Run shadow mapper in camera relative space

4 files changed, 22 insertions, 19 deletions

diff --git a/gfx/gl/sceneRenderer.cpp b/gfx/gl/sceneRenderer.cpp
index 2854dea..c856279 100644
--- a/gfx/gl/sceneRenderer.cpp
+++ b/gfx/gl/sceneRenderer.cpp
@@ -116,7 +116,7 @@ SceneRenderer::setDirectionalLight(const RGB & colour, const Direction3D & direc
 		glBindFramebuffer(GL_FRAMEBUFFER, gBufferIll);
 		glViewport(0, 0, size.x, size.y);
 		dirLight.use();
-		dirLight.setDirectionalLight(colour, direction, lvp.projections, lvp.regions, lvp.maps);
+		dirLight.setDirectionalLight(colour, direction, camera.getPosition(), lvp.projections, lvp.regions, lvp.maps);
 		renderQuad();
 	}
 }
@@ -131,7 +131,8 @@ SceneRenderer::renderQuad() const
 
 SceneRenderer::DirectionalLightProgram::DirectionalLightProgram() :
 	Program {lighting_vs, directionalLight_fs}, directionLoc {*this, "lightDirection"},
-	colourLoc {*this, "lightColour"}, lightViewProjectionLoc {*this, "lightViewProjection"},
+	colourLoc {*this, "lightColour"}, lightPointLoc {*this, "lightPoint"},
+	lightViewProjectionLoc {*this, "lightViewProjection"},
 	lightViewProjectionCountLoc {*this, "lightViewProjectionCount"},
 	lightViewShadowMapRegionLoc {*this, "shadowMapRegion"}
 {
@@ -139,12 +140,13 @@ SceneRenderer::DirectionalLightProgram::DirectionalLightProgram() :
 
 void
 SceneRenderer::DirectionalLightProgram::setDirectionalLight(const RGB & c, const Direction3D & d,
-		const std::span<const glm::mat4x4> lvp, const std::span<const TextureRelRegion> shadowMapRegions,
-		std::size_t maps) const
+		const GlobalPosition3D & p, const std::span<const glm::mat4x4> lvp,
+		const std::span<const TextureRelRegion> shadowMapRegions, std::size_t maps) const
 {
 	glUniform3fv(colourLoc, 1, glm::value_ptr(c));
 	const auto nd = glm::normalize(d);
 	glUniform3fv(directionLoc, 1, glm::value_ptr(nd));
+	glUniform3iv(lightPointLoc, 1, glm::value_ptr(p));
 	glUniform1ui(lightViewProjectionCountLoc, static_cast<GLuint>(maps));
 	glUniformMatrix4fv(lightViewProjectionLoc, static_cast<GLsizei>(maps), GL_FALSE, glm::value_ptr(lvp.front()));
 	glUniform4fv(lightViewShadowMapRegionLoc, static_cast<GLsizei>(maps), glm::value_ptr(shadowMapRegions.front()));
diff --git a/gfx/gl/sceneRenderer.h b/gfx/gl/sceneRenderer.h
index c935f93..797ecf1 100644
--- a/gfx/gl/sceneRenderer.h
+++ b/gfx/gl/sceneRenderer.h
@@ -39,12 +39,12 @@ protected:
 		DirectionalLightProgram();
 		using Program::use;
 
-		void setDirectionalLight(const RGB &, const Direction3D &, const std::span<const glm::mat4x4>,
-				const std::span<const TextureRelRegion>, std::size_t maps) const;
+		void setDirectionalLight(const RGB &, const Direction3D &, const GlobalPosition3D &,
+				const std::span<const glm::mat4x4>, const std::span<const TextureRelRegion>, std::size_t maps) const;
 
 	private:
-		RequiredUniformLocation directionLoc, colourLoc, lightViewProjectionLoc, lightViewProjectionCountLoc,
-				lightViewShadowMapRegionLoc;
+		RequiredUniformLocation directionLoc, colourLoc, lightPointLoc, lightViewProjectionLoc,
+				lightViewProjectionCountLoc, lightViewShadowMapRegionLoc;
 	};
 
 	DeferredLightProgram lighting;
diff --git a/gfx/gl/shaders/directionalLight.fs b/gfx/gl/shaders/directionalLight.fs
index 3756db7..f36d83f 100644
--- a/gfx/gl/shaders/directionalLight.fs
+++ b/gfx/gl/shaders/directionalLight.fs
@@ -13,6 +13,7 @@ layout(binding = 2) uniform sampler2D shadowMap;
 
 uniform vec3 lightDirection;
 uniform vec3 lightColour;
+uniform ivec3 lightPoint;
 uniform mat4 lightViewProjection[MAX_MAPS];
 uniform vec4 shadowMapRegion[MAX_MAPS];
 uniform uint lightViewProjectionCount;
@@ -27,10 +28,10 @@ insideShadowCube(vec3 v)
 }
 
 float
-isShaded(ivec3 Position)
+isShaded(vec4 Position)
 {
 	for (uint m = 0u; m < lightViewProjectionCount; m++) {
-		vec3 PositionInLightSpace = (lightViewProjection[m] * vec4(Position, 1.0f)).xyz;
+		const vec3 PositionInLightSpace = (lightViewProjection[m] * Position).xyz;
 		const float inside = insideShadowCube(PositionInLightSpace);
 		if (inside > 0) {
 			const float lightSpaceDepth
@@ -44,7 +45,7 @@ isShaded(ivec3 Position)
 void
 main()
 {
-	const ivec3 Position = texture(gPosition, TexCoords).xyz;
+	const vec4 Position = vec4(texture(gPosition, TexCoords).xyz - lightPoint, 1);
 	const vec3 Normal = texture(gNormal, TexCoords).rgb;
 	const float shaded = isShaded(Position);
 	FragColor = (1 - shaded) * max(dot(-lightDirection, Normal) * lightColour, 0);
diff --git a/gfx/gl/shadowMapper.cpp b/gfx/gl/shadowMapper.cpp
index deb0630..74d93bd 100644
--- a/gfx/gl/shadowMapper.cpp
+++ b/gfx/gl/shadowMapper.cpp
@@ -106,14 +106,15 @@ struct DefinitionsInserter {
 };
 
 std::vector<std::array<Position3D, 4>>
-ShadowMapper::getBandViewExtents(const Camera & camera, const glm::mat4 & lightView)
+ShadowMapper::getBandViewExtents(const Camera & camera, const glm::mat4 & lightViewDir)
 {
 	std::vector<std::array<Position3D, 4>> bandViewExtents;
 	for (const auto dist : shadowBands) {
 		const auto extents = camera.extentsAtDist(dist);
-		bandViewExtents.emplace_back(extents * [&lightView](const auto & e) -> Position3D {
-			return lightView * glm::vec4(Position3D {e}, 1);
-		});
+		bandViewExtents.emplace_back(
+				extents * [&lightViewDir, cameraPos = camera.getPosition()](const auto & e) -> Position3D {
+					return lightViewDir * RelativePosition4D(e.xyz() - cameraPos, 1);
+				});
 		if (std::none_of(extents.begin(), extents.end(), [targetDist = dist - 1](const auto & e) {
 				return e.w > targetDist;
 			})) {
@@ -131,14 +132,13 @@ ShadowMapper::update(const SceneProvider & scene, const Direction3D & dir, const
 	glCullFace(GL_FRONT);
 
 	const auto lightViewDir = glm::lookAt(origin, dir, up);
-	const auto lightView = lightViewDir * glm::translate(RelativePosition3D {-camera.getPosition()});
 	const auto lightViewPoint = camera.getPosition();
-	const auto bandViewExtents = getBandViewExtents(camera, lightView);
+	const auto bandViewExtents = getBandViewExtents(camera, lightViewDir);
 
 	Definitions out;
 	std::transform(bandViewExtents.begin(), std::prev(bandViewExtents.end()), std::next(bandViewExtents.begin()),
 			DefinitionsInserter {out},
-			[&scene, this, &lightView, bands = bandViewExtents.size() - 2, &out, &lightViewPoint, &lightViewDir](
+			[&scene, this, bands = bandViewExtents.size() - 2, &out, &lightViewPoint, &lightViewDir](
 					const auto & near, const auto & far) {
 				const auto extents_minmax = [extents = std::span {near.begin(), far.end()}](auto && comp) {
 					const auto mm = std::minmax_element(extents.begin(), extents.end(), comp);
@@ -158,7 +158,7 @@ ShadowMapper::update(const SceneProvider & scene, const Direction3D & dir, const
 				glViewport(size.x >> viewport.x, size.y >> viewport.y, size.x >> viewport.z, size.y >> viewport.w);
 				scene.shadows(*this);
 
-				return std::make_pair(lightProjection * lightView, shadowMapRegions[bands][out.maps]);
+				return std::make_pair(lightViewDirProjection, shadowMapRegions[bands][out.maps]);
 			});
 
 	glCullFace(GL_BACK);