skgpu::graphite::VelloRenderer Class Reference

#include <VelloRenderer.h>

Classes
struct	RenderParams

Public Member Functions
	VelloRenderer (const Caps *)
	~VelloRenderer ()
std::unique_ptr< DispatchGroup >	renderScene (const RenderParams &, const VelloScene &, sk_sp< TextureProxy > target, Recorder *) const

Detailed Description

Definition at line 75 of file VelloRenderer.h.

Constructor & Destructor Documentation

VelloRenderer()

skgpu::graphite::VelloRenderer::VelloRenderer ( const Caps *  caps )

explicit

Definition at line 244 of file VelloRenderer.cpp.

                                             {
    if (ComputeShaderCoverageMaskTargetFormat(caps) == kAlpha_8_SkColorType) {
        fFineArea = std::make_unique<VelloFineAreaAlpha8Step>();
        fFineMsaa16 = std::make_unique<VelloFineMsaa16Alpha8Step>();
        fFineMsaa8 = std::make_unique<VelloFineMsaa8Alpha8Step>();
    } else {
        fFineArea = std::make_unique<VelloFineAreaStep>();
        fFineMsaa16 = std::make_unique<VelloFineMsaa16Step>();
        fFineMsaa8 = std::make_unique<VelloFineMsaa8Step>();
    }
}

~VelloRenderer()

skgpu::graphite::VelloRenderer::~VelloRenderer ( )

default

Member Function Documentation

renderScene()

std::unique_ptr< DispatchGroup > skgpu::graphite::VelloRenderer::renderScene	(	const RenderParams &	params,
		const VelloScene &	scene,
		sk_sp< TextureProxy >	target,
		Recorder *	recorder
	)		const

Definition at line 258 of file VelloRenderer.cpp.

                                                                                    {
    TRACE_EVENT0("skia.gpu", TRACE_FUNC);
    SkASSERT(target);
 
    if (scene.fEncoding->is_empty()) {
        return nullptr;
    }
 
    if (params.fWidth == 0 || params.fHeight == 0) {
        return nullptr;
    }
 
    // TODO: validate that the pixel format matches the pipeline layout.
    // Clamp the draw region to the target texture dimensions.
    const SkISize dims = target->dimensions();
    if (dims.isEmpty() || dims.fWidth < 0 || dims.fHeight < 0) {
        SKGPU_LOG_W("VelloRenderer: cannot render to an empty target");
        return nullptr;
    }
 
    SkASSERT(scene.fLayers == 0);  // Begin/end clips must be matched.
    auto config = scene.fEncoding->prepare_render(
            std::min(params.fWidth, static_cast<uint32_t>(dims.fWidth)),
            std::min(params.fHeight, static_cast<uint32_t>(dims.fHeight)),
            to_vello_color(params.fBaseColor));
    auto dispatchInfo = config->workgroup_counts();
    auto bufferSizes = config->buffer_sizes();
 
    DispatchGroup::Builder builder(recorder);
 
    // In total there are 25 resources that are used across the full pipeline stages. The sizes of
    // these resources depend on the encoded scene. We allocate all of them and assign them
    // directly to the builder here instead of delegating the logic to the ComputeSteps.
    DrawBufferManager* bufMgr = recorder->priv().drawBufferManager();
 
    size_t uboSize = config->config_uniform_buffer_size();
    auto [uboPtr, configBuf] = bufMgr->getUniformPointer(uboSize);
    if (!uboPtr || !config->write_config_uniform_buffer(to_slice(uboPtr, uboSize))) {
        return nullptr;
    }
 
    size_t sceneSize = config->scene_buffer_size();
    auto [scenePtr, sceneBuf] = bufMgr->getStoragePointer(sceneSize);
    if (!scenePtr || !config->write_scene_buffer(to_slice(scenePtr, sceneSize))) {
        return nullptr;
    }
 
    // TODO(b/285189802): The default sizes for the bump buffers (~97MB) exceed Graphite's resource
    // budget if multiple passes are necessary per frame (250MB, see ResouceCache.h). We apply a
    // crude size reduction here which seems to be enough for a 4k x 4k atlas render for the GMs
    // that we have tested. The numbers below are able to render GM_longpathdash with CPU-side
    // stroke expansion.
    //
    // We need to come up with a better approach to accurately predict the sizes for these buffers
    // based on the scene encoding and our resource budget. It should be possible to build a
    // conservative estimate using the total number of path verbs, some heuristic based on the verb
    // and the path's transform, and the total number of tiles.
    //
    // The following numbers amount to ~48MB
    const size_t lines_size = bufferSizes.lines;
    const size_t bin_data_size = bufferSizes.bin_data;
    const size_t tiles_size = bufferSizes.tiles;
    const size_t segments_size = bufferSizes.segments;
    const size_t seg_counts_size = bufferSizes.seg_counts;
    const size_t ptcl_size = bufferSizes.ptcl;
 
    // See the comments in VelloComputeSteps.h for an explanation of the logic here.
 
    builder.assignSharedBuffer({configBuf, uboSize}, kVelloSlot_ConfigUniform);
    builder.assignSharedBuffer({sceneBuf, sceneSize}, kVelloSlot_Scene);
 
    // Buffers get cleared ahead of the entire DispatchGroup. Allocate the bump buffer early to
    // avoid a potentially recycled (and prematurely cleared) scratch buffer.
    ScratchBuffer bump = bufMgr->getScratchStorage(bufferSizes.bump_alloc);
    builder.assignSharedBuffer(new_scratch_slice(bump), kVelloSlot_BumpAlloc, ClearBuffer::kYes);
 
    // path_reduce
    ScratchBuffer tagmonoids = bufMgr->getScratchStorage(bufferSizes.path_monoids);
    {
        // This can be immediately returned after input processing.
        ScratchBuffer pathtagReduceOutput = bufMgr->getScratchStorage(bufferSizes.path_reduced);
        builder.assignSharedBuffer(new_scratch_slice(pathtagReduceOutput),
                                   kVelloSlot_PathtagReduceOutput);
        builder.assignSharedBuffer(new_scratch_slice(tagmonoids), kVelloSlot_TagMonoid);
        builder.appendStep(&fPathtagReduce, to_wg_size(dispatchInfo.path_reduce));
 
        // If the input is too large to be fully processed by a single workgroup then a second
        // reduce step and two scan steps are necessary. Otherwise one reduce+scan pair is
        // sufficient.
        //
        // In either case, the result is `tagmonoids`.
        if (dispatchInfo.use_large_path_scan) {
            ScratchBuffer reduced2 = bufMgr->getScratchStorage(bufferSizes.path_reduced2);
            ScratchBuffer reducedScan = bufMgr->getScratchStorage(bufferSizes.path_reduced_scan);
 
            builder.assignSharedBuffer(new_scratch_slice(reduced2),
                                       kVelloSlot_LargePathtagReduceSecondPassOutput);
            builder.assignSharedBuffer(new_scratch_slice(reducedScan),
                                       kVelloSlot_LargePathtagScanFirstPassOutput);
 
            builder.appendStep(&fPathtagReduce2, to_wg_size(dispatchInfo.path_reduce2));
            builder.appendStep(&fPathtagScan1, to_wg_size(dispatchInfo.path_scan1));
            builder.appendStep(&fPathtagScanLarge, to_wg_size(dispatchInfo.path_scan));
        } else {
            builder.appendStep(&fPathtagScanSmall, to_wg_size(dispatchInfo.path_scan));
        }
    }
 
    // bbox_clear
    ScratchBuffer pathBboxes = bufMgr->getScratchStorage(bufferSizes.path_bboxes);
    builder.assignSharedBuffer(new_scratch_slice(pathBboxes), kVelloSlot_PathBBoxes);
    builder.appendStep(&fBboxClear, to_wg_size(dispatchInfo.bbox_clear));
 
    // flatten
    ScratchBuffer lines = bufMgr->getScratchStorage(lines_size);
    builder.assignSharedBuffer(new_scratch_slice(lines), kVelloSlot_Lines);
    builder.appendStep(&fFlatten, to_wg_size(dispatchInfo.flatten));
 
    tagmonoids.returnToPool();
 
    // draw_reduce
    ScratchBuffer drawReduced = bufMgr->getScratchStorage(bufferSizes.draw_reduced);
    builder.assignSharedBuffer(new_scratch_slice(drawReduced), kVelloSlot_DrawReduceOutput);
    builder.appendStep(&fDrawReduce, to_wg_size(dispatchInfo.draw_reduce));
 
    // draw_leaf
    ScratchBuffer drawMonoids = bufMgr->getScratchStorage(bufferSizes.draw_monoids);
    ScratchBuffer binData = bufMgr->getScratchStorage(bin_data_size);
    // A clip input buffer must still get bound even if the encoding doesn't contain any clips
    ScratchBuffer clipInput = bufMgr->getScratchStorage(bufferSizes.clip_inps);
    builder.assignSharedBuffer(new_scratch_slice(drawMonoids), kVelloSlot_DrawMonoid);
    builder.assignSharedBuffer(new_scratch_slice(binData), kVelloSlot_InfoBinData);
    builder.assignSharedBuffer(new_scratch_slice(clipInput), kVelloSlot_ClipInput);
    builder.appendStep(&fDrawLeaf, to_wg_size(dispatchInfo.draw_leaf));
 
    drawReduced.returnToPool();
 
    // clip_reduce, clip_leaf
    // The clip bbox buffer is always an input to the binning stage, even when the encoding doesn't
    // contain any clips
    ScratchBuffer clipBboxes = bufMgr->getScratchStorage(bufferSizes.clip_bboxes);
    builder.assignSharedBuffer(new_scratch_slice(clipBboxes), kVelloSlot_ClipBBoxes);
    WorkgroupSize clipReduceWgCount = to_wg_size(dispatchInfo.clip_reduce);
    WorkgroupSize clipLeafWgCount = to_wg_size(dispatchInfo.clip_leaf);
    bool doClipReduce = clipReduceWgCount.scalarSize() > 0u;
    bool doClipLeaf = clipLeafWgCount.scalarSize() > 0u;
    if (doClipReduce || doClipLeaf) {
        ScratchBuffer clipBic = bufMgr->getScratchStorage(bufferSizes.clip_bics);
        ScratchBuffer clipEls = bufMgr->getScratchStorage(bufferSizes.clip_els);
        builder.assignSharedBuffer(new_scratch_slice(clipBic), kVelloSlot_ClipBicyclic);
        builder.assignSharedBuffer(new_scratch_slice(clipEls), kVelloSlot_ClipElement);
        if (doClipReduce) {
            builder.appendStep(&fClipReduce, clipReduceWgCount);
        }
        if (doClipLeaf) {
            builder.appendStep(&fClipLeaf, clipLeafWgCount);
        }
    }
 
    clipInput.returnToPool();
 
    // binning
    ScratchBuffer drawBboxes = bufMgr->getScratchStorage(bufferSizes.draw_bboxes);
    ScratchBuffer binHeaders = bufMgr->getScratchStorage(bufferSizes.bin_headers);
    builder.assignSharedBuffer(new_scratch_slice(drawBboxes), kVelloSlot_DrawBBoxes);
    builder.assignSharedBuffer(new_scratch_slice(binHeaders), kVelloSlot_BinHeader);
    builder.appendStep(&fBinning, to_wg_size(dispatchInfo.binning));
 
    pathBboxes.returnToPool();
    clipBboxes.returnToPool();
 
    // tile_alloc
    ScratchBuffer paths = bufMgr->getScratchStorage(bufferSizes.paths);
    ScratchBuffer tiles = bufMgr->getScratchStorage(tiles_size);
    builder.assignSharedBuffer(new_scratch_slice(paths), kVelloSlot_Path);
    builder.assignSharedBuffer(new_scratch_slice(tiles), kVelloSlot_Tile);
    builder.appendStep(&fTileAlloc, to_wg_size(dispatchInfo.tile_alloc));
 
    drawBboxes.returnToPool();
 
    // path_count_setup
    auto indirectCountBuffer = new_indirect_slice(bufMgr, bufferSizes.indirect_count);
    builder.assignSharedBuffer(indirectCountBuffer, kVelloSlot_IndirectCount);
    builder.appendStep(&fPathCountSetup, to_wg_size(dispatchInfo.path_count_setup));
 
    // Rasterization stage scratch buffers.
    ScratchBuffer seg_counts = bufMgr->getScratchStorage(seg_counts_size);
    ScratchBuffer segments = bufMgr->getScratchStorage(segments_size);
    ScratchBuffer ptcl = bufMgr->getScratchStorage(ptcl_size);
 
    // path_count
    builder.assignSharedBuffer(new_scratch_slice(seg_counts), kVelloSlot_SegmentCounts);
    builder.appendStepIndirect(&fPathCount, indirectCountBuffer);
 
    // backdrop
    builder.appendStep(&fBackdrop, to_wg_size(dispatchInfo.backdrop));
 
    // coarse
    builder.assignSharedBuffer(new_scratch_slice(ptcl), kVelloSlot_PTCL);
    builder.appendStep(&fCoarse, to_wg_size(dispatchInfo.coarse));
 
    // path_tiling_setup
    builder.appendStep(&fPathTilingSetup, to_wg_size(dispatchInfo.path_tiling_setup));
 
    // path_tiling
    builder.assignSharedBuffer(new_scratch_slice(segments), kVelloSlot_Segments);
    builder.appendStepIndirect(&fPathTiling, indirectCountBuffer);
 
    // fine
    builder.assignSharedTexture(std::move(target), kVelloSlot_OutputImage);
    const ComputeStep* fineVariant = nullptr;
    switch (params.fAaConfig) {
        case VelloAaConfig::kAnalyticArea:
            fineVariant = fFineArea.get();
            break;
        case VelloAaConfig::kMSAA16:
            fineVariant = fFineMsaa16.get();
            break;
        case VelloAaConfig::kMSAA8:
            fineVariant = fFineMsaa8.get();
            break;
    }
    SkASSERT(fineVariant != nullptr);
    builder.appendStep(fineVariant, to_wg_size(dispatchInfo.fine));
 
    return builder.finalize();
}

---

The documentation for this class was generated from the following files:

• third_party/skia/src/gpu/graphite/compute/VelloRenderer.h
• third_party/skia/src/gpu/graphite/compute/VelloRenderer.cpp