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.

7 files changed, 175 insertions, 0 deletions

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;
+};