->shadows(shadowMapper, location);
+}
+
+void
 RailVehicle::move(const Train * t, float & trailBy)
 {
 	const auto overhang {(rvClass->length - rvClass->wheelBase) / 2};
diff --git a/game/vehicles/railVehicle.h b/game/vehicles/railVehicle.h
index 39900cc..f172a28 100644
--- a/game/vehicles/railVehicle.h
+++ b/game/vehicles/railVehicle.h
@@ -10,6 +10,7 @@
 #include <utility>
 
 class SceneShader;
+class ShadowMapper;
 class Ray;
 
 class Train;
@@ -20,6 +21,7 @@ public:
 	void move(const Train *, float & trailBy);
 
 	void render(const SceneShader & shader) const override;
+	void shadows(const ShadowMapper & shadowMapper) const override;
 	[[nodiscard]] bool intersectRay(const Ray &, glm::vec2 *, float *) const override;
 
 	Location location;
diff --git a/game/vehicles/railVehicleClass.cpp b/game/vehicles/railVehicleClass.cpp
index 5bcdc6e..dff1416 100644
--- a/game/vehicles/railVehicleClass.cpp
+++ b/game/vehicles/railVehicleClass.cpp
@@ -1,5 +1,6 @@
 #include "railVehicleClass.h"
 #include "gfx/gl/sceneShader.h"
+#include "gfx/gl/shadowMapper.h"
 #include "gfx/models/mesh.h"
 #include "gfx/models/obj.h"
 #include "gfx/models/texture.h"
@@ -50,6 +51,12 @@ RailVehicleClass::render(
 		bogies[b]->Draw();
 	}
 }
+void
+RailVehicleClass::shadows(const ShadowMapper & shadowMapper, const Location & location) const
+{
+	shadowMapper.dynamicPoint.use(location);
+	bodyMesh->Draw();
+}
 
 float
 RailVehicleClass::bogieOffset(ObjParser & o)
diff --git a/game/vehicles/railVehicleClass.h b/game/vehicles/railVehicleClass.h
index 7249e76..bd74ab9 100644
--- a/game/vehicles/railVehicleClass.h
+++ b/game/vehicles/railVehicleClass.h
@@ -6,6 +6,7 @@
 #include <string>
 
 class SceneShader;
+class ShadowMapper;
 class Texture;
 class ObjParser;
 class Location;
@@ -15,6 +16,7 @@ public:
 	explicit RailVehicleClass(const std::string & name);
 
 	void render(const SceneShader &, const Location &, const std::array<Location, 2> &) const;
+	void shadows(const ShadowMapper &, const Location &) const;
 
 	std::array<Mesh::Ptr, 2> bogies;
 	Mesh::Ptr bodyMesh;
diff --git a/game/vehicles/train.cpp b/game/vehicles/train.cpp
index 8fb48f5..0332c04 100644
--- a/game/vehicles/train.cpp
+++ b/game/vehicles/train.cpp
@@ -16,6 +16,11 @@ Train::render(const SceneShader & shader) const
 {
 	apply(&Renderable::render, shader);
 }
+void
+Train::shadows(const ShadowMapper & shadowMapper) const
+{
+	apply(&Renderable::shadows, shadowMapper);
+}
 
 Location
 Train::getBogiePosition(float linkDist, float dist) const
diff --git a/game/vehicles/train.h b/game/vehicles/train.h
index dfdcf62..91f7ddb 100644
--- a/game/vehicles/train.h
+++ b/game/vehicles/train.h
@@ -14,6 +14,7 @@
 #include <vector>
 
 class SceneShader;
+class ShadowMapper;
 class Ray;
 
 class Train : public Vehicle, public Collection<RailVehicle, false>, public Can<Go>, public Can<Idle> {
@@ -27,6 +28,7 @@ public:
 	}
 
 	void render(const SceneShader & shader) const override;
+	void shadows(const ShadowMapper & shadowMapper) const override;
 
 	[[nodiscard]] bool intersectRay(const Ray &, glm::vec2 *, float *) const override;
 
diff --git a/gfx/gl/sceneProvider.cpp b/gfx/gl/sceneProvider.cpp
index d73ac3c..9152bfa 100644
--- a/gfx/gl/sceneProvider.cpp
+++ b/gfx/gl/sceneProvider.cpp
@@ -7,3 +7,7 @@ SceneProvider::environment(const SceneShader &, const SceneRenderer & renderer)
 	renderer.setAmbientLight({0.5F, 0.5F, 0.5F});
 	renderer.setDirectionalLight({0.6F, 0.6F, 0.6F}, {1, 0, -1});
 }
+void
+SceneProvider::shadows(const ShadowMapper &) const
+{
+}
diff --git a/gfx/gl/sceneProvider.h b/gfx/gl/sceneProvider.h
index a966f9c..ef269b3 100644
--- a/gfx/gl/sceneProvider.h
+++ b/gfx/gl/sceneProvider.h
@@ -1,6 +1,7 @@
 #pragma once
 
 class SceneRenderer;
+class ShadowMapper;
 class SceneShader;
 
 class SceneProvider {
@@ -9,4 +10,5 @@ public:
 	virtual void content(const SceneShader &) const = 0;
 	virtual void environment(const SceneShader &, const SceneRenderer &) const;
 	virtual void lights(const SceneShader &) const = 0;
+	virtual void shadows(const ShadowMapper &) const;
 };
diff --git a/gfx/gl/shaders/shadowCast.fs b/gfx/gl/shaders/shadowCast.fs
new file mode 100644
index 0000000..d427da2
--- /dev/null
+++ b/gfx/gl/shaders/shadowCast.fs
@@ -0,0 +1,6 @@
+#version 330 core
+
+void
+main()
+{
+}
diff --git a/gfx/gl/shaders/shadowDynamicPoint.vs b/gfx/gl/shaders/shadowDynamicPoint.vs
new file mode 100644
index 0000000..91d8bf7
--- /dev/null
+++ b/gfx/gl/shaders/shadowDynamicPoint.vs
@@ -0,0 +1,12 @@
+#version 330 core
+
+in vec3 position;
+
+uniform mat4 viewProjection;
+uniform mat4 model;
+
+void
+main()
+{
+	gl_Position = viewProjection * model * vec4(position, 1.0);
+}
diff --git a/gfx/gl/shaders/shadowFixedPoint.vs b/gfx/gl/shaders/shadowFixedPoint.vs
new file mode 100644
index 0000000..9e1cc62
--- /dev/null
+++ b/gfx/gl/shaders/shadowFixedPoint.vs
@@ -0,0 +1,13 @@
+#version 330 core
+
+layout(location = 0) in vec3 position;
+layout(location = 1) in vec3 normal;
+layout(location = 2) in vec2 tex;
+
+uniform mat4 viewProjection;
+
+void
+main()
+{
+	gl_Position = viewProjection * vec4(position, 1.0);
+}
diff --git a/gfx/gl/shadowMapper.cpp b/gfx/gl/shadowMapper.cpp
new file mode 100644
index 0000000..4cc2e24
--- /dev/null
+++ b/gfx/gl/shadowMapper.cpp
@@ -0,0 +1,92 @@
+#include "shadowMapper.h"
+#include "gfx/gl/shaders/fs-shadowCast.h"
+#include "gfx/gl/shaders/vs-shadowDynamicPoint.h"
+#include "gfx/gl/shaders/vs-shadowFixedPoint.h"
+#include "gfx/models/texture.h"
+#include "location.hpp"
+#include "maths.h"
+#include "sceneProvider.h"
+#include "sceneShader.h"
+#include <glm/gtc/type_ptr.hpp>
+#include <glm/gtx/transform.hpp>
+#include <glm/matrix.hpp>
+
+ShadowMapper::ShadowMapper(const glm::ivec2 & s) : size {s}
+{
+	glBindTexture(GL_TEXTURE_2D, depthMap);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, size.x, size.y, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
+	static constexpr glm::vec3 border {std::numeric_limits<float>::infinity()};
+	// static constexpr glm::vec3 border {1};
+	glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, glm::value_ptr(border));
+
+	glBindFramebuffer(GL_FRAMEBUFFER, depthMapFBO);
+	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depthMap, 0);
+	glDrawBuffer(GL_NONE);
+	glReadBuffer(GL_NONE);
+	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
+		throw std::runtime_error("Framebuffer not complete!");
+	}
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+}
+
+glm::mat4x4
+ShadowMapper::update(const SceneProvider & scene, const glm::vec3 & dir) const
+{
+	const glm::vec3 centre {1200.F, 1200.F, 0.F};
+	const glm::vec3 range = glm::normalize(dir) * 1800.F;
+	const auto lightProjection = glm::ortho(-1200.F, 1200.F, -1200.F, 1200.F, 0.F, 3600.F);
+	const auto lightView = glm::lookAt(centre - range, centre, north);
+	const auto lightViewProjection = lightProjection * lightView;
+	fixedPoint.setViewProjection(lightViewProjection);
+	dynamicPoint.setViewProjection(lightViewProjection);
+
+	glBindFramebuffer(GL_FRAMEBUFFER, depthMapFBO);
+	glViewport(0, 0, size.x, size.y);
+	glClear(GL_DEPTH_BUFFER_BIT);
+	glEnable(GL_DEPTH_TEST);
+	glCullFace(GL_FRONT);
+	scene.shadows(*this);
+	glCullFace(GL_BACK);
+
+	// Texture::saveDepth(depthMap, size, "/tmp/depth.tga");
+	return lightViewProjection;
+}
+
+ShadowMapper::FixedPoint::FixedPoint() :
+	Program {shadowFixedPoint_vs, shadowCast_fs}, viewProjectionLoc {*this, "viewProjection"}
+{
+}
+void
+ShadowMapper::FixedPoint::setViewProjection(const glm::mat4 & viewProjection) const
+{
+	use();
+	glUniformMatrix4fv(viewProjectionLoc, 1, GL_FALSE, glm::value_ptr(viewProjection));
+}
+void
+ShadowMapper::FixedPoint::use() const
+{
+	glUseProgram(*this);
+}
+
+ShadowMapper::DynamicPoint::DynamicPoint() :
+	Program {shadowDynamicPoint_vs, shadowCast_fs}, viewProjectionLoc {*this, "viewProjection"}, modelLoc {
+																										 *this, "model"}
+{
+}
+void
+ShadowMapper::DynamicPoint::setViewProjection(const glm::mat4 & viewProjection) const
+{
+	glUseProgram(*this);
+	glUniformMatrix4fv(viewProjectionLoc, 1, GL_FALSE, glm::value_ptr(viewProjection));
+}
+void
+ShadowMapper::DynamicPoint::use(const Location & location) const
+{
+	glUseProgram(*this);
+	const auto model = glm::translate(location.pos) * rotate_ypr(location.rot);
+	glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(model));
+}
diff --git a/gfx/gl/shadowMapper.h b/gfx/gl/shadowMapper.h
new file mode 100644
index 0000000..dcd0a02
--- /dev/null
+++ b/gfx/gl/shadowMapper.h
@@ -0,0 +1,46 @@
+#pragma once
+
+#include "lib/glArrays.h"
+#include "program.h"
+#include <glm/vec2.hpp>
+
+class SceneProvider;
+
+class ShadowMapper {
+public:
+	ShadowMapper(const glm::ivec2 & size = {1024, 1024});
+
+	glm::mat4x4 update(const SceneProvider &, const glm::vec3 & direction) const;
+
+	class FixedPoint : public Program {
+	public:
+		FixedPoint();
+		void setViewProjection(const glm::mat4 &) const;
+		void use() const;
+
+	private:
+		RequiredUniformLocation viewProjectionLoc;
+	};
+	class DynamicPoint : public Program {
+	public:
+		DynamicPoint();
+		void setViewProjection(const glm::mat4 &) const;
+		void use(const Location &) const;
+
+	private:
+		RequiredUniformLocation viewProjectionLoc;
+		RequiredUniformLocation modelLoc;
+	};
+	FixedPoint fixedPoint;
+	DynamicPoint dynamicPoint;
+
+	operator GLuint() const
+	{
+		return depthMap;
+	}
+
+private:
+	glFrameBuffer depthMapFBO;
+	glTexture depthMap;
+	glm::ivec2 size;
+};
diff --git a/gfx/renderable.cpp b/gfx/renderable.cpp
index 9e8d122..539efb1 100644
--- a/gfx/renderable.cpp
+++ b/gfx/renderable.cpp
@@ -4,3 +4,7 @@ void
 Renderable::lights(const SceneShader &) const
 {
 }
+void
+Renderable::shadows(const ShadowMapper &) const
+{
+}
diff --git a/gfx/renderable.h b/gfx/renderable.h
index f75c36f..5a9b1cd 100644
--- a/gfx/renderable.h
+++ b/gfx/renderable.h
@@ -3,6 +3,7 @@
 #include <special_members.hpp>
 
 class SceneShader;
+class ShadowMapper;
 
 class Renderable {
 public:
@@ -12,4 +13,5 @@ public:
 
 	virtual void render(const SceneShader & shader) const = 0;
 	virtual void lights(const SceneShader & shader) const;
+	virtual void shadows(const ShadowMapper & shadowMapper) const;
 };
diff --git a/ui/gameMainWindow.cpp b/ui/gameMainWindow.cpp
index 7a47a25..0b30cad 100644
--- a/ui/gameMainWindow.cpp
+++ b/ui/gameMainWindow.cpp
@@ -65,3 +65,8 @@ GameMainWindow::lights(const SceneShader & shader) const
 {
 	gameState->world.apply<Renderable>(&Renderable::lights, shader);
 }
+void
+GameMainWindow::shadows(const ShadowMapper & shadowMapper) const
+{
+	gameState->world.apply<Renderable>(&Renderable::shadows, shadowMapper);
+}
diff --git a/ui/gameMainWindow.h b/ui/gameMainWindow.h
index f3fc21f..d5bcf41 100644
--- a/ui/gameMainWindow.h
+++ b/ui/gameMainWindow.h
@@ -17,4 +17,5 @@ private:
 	void content(const SceneShader &) const override;
 	void environment(const SceneShader &, const SceneRenderer &) const override;
 	void lights(const SceneShader &) const override;
+	void shadows(const ShadowMapper &) const override;
 };