Skip to main content

viewport_lib/renderer/
mod.rs

1//! `ViewportRenderer` : the main entry point for the viewport library.
2//!
3//! Wraps [`ViewportGpuResources`] and provides `prepare()` / `paint()` methods
4//! that take raw `wgpu` types. GUI framework adapters (e.g. the egui
5//! `CallbackTrait` impl in the application crate) delegate to these methods.
6
7#[macro_use]
8mod types;
9mod picking;
10mod prepare;
11mod render;
12pub mod shader_hashes;
13mod shadows;
14pub mod stats;
15
16pub(crate) use self::types::ClipPlane;
17pub use self::types::{
18    CameraFrame, CameraFrustumItem, ClipObject, ClipShape, ComputeFilterItem, ComputeFilterKind,
19    EffectsFrame, EnvironmentMap, FilterMode, FrameData, GlyphItem, GlyphType, GroundPlane,
20    GroundPlaneMode, ImageAnchor, InteractionFrame, LabelAnchor, LabelItem, LightKind, LightSource,
21    LightingSettings, OverlayFrame, OverlayImageItem, PickId, PointCloudItem, PointRenderMode,
22    PolylineItem, PostProcessSettings, RenderCamera, RulerItem, ScalarBarAnchor, ScalarBarItem,
23    ScalarBarOrientation, SceneEffects,
24    SceneFrame, SceneRenderItem, ScreenImageItem,
25    ShadowFilter, StreamtubeItem, SurfaceSubmission, ToneMapping, ViewportEffects, ViewportFrame,
26    VolumeItem,
27};
28
29/// An opaque handle to a per-viewport GPU state slot.
30///
31/// Obtained from [`ViewportRenderer::create_viewport`] and passed to
32/// [`ViewportRenderer::prepare_viewport`], [`ViewportRenderer::paint_viewport`],
33/// and [`ViewportRenderer::render_viewport`].
34///
35/// The inner `usize` is the slot index and doubles as the value for
36/// [`CameraFrame::with_viewport_index`].  Single-viewport applications that use
37/// the legacy [`ViewportRenderer::prepare`] / [`ViewportRenderer::paint`] API do
38/// not need this type.
39#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
40pub struct ViewportId(pub usize);
41
42use self::shadows::{compute_cascade_matrix, compute_cascade_splits};
43use self::types::{INSTANCING_THRESHOLD, InstancedBatch};
44use crate::resources::{
45    CameraUniform, ClipPlanesUniform, ClipVolumeUniform, GridUniform, InstanceData, LightsUniform,
46    ObjectUniform, OutlineEdgeUniform, OutlineObjectBuffers, OutlineUniform, PickInstance,
47    ShadowAtlasUniform,
48    SingleLightUniform, ViewportGpuResources,
49};
50
51/// Per-viewport GPU state: uniform buffers and bind groups that differ per viewport.
52///
53/// Each viewport slot owns its own camera, clip planes, clip volume, shadow info,
54/// and grid buffers, plus the bind groups that reference them. Scene-global
55/// resources (lights, shadow atlas texture, IBL) are shared via the bind group
56/// pointing to buffers on `ViewportGpuResources`.
57pub(crate) struct ViewportSlot {
58    pub camera_buf: wgpu::Buffer,
59    pub clip_planes_buf: wgpu::Buffer,
60    pub clip_volume_buf: wgpu::Buffer,
61    pub shadow_info_buf: wgpu::Buffer,
62    pub grid_buf: wgpu::Buffer,
63    /// Camera bind group (group 0) referencing this slot's per-viewport buffers
64    /// plus shared scene-global resources.
65    pub camera_bind_group: wgpu::BindGroup,
66    /// Grid bind group (group 0 for grid pipeline) referencing this slot's grid buffer.
67    pub grid_bind_group: wgpu::BindGroup,
68    /// Per-viewport HDR post-process render targets.
69    ///
70    /// Created lazily on first HDR render call and resized when viewport dimensions change.
71    pub hdr: Option<crate::resources::ViewportHdrState>,
72
73    // --- Per-viewport interaction state (Phase 4) ---
74    /// Per-frame outline buffers for selected objects, rebuilt in prepare().
75    pub outline_object_buffers: Vec<OutlineObjectBuffers>,
76    /// Per-frame x-ray buffers for selected objects, rebuilt in prepare().
77    pub xray_object_buffers: Vec<(crate::resources::mesh_store::MeshId, wgpu::Buffer, wgpu::BindGroup)>,
78    /// Per-frame constraint guide line buffers, rebuilt in prepare().
79    pub constraint_line_buffers: Vec<(
80        wgpu::Buffer,
81        wgpu::Buffer,
82        u32,
83        wgpu::Buffer,
84        wgpu::BindGroup,
85    )>,
86    /// Per-frame cap geometry buffers (section view cross-section fill), rebuilt in prepare().
87    pub cap_buffers: Vec<(
88        wgpu::Buffer,
89        wgpu::Buffer,
90        u32,
91        wgpu::Buffer,
92        wgpu::BindGroup,
93    )>,
94    /// Per-frame clip plane fill overlay buffers, rebuilt in prepare().
95    pub clip_plane_fill_buffers: Vec<(
96        wgpu::Buffer,
97        wgpu::Buffer,
98        u32,
99        wgpu::Buffer,
100        wgpu::BindGroup,
101    )>,
102    /// Per-frame clip plane line overlay buffers, rebuilt in prepare().
103    pub clip_plane_line_buffers: Vec<(
104        wgpu::Buffer,
105        wgpu::Buffer,
106        u32,
107        wgpu::Buffer,
108        wgpu::BindGroup,
109    )>,
110    /// Vertex buffer for axes indicator geometry (rebuilt each frame).
111    pub axes_vertex_buffer: wgpu::Buffer,
112    /// Number of vertices in the axes indicator buffer.
113    pub axes_vertex_count: u32,
114    /// Gizmo model-matrix uniform buffer.
115    pub gizmo_uniform_buf: wgpu::Buffer,
116    /// Gizmo bind group (group 1: model matrix uniform).
117    pub gizmo_bind_group: wgpu::BindGroup,
118    /// Gizmo vertex buffer.
119    pub gizmo_vertex_buffer: wgpu::Buffer,
120    /// Gizmo index buffer.
121    pub gizmo_index_buffer: wgpu::Buffer,
122    /// Number of indices in the current gizmo mesh.
123    pub gizmo_index_count: u32,
124
125    // --- Sub-object highlight (per-viewport, generation-cached) ---
126    /// Per-viewport dynamic resolution intermediate render target.
127    /// `None` when render_scale == 1.0 or not yet initialised.
128    pub dyn_res: Option<crate::resources::dyn_res::DynResTarget>,
129    /// Cached GPU data for sub-object highlight rendering.
130    /// `None` when no sub-object selection is active.
131    pub sub_highlight: Option<crate::resources::SubHighlightGpuData>,
132    /// Version of the last sub-selection snapshot that was uploaded.
133    /// `u64::MAX` forces a rebuild on the first frame.
134    pub sub_highlight_generation: u64,
135}
136
137/// High-level renderer wrapping all GPU resources and providing framework-agnostic
138/// `prepare()` and `paint()` methods.
139pub struct ViewportRenderer {
140    resources: ViewportGpuResources,
141    /// Instanced batches prepared for the current frame. Empty when using per-object path.
142    instanced_batches: Vec<InstancedBatch>,
143    /// Whether the current frame uses the instanced draw path.
144    use_instancing: bool,
145    /// Performance counters from the last frame.
146    last_stats: crate::renderer::stats::FrameStats,
147    /// Last scene generation seen during prepare(). u64::MAX forces rebuild on first frame.
148    last_scene_generation: u64,
149    /// Last selection generation seen during prepare(). u64::MAX forces rebuild on first frame.
150    last_selection_generation: u64,
151    /// Last scene_items count seen during prepare(). usize::MAX forces rebuild on first frame.
152    /// Included in cache key so that frustum-culling changes (different visible set, different
153    /// count) correctly invalidate the instance buffer even when scene_generation is stable.
154    last_scene_items_count: usize,
155    /// Cached instance data from last rebuild (mirrors the GPU buffer contents).
156    cached_instance_data: Vec<InstanceData>,
157    /// Cached instanced batch descriptors from last rebuild.
158    cached_instanced_batches: Vec<InstancedBatch>,
159    /// Per-frame point cloud GPU data, rebuilt in prepare(), consumed in paint().
160    point_cloud_gpu_data: Vec<crate::resources::PointCloudGpuData>,
161    /// Per-frame glyph GPU data, rebuilt in prepare(), consumed in paint().
162    glyph_gpu_data: Vec<crate::resources::GlyphGpuData>,
163    /// Per-frame polyline GPU data, rebuilt in prepare(), consumed in paint().
164    polyline_gpu_data: Vec<crate::resources::PolylineGpuData>,
165    /// Per-frame volume GPU data, rebuilt in prepare(), consumed in paint().
166    volume_gpu_data: Vec<crate::resources::VolumeGpuData>,
167    /// Per-frame streamtube GPU data, rebuilt in prepare(), consumed in paint().
168    streamtube_gpu_data: Vec<crate::resources::StreamtubeGpuData>,
169    /// Per-frame GPU implicit surface data, rebuilt in prepare(), consumed in paint() (Phase 16).
170    implicit_gpu_data: Vec<crate::resources::implicit::ImplicitGpuItem>,
171    /// Per-frame GPU marching cubes render data, rebuilt in prepare(), consumed in paint() (Phase 17).
172    mc_gpu_data: Vec<crate::resources::gpu_marching_cubes::McFrameData>,
173    /// Per-frame screen-image GPU data, rebuilt in prepare(), consumed in paint() (Phase 10B).
174    screen_image_gpu_data: Vec<crate::resources::ScreenImageGpuData>,
175    /// Per-frame overlay image GPU data, rebuilt in prepare(), consumed in paint() (Phase 7).
176    overlay_image_gpu_data: Vec<crate::resources::ScreenImageGpuData>,
177    /// Per-frame overlay label GPU data, rebuilt in prepare(), consumed in paint().
178    label_gpu_data: Option<crate::resources::LabelGpuData>,
179    /// Per-frame scalar bar GPU data, rebuilt in prepare(), consumed in paint().
180    scalar_bar_gpu_data: Option<crate::resources::LabelGpuData>,
181    /// Per-frame ruler GPU data, rebuilt in prepare(), consumed in paint().
182    ruler_gpu_data: Option<crate::resources::LabelGpuData>,
183    /// Per-viewport GPU state slots.
184    ///
185    /// Indexed by `FrameData::camera.viewport_index`. Each slot owns independent
186    /// uniform buffers and bind groups for camera, clip planes, clip volume,
187    /// shadow info, and grid. Slots are grown lazily in `prepare` via
188    /// `ensure_viewport_slot`. There are at most 4 in the current UI.
189    viewport_slots: Vec<ViewportSlot>,
190    /// Phase G : GPU compute filter results from the last `prepare()` call.
191    ///
192    /// Each entry contains a compacted index buffer + count for one filtered mesh.
193    /// Consumed during `paint()` to override the mesh's default index buffer.
194    /// Cleared and rebuilt each frame.
195    compute_filter_results: Vec<crate::resources::ComputeFilterResult>,
196    /// Cascade-0 light-space view-projection matrix from the last shadow prepare.
197    /// Cached here so `prepare_viewport_internal` can copy it into the ground plane uniform.
198    last_cascade0_shadow_mat: glam::Mat4,
199    /// Current runtime mode controlling internal default behavior.
200    runtime_mode: crate::renderer::stats::RuntimeMode,
201    /// Active performance policy: target FPS, render scale bounds, and permitted reductions.
202    performance_policy: crate::renderer::stats::PerformancePolicy,
203    /// Current render scale tracked by the adaptation controller (or set manually).
204    ///
205    /// Clamped to `[policy.min_render_scale, policy.max_render_scale]`.
206    /// Reported in `FrameStats::render_scale` each frame.
207    current_render_scale: f32,
208    /// Instant recorded at the start of the most recent `prepare()` call.
209    /// Used to compute `total_frame_ms` on the following frame.
210    last_prepare_instant: Option<std::time::Instant>,
211    /// Frame counter incremented each `prepare()` call. Used for picking throttle in Playback mode.
212    frame_counter: u64,
213
214    // --- Phase 4 : GPU timestamp queries ---
215    /// Timestamp query set with 2 entries (scene-pass begin + end).
216    /// `None` when `TIMESTAMP_QUERY` is unavailable or not yet initialized.
217    ts_query_set: Option<wgpu::QuerySet>,
218    /// Resolve buffer: 2 × u64, GPU-only (`QUERY_RESOLVE | COPY_SRC`).
219    ts_resolve_buf: Option<wgpu::Buffer>,
220    /// Staging buffer: 2 × u64, CPU-readable (`COPY_DST | MAP_READ`).
221    ts_staging_buf: Option<wgpu::Buffer>,
222    /// Nanoseconds per GPU timestamp tick, from `queue.get_timestamp_period()`.
223    ts_period: f32,
224    /// Whether the staging buffer holds unread timestamp data from the previous frame.
225    ts_needs_readback: bool,
226}
227
228impl ViewportRenderer {
229    /// Create a new renderer with default settings (no MSAA).
230    /// Call once at application startup.
231    pub fn new(device: &wgpu::Device, target_format: wgpu::TextureFormat) -> Self {
232        Self::with_sample_count(device, target_format, 1)
233    }
234
235    /// Create a new renderer with the specified MSAA sample count (1, 2, or 4).
236    ///
237    /// When using MSAA (sample_count > 1), the caller must create multisampled
238    /// color and depth textures and use them as render pass attachments with the
239    /// final surface texture as the resolve target.
240    pub fn with_sample_count(
241        device: &wgpu::Device,
242        target_format: wgpu::TextureFormat,
243        sample_count: u32,
244    ) -> Self {
245        Self {
246            resources: ViewportGpuResources::new(device, target_format, sample_count),
247            instanced_batches: Vec::new(),
248            use_instancing: false,
249            last_stats: crate::renderer::stats::FrameStats::default(),
250            last_scene_generation: u64::MAX,
251            last_selection_generation: u64::MAX,
252            last_scene_items_count: usize::MAX,
253            cached_instance_data: Vec::new(),
254            cached_instanced_batches: Vec::new(),
255            point_cloud_gpu_data: Vec::new(),
256            glyph_gpu_data: Vec::new(),
257            polyline_gpu_data: Vec::new(),
258            volume_gpu_data: Vec::new(),
259            streamtube_gpu_data: Vec::new(),
260            implicit_gpu_data: Vec::new(),
261            mc_gpu_data: Vec::new(),
262            screen_image_gpu_data: Vec::new(),
263            overlay_image_gpu_data: Vec::new(),
264            label_gpu_data: None,
265            scalar_bar_gpu_data: None,
266            ruler_gpu_data: None,
267            viewport_slots: Vec::new(),
268            compute_filter_results: Vec::new(),
269            last_cascade0_shadow_mat: glam::Mat4::IDENTITY,
270            runtime_mode: crate::renderer::stats::RuntimeMode::Interactive,
271            performance_policy: crate::renderer::stats::PerformancePolicy::default(),
272            current_render_scale: 1.0,
273            last_prepare_instant: None,
274            frame_counter: 0,
275            ts_query_set: None,
276            ts_resolve_buf: None,
277            ts_staging_buf: None,
278            ts_period: 1.0,
279            ts_needs_readback: false,
280        }
281    }
282
283    /// Access the underlying GPU resources (e.g. for mesh uploads).
284    pub fn resources(&self) -> &ViewportGpuResources {
285        &self.resources
286    }
287
288    /// Performance counters from the last completed frame.
289    pub fn last_frame_stats(&self) -> crate::renderer::stats::FrameStats {
290        self.last_stats
291    }
292
293    /// Set the runtime mode controlling internal default behavior.
294    ///
295    /// - [`RuntimeMode::Interactive`]: full picking rate, full quality (default).
296    /// - [`RuntimeMode::Playback`]: picking throttled to reduce CPU overhead during animation.
297    /// - [`RuntimeMode::Paused`]: full picking rate, full quality.
298    /// - [`RuntimeMode::Capture`]: full quality, intended for screenshot/export workflows.
299    pub fn set_runtime_mode(&mut self, mode: crate::renderer::stats::RuntimeMode) {
300        self.runtime_mode = mode;
301    }
302
303    /// Return the current runtime mode.
304    pub fn runtime_mode(&self) -> crate::renderer::stats::RuntimeMode {
305        self.runtime_mode
306    }
307
308    /// Set the performance policy controlling target FPS, render scale bounds,
309    /// and permitted quality reductions.
310    ///
311    /// The internal adaptation controller activates when
312    /// `policy.allow_dynamic_resolution` is `true` and `policy.target_fps` is
313    /// `Some`. It adjusts `render_scale` within `[min_render_scale,
314    /// max_render_scale]` each frame based on `total_frame_ms`.
315    pub fn set_performance_policy(
316        &mut self,
317        policy: crate::renderer::stats::PerformancePolicy,
318    ) {
319        self.performance_policy = policy;
320        // Clamp current scale into the new bounds immediately.
321        self.current_render_scale = self.current_render_scale.clamp(
322            policy.min_render_scale,
323            policy.max_render_scale,
324        );
325    }
326
327    /// Return the active performance policy.
328    pub fn performance_policy(&self) -> crate::renderer::stats::PerformancePolicy {
329        self.performance_policy
330    }
331
332    /// Manually set the render scale.
333    ///
334    /// Effective when `performance_policy.allow_dynamic_resolution` is `false`.
335    /// When dynamic resolution is enabled the adaptation controller overrides
336    /// this value each frame.
337    ///
338    /// The value is clamped to `[policy.min_render_scale, policy.max_render_scale]`.
339    pub fn set_render_scale(&mut self, scale: f32) {
340        self.current_render_scale = scale.clamp(
341            self.performance_policy.min_render_scale,
342            self.performance_policy.max_render_scale,
343        );
344    }
345
346    /// Set the target frame rate used to compute [`FrameStats::missed_budget`].
347    ///
348    /// Convenience wrapper that updates `performance_policy.target_fps`.
349    pub fn set_target_fps(&mut self, fps: Option<f32>) {
350        self.performance_policy.target_fps = fps;
351    }
352
353    /// Mutable access to the underlying GPU resources (e.g. for mesh uploads).
354    pub fn resources_mut(&mut self) -> &mut ViewportGpuResources {
355        &mut self.resources
356    }
357
358    /// Upload an equirectangular HDR environment map and precompute IBL textures.
359    ///
360    /// `pixels` is row-major RGBA f32 data (4 floats per texel), `width`×`height`.
361    /// This rebuilds camera bind groups so shaders immediately see the new textures.
362    pub fn upload_environment_map(
363        &mut self,
364        device: &wgpu::Device,
365        queue: &wgpu::Queue,
366        pixels: &[f32],
367        width: u32,
368        height: u32,
369    ) {
370        crate::resources::environment::upload_environment_map(
371            &mut self.resources,
372            device,
373            queue,
374            pixels,
375            width,
376            height,
377        );
378        self.rebuild_camera_bind_groups(device);
379    }
380
381    /// Rebuild the primary + per-viewport camera bind groups.
382    ///
383    /// Call after IBL textures are uploaded so shaders see the new environment.
384    fn rebuild_camera_bind_groups(&mut self, device: &wgpu::Device) {
385        self.resources.camera_bind_group = self.resources.create_camera_bind_group(
386            device,
387            &self.resources.camera_uniform_buf,
388            &self.resources.clip_planes_uniform_buf,
389            &self.resources.shadow_info_buf,
390            &self.resources.clip_volume_uniform_buf,
391            "camera_bind_group",
392        );
393
394        for slot in &mut self.viewport_slots {
395            slot.camera_bind_group = self.resources.create_camera_bind_group(
396                device,
397                &slot.camera_buf,
398                &slot.clip_planes_buf,
399                &slot.shadow_info_buf,
400                &slot.clip_volume_buf,
401                "per_viewport_camera_bg",
402            );
403        }
404    }
405
406    /// Ensure a per-viewport slot exists for `viewport_index`.
407    ///
408    /// Creates a full `ViewportSlot` with independent uniform buffers for camera,
409    /// clip planes, clip volume, shadow info, and grid. The camera bind group
410    /// references this slot's per-viewport buffers plus shared scene-global
411    /// resources. Slots are created lazily and never destroyed.
412    fn ensure_viewport_slot(&mut self, device: &wgpu::Device, viewport_index: usize) {
413        while self.viewport_slots.len() <= viewport_index {
414            let camera_buf = device.create_buffer(&wgpu::BufferDescriptor {
415                label: Some("vp_camera_buf"),
416                size: std::mem::size_of::<CameraUniform>() as u64,
417                usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
418                mapped_at_creation: false,
419            });
420            let clip_planes_buf = device.create_buffer(&wgpu::BufferDescriptor {
421                label: Some("vp_clip_planes_buf"),
422                size: std::mem::size_of::<ClipPlanesUniform>() as u64,
423                usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
424                mapped_at_creation: false,
425            });
426            let clip_volume_buf = device.create_buffer(&wgpu::BufferDescriptor {
427                label: Some("vp_clip_volume_buf"),
428                size: std::mem::size_of::<ClipVolumeUniform>() as u64,
429                usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
430                mapped_at_creation: false,
431            });
432            let shadow_info_buf = device.create_buffer(&wgpu::BufferDescriptor {
433                label: Some("vp_shadow_info_buf"),
434                size: std::mem::size_of::<ShadowAtlasUniform>() as u64,
435                usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
436                mapped_at_creation: false,
437            });
438            let grid_buf = device.create_buffer(&wgpu::BufferDescriptor {
439                label: Some("vp_grid_buf"),
440                size: std::mem::size_of::<GridUniform>() as u64,
441                usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
442                mapped_at_creation: false,
443            });
444
445            let camera_bind_group = self.resources.create_camera_bind_group(
446                device,
447                &camera_buf,
448                &clip_planes_buf,
449                &shadow_info_buf,
450                &clip_volume_buf,
451                "per_viewport_camera_bg",
452            );
453
454            let grid_bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
455                label: Some("vp_grid_bind_group"),
456                layout: &self.resources.grid_bind_group_layout,
457                entries: &[wgpu::BindGroupEntry {
458                    binding: 0,
459                    resource: grid_buf.as_entire_binding(),
460                }],
461            });
462
463            // Per-viewport gizmo buffers (initial mesh: Translate, no hover, identity orientation).
464            let (gizmo_verts, gizmo_indices) = crate::interaction::gizmo::build_gizmo_mesh(
465                crate::interaction::gizmo::GizmoMode::Translate,
466                crate::interaction::gizmo::GizmoAxis::None,
467                glam::Quat::IDENTITY,
468            );
469            let gizmo_vertex_buffer = device.create_buffer(&wgpu::BufferDescriptor {
470                label: Some("vp_gizmo_vertex_buf"),
471                size: (std::mem::size_of::<crate::resources::Vertex>() * gizmo_verts.len().max(1))
472                    as u64,
473                usage: wgpu::BufferUsages::VERTEX | wgpu::BufferUsages::COPY_DST,
474                mapped_at_creation: true,
475            });
476            gizmo_vertex_buffer
477                .slice(..)
478                .get_mapped_range_mut()
479                .copy_from_slice(bytemuck::cast_slice(&gizmo_verts));
480            gizmo_vertex_buffer.unmap();
481            let gizmo_index_count = gizmo_indices.len() as u32;
482            let gizmo_index_buffer = device.create_buffer(&wgpu::BufferDescriptor {
483                label: Some("vp_gizmo_index_buf"),
484                size: (std::mem::size_of::<u32>() * gizmo_indices.len().max(1)) as u64,
485                usage: wgpu::BufferUsages::INDEX | wgpu::BufferUsages::COPY_DST,
486                mapped_at_creation: true,
487            });
488            gizmo_index_buffer
489                .slice(..)
490                .get_mapped_range_mut()
491                .copy_from_slice(bytemuck::cast_slice(&gizmo_indices));
492            gizmo_index_buffer.unmap();
493            let gizmo_uniform = crate::interaction::gizmo::GizmoUniform {
494                model: glam::Mat4::IDENTITY.to_cols_array_2d(),
495            };
496            let gizmo_uniform_buf = device.create_buffer(&wgpu::BufferDescriptor {
497                label: Some("vp_gizmo_uniform_buf"),
498                size: std::mem::size_of::<crate::interaction::gizmo::GizmoUniform>() as u64,
499                usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
500                mapped_at_creation: true,
501            });
502            gizmo_uniform_buf
503                .slice(..)
504                .get_mapped_range_mut()
505                .copy_from_slice(bytemuck::cast_slice(&[gizmo_uniform]));
506            gizmo_uniform_buf.unmap();
507            let gizmo_bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
508                label: Some("vp_gizmo_bind_group"),
509                layout: &self.resources.gizmo_bind_group_layout,
510                entries: &[wgpu::BindGroupEntry {
511                    binding: 0,
512                    resource: gizmo_uniform_buf.as_entire_binding(),
513                }],
514            });
515
516            // Per-viewport axes vertex buffer (2048 vertices = enough for all axes geometry).
517            let axes_vertex_buffer = device.create_buffer(&wgpu::BufferDescriptor {
518                label: Some("vp_axes_vertex_buf"),
519                size: (std::mem::size_of::<crate::widgets::axes_indicator::AxesVertex>() * 2048)
520                    as u64,
521                usage: wgpu::BufferUsages::VERTEX | wgpu::BufferUsages::COPY_DST,
522                mapped_at_creation: false,
523            });
524
525            self.viewport_slots.push(ViewportSlot {
526                camera_buf,
527                clip_planes_buf,
528                clip_volume_buf,
529                shadow_info_buf,
530                grid_buf,
531                camera_bind_group,
532                grid_bind_group,
533                hdr: None,
534                outline_object_buffers: Vec::new(),
535                xray_object_buffers: Vec::new(),
536                constraint_line_buffers: Vec::new(),
537                cap_buffers: Vec::new(),
538                clip_plane_fill_buffers: Vec::new(),
539                clip_plane_line_buffers: Vec::new(),
540                axes_vertex_buffer,
541                axes_vertex_count: 0,
542                gizmo_uniform_buf,
543                gizmo_bind_group,
544                gizmo_vertex_buffer,
545                gizmo_index_buffer,
546                gizmo_index_count,
547                sub_highlight: None,
548                sub_highlight_generation: u64::MAX,
549                dyn_res: None,
550            });
551        }
552    }
553
554    // -----------------------------------------------------------------------
555    // Multi-viewport public API (Phase 5)
556    // -----------------------------------------------------------------------
557
558    /// Create a new viewport slot and return its handle.
559    ///
560    /// The returned [`ViewportId`] is stable for the lifetime of the renderer.
561    /// Pass it to [`prepare_viewport`](Self::prepare_viewport),
562    /// [`paint_viewport`](Self::paint_viewport), and
563    /// [`render_viewport`](Self::render_viewport) each frame.
564    ///
565    /// Also set `CameraFrame::viewport_index` to `id.0` when building the
566    /// [`FrameData`] for this viewport:
567    /// ```rust,ignore
568    /// let id = renderer.create_viewport(&device);
569    /// let frame = FrameData {
570    ///     camera: CameraFrame::from_camera(&cam, size).with_viewport_index(id.0),
571    ///     ..Default::default()
572    /// };
573    /// ```
574    pub fn create_viewport(&mut self, device: &wgpu::Device) -> ViewportId {
575        let idx = self.viewport_slots.len();
576        self.ensure_viewport_slot(device, idx);
577        ViewportId(idx)
578    }
579
580    /// Release the heavy GPU texture memory (HDR targets, OIT, bloom, SSAO) held
581    /// by `id`.
582    ///
583    /// The slot index is not reclaimed : future calls with this `ViewportId` will
584    /// lazily recreate the texture resources as needed.  This is useful when a
585    /// viewport is hidden or minimised and you want to reduce VRAM pressure without
586    /// invalidating the handle.
587    pub fn destroy_viewport(&mut self, id: ViewportId) {
588        if let Some(slot) = self.viewport_slots.get_mut(id.0) {
589            slot.hdr = None;
590        }
591    }
592
593    /// Prepare shared scene data.  Call **once per frame**, before any
594    /// [`prepare_viewport`](Self::prepare_viewport) calls.
595    ///
596    /// `frame` provides the scene content (`frame.scene`) and the primary camera
597    /// used for shadow cascade framing (`frame.camera`).  In a multi-viewport
598    /// setup use any one viewport's `FrameData` here : typically the perspective
599    /// view : as the shadow framing reference.
600    ///
601    /// `scene_effects` carries the scene-global effects: lighting, environment
602    /// map, and compute filters.  Obtain it by constructing [`SceneEffects`]
603    /// directly or via [`EffectsFrame::split`].
604    pub fn prepare_scene(
605        &mut self,
606        device: &wgpu::Device,
607        queue: &wgpu::Queue,
608        frame: &FrameData,
609        scene_effects: &SceneEffects<'_>,
610    ) {
611        self.prepare_scene_internal(device, queue, frame, scene_effects);
612    }
613
614    /// Prepare per-viewport GPU state (camera, clip planes, overlays, axes).
615    ///
616    /// Call once per viewport per frame, **after** [`prepare_scene`](Self::prepare_scene).
617    ///
618    /// `id` must have been obtained from [`create_viewport`](Self::create_viewport).
619    /// `frame.camera.viewport_index` must equal `id.0`; use
620    /// [`CameraFrame::with_viewport_index`] when building the frame.
621    pub fn prepare_viewport(
622        &mut self,
623        device: &wgpu::Device,
624        queue: &wgpu::Queue,
625        id: ViewportId,
626        frame: &FrameData,
627    ) {
628        debug_assert_eq!(
629            frame.camera.viewport_index, id.0,
630            "frame.camera.viewport_index ({}) must equal the ViewportId ({}); \
631             use CameraFrame::with_viewport_index(id.0)",
632            frame.camera.viewport_index, id.0,
633        );
634        let (_, viewport_fx) = frame.effects.split();
635        self.prepare_viewport_internal(device, queue, frame, &viewport_fx);
636    }
637
638    /// Issue draw calls for `id` into a `'static` render pass (as provided by egui callbacks).
639    ///
640    /// This is the method to use from an egui/eframe `CallbackTrait::paint` implementation.
641    /// Call [`prepare_scene`](Self::prepare_scene) and [`prepare_viewport`](Self::prepare_viewport)
642    /// first (in `CallbackTrait::prepare`), then set the render pass viewport/scissor to confine
643    /// drawing to the correct quadrant, and call this method.
644    ///
645    /// For non-`'static` render passes (winit, iced, manual wgpu), use
646    /// [`paint_viewport_to`](Self::paint_viewport_to).
647    pub fn paint_viewport(
648        &self,
649        render_pass: &mut wgpu::RenderPass<'static>,
650        id: ViewportId,
651        frame: &FrameData,
652    ) {
653        let vp_idx = id.0;
654        let camera_bg = self.viewport_camera_bind_group(vp_idx);
655        let grid_bg = self.viewport_grid_bind_group(vp_idx);
656        let vp_slot = self.viewport_slots.get(vp_idx);
657        emit_draw_calls!(
658            &self.resources,
659            &mut *render_pass,
660            frame,
661            self.use_instancing,
662            &self.instanced_batches,
663            camera_bg,
664            grid_bg,
665            &self.compute_filter_results,
666            vp_slot
667        );
668        emit_scivis_draw_calls!(
669            &self.resources,
670            render_pass,
671            &self.point_cloud_gpu_data,
672            &self.glyph_gpu_data,
673            &self.polyline_gpu_data,
674            &self.volume_gpu_data,
675            &self.streamtube_gpu_data,
676            camera_bg
677        );
678    }
679
680    /// Issue draw calls for `id` into a render pass with any lifetime.
681    ///
682    /// Identical to [`paint_viewport`](Self::paint_viewport) but accepts a render pass with a
683    /// non-`'static` lifetime, making it usable from winit, iced, or raw wgpu where the encoder
684    /// creates its own render pass.
685    pub fn paint_viewport_to<'rp>(
686        &'rp self,
687        render_pass: &mut wgpu::RenderPass<'rp>,
688        id: ViewportId,
689        frame: &FrameData,
690    ) {
691        let vp_idx = id.0;
692        let camera_bg = self.viewport_camera_bind_group(vp_idx);
693        let grid_bg = self.viewport_grid_bind_group(vp_idx);
694        let vp_slot = self.viewport_slots.get(vp_idx);
695        emit_draw_calls!(
696            &self.resources,
697            &mut *render_pass,
698            frame,
699            self.use_instancing,
700            &self.instanced_batches,
701            camera_bg,
702            grid_bg,
703            &self.compute_filter_results,
704            vp_slot
705        );
706        emit_scivis_draw_calls!(
707            &self.resources,
708            render_pass,
709            &self.point_cloud_gpu_data,
710            &self.glyph_gpu_data,
711            &self.polyline_gpu_data,
712            &self.volume_gpu_data,
713            &self.streamtube_gpu_data,
714            camera_bg
715        );
716    }
717
718    /// Return a reference to the camera bind group for the given viewport slot.
719    ///
720    /// Falls back to `resources.camera_bind_group` if no per-viewport slot
721    /// exists (e.g. in single-viewport mode before the first prepare call).
722    fn viewport_camera_bind_group(&self, viewport_index: usize) -> &wgpu::BindGroup {
723        self.viewport_slots
724            .get(viewport_index)
725            .map(|slot| &slot.camera_bind_group)
726            .unwrap_or(&self.resources.camera_bind_group)
727    }
728
729    /// Return a reference to the grid bind group for the given viewport slot.
730    ///
731    /// Falls back to `resources.grid_bind_group` if no per-viewport slot exists.
732    fn viewport_grid_bind_group(&self, viewport_index: usize) -> &wgpu::BindGroup {
733        self.viewport_slots
734            .get(viewport_index)
735            .map(|slot| &slot.grid_bind_group)
736            .unwrap_or(&self.resources.grid_bind_group)
737    }
738
739    /// Ensure the dyn-res intermediate render target exists for `vp_idx` at the
740    /// given `scaled_size`, creating or recreating it when size changes.
741    ///
742    /// `surface_size` is the native output dimensions (used to size the upscale
743    /// blit correctly). `ensure_dyn_res_pipeline` is called automatically.
744    pub(crate) fn ensure_dyn_res_target(
745        &mut self,
746        device: &wgpu::Device,
747        vp_idx: usize,
748        scaled_size: [u32; 2],
749        surface_size: [u32; 2],
750    ) {
751        self.resources.ensure_dyn_res_pipeline(device);
752        let needs_create = match &self.viewport_slots[vp_idx].dyn_res {
753            None => true,
754            Some(dr) => dr.scaled_size != scaled_size || dr.surface_size != surface_size,
755        };
756        if needs_create {
757            let target =
758                self.resources.create_dyn_res_target(device, scaled_size, surface_size);
759            self.viewport_slots[vp_idx].dyn_res = Some(target);
760        }
761    }
762
763    /// Ensure per-viewport HDR state exists for `viewport_index` at dimensions `w`×`h`.
764    ///
765    /// Calls `ensure_hdr_shared` once to initialise shared pipelines/BGLs/samplers, then
766    /// lazily creates or resizes the `ViewportHdrState` inside the slot. Idempotent: if the
767    /// slot already has HDR state at the correct size nothing is recreated.
768    pub(crate) fn ensure_viewport_hdr(
769        &mut self,
770        device: &wgpu::Device,
771        queue: &wgpu::Queue,
772        viewport_index: usize,
773        w: u32,
774        h: u32,
775        ssaa_factor: u32,
776    ) {
777        let format = self.resources.target_format;
778        // Ensure shared infrastructure (pipelines, BGLs, samplers) exists.
779        self.resources.ensure_hdr_shared(device, queue, format);
780        // Ensure the slot exists.
781        self.ensure_viewport_slot(device, viewport_index);
782        let slot = &mut self.viewport_slots[viewport_index];
783        // Create or resize the per-viewport HDR state.
784        let needs_create = match &slot.hdr {
785            None => true,
786            Some(h_state) => h_state.size != [w, h] || h_state.ssaa_factor != ssaa_factor,
787        };
788        if needs_create {
789            slot.hdr = Some(self.resources.create_hdr_viewport_state(
790                device,
791                queue,
792                format,
793                w,
794                h,
795                ssaa_factor,
796            ));
797        }
798    }
799}