From a374411279a9844367c99fe851c42e7ec024bf7e Mon Sep 17 00:00:00 2001
From: Vladislav Belov <vladislavbelovdev@gmail.com>
Date: Thu, 10 Sep 2026 15:27:04 +0200
Subject: [PATCH] Separates preparing for rendering of CPU skinned

Only CPU skinned models require preparing for rendering to mark vertex
buffer chunks as needed.
---
 source/renderer/CPUSkinnedModelRenderer.cpp | 13 ++++++++++---
 source/renderer/CPUSkinnedModelRenderer.h   |  6 ++++++
 source/renderer/SceneRenderer.cpp           | 10 ++++++++++
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/source/renderer/CPUSkinnedModelRenderer.cpp b/source/renderer/CPUSkinnedModelRenderer.cpp
index 013a4aa3ee..248841e592 100644
--- a/source/renderer/CPUSkinnedModelRenderer.cpp
+++ b/source/renderer/CPUSkinnedModelRenderer.cpp
@@ -206,10 +206,10 @@ void CPUSkinnedModelVertexRenderer::UpdateModelsData(Renderer::Backend::IDeviceC
 // Fill in and upload dynamic vertex array
 void CPUSkinnedModelVertexRenderer::UpdateModelData(CModel* model, CModelRData* data, int updateflags)
 {
-	ModelRData* modelRData = static_cast<ModelRData*>(data);
-
 	if (updateflags & RENDERDATA_UPDATE_VERTICES)
 	{
+		ModelRData* modelRData = static_cast<ModelRData*>(data);
+
 		// build vertices
 		VertexArrayIterator<CVector3D> Position = modelRData->m_Position.GetIterator<CVector3D>();
 		VertexArrayIterator<CVector3D> Normal = modelRData->m_Normal.GetIterator<CVector3D>();
@@ -219,8 +219,15 @@ void CPUSkinnedModelVertexRenderer::UpdateModelData(CModel* model, CModelRData*
 		// upload everything to vertex buffer
 		modelRData->m_Array.Upload();
 	}
+}
 
-	modelRData->m_Array.PrepareForRendering();
+void CPUSkinnedModelVertexRenderer::PrepareForRendering(std::span<CModel*> models)
+{
+	for (CModel* model : models)
+	{
+		ModelRData* modelRData{static_cast<ModelRData*>(static_cast<CModelRData*>(model->GetRenderData()))};
+		modelRData->m_Array.PrepareForRendering();
+	}
 }
 
 void CPUSkinnedModelVertexRenderer::UploadModelsData(
diff --git a/source/renderer/CPUSkinnedModelRenderer.h b/source/renderer/CPUSkinnedModelRenderer.h
index 26a4b62896..038115cf14 100644
--- a/source/renderer/CPUSkinnedModelRenderer.h
+++ b/source/renderer/CPUSkinnedModelRenderer.h
@@ -55,6 +55,12 @@ public:
 		Renderer::Backend::IDeviceCommandContext* deviceCommandContext,
 		Renderer::Backend::IShaderProgram* shader, CModel* model, CModelRData* data) override;
 
+	/**
+	 * For CPU skinning we need to mark dynamic buffer chunks as needed before rendering.
+	 * It must be called before uploading.
+	 */
+	void PrepareForRendering(std::span<CModel*> models);
+
 protected:
 	void UpdateModelData(
 		CModel* model, CModelRData* data, int updateflags);
diff --git a/source/renderer/SceneRenderer.cpp b/source/renderer/SceneRenderer.cpp
index 5b7cf1c4bd..1fd393964f 100644
--- a/source/renderer/SceneRenderer.cpp
+++ b/source/renderer/SceneRenderer.cpp
@@ -205,6 +205,16 @@ public:
 			PrepareModels(deviceCommandContext, modelVertexSkinningRenderer, Model.TransparentSkinned.submissions[cullGroup]);
 		}
 
+		// See CPUSkinnedModelVertexRenderer::PrepareForRendering comment.
+		if (!Model.GPUSkinningEnabled)
+		{
+			for (int cullGroup{0}; cullGroup < CSceneRenderer::CULL_MAX; ++cullGroup)
+			{
+				Model.VertexCPUSkinningShader.PrepareForRendering(Model.OpaqueSkinned.submissions[cullGroup]);
+				Model.VertexCPUSkinningShader.PrepareForRendering(Model.TransparentSkinned.submissions[cullGroup]);
+			}
+		}
+
 		for (int cullGroup{0}; cullGroup < CSceneRenderer::CULL_MAX; ++cullGroup)
 		{
 			PrepareModels(deviceCommandContext, Model.VertexInstancingShader, Model.OpaqueUnskinned.submissions[cullGroup]);