IfcOpenShell/src/ifcviewer/ViewportCore.h

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 * This file is part of IfcOpenShell.                                           *
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#ifndef VIEWPORTCORE_H
#define VIEWPORTCORE_H

// Platform-agnostic render core. Owns the wgpu lifecycle state +
// (eventually) scene state + per-frame render path. Talks to its
// embedder through ViewportHost (window/canvas surface, scheduling,
// notifications) — has no Qt or browser dependencies of its own.
//
// First migration target (#84-a): wgpu instance/adapter/device/queue/
// surface ownership. The next subsystems (pipelines, models, render
// path) move incrementally across subsequent commits — each leaving
// the desktop build green. ViewportWindow currently holds reference
// members pointing back at ViewportCore's storage so its body doesn't
// have to acquire a `core_.` prefix on every wgpu touch. Those
// references shrink as render methods themselves move over.

#include <webgpu/webgpu.h>

#include "ViewportHost.h"

class ViewportCore {
public:
    explicit ViewportCore(ViewportHost* host);
    ~ViewportCore();

    ViewportCore(const ViewportCore&)            = delete;
    ViewportCore& operator=(const ViewportCore&) = delete;

    ViewportHost* host() const { return host_; }

    // Friend access for ViewportWindow's reference proxies. As each
    // render method moves into ViewportCore it stops needing these
    // (it touches the fields directly); once everything has migrated
    // the friend declaration goes away.
    friend class ViewportWindow;

private:
    ViewportHost* host_;

    // ---- wgpu lifecycle state ------------------------------------------------
    //
    // Plain pointers (wgpu C handles); zero-init means "not yet
    // initialised". Owned by ViewportCore now; reference members in
    // ViewportWindow alias these so the existing call sites don't
    // need to change to use a `core_.` prefix.
    WGPUInstance      instance_           = nullptr;
    WGPUAdapter       adapter_            = nullptr;
    WGPUDevice        device_             = nullptr;
    WGPUQueue         queue_              = nullptr;
    WGPUSurface       surface_            = nullptr;
    WGPUTextureFormat surface_format_     = WGPUTextureFormat_Undefined;
    bool              surface_configured_ = false;

    // ---- Pipelines + bind-group layouts (built once after init) -------------
    //
    // Main render pipeline group: one shader module + two bind group
    // layouts (frame uniforms at group=0, per-model storages at
    // group=1) feeding both the opaque-pass pipeline and the
    // transparent-pass variant. The transparent pipeline shares the
    // shader and layout; it differs only in depthWriteEnabled=False
    // and the SrcAlpha / OneMinusSrcAlpha blend on the color target.
    WGPUShaderModule    main_shader_module_       = nullptr;
    WGPUBindGroupLayout frame_bgl_                = nullptr;  // group 0
    WGPUBindGroupLayout model_bgl_                = nullptr;  // group 1
    WGPUPipelineLayout  pipeline_layout_          = nullptr;
    WGPURenderPipeline  main_pipeline_            = nullptr;
    WGPURenderPipeline  main_pipeline_transparent_ = nullptr;

    // HiZ occlusion-cull pipeline group. Downsamples MSAA depth into a
    // mip pyramid; consumed by next-frame cull.
    WGPUShaderModule    hiz_shader_module_   = nullptr;
    WGPUBindGroupLayout hiz_bgl_             = nullptr;
    WGPUPipelineLayout  hiz_pipeline_layout_ = nullptr;
    WGPURenderPipeline  hiz_pipeline_        = nullptr;

    // Edge-silhouette pipeline group. Drawn after the main pass; reads
    // the depth/normal attachments to emit dark outlines.
    WGPUShaderModule    edge_shader_module_   = nullptr;
    WGPUBindGroupLayout edge_bgl_             = nullptr;
    WGPUPipelineLayout  edge_pipeline_layout_ = nullptr;
    WGPURenderPipeline  edge_pipeline_        = nullptr;

    // Pick pass. Reuses pipeline_layout_ — same set of bindings as the
    // main pass since the pick fragment also vertex-pulls instance data.
    WGPURenderPipeline  pick_pipeline_ = nullptr;
};

#endif  // VIEWPORTCORE_H