third_party/skia/modules/skottie/src/effects/MotionBlurEffect.cpp - cobalt - Git at Google

 /*
  * Copyright 2019 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "modules/skottie/src/effects/MotionBlurEffect.h"

 #include "include/core/SkCanvas.h"
 #include "include/core/SkMath.h"
 #include "include/core/SkPixmap.h"
 #include "include/private/SkVx.h"
 #include "modules/skottie/src/animator/Animator.h"
 #include "src/core/SkMathPriv.h"

 namespace skottie {
 namespace internal {

 class MotionBlurEffect::AutoInvalBlocker {
 public:
     AutoInvalBlocker(const MotionBlurEffect* mb, const sk_sp<RenderNode>& child)
         : fMBNode(const_cast<MotionBlurEffect*>(mb))
         , fChild(child) {
         fMBNode->unobserveInval(fChild);
     }

     ~AutoInvalBlocker() {
         fMBNode->observeInval(fChild);
     }

 private:
     MotionBlurEffect*        fMBNode;
     const sk_sp<RenderNode>& fChild;
 };

 sk_sp<MotionBlurEffect> MotionBlurEffect::Make(sk_sp<Animator> animator,
                                                sk_sp<sksg::RenderNode> child,
                                                size_t samples_per_frame,
                                                float shutter_angle, float shutter_phase) {
     if (!samples_per_frame || shutter_angle <= 0) {
         return nullptr;
     }

     // shutter_angle is [   0 .. 720], mapped to [ 0 .. 2] (frame space)
     // shutter_phase is [-360 .. 360], mapped to [-1 .. 1] (frame space)
     const auto samples_duration = shutter_angle / 360,
                           phase = shutter_phase / 360,
                              dt = samples_duration / (samples_per_frame - 1);

     return sk_sp<MotionBlurEffect>(new MotionBlurEffect(std::move(animator),
                                                         std::move(child),
                                                         samples_per_frame,
                                                         phase, dt));
 }

 MotionBlurEffect::MotionBlurEffect(sk_sp<Animator> animator,
                                    sk_sp<sksg::RenderNode> child,
                                    size_t samples, float phase, float dt)
     : INHERITED({std::move(child)})
     , fAnimator(std::move(animator))
     , fSampleCount(samples)
     , fPhase(phase)
     , fDT(dt) {}

 const sksg::RenderNode* MotionBlurEffect::onNodeAt(const SkPoint&) const {
     return nullptr;
 }

 SkRect MotionBlurEffect::seekToSample(size_t sample_idx, const SkMatrix& ctm) const {
     SkASSERT(sample_idx < fSampleCount);
     fAnimator->seek(fT + fPhase + fDT * sample_idx);

     SkASSERT(this->children().size() == 1ul);
     return this->children()[0]->revalidate(nullptr, ctm);
 }

 SkRect MotionBlurEffect::onRevalidate(sksg::InvalidationController*, const SkMatrix& ctm) {
     SkRect bounds       = SkRect::MakeEmpty();
     fVisibleSampleCount = 0;

     for (size_t i = 0; i < fSampleCount; ++i) {
         bounds.join(this->seekToSample(i, ctm));
         fVisibleSampleCount += SkToSizeT(this->children()[0]->isVisible());
     }

     return bounds;
 }

 void MotionBlurEffect::renderToRaster8888Pow2Samples(SkCanvas* canvas,
                                                      const RenderContext* ctx) const {
     // canvas is raster backed and RGBA 8888 or BGRA 8888, and fSamples is a power of 2.
     // We can play dirty tricks.

     // Don't worry about "Next"... this is exact.
     const int shift = SkNextLog2(fVisibleSampleCount);
     SkASSERT((size_t(1)<<shift) == fVisibleSampleCount);

     SkASSERT(this->children().size() == 1ul);
     const sk_sp<RenderNode>& child = this->children()[0];

     SkAutoCanvasRestore acr(canvas, false);
     canvas->saveLayer(this->bounds(), nullptr);

     SkImageInfo info;
     size_t rowBytes;
     auto layer = (uint32_t*)canvas->accessTopLayerPixels(&info, &rowBytes);
     SkASSERT(layer);
     SkASSERT(info.colorType() == kRGBA_8888_SkColorType ||
              info.colorType() == kBGRA_8888_SkColorType);

     SkASSERT(!info.isEmpty());
     std::vector<uint64_t> accum(info.width() * info.height());

     SkDEBUGCODE(size_t frames_rendered = 0;)
     bool needs_clear = false;  // Cleared initially by saveLayer().
     for (size_t i = 0; i < fSampleCount; ++i) {
         this->seekToSample(i, canvas->getTotalMatrix());

         if (!child->isVisible()) {
             continue;
         }

         // Draw this subframe.
         if (needs_clear) {
             canvas->clear(0);
         }
         needs_clear = true;
         child->render(canvas, ctx);
         SkDEBUGCODE(frames_rendered++;)

         // Pluck out the pixels we've drawn in the layer.
         const uint32_t* src = layer;
               uint64_t* dst = accum.data();

         for (int y = 0; y < info.height(); y++) {
             // Expand 8-bit to 16-bit and accumulate.
             int n = info.width();
             const auto row = src;
             while (n >= 4) {
                 auto s = skvx::Vec<16, uint8_t >::Load(src);
                 auto d = skvx::Vec<16, uint16_t>::Load(dst);

                 (d + skvx::cast<uint16_t>(s)).store(dst);

                 src += 4;
                 dst += 4;
                 n   -= 4;
             }
             while (n) {
                 auto s = skvx::Vec<4, uint8_t >::Load(src);
                 auto d = skvx::Vec<4, uint16_t>::Load(dst);

                 (d + skvx::cast<uint16_t>(s)).store(dst);

                 src += 1;
                 dst += 1;
                 n   -= 1;
             }
             src = (const uint32_t*)( (const char*)row + rowBytes );
         }
     }
     SkASSERT(frames_rendered == fVisibleSampleCount);

     // Actually draw the frame using the accumulated subframes.
     const uint64_t* src = accum.data();
           uint32_t* dst = layer;
     for (int y = 0; y < info.height(); y++) {
         // Divide accumulated subframes through by sample count.
         int n = info.width();
         const auto row = dst;
         while (n >= 4) {
             auto s = skvx::Vec<16, uint16_t>::Load(src);
             skvx::cast<uint8_t>(s >> shift).store(dst);

             src += 4;
             dst += 4;
             n   -= 4;
         }
         while (n) {
             auto s = skvx::Vec<4, uint16_t>::Load(src);
             skvx::cast<uint8_t>(s >> shift).store(dst);

             src += 1;
             dst += 1;
             n   -= 1;
         }

         dst = (uint32_t*)( (char*)row + rowBytes );
     }
 }

 void MotionBlurEffect::onRender(SkCanvas* canvas, const RenderContext* ctx) const {
     if (!fVisibleSampleCount) {
         return;
     }

     SkASSERT(this->children().size() == 1ul);
     const auto& child = this->children()[0];

     // We're about to mutate/revalidate the subtree for sampling.  Capture the invalidation
     // at this scope, to prevent dirtying ancestor SG nodes (no way to revalidate the global scene).
     AutoInvalBlocker aib(this, child);

     SkPixmap pm;
     if (canvas->peekPixels(&pm) && (canvas->imageInfo().colorType() == kRGBA_8888_SkColorType ||
                                     canvas->imageInfo().colorType() == kBGRA_8888_SkColorType   )
                                 && SkIsPow2(fVisibleSampleCount)) {
         this->renderToRaster8888Pow2Samples(canvas, ctx);
         return;
     }

     SkAutoCanvasRestore acr1(canvas, false);

     // Accumulate in F16 for more precision.
     canvas->saveLayer(SkCanvas::SaveLayerRec(&this->bounds(), nullptr, SkCanvas::kF16ColorType));

     const float frame_alpha = 1.0f / fVisibleSampleCount;

     // Depending on whether we can defer frame blending,
     // use a local (deferred) RenderContext or an explicit layer for frame/content rendering.
     ScopedRenderContext frame_ctx(canvas, ctx);
     SkPaint             frame_paint;

     const bool isolate_frames = frame_ctx->fBlendMode != SkBlendMode::kSrcOver;
     if (isolate_frames) {
         frame_paint.setAlphaf(frame_alpha);
         frame_paint.setBlendMode(SkBlendMode::kPlus);
     } else {
         frame_ctx = frame_ctx.modulateOpacity(frame_alpha)
                              .modulateBlendMode(SkBlendMode::kPlus);
     }

     SkDEBUGCODE(size_t frames_rendered = 0;)
     for (size_t i = 0; i < fSampleCount; ++i) {
         this->seekToSample(i, canvas->getTotalMatrix());

         if (!child->isVisible()) {
             continue;
         }

         SkAutoCanvasRestore acr2(canvas, false);
         if (isolate_frames) {
             canvas->saveLayer(nullptr, &frame_paint);
         }

         child->render(canvas, frame_ctx);
         SkDEBUGCODE(frames_rendered++;)
     }

     SkASSERT(frames_rendered == fVisibleSampleCount);
 }

 } // namespace internal
 } // namespace skottie
	/*
	* Copyright 2019 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "modules/skottie/src/effects/MotionBlurEffect.h"

	#include "include/core/SkCanvas.h"
	#include "include/core/SkMath.h"
	#include "include/core/SkPixmap.h"
	#include "include/private/SkVx.h"
	#include "modules/skottie/src/animator/Animator.h"
	#include "src/core/SkMathPriv.h"

	namespace skottie {
	namespace internal {

	class MotionBlurEffect::AutoInvalBlocker {
	public:
	AutoInvalBlocker(const MotionBlurEffect* mb, const sk_sp<RenderNode>& child)
	: fMBNode(const_cast<MotionBlurEffect*>(mb))
	, fChild(child) {
	fMBNode->unobserveInval(fChild);
	}

	~AutoInvalBlocker() {
	fMBNode->observeInval(fChild);
	}

	private:
	MotionBlurEffect* fMBNode;
	const sk_sp<RenderNode>& fChild;
	};

	sk_sp<MotionBlurEffect> MotionBlurEffect::Make(sk_sp<Animator> animator,
	sk_sp<sksg::RenderNode> child,
	size_t samples_per_frame,
	float shutter_angle, float shutter_phase) {
	if (!samples_per_frame \|\| shutter_angle <= 0) {
	return nullptr;
	}

	// shutter_angle is [ 0 .. 720], mapped to [ 0 .. 2] (frame space)
	// shutter_phase is [-360 .. 360], mapped to [-1 .. 1] (frame space)
	const auto samples_duration = shutter_angle / 360,
	phase = shutter_phase / 360,
	dt = samples_duration / (samples_per_frame - 1);

	return sk_sp<MotionBlurEffect>(new MotionBlurEffect(std::move(animator),
	std::move(child),
	samples_per_frame,
	phase, dt));
	}

	MotionBlurEffect::MotionBlurEffect(sk_sp<Animator> animator,
	sk_sp<sksg::RenderNode> child,
	size_t samples, float phase, float dt)
	: INHERITED({std::move(child)})
	, fAnimator(std::move(animator))
	, fSampleCount(samples)
	, fPhase(phase)
	, fDT(dt) {}

	const sksg::RenderNode* MotionBlurEffect::onNodeAt(const SkPoint&) const {
	return nullptr;
	}

	SkRect MotionBlurEffect::seekToSample(size_t sample_idx, const SkMatrix& ctm) const {
	SkASSERT(sample_idx < fSampleCount);
	fAnimator->seek(fT + fPhase + fDT * sample_idx);

	SkASSERT(this->children().size() == 1ul);
	return this->children()[0]->revalidate(nullptr, ctm);
	}

	SkRect MotionBlurEffect::onRevalidate(sksg::InvalidationController*, const SkMatrix& ctm) {
	SkRect bounds = SkRect::MakeEmpty();
	fVisibleSampleCount = 0;

	for (size_t i = 0; i < fSampleCount; ++i) {
	bounds.join(this->seekToSample(i, ctm));
	fVisibleSampleCount += SkToSizeT(this->children()[0]->isVisible());
	}

	return bounds;
	}

	void MotionBlurEffect::renderToRaster8888Pow2Samples(SkCanvas* canvas,
	const RenderContext* ctx) const {
	// canvas is raster backed and RGBA 8888 or BGRA 8888, and fSamples is a power of 2.
	// We can play dirty tricks.

	// Don't worry about "Next"... this is exact.
	const int shift = SkNextLog2(fVisibleSampleCount);
	SkASSERT((size_t(1)<<shift) == fVisibleSampleCount);

	SkASSERT(this->children().size() == 1ul);
	const sk_sp<RenderNode>& child = this->children()[0];

	SkAutoCanvasRestore acr(canvas, false);
	canvas->saveLayer(this->bounds(), nullptr);

	SkImageInfo info;
	size_t rowBytes;
	auto layer = (uint32_t*)canvas->accessTopLayerPixels(&info, &rowBytes);
	SkASSERT(layer);
	SkASSERT(info.colorType() == kRGBA_8888_SkColorType \|\|
	info.colorType() == kBGRA_8888_SkColorType);

	SkASSERT(!info.isEmpty());
	std::vector<uint64_t> accum(info.width() * info.height());

	SkDEBUGCODE(size_t frames_rendered = 0;)
	bool needs_clear = false; // Cleared initially by saveLayer().
	for (size_t i = 0; i < fSampleCount; ++i) {
	this->seekToSample(i, canvas->getTotalMatrix());

	if (!child->isVisible()) {
	continue;
	}

	// Draw this subframe.
	if (needs_clear) {
	canvas->clear(0);
	}
	needs_clear = true;
	child->render(canvas, ctx);
	SkDEBUGCODE(frames_rendered++;)

	// Pluck out the pixels we've drawn in the layer.
	const uint32_t* src = layer;
	uint64_t* dst = accum.data();

	for (int y = 0; y < info.height(); y++) {
	// Expand 8-bit to 16-bit and accumulate.
	int n = info.width();
	const auto row = src;
	while (n >= 4) {
	auto s = skvx::Vec<16, uint8_t >::Load(src);
	auto d = skvx::Vec<16, uint16_t>::Load(dst);

	(d + skvx::cast<uint16_t>(s)).store(dst);

	src += 4;
	dst += 4;
	n -= 4;
	}
	while (n) {
	auto s = skvx::Vec<4, uint8_t >::Load(src);
	auto d = skvx::Vec<4, uint16_t>::Load(dst);

	(d + skvx::cast<uint16_t>(s)).store(dst);

	src += 1;
	dst += 1;
	n -= 1;
	}
	src = (const uint32_t)( (const char)row + rowBytes );
	}
	}
	SkASSERT(frames_rendered == fVisibleSampleCount);

	// Actually draw the frame using the accumulated subframes.
	const uint64_t* src = accum.data();
	uint32_t* dst = layer;
	for (int y = 0; y < info.height(); y++) {
	// Divide accumulated subframes through by sample count.
	int n = info.width();
	const auto row = dst;
	while (n >= 4) {
	auto s = skvx::Vec<16, uint16_t>::Load(src);
	skvx::cast<uint8_t>(s >> shift).store(dst);

	src += 4;
	dst += 4;
	n -= 4;
	}
	while (n) {
	auto s = skvx::Vec<4, uint16_t>::Load(src);
	skvx::cast<uint8_t>(s >> shift).store(dst);

	src += 1;
	dst += 1;
	n -= 1;
	}

	dst = (uint32_t)( (char)row + rowBytes );
	}
	}

	void MotionBlurEffect::onRender(SkCanvas* canvas, const RenderContext* ctx) const {
	if (!fVisibleSampleCount) {
	return;
	}

	SkASSERT(this->children().size() == 1ul);
	const auto& child = this->children()[0];

	// We're about to mutate/revalidate the subtree for sampling. Capture the invalidation
	// at this scope, to prevent dirtying ancestor SG nodes (no way to revalidate the global scene).
	AutoInvalBlocker aib(this, child);

	SkPixmap pm;
	if (canvas->peekPixels(&pm) && (canvas->imageInfo().colorType() == kRGBA_8888_SkColorType \|\|
	canvas->imageInfo().colorType() == kBGRA_8888_SkColorType )
	&& SkIsPow2(fVisibleSampleCount)) {
	this->renderToRaster8888Pow2Samples(canvas, ctx);
	return;
	}

	SkAutoCanvasRestore acr1(canvas, false);

	// Accumulate in F16 for more precision.
	canvas->saveLayer(SkCanvas::SaveLayerRec(&this->bounds(), nullptr, SkCanvas::kF16ColorType));

	const float frame_alpha = 1.0f / fVisibleSampleCount;

	// Depending on whether we can defer frame blending,
	// use a local (deferred) RenderContext or an explicit layer for frame/content rendering.
	ScopedRenderContext frame_ctx(canvas, ctx);
	SkPaint frame_paint;

	const bool isolate_frames = frame_ctx->fBlendMode != SkBlendMode::kSrcOver;
	if (isolate_frames) {
	frame_paint.setAlphaf(frame_alpha);
	frame_paint.setBlendMode(SkBlendMode::kPlus);
	} else {
	frame_ctx = frame_ctx.modulateOpacity(frame_alpha)
	.modulateBlendMode(SkBlendMode::kPlus);
	}

	SkDEBUGCODE(size_t frames_rendered = 0;)
	for (size_t i = 0; i < fSampleCount; ++i) {
	this->seekToSample(i, canvas->getTotalMatrix());

	if (!child->isVisible()) {
	continue;
	}

	SkAutoCanvasRestore acr2(canvas, false);
	if (isolate_frames) {
	canvas->saveLayer(nullptr, &frame_paint);
	}

	child->render(canvas, frame_ctx);
	SkDEBUGCODE(frames_rendered++;)
	}

	SkASSERT(frames_rendered == fVisibleSampleCount);
	}

	} // namespace internal
	} // namespace skottie