Improvements to decal projector editor gizmo.

com.unity.render-pipelines.high-definition/HDRP/Editor/Material/Decal/DecalProjectorComponentEditor.cs

         private SerializedProperty m_UVScaleProperty;
         private SerializedProperty m_UVBiasProperty;
         private SerializedProperty m_AffectsTransparencyProperty;
-        private SerializedProperty m_Center;
-       
-        private BoxBoundsHandle m_Handle = new BoxBoundsHandle();
+        private SerializedProperty m_IsCropModeEnabledProperty;
+
+        private DecalProjectorComponentHandle m_Handle = new DecalProjectorComponentHandle();
 
         private void OnEnable()
         {
             m_UVScaleProperty = serializedObject.FindProperty("m_UVScale");
             m_UVBiasProperty = serializedObject.FindProperty("m_UVBias");
             m_AffectsTransparencyProperty = serializedObject.FindProperty("m_AffectsTransparency");
-            m_Center = serializedObject.FindProperty("m_Offset");
+            m_IsCropModeEnabledProperty = serializedObject.FindProperty("m_IsCropModeEnabled");
         }
 
         private void OnDisable()
         }
 
         void OnSceneGUI()
-        {            
+        {
-            Handles.matrix = m_DecalProjectorComponent.transform.localToWorldMatrix;   
+            Handles.matrix = m_DecalProjectorComponent.transform.localToWorldMatrix;
+
+            Vector3 boundsSizePreviousOS = m_Handle.size;
+            Vector3 boundsMinPreviousOS = m_Handle.size * -0.5f + m_Handle.center;
+
-                // adjust decal transform if handle changed
+                // Adjust decal transform if handle changed.
+                Undo.RecordObject(m_DecalProjectorComponent, "Decal Projector Change");
+
+                m_DecalProjectorComponent.m_Size = m_Handle.size;
-                m_DecalProjectorComponent.m_Size = m_Handle.size;
-                EditorUtility.SetDirty(m_DecalProjectorComponent);
+
+                Vector3 boundsSizeCurrentOS = m_Handle.size;
+                Vector3 boundsMinCurrentOS = m_Handle.size * -0.5f + m_Handle.center;
+
+                if (m_DecalProjectorComponent.m_IsCropModeEnabled)
+                {
+                    // Treat decal projector bounds as a crop tool, rather than a scale tool.
+                    // Compute a new uv scale and bias terms to pin decal projection pixels in world space, irrespective of projector bounds.
+                    m_DecalProjectorComponent.m_UVScale.x *= Mathf.Max(1e-5f, boundsSizeCurrentOS.x) / Mathf.Max(1e-5f, boundsSizePreviousOS.x);
+                    m_DecalProjectorComponent.m_UVScale.y *= Mathf.Max(1e-5f, boundsSizeCurrentOS.z) / Mathf.Max(1e-5f, boundsSizePreviousOS.z);
+
+                    m_DecalProjectorComponent.m_UVBias.x += (boundsMinCurrentOS.x - boundsMinPreviousOS.x) / Mathf.Max(1e-5f, boundsSizeCurrentOS.x) * m_DecalProjectorComponent.m_UVScale.x;
+                    m_DecalProjectorComponent.m_UVBias.y += (boundsMinCurrentOS.z - boundsMinPreviousOS.z) / Mathf.Max(1e-5f, boundsSizeCurrentOS.z) * m_DecalProjectorComponent.m_UVScale.y;
+                }
+
+            // Automatically recenter our transform component if necessary.
+            // In order to correctly handle world-space snapping, we only perform this recentering when the user is no longer interacting with the gizmo.
+            if ((GUIUtility.hotControl == 0) && (m_DecalProjectorComponent.m_Offset != Vector3.zero))
+            {
+                // Both the DecalProjectorComponent, and the transform will be modified.
+                // The undo system will automatically group all RecordObject() calls here into a single action.
+                Undo.RecordObject(m_DecalProjectorComponent.transform, "Decal Projector Change");
+
+                // Re-center the transform to the center of the decal projector bounds,
+                // while maintaining the world-space coordinates of the decal projector boundings vertices.
+                m_DecalProjectorComponent.transform.Translate(
+                    Vector3.Scale(m_DecalProjectorComponent.m_Offset, m_DecalProjectorComponent.transform.localScale),
+                    Space.Self
+                );
+
+                m_DecalProjectorComponent.m_Offset = Vector3.zero;
+            }
+
             Handles.matrix = mat;
             Handles.color = col;
         }
             EditorGUI.BeginChangeCheck();
-            EditorGUILayout.PropertyField(m_Center);
+            EditorGUILayout.PropertyField(m_IsCropModeEnabledProperty, new GUIContent("Crop Decal with Gizmo"));
+
             EditorGUILayout.PropertyField(m_Size);
             EditorGUILayout.PropertyField(m_MaterialProperty);
             EditorGUILayout.PropertyField(m_DrawDistanceProperty);
             EditorGUILayout.PropertyField(m_AffectsTransparencyProperty);
+
             if (EditorGUI.EndChangeCheck())
             {
                 serializedObject.ApplyModifiedProperties();

com.unity.render-pipelines.high-definition/HDRP/Material/Decal/DecalProjectorComponent.cs

         public Vector3 m_Size = new Vector3(1, 1, 1);
         private Material m_OldMaterial = null;
         private DecalSystem.DecalHandle m_Handle = null;
+        public bool m_IsCropModeEnabled = false;
 
         public DecalSystem.DecalHandle Handle
         {
             }
 
             if (m_Handle != null)
-            { 
+            {
                 DecalSystem.instance.RemoveDecal(m_Handle);
                 m_Handle = null;
             }
         public void OnDisable()
         {
             if (m_Handle != null)
-            { 
+            {
                 DecalSystem.instance.RemoveDecal(m_Handle);
                 m_Handle = null;
             }
         public event OnMaterialChangeDelegate OnMaterialChange;
 
         public void OnValidate()
-        {            
+        {
             if (m_Handle != null) // don't do anything if OnEnable hasn't been called yet when scene is loading.
             {
                 Vector4 uvScaleBias = new Vector4(m_UVScale.x, m_UVScale.y, m_UVBias.x, m_UVBias.y);

com.unity.render-pipelines.high-definition/HDRP/Editor/Material/Decal/DecalProjectorComponentHandle.cs

+using System;
+using UnityEngine;
+
+namespace UnityEditor.IMGUI.Controls
+{
+    public class DecalProjectorComponentHandle : PrimitiveBoundsHandle
+    {
+        public DecalProjectorComponentHandle() : base()
+        {
+            midpointHandleDrawFunction = DrawHandleMidpoint;
+        }
+
+        public UnityEngine.Vector3 size { get { return GetSize(); } set { SetSize(value); } }
+
+        protected override void DrawWireframe()
+        {
+            Handles.DrawWireCube(center, size);
+            DrawArrowDownProjectionDirection();
+        }
+
+        protected void DrawArrowDownProjectionDirection()
+        {
+            int controlID = GUIUtility.GetControlID(GetHashCode(), FocusType.Passive);
+            Quaternion arrowRotation = Quaternion.LookRotation(Vector3.down, Vector3.right);
+            float arrowSize = size.y * 0.25f;
+            Handles.ArrowHandleCap(controlID, center, arrowRotation, arrowSize, EventType.Repaint);
+        }
+
+        // Could use a static readonly LUT, but this would require syncing with order with enum HandleDirection.
+        protected static Color ColorFromHandleDirection(HandleDirection handleDirection)
+        {
+            switch (handleDirection)
+            {
+                case HandleDirection.PositiveX:
+                case HandleDirection.NegativeX:
+                    return Handles.xAxisColor;
+
+                case HandleDirection.PositiveY:
+                case HandleDirection.NegativeY:
+                    return Handles.yAxisColor;
+
+                case HandleDirection.PositiveZ:
+                case HandleDirection.NegativeZ:
+                    return Handles.zAxisColor;
+
+                default:
+                    throw new ArgumentOutOfRangeException("handleDirection", "Must be PositiveX, NegativeX, PositiveY, NegativeY, PositiveZ, or NegativeZ");
+            }
+        }
+
+        protected static void PlaneVerticesFromHandleDirection(ref Vector3[] outVertices, HandleDirection handleDirection, Vector3 boundsSize, Vector3 boundsCenter)
+        {
+            Vector3 boundsMin = boundsSize * -0.5f + boundsCenter;
+            Vector3 boundsMax = boundsSize * 0.5f + boundsCenter;
+
+            switch (handleDirection)
+            {
+                case HandleDirection.PositiveX:
+                    outVertices[0] = new Vector3(boundsMax.x, boundsMin.y, boundsMin.z);
+                    outVertices[1] = new Vector3(boundsMax.x, boundsMax.y, boundsMin.z);
+                    outVertices[2] = new Vector3(boundsMax.x, boundsMax.y, boundsMax.z);
+                    outVertices[3] = new Vector3(boundsMax.x, boundsMin.y, boundsMax.z);
+                    break;
+
+                case HandleDirection.NegativeX:
+                    outVertices[0] = new Vector3(boundsMin.x, boundsMin.y, boundsMin.z);
+                    outVertices[1] = new Vector3(boundsMin.x, boundsMax.y, boundsMin.z);
+                    outVertices[2] = new Vector3(boundsMin.x, boundsMax.y, boundsMax.z);
+                    outVertices[3] = new Vector3(boundsMin.x, boundsMin.y, boundsMax.z);
+                    break;
+
+                case HandleDirection.PositiveY:
+                    outVertices[0] = new Vector3(boundsMin.x, boundsMax.y, boundsMin.z);
+                    outVertices[1] = new Vector3(boundsMax.x, boundsMax.y, boundsMin.z);
+                    outVertices[2] = new Vector3(boundsMax.x, boundsMax.y, boundsMax.z);
+                    outVertices[3] = new Vector3(boundsMin.x, boundsMax.y, boundsMax.z);
+                    break;
+
+                case HandleDirection.NegativeY:
+                    outVertices[0] = new Vector3(boundsMin.x, boundsMin.y, boundsMin.z);
+                    outVertices[1] = new Vector3(boundsMax.x, boundsMin.y, boundsMin.z);
+                    outVertices[2] = new Vector3(boundsMax.x, boundsMin.y, boundsMax.z);
+                    outVertices[3] = new Vector3(boundsMin.x, boundsMin.y, boundsMax.z);
+                    break;
+
+                case HandleDirection.PositiveZ:
+                    outVertices[0] = new Vector3(boundsMin.x, boundsMin.y, boundsMax.z);
+                    outVertices[1] = new Vector3(boundsMax.x, boundsMin.y, boundsMax.z);
+                    outVertices[2] = new Vector3(boundsMax.x, boundsMax.y, boundsMax.z);
+                    outVertices[3] = new Vector3(boundsMin.x, boundsMax.y, boundsMax.z);
+                    break;
+
+                case HandleDirection.NegativeZ:
+                    outVertices[0] = new Vector3(boundsMin.x, boundsMin.y, boundsMin.z);
+                    outVertices[1] = new Vector3(boundsMax.x, boundsMin.y, boundsMin.z);
+                    outVertices[2] = new Vector3(boundsMax.x, boundsMax.y, boundsMin.z);
+                    outVertices[3] = new Vector3(boundsMin.x, boundsMax.y, boundsMin.z);
+                    break;
+
+                default:
+                    throw new ArgumentOutOfRangeException("handleDirection", "Must be PositiveX, NegativeX, PositiveY, NegativeY, PositiveZ, or NegativeZ");
+            }
+        }
+
+        // As DrawHandleDirectionPlane() is called every frame during gizmo rendering, we pre-allocate a scratch array for passing along to DrawSolidRectangleWithOutline()
+        // rather than putting pressure on the garbage collector every frame. Since DrawHandleDirectionPlane() is responsible for drawing handles, we will only ever call
+        // it from the main thread, so there is no realistic risk of a race condition occuring due to this static allocation.
+        private static Vector3[] s_PlaneVertices = new Vector3[4];
+        protected static void DrawHandleDirectionPlane(HandleDirection handleDirection, Vector3 size, Vector3 center)
+        {
+            // Set global Handles.color to white to avoid global state from interfering with the desired colors set at DrawSolidRectangleWithOutline().
+            Color handlesColorPrevious = Handles.color;
+            Handles.color = Color.white;
+
+            Color planeColorOutline = ColorFromHandleDirection(handleDirection);
+            const float planeColorFillAlpha = 0.25f;
+            Color planeColorFill = planeColorOutline * planeColorFillAlpha;
+
+            PlaneVerticesFromHandleDirection(ref s_PlaneVertices, handleDirection, size, center);
+            Handles.DrawSolidRectangleWithOutline(s_PlaneVertices, planeColorFill, planeColorOutline);
+
+            Handles.color = handlesColorPrevious;
+        }
+
+        // Utility function for determining the handle direction (which face) we are currently rendering within DrawHandleMidpoint().
+        // Ideally, the base class PrimitiveBoundsHandle would expose the reverse lookup: HandleDirectionFromControlID().
+        // In lieu of an explicit way to handle this look up, we derive the handle direction from the handle rotation.
+        protected static HandleDirection HandleDirectionFromRotation(Quaternion rotation)
+        {
+            if (rotation.x == 0.0f && rotation.y == 0.7071068f && rotation.z == 0.0f && rotation.w == 0.7071068f)
+            {
+                return HandleDirection.PositiveX;
+            }
+            else if (rotation.x == 0.0f && rotation.y == -0.7071068f && rotation.z == 0.0f && rotation.w == 0.7071068f)
+            {
+                return HandleDirection.NegativeX;
+            }
+            else if (rotation.x == -0.7071068f && rotation.y == 0.0f && rotation.z == 0.0f && rotation.w == 0.7071068f)
+            {
+                return HandleDirection.PositiveY;
+            }
+            else if (rotation.x == 0.7071068f && rotation.y == 0.0f && rotation.z == 0.0f && rotation.w == 0.7071068f)
+            {
+                return HandleDirection.NegativeY;
+            }
+            else if (rotation.x == 0.0f && rotation.y == 0.0f && rotation.z == 0.0f && rotation.w == 1.0f)
+            {
+                return HandleDirection.PositiveZ;
+            }
+            else if (rotation.x == 0.0f && rotation.y == 1.0f && rotation.z == 0.0f && rotation.w == 0.0f)
+            {
+                return HandleDirection.NegativeZ;
+            }
+            else
+            {
+                throw new ArgumentOutOfRangeException("rotation", "Must point down PositiveX, NegativeX, PositiveY, NegativeY, PositiveZ, or NegativeZ");
+            }
+        }
+
+        protected void DrawHandleMidpoint(int handleControlID, Vector3 handlePosition, Quaternion handleRotation, float handleSize, EventType eventType)
+        {
+            // Highlight the plane we are currently interacting with.
+            if (handleControlID == GUIUtility.hotControl)
+            {
+                HandleDirection handleDirection = HandleDirectionFromRotation(handleRotation);
+                DrawHandleDirectionPlane(handleDirection, size, center);
+            }
+
+            // Draw standard PrimitiveBoundsHandle mindpoint handle.
+            Handles.DotHandleCap(handleControlID, handlePosition, handleRotation, handleSize, eventType);
+        }
+    }
+}

com.unity.render-pipelines.high-definition/HDRP/Editor/Material/Decal/DecalProjectorComponentHandle.cs.meta

+fileFormatVersion: 2
+guid: b29d5aac6308c3a4088143d90a1f1925
+MonoImporter:
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+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: