From 867ae2ceaa918121f1e0f64c1973db4f123f9ab8 Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Mon, 23 Jun 2025 09:31:15 +0200
Subject: [PATCH] Add `Texture Size` node to particles

---
 Source/Editor/Surface/Archetypes/Textures.cs  | 15 ++++++++++++++-
 .../ParticleEmitterGraph.CPU.Particles.cpp    |  7 +++++++
 .../GPU/ParticleEmitterGraph.GPU.Textures.cpp | 19 +++++++++++++++++--
 3 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/Source/Editor/Surface/Archetypes/Textures.cs b/Source/Editor/Surface/Archetypes/Textures.cs
index 1e7dfb56f..56f8154d7 100644
--- a/Source/Editor/Surface/Archetypes/Textures.cs
+++ b/Source/Editor/Surface/Archetypes/Textures.cs
@@ -459,7 +459,7 @@ namespace FlaxEditor.Surface.Archetypes
                 AlternativeTitles = new string[] { "Lightmap TexCoord" }, 
                 Description = "Lightmap UVs",
                 Flags = NodeFlags.MaterialGraph,
-                Size = new Float2(110, 30),
+                Size = new Float2(110, 20),
                 Elements = new []
                 {
                     NodeElementArchetype.Factory.Output(0, "UVs", typeof(Float2), 0)
@@ -493,6 +493,19 @@ namespace FlaxEditor.Surface.Archetypes
                     NodeElementArchetype.Factory.Bool(190, Surface.Constants.LayoutOffsetY * 4, 4),
                 }
             },
+            new NodeArchetype
+            {
+                TypeID = 24,
+                Title = "Texture Size",
+                Description = "Gets the size of the texture (in pixels). If texture is during streaming, then returns size of the highest resident mip.",
+                Flags = NodeFlags.ParticleEmitterGraph,
+                Size = new Float2(160, 20),
+                Elements = new[]
+                {
+                    NodeElementArchetype.Factory.Input(0, "Texture", true, typeof(FlaxEngine.Object), 0),
+                    NodeElementArchetype.Factory.Output(0, "Size", typeof(Float3), 1),
+                }
+            },
         };
     }
 }
diff --git a/Source/Engine/Particles/Graph/CPU/ParticleEmitterGraph.CPU.Particles.cpp b/Source/Engine/Particles/Graph/CPU/ParticleEmitterGraph.CPU.Particles.cpp
index 58058afc1..a47e15275 100644
--- a/Source/Engine/Particles/Graph/CPU/ParticleEmitterGraph.CPU.Particles.cpp
+++ b/Source/Engine/Particles/Graph/CPU/ParticleEmitterGraph.CPU.Particles.cpp
@@ -162,6 +162,13 @@ void ParticleEmitterGraphCPUExecutor::ProcessGroupTextures(Box* box, Node* node,
         value = Value::Zero;
         break;
     }
+    // Texture Size
+    case 24:
+    {
+        // TODO: support sampling textures in CPU particles
+        value = Value::Zero;
+        break;
+    }
     default:
         break;
     }
diff --git a/Source/Engine/Particles/Graph/GPU/ParticleEmitterGraph.GPU.Textures.cpp b/Source/Engine/Particles/Graph/GPU/ParticleEmitterGraph.GPU.Textures.cpp
index 355548e37..820f8da3d 100644
--- a/Source/Engine/Particles/Graph/GPU/ParticleEmitterGraph.GPU.Textures.cpp
+++ b/Source/Engine/Particles/Graph/GPU/ParticleEmitterGraph.GPU.Textures.cpp
@@ -34,8 +34,8 @@ bool ParticleEmitterGPUGenerator::loadTexture(Node* caller, Box* box, const Seri
     Value location = tryGetValue(locationBox, Value::InitForZero(VariantType::Float2));
 
     // Convert into a proper type
-    if (isCubemap || isVolume || isArray)
-        location = Value::Cast(location, VariantType::Float3);
+    if (isVolume || isArray)
+        location = Value::Cast(location, VariantType::Float4);
     else
         location = Value::Cast(location, VariantType::Float3);
 
@@ -332,6 +332,21 @@ void ParticleEmitterGPUGenerator::ProcessGroupTextures(Box* box, Node* node, Val
         value = box == gradientBox ? gradient : distance;
         break;
     }
+    // Texture Size
+    case 24:
+    {
+        value = Value::Zero;
+        auto textureBox = node->GetBox(0);
+        if (!textureBox->HasConnection())
+            break;
+        const auto texture = eatBox(textureBox->GetParent<Node>(), textureBox->FirstConnection());
+        const auto textureParam = findParam(texture.Value);
+        if (!textureParam)
+            break;
+        value = writeLocal(VariantType::Float2, node);
+        _writer.Write(TEXT("\t{0}.GetDimensions({1}.x, {1}.y);\n"), textureParam->ShaderName, value.Value);
+        break;
+    }
     default:
         break;
     }