Gizmo snapping implemented

Gizmo behaviour can now be changed by pressing the CTRL key. While this
key is pressed, any translation, rotation or scaling will be subject to
snapping. The snapping units for each operation can be defined in the
settings drop down menu.

Author: Adrien GIVRY

Sources/Overload/OvEditor/include/OvEditor/Core/GizmoBehaviour.h

@@ -27,6 +27,11 @@ namespace OvEditor::Core
 			Y,
 			Z
 		};
+		
+		/**
+		* Returns true if the snapping behaviour is enabled
+		*/
+		bool IsSnappedBehaviourEnabled() const;
 
 		/**
 		* Starts the gizmo picking behaviour for the given target in the given direction

Sources/Overload/OvEditor/include/OvEditor/Settings/EditorSettings.h

@@ -77,5 +77,8 @@ namespace OvEditor::Settings
 		inline static Property<bool> ShowLightBounds = { false };
 		inline static Property<bool> ShowGeometryFrustumCullingInSceneView = { false };
 		inline static Property<bool> ShowLightFrustumCullingInSceneView = { false };
+		inline static Property<float> TranslationSnapUnit = { 1.0f };
+		inline static Property<float> RotationSnapUnit = { 15.0f };
+		inline static Property<float> ScalingSnapUnit = { 1.0f };
 	};
 }

Sources/Overload/OvEditor/src/OvEditor/Core/GizmoBehaviour.cpp

@@ -5,6 +5,20 @@
 */
 
 #include "OvEditor/Core/GizmoBehaviour.h"
+#include "OvEditor/Settings/EditorSettings.h"
+
+float SnapValue(float p_value, float p_step)
+{
+	return p_value - std::fmod(p_value, p_step);
+}
+
+bool OvEditor::Core::GizmoBehaviour::IsSnappedBehaviourEnabled() const
+{
+	using namespace OvWindowing::Inputs;
+
+	const auto& inputManager = EDITOR_CONTEXT(inputManager);
+	return inputManager->GetKeyState(EKey::KEY_LEFT_CONTROL) == EKeyState::KEY_DOWN || inputManager->GetKeyState(EKey::KEY_RIGHT_CONTROL) == EKeyState::KEY_DOWN;
+}
 
 void OvEditor::Core::GizmoBehaviour::StartPicking(OvCore::ECS::Actor& p_target, const OvMaths::FVector3& p_cameraPosition, EGizmoOperation p_operation, EDirection p_direction)
 {
@@ -101,9 +115,14 @@ void OvEditor::Core::GizmoBehaviour::ApplyTranslation(const OvMaths::FMatrix4& p
 	auto screenDirection = GetScreenDirection(p_viewMatrix, p_projectionMatrix, p_viewSize);
 
 	auto totalDisplacement = m_currentMouse - m_originMouse;
-	auto translationCoefficient = OvMaths::FVector2::Dot(totalDisplacement, screenDirection);
+	auto translationCoefficient = OvMaths::FVector2::Dot(totalDisplacement, screenDirection) * unitsPerPixel;
+
+	if (IsSnappedBehaviourEnabled())
+	{
+		translationCoefficient = SnapValue(translationCoefficient, OvEditor::Settings::EditorSettings::TranslationSnapUnit);
+	}
 
-	m_target->transform.SetLocalPosition(originPosition + GetRealDirection() * translationCoefficient * unitsPerPixel);
+	m_target->transform.SetLocalPosition(originPosition + GetRealDirection() * translationCoefficient);
 }
 
 void OvEditor::Core::GizmoBehaviour::ApplyRotation(const OvMaths::FMatrix4& p_viewMatrix, const OvMaths::FMatrix4& p_projectionMatrix, const OvMaths::FVector2& p_viewSize) const
@@ -115,9 +134,14 @@ void OvEditor::Core::GizmoBehaviour::ApplyRotation(const OvMaths::FMatrix4& p_vi
 	screenDirection = OvMaths::FVector2(-screenDirection.y, screenDirection.x);
 
 	auto totalDisplacement = m_currentMouse - m_originMouse;
-	auto rotationCoefficient = OvMaths::FVector2::Dot(totalDisplacement, screenDirection);
+	auto rotationCoefficient = OvMaths::FVector2::Dot(totalDisplacement, screenDirection) * unitsPerPixel;
+
+	if (IsSnappedBehaviourEnabled())
+	{
+		rotationCoefficient = SnapValue(rotationCoefficient, OvEditor::Settings::EditorSettings::RotationSnapUnit);
+	}
 
-	auto rotationToApply = OvMaths::FQuaternion(OvMaths::FVector3(GetFakeDirection() * rotationCoefficient * unitsPerPixel));
+	auto rotationToApply = OvMaths::FQuaternion(OvMaths::FVector3(GetFakeDirection() * rotationCoefficient));
 	m_target->transform.SetLocalRotation(originRotation * rotationToApply);
 }
 
@@ -129,9 +153,14 @@ void OvEditor::Core::GizmoBehaviour::ApplyScale(const OvMaths::FMatrix4& p_viewM
 	auto screenDirection = GetScreenDirection(p_viewMatrix, p_projectionMatrix, p_viewSize);
 
 	auto totalDisplacement = m_currentMouse - m_originMouse;
-	auto scaleCoefficient = OvMaths::FVector2::Dot(totalDisplacement, screenDirection);
+	auto scaleCoefficient = OvMaths::FVector2::Dot(totalDisplacement, screenDirection) * unitsPerPixel;
+
+	if (IsSnappedBehaviourEnabled())
+	{
+		scaleCoefficient = SnapValue(scaleCoefficient, OvEditor::Settings::EditorSettings::ScalingSnapUnit);
+	}
 
-	auto newScale = originScale + GetFakeDirection() * scaleCoefficient * unitsPerPixel;
+	auto newScale = originScale + GetFakeDirection() * scaleCoefficient;
 
 	/* Prevent scale from being negative*/
 	newScale.x = std::max(newScale.x, 0.0001f);

Sources/Overload/OvEditor/src/OvEditor/Panels/MenuBar.cpp

@@ -20,6 +20,7 @@
 
 #include <OvUI/Widgets/Visual/Separator.h>
 #include <OvUI/Widgets/Sliders/SliderInt.h>
+#include <OvUI/Widgets/Drags/DragFloat.h>
 #include <OvUI/Widgets/Selection/ColorEdit.h>
 
 #include "OvEditor/Panels/MenuBar.h"
@@ -200,6 +201,11 @@ void OvEditor::Panels::MenuBar::CreateSettingsMenu()
 		assetViewGridPicker.color = OvUI::Types::Color::White;
 	};
 
+	auto& snappingMenu = settingsMenu.CreateWidget<MenuList>("Snapping");
+	snappingMenu.CreateWidget<Drags::DragFloat>(0.001f, 999999.0f, Settings::EditorSettings::TranslationSnapUnit, 0.05f, "Translation Unit").ValueChangedEvent += [this](float p_value) { Settings::EditorSettings::TranslationSnapUnit = p_value; };
+	snappingMenu.CreateWidget<Drags::DragFloat>(0.001f, 999999.0f, Settings::EditorSettings::RotationSnapUnit, 1.0f, "Rotation Unit").ValueChangedEvent += [this](float p_value) { Settings::EditorSettings::RotationSnapUnit = p_value; };
+	snappingMenu.CreateWidget<Drags::DragFloat>(0.001f, 999999.0f, Settings::EditorSettings::ScalingSnapUnit, 0.05f, "Scaling Unit").ValueChangedEvent += [this](float p_value) { Settings::EditorSettings::ScalingSnapUnit = p_value; };
+
 	auto& debuggingMenu = settingsMenu.CreateWidget<MenuList>("Debugging");
 	debuggingMenu.CreateWidget<MenuItem>("Show geometry bounds", "", true, Settings::EditorSettings::ShowGeometryBounds).ValueChangedEvent += [this](bool p_value) { Settings::EditorSettings::ShowGeometryBounds = p_value; };
 	debuggingMenu.CreateWidget<MenuItem>("Show lights bounds", "", true, Settings::EditorSettings::ShowLightBounds).ValueChangedEvent += [this](bool p_value) { Settings::EditorSettings::ShowLightBounds = p_value; };