render stencil portals (opaque)

2023-03-03 16:25:24 +01:00
parent 5e911f2df1
commit 6d2b5c52a1
16 changed files with 781 additions and 947 deletions
--- a/Assets/Portal/Runtime/RenderPortalCameras.cs
+++ b/Assets/Portal/Runtime/RenderPortalCameras.cs
@@ -0,0 +1,113 @@
+using System.Collections.Generic;
+using EscapeRoomEngine.VR.Runtime;
+using UnityEngine;
+using UnityEngine.Rendering;
+using UnityEngine.Rendering.Universal;
+
+namespace EscapeRoomEngine.Portal.Runtime
+{
+    public class RenderPortalCameras : ScriptableRendererFeature
+    {
+        private enum PassType
+        {
+            Opaque,
+            Transparent
+        }
+
+        private class PortalCameraRenderPass : ScriptableRenderPass
+        {
+            private static readonly List<ShaderTagId> ShaderTagIds = new List<ShaderTagId>
+            {
+                new("SRPDefaultUnlit"), new("UniversalForward"), new("UniversalForwardOnly")
+            };
+
+            private RenderStateBlock _renderStateBlock;
+            private CommandBuffer _commandBuffer;
+
+            private readonly LayerMask _layers;
+            private readonly PassType _passType;
+
+            public PortalCameraRenderPass(LayerMask layers, PassType passType)
+            {
+                _layers = layers;
+                _passType = passType;
+
+                renderPassEvent = RenderPassEvent.AfterRenderingOpaques;
+                _renderStateBlock = new RenderStateBlock(RenderStateMask.Nothing);
+
+                // set stencil
+                var stencilState = StencilState.defaultValue;
+                stencilState.enabled = true;
+                stencilState.SetCompareFunction(CompareFunction.Equal);
+                stencilState.SetPassOperation(StencilOp.Keep);
+                stencilState.SetFailOperation(StencilOp.Keep);
+                stencilState.SetZFailOperation(StencilOp.Keep);
+                _renderStateBlock.mask |= RenderStateMask.Stencil;
+                _renderStateBlock.stencilState = stencilState;
+            }
+
+            public override void OnCameraSetup(CommandBuffer cmd, ref RenderingData renderingData)
+            {
+                // we need to store a reference to the command buffer before executing, because the reference in RenderingData is internal
+                _commandBuffer = cmd;
+            }
+
+            public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
+            {
+                if (Player.Instance)
+                {
+                    var drawingSettings = CreateDrawingSettings(ShaderTagIds, ref renderingData, _passType == PassType.Opaque ? renderingData.cameraData.defaultOpaqueSortFlags : SortingCriteria.CommonTransparent);
+                    var filteringSettings = new FilteringSettings(_passType == PassType.Opaque ? RenderQueueRange.opaque : RenderQueueRange.transparent, _layers);
+                    
+                    foreach (var portal in FindObjectsByType<Portal>(FindObjectsInactive.Exclude, FindObjectsSortMode.None))
+                    {
+                        var linkedPortal = portal.linkedPortal;
+                        if (linkedPortal)
+                        {
+                            // set which portal to render
+                            _renderStateBlock.stencilReference = portal.PortalNumber;
+                            
+                            // prepare the camera
+                            ref var cameraData = ref renderingData.cameraData;
+                            var camera = cameraData.camera;
+                            var cameraTransform = camera.transform;
+                            var originalPosition = cameraTransform.position;
+                            var originalRotation = cameraTransform.rotation;
+                            var originalProjection = camera.projectionMatrix;
+                            camera = linkedPortal.SetUpCamera(camera);
+                            RenderingUtils.SetViewAndProjectionMatrices(_commandBuffer, camera.worldToCameraMatrix, GL.GetGPUProjectionMatrix(camera.projectionMatrix, true), false);
+
+                            // execute command buffer
+                            context.ExecuteCommandBuffer(_commandBuffer);
+                            _commandBuffer.Clear();
+                            
+                            // render the portal
+                            context.DrawRenderers(renderingData.cullResults, ref drawingSettings, ref filteringSettings, ref _renderStateBlock);
+
+                            // reset
+                            RenderingUtils.SetViewAndProjectionMatrices(_commandBuffer, cameraData.GetViewMatrix(), cameraData.GetGPUProjectionMatrix(), false);
+                            camera.transform.SetPositionAndRotation(originalPosition, originalRotation);
+                            camera.projectionMatrix = originalProjection;
+                        }
+                    }
+                }
+            }
+        }
+
+        private PortalCameraRenderPass _opaquePass, _transparentPass;
+
+        public LayerMask layers;
+
+        public override void Create()
+        {
+            _opaquePass = new PortalCameraRenderPass(layers, PassType.Opaque);
+            _transparentPass = new PortalCameraRenderPass(layers, PassType.Transparent);
+        }
+
+        public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
+        {
+            renderer.EnqueuePass(_opaquePass);
+            // renderer.EnqueuePass(_transparentPass); TODO: enable
+        }
+    }
+}