wgpu backend: load .ifcview sidecars onto GPU buffers

Stage 2 of the wgpu port. WgpuViewportWindow gains a queueLoadSidecar API (called from the minimal driver before init) and an applyCachedModel that runs after init: reads via SidecarCache::readSidecar, allocates four wgpu buffers per model (vertex storage, index, mesh-quant storage, instance storage), uploads via wgpuQueueWriteBuffer, retains a CPU mirror of the MeshInfo/InstanceCpu arrays for the cull and picking paths that arrive in later stages. MeshGpu (the per-mesh quantization basis) is derived from MeshInfo on the fly; InstanceGpu (transform + ids) is derived from InstanceCpu and uses the cached float transform — composing from placement_transformation against federation-stage matrices lands when stage 5 wires those. SidecarCache.cpp is compiled into IfcViewerWgpu directly: it's pure C++ with no Qt/OCCT/IFC-parse deps, so dragging in the IfcViewer static lib for one source file would be wasteful. This duplication goes away once src/ifcviewer-core/ is extracted (task #12). Verified on a synthesised v13 sidecar (4 verts, 6 indices, 1 mesh, 1 instance) and a multi-sidecar load that assigns successive model_ids. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-08-31 00:46:36 +00:00 · 2026-05-27 12:48:03 +10:00
parent 19a39a0413
commit 9daa5fe195
5 changed files with 325 additions and 5 deletions
@@ -0,0 +1,71 @@
+/********************************************************************************
+ *                                                                              *
+ * This file is part of IfcOpenShell.                                           *
+ *                                                                              *
+ * IfcOpenShell is free software: you can redistribute it and/or modify         *
+ * it under the terms of the Lesser GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3.0 of the License, or          *
+ * (at your option) any later version.                                          *
+ *                                                                              *
+ * IfcOpenShell is distributed in the hope that it will be useful,              *
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of               *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                 *
+ * Lesser GNU General Public License for more details.                          *
+ *                                                                              *
+ * You should have received a copy of the Lesser GNU General Public License     *
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.         *
+ *                                                                              *
+ ********************************************************************************/
+
+#ifndef WGPUMODELGPUDATA_H
+#define WGPUMODELGPUDATA_H
+
+#include <webgpu/webgpu.h>
+
+#include <cstddef>
+#include <cstdint>
+#include <vector>
+
+#include "InstancedGeometry.h"
+
+// Per-model wgpu state. Mirrors the GL backend's ModelGpuData but with
+// wgpu handles. Stage 2 only allocates and uploads the four core buffers;
+// bind groups, pipelines, BVH and cull scratch land in later stages.
+//
+// All vertex/index/mesh/instance bytes are uploaded once at load time via
+// wgpuQueueWriteBuffer. The vertex storage buffer is read by the vertex
+// shader (vertex pulling), not used as a classic vertex buffer — there is
+// no input-assembler vertex layout to match.
+struct WgpuModelGpuData {
+    // Raw VBO bytes at the INSTANCED_VERTEX_STRIDE_BYTES layout (12 B/vertex).
+    // Bound as a read-only storage buffer in the vertex shader.
+    WGPUBuffer vertex_storage = nullptr;
+    // Mesh-local u32 indices. base_vertex applied at draw time so a single
+    // index buffer per model is shared across meshes.
+    WGPUBuffer index_buffer = nullptr;
+    // MeshGpu[] — per-mesh quantization basis (aabb_min/max as vec4 pair).
+    // Derived from MeshInfo on upload.
+    WGPUBuffer mesh_storage = nullptr;
+    // InstanceGpu[] — per-instance transform + ids. Derived from InstanceCpu
+    // on upload. Stage 2 stores the cached `transform`; later stages will
+    // recompose from placement_transformation when stage matrices change.
+    WGPUBuffer instance_storage = nullptr;
+
+    // Size mirrors for stats / range checks.
+    size_t   vertex_bytes   = 0;
+    uint32_t index_count    = 0;
+    uint32_t mesh_count     = 0;
+    uint32_t instance_count = 0;
+
+    // CPU side, kept for cull / picking / federation recompose.
+    std::vector<MeshInfo>    meshes;
+    std::vector<InstanceCpu> instances;
+
+    bool hidden = false;
+};
+
+// Release every wgpu handle in `m` and clear its size mirrors. Safe to call
+// repeatedly; idempotent on already-released entries.
+void releaseWgpuModelGpuData(WgpuModelGpuData& m);
+
+#endif // WGPUMODELGPUDATA_H