2 * Copyright (c) 2020 Samsung Electronics Co., Ltd.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
19 #include "gaussian-blur-view-impl.h"
24 #include <dali/public-api/animation/constraint.h>
25 #include <dali/public-api/animation/constraints.h>
26 #include <dali/devel-api/common/stage.h>
27 #include <dali/public-api/object/type-registry.h>
28 #include <dali/public-api/object/type-registry-helper.h>
29 #include <dali/public-api/rendering/geometry.h>
30 #include <dali/public-api/rendering/property-buffer.h>
31 #include <dali/public-api/rendering/renderer.h>
32 #include <dali/public-api/rendering/shader.h>
33 #include <dali/public-api/render-tasks/render-task-list.h>
34 #include <dali/integration-api/debug.h>
35 #include <dali/devel-api/actors/actor-devel.h>
38 #include <dali-toolkit/public-api/visuals/visual-properties.h>
39 #include <dali-toolkit/internal/controls/control/control-renderers.h>
42 // pixel format / size - set from JSON
43 // aspect ratio property needs to be able to be constrained also for cameras, not possible currently. Therefore changing aspect ratio of GaussianBlurView won't currently work
44 // default near clip value
45 // Manager object - re-use render targets if there are multiple GaussianBlurViews created
48 /////////////////////////////////////////////////////////
49 // IMPLEMENTATION NOTES
51 // As the GaussianBlurView actor changes size, the amount of pixels we need to blur changes. Therefore we need some way of doing this. However:-
52 // OnSetSize() does not get called when GaussianBlurView object size is modified using a Constraint.
53 // OnSizeAnimation() only gets called once per AnimateTo/By() and if an Animation has N such calls then only the final one will end up being used. Therefore we can't use
54 // OnSizeAnimation() to alter render target sizes.
55 // To get around the above problems, we use fixed sized render targets, from the last SetSize() call (which calls OnSetSize()), then we adjust the internal cameras / actors
56 // to take account of the changed GaussianBlurView object size, projecting to the unchanged render target sizes. This is done relative to the fixed render target / actor sizes
57 // by using constraints relative to the GaussianBlurView actor size.
61 // 1st mode, this control has a tree of actors (use Add() to add children) that are rendered and blurred.
62 // mRenderChildrenTask renders children to FB mRenderTargetForRenderingChildren
63 // mHorizBlurTask renders mHorizBlurActor Actor showing FB mRenderTargetForRenderingChildren into FB mRenderTarget2
64 // mVertBlurTask renders mVertBlurActor Actor showing FB mRenderTarget2 into FB mRenderTarget1
65 // mCompositeTask renders mCompositingActor Actor showing FB mRenderTarget1 into FB mRenderTargetForRenderingChildren
67 // 2nd mode, an image is blurred and rendered to a supplied target framebuffer
68 // mHorizBlurTask renders mHorizBlurActor Actor showing mUserInputImage into FB mRenderTarget2
69 // mVertBlurTask renders mVertBlurActor Actor showing mRenderTarget2 into FB mUserOutputRenderTarget
71 // Only this 2nd mode handles ActivateOnce
89 return Toolkit::GaussianBlurView::New();
92 DALI_TYPE_REGISTRATION_BEGIN( Toolkit::GaussianBlurView, Toolkit::Control, Create )
93 DALI_TYPE_REGISTRATION_END()
95 const unsigned int GAUSSIAN_BLUR_VIEW_DEFAULT_NUM_SAMPLES = 5;
96 const float GAUSSIAN_BLUR_VIEW_DEFAULT_BLUR_BELL_CURVE_WIDTH = 1.5f;
97 const Pixel::Format GAUSSIAN_BLUR_VIEW_DEFAULT_RENDER_TARGET_PIXEL_FORMAT = Pixel::RGBA8888;
98 const float GAUSSIAN_BLUR_VIEW_DEFAULT_BLUR_STRENGTH = 1.0f; // default, fully blurred
99 const char* const GAUSSIAN_BLUR_VIEW_STRENGTH_PROPERTY_NAME = "GaussianBlurStrengthPropertyName";
100 const float GAUSSIAN_BLUR_VIEW_DEFAULT_DOWNSAMPLE_WIDTH_SCALE = 0.5f;
101 const float GAUSSIAN_BLUR_VIEW_DEFAULT_DOWNSAMPLE_HEIGHT_SCALE = 0.5f;
103 const float ARBITRARY_FIELD_OF_VIEW = Math::PI / 4.0f;
105 const char* const GAUSSIAN_BLUR_FRAGMENT_SOURCE = DALI_COMPOSE_SHADER(
106 varying mediump vec2 vTexCoord;\n
107 uniform sampler2D sTexture;\n
108 uniform lowp vec4 uColor;\n
109 uniform mediump vec2 uSampleOffsets[NUM_SAMPLES];\n
110 uniform mediump float uSampleWeights[NUM_SAMPLES];\n
114 mediump vec4 col = texture2D(sTexture, vTexCoord + uSampleOffsets[0]) * uSampleWeights[0];\n
115 for (int i=1; i<NUM_SAMPLES; ++i)\n
117 col += texture2D(sTexture, vTexCoord + uSampleOffsets[i]) * uSampleWeights[i];\n
119 gl_FragColor = col;\n
126 GaussianBlurView::GaussianBlurView()
127 : Control( ControlBehaviour( DISABLE_SIZE_NEGOTIATION | DISABLE_STYLE_CHANGE_SIGNALS ) ),
128 mNumSamples(GAUSSIAN_BLUR_VIEW_DEFAULT_NUM_SAMPLES),
129 mBlurBellCurveWidth( 0.001f ),
130 mPixelFormat(GAUSSIAN_BLUR_VIEW_DEFAULT_RENDER_TARGET_PIXEL_FORMAT),
131 mDownsampleWidthScale(GAUSSIAN_BLUR_VIEW_DEFAULT_DOWNSAMPLE_WIDTH_SCALE),
132 mDownsampleHeightScale(GAUSSIAN_BLUR_VIEW_DEFAULT_DOWNSAMPLE_HEIGHT_SCALE),
133 mDownsampledWidth( 0.0f ),
134 mDownsampledHeight( 0.0f ),
135 mBlurUserImage( false ),
136 mRenderOnce( false ),
137 mBackgroundColor( Color::BLACK ),
138 mTargetSize(Vector2::ZERO),
139 mLastSize(Vector2::ZERO),
140 mChildrenRoot(Actor::New()),
141 mInternalRoot(Actor::New()),
142 mBlurStrengthPropertyIndex(Property::INVALID_INDEX),
145 SetBlurBellCurveWidth(GAUSSIAN_BLUR_VIEW_DEFAULT_BLUR_BELL_CURVE_WIDTH);
148 GaussianBlurView::GaussianBlurView( const unsigned int numSamples,
149 const float blurBellCurveWidth,
150 const Pixel::Format renderTargetPixelFormat,
151 const float downsampleWidthScale,
152 const float downsampleHeightScale,
154 : Control( ControlBehaviour( DISABLE_SIZE_NEGOTIATION | DISABLE_STYLE_CHANGE_SIGNALS ) ),
155 mNumSamples(numSamples),
156 mBlurBellCurveWidth( 0.001f ),
157 mPixelFormat(renderTargetPixelFormat),
158 mDownsampleWidthScale(downsampleWidthScale),
159 mDownsampleHeightScale(downsampleHeightScale),
160 mDownsampledWidth( 0.0f ),
161 mDownsampledHeight( 0.0f ),
162 mBlurUserImage( blurUserImage ),
163 mRenderOnce( false ),
164 mBackgroundColor( Color::BLACK ),
165 mTargetSize(Vector2::ZERO),
166 mLastSize(Vector2::ZERO),
167 mChildrenRoot(Actor::New()),
168 mInternalRoot(Actor::New()),
169 mBlurStrengthPropertyIndex(Property::INVALID_INDEX),
172 SetBlurBellCurveWidth(blurBellCurveWidth);
175 GaussianBlurView::~GaussianBlurView()
180 Toolkit::GaussianBlurView GaussianBlurView::New()
182 GaussianBlurView* impl = new GaussianBlurView();
184 Dali::Toolkit::GaussianBlurView handle = Dali::Toolkit::GaussianBlurView( *impl );
186 // Second-phase init of the implementation
187 // This can only be done after the CustomActor connection has been made...
193 Toolkit::GaussianBlurView GaussianBlurView::New(const unsigned int numSamples, const float blurBellCurveWidth, const Pixel::Format renderTargetPixelFormat,
194 const float downsampleWidthScale, const float downsampleHeightScale,
197 GaussianBlurView* impl = new GaussianBlurView( numSamples, blurBellCurveWidth, renderTargetPixelFormat,
198 downsampleWidthScale, downsampleHeightScale,
201 Dali::Toolkit::GaussianBlurView handle = Dali::Toolkit::GaussianBlurView( *impl );
203 // Second-phase init of the implementation
204 // This can only be done after the CustomActor connection has been made...
210 void GaussianBlurView::SetUserImageAndOutputRenderTarget(Texture inputImage, FrameBuffer outputRenderTarget)
212 // can only do this if the GaussianBlurView object was created with this parameter set
213 DALI_ASSERT_ALWAYS(mBlurUserImage);
215 mUserInputImage = inputImage;
217 SetRendererTexture( mHorizBlurActor.GetRendererAt(0), inputImage );
219 mUserOutputRenderTarget = outputRenderTarget;
222 FrameBuffer GaussianBlurView::GetBlurredRenderTarget() const
224 if(!mUserOutputRenderTarget)
226 return mRenderTargetForRenderingChildren;
229 return mUserOutputRenderTarget;
232 void GaussianBlurView::SetBackgroundColor( const Vector4& color )
234 mBackgroundColor = color;
237 Vector4 GaussianBlurView::GetBackgroundColor() const
239 return mBackgroundColor;
242 ///////////////////////////////////////////////////////////
247 void GaussianBlurView::OnInitialize()
249 // root actor to parent all user added actors, needed to allow us to set that subtree as exclusive for our child render task
250 mChildrenRoot.SetProperty( Actor::Property::PARENT_ORIGIN,ParentOrigin::CENTER );
251 mInternalRoot.SetProperty( Actor::Property::PARENT_ORIGIN,ParentOrigin::CENTER );
253 //////////////////////////////////////////////////////
256 std::ostringstream fragmentStringStream;
257 fragmentStringStream << "#define NUM_SAMPLES " << mNumSamples << "\n";
258 fragmentStringStream << GAUSSIAN_BLUR_FRAGMENT_SOURCE;
259 std::string fragmentSource(fragmentStringStream.str());
261 //////////////////////////////////////////////////////
264 // Create an actor for performing a horizontal blur on the texture
265 mHorizBlurActor = Actor::New();
266 mHorizBlurActor.SetProperty( Actor::Property::PARENT_ORIGIN,ParentOrigin::CENTER );
267 Renderer renderer = CreateRenderer( BASIC_VERTEX_SOURCE, fragmentSource.c_str() );
268 mHorizBlurActor.AddRenderer( renderer );
270 // Create an actor for performing a vertical blur on the texture
271 mVertBlurActor = Actor::New();
272 mVertBlurActor.SetProperty( Actor::Property::PARENT_ORIGIN,ParentOrigin::CENTER );
273 renderer = CreateRenderer( BASIC_VERTEX_SOURCE, fragmentSource.c_str() );
274 mVertBlurActor.AddRenderer( renderer );
276 // Register a property that the user can control to fade the blur in / out via the GaussianBlurView object
278 mBlurStrengthPropertyIndex = self.RegisterProperty(GAUSSIAN_BLUR_VIEW_STRENGTH_PROPERTY_NAME, GAUSSIAN_BLUR_VIEW_DEFAULT_BLUR_STRENGTH);
280 // Create an image view for compositing the blur and the original child actors render
283 mCompositingActor = Actor::New();
284 mCompositingActor.SetProperty( Actor::Property::PARENT_ORIGIN,ParentOrigin::CENTER );
285 mCompositingActor.SetProperty( Actor::Property::OPACITY,GAUSSIAN_BLUR_VIEW_DEFAULT_BLUR_STRENGTH); // ensure alpha is enabled for this object and set default value
286 renderer = CreateRenderer( BASIC_VERTEX_SOURCE, BASIC_FRAGMENT_SOURCE );
287 mCompositingActor.AddRenderer( renderer );
289 Constraint blurStrengthConstraint = Constraint::New<float>( mCompositingActor, Actor::Property::COLOR_ALPHA, EqualToConstraint());
290 blurStrengthConstraint.AddSource( Source( self, mBlurStrengthPropertyIndex) );
291 blurStrengthConstraint.Apply();
293 // Create an image view for holding final result, i.e. the blurred image. This will get rendered to screen later, via default / user render task
294 mTargetActor = Actor::New();
295 mTargetActor.SetProperty( Actor::Property::PARENT_ORIGIN,ParentOrigin::CENTER );
296 renderer = CreateRenderer( BASIC_VERTEX_SOURCE, BASIC_FRAGMENT_SOURCE );
297 mTargetActor.AddRenderer( renderer );
299 //////////////////////////////////////////////////////
300 // Create cameras for the renders corresponding to the view size
301 mRenderFullSizeCamera = CameraActor::New();
302 mRenderFullSizeCamera.SetInvertYAxis( true );
303 mRenderFullSizeCamera.SetProperty( Actor::Property::PARENT_ORIGIN,ParentOrigin::CENTER );
305 //////////////////////////////////////////////////////
306 // Connect to actor tree
307 mInternalRoot.Add( mCompositingActor );
308 mInternalRoot.Add( mTargetActor );
309 mInternalRoot.Add( mRenderFullSizeCamera );
312 //////////////////////////////////////////////////////
313 // Create camera for the renders corresponding to the (potentially downsampled) render targets' size
314 mRenderDownsampledCamera = CameraActor::New();
315 mRenderDownsampledCamera.SetInvertYAxis( true );
316 mRenderDownsampledCamera.SetProperty( Actor::Property::PARENT_ORIGIN,ParentOrigin::CENTER );
318 //////////////////////////////////////////////////////
319 // Connect to actor tree
320 Self().Add( mChildrenRoot );
321 mInternalRoot.Add( mHorizBlurActor );
322 mInternalRoot.Add( mVertBlurActor );
323 mInternalRoot.Add( mRenderDownsampledCamera );
327 void GaussianBlurView::OnSizeSet(const Vector3& targetSize)
329 mTargetSize = Vector2(targetSize);
331 mChildrenRoot.SetProperty( Actor::Property::SIZE, targetSize);
333 if( !mBlurUserImage )
335 mCompositingActor.SetProperty( Actor::Property::SIZE, targetSize);
336 mTargetActor.SetProperty( Actor::Property::SIZE, targetSize);
338 // Children render camera must move when GaussianBlurView object is resized. This is since we cannot change render target size - so we need to remap the child actors' rendering
339 // accordingly so they still exactly fill the render target. Note that this means the effective resolution of the child render changes as the GaussianBlurView object changes
340 // size, this is the trade off for not being able to modify render target size
341 // Change camera z position based on GaussianBlurView actor height
342 float cameraPosConstraintScale = 0.5f / tanf(ARBITRARY_FIELD_OF_VIEW * 0.5f);
343 mRenderFullSizeCamera.SetProperty( Actor::Property::POSITION_Z, mTargetSize.height * cameraPosConstraintScale);
347 // if we have already activated the blur, need to update render target sizes now to reflect the new size of this actor
354 Control::OnSizeSet( targetSize );
357 void GaussianBlurView::OnChildAdd( Actor& child )
359 if( child != mChildrenRoot && child != mInternalRoot)
361 mChildrenRoot.Add( child );
364 Control::OnChildAdd( child );
367 void GaussianBlurView::OnChildRemove( Actor& child )
369 mChildrenRoot.Remove( child );
371 Control::OnChildRemove( child );
374 void GaussianBlurView::AllocateResources()
376 mLastSize = mTargetSize;
378 // get size of downsampled render targets
379 mDownsampledWidth = mTargetSize.width * mDownsampleWidthScale;
380 mDownsampledHeight = mTargetSize.height * mDownsampleHeightScale;
382 // Create and place a camera for the renders corresponding to the (potentially downsampled) render targets' size
383 mRenderDownsampledCamera.SetFieldOfView(ARBITRARY_FIELD_OF_VIEW);
384 // TODO: how do we pick a reasonable value for near clip? Needs to relate to normal camera the user renders with, but we don't have a handle on it
385 mRenderDownsampledCamera.SetNearClippingPlane(1.0f);
386 mRenderDownsampledCamera.SetAspectRatio(mDownsampledWidth / mDownsampledHeight);
387 mRenderDownsampledCamera.SetType(Dali::Camera::FREE_LOOK); // camera orientation based solely on actor
389 mRenderDownsampledCamera.SetProperty( Actor::Property::POSITION, Vector3(0.0f, 0.0f, ((mDownsampledHeight * 0.5f) / tanf(ARBITRARY_FIELD_OF_VIEW * 0.5f))));
391 // setup for normal operation
394 // Create and place a camera for the children render, corresponding to its render target size
395 mRenderFullSizeCamera.SetFieldOfView(ARBITRARY_FIELD_OF_VIEW);
396 // TODO: how do we pick a reasonable value for near clip? Needs to relate to normal camera the user renders with, but we don't have a handle on it
397 mRenderFullSizeCamera.SetNearClippingPlane(1.0f);
398 mRenderFullSizeCamera.SetAspectRatio(mTargetSize.width / mTargetSize.height);
399 mRenderFullSizeCamera.SetType(Dali::Camera::FREE_LOOK); // camera orientation based solely on actor
401 float cameraPosConstraintScale = 0.5f / tanf(ARBITRARY_FIELD_OF_VIEW * 0.5f);
402 mRenderFullSizeCamera.SetProperty( Actor::Property::POSITION, Vector3(0.0f, 0.0f, mTargetSize.height * cameraPosConstraintScale));
404 // create offscreen buffer of new size to render our child actors to
405 mRenderTargetForRenderingChildren = FrameBuffer::New( mTargetSize.width, mTargetSize.height, FrameBuffer::Attachment::NONE );
406 Texture texture = Texture::New( TextureType::TEXTURE_2D, mPixelFormat, unsigned(mTargetSize.width), unsigned(mTargetSize.height) );
407 mRenderTargetForRenderingChildren.AttachColorTexture( texture );
409 // Set actor for performing a horizontal blur
410 SetRendererTexture( mHorizBlurActor.GetRendererAt(0), mRenderTargetForRenderingChildren );
412 // Create offscreen buffer for vert blur pass
413 mRenderTarget1 = FrameBuffer::New( mDownsampledWidth, mDownsampledHeight, FrameBuffer::Attachment::NONE );
414 texture = Texture::New(TextureType::TEXTURE_2D, mPixelFormat, unsigned(mDownsampledWidth), unsigned(mDownsampledHeight));
415 mRenderTarget1.AttachColorTexture( texture );
417 // use the completed blur in the first buffer and composite with the original child actors render
418 SetRendererTexture( mCompositingActor.GetRendererAt(0), mRenderTarget1 );
420 // set up target actor for rendering result, i.e. the blurred image
421 SetRendererTexture( mTargetActor.GetRendererAt(0), mRenderTargetForRenderingChildren );
424 // Create offscreen buffer for horiz blur pass
425 mRenderTarget2 = FrameBuffer::New( mDownsampledWidth, mDownsampledHeight, FrameBuffer::Attachment::NONE );
426 Texture texture = Texture::New(TextureType::TEXTURE_2D, mPixelFormat, unsigned(mDownsampledWidth), unsigned(mDownsampledHeight));
427 mRenderTarget2.AttachColorTexture( texture );
429 // size needs to match render target
430 mHorizBlurActor.SetProperty( Actor::Property::SIZE, Vector2(mDownsampledWidth, mDownsampledHeight) );
432 // size needs to match render target
433 mVertBlurActor.SetProperty( Actor::Property::SIZE, Vector2(mDownsampledWidth, mDownsampledHeight) );
434 SetRendererTexture( mVertBlurActor.GetRendererAt(0), mRenderTarget2 );
436 // set gaussian blur up for new sized render targets
437 SetShaderConstants();
440 void GaussianBlurView::CreateRenderTasks()
442 RenderTaskList taskList = Stage::GetCurrent().GetRenderTaskList();
446 // create render task to render our child actors to offscreen buffer
447 mRenderChildrenTask = taskList.CreateTask();
448 mRenderChildrenTask.SetSourceActor( mChildrenRoot );
449 mRenderChildrenTask.SetExclusive(true);
450 mRenderChildrenTask.SetInputEnabled( false );
451 mRenderChildrenTask.SetClearEnabled( true );
452 mRenderChildrenTask.SetClearColor( mBackgroundColor );
454 mRenderChildrenTask.SetCameraActor(mRenderFullSizeCamera);
455 mRenderChildrenTask.SetFrameBuffer( mRenderTargetForRenderingChildren );
459 mRenderChildrenTask.SetRefreshRate(RenderTask::REFRESH_ONCE);
463 // perform a horizontal blur targeting the second buffer
464 mHorizBlurTask = taskList.CreateTask();
465 mHorizBlurTask.SetSourceActor( mHorizBlurActor );
466 mHorizBlurTask.SetExclusive(true);
467 mHorizBlurTask.SetInputEnabled( false );
468 mHorizBlurTask.SetClearEnabled( true );
469 mHorizBlurTask.SetClearColor( mBackgroundColor );
470 mHorizBlurTask.SetCameraActor(mRenderDownsampledCamera);
471 mHorizBlurTask.SetFrameBuffer( mRenderTarget2 );
472 if( mRenderOnce || ( mRenderOnce && mBlurUserImage ) )
474 mHorizBlurTask.SetRefreshRate(RenderTask::REFRESH_ONCE);
477 // use the second buffer and perform a horizontal blur targeting the first buffer
478 mVertBlurTask = taskList.CreateTask();
479 mVertBlurTask.SetSourceActor( mVertBlurActor );
480 mVertBlurTask.SetExclusive(true);
481 mVertBlurTask.SetInputEnabled( false );
482 mVertBlurTask.SetClearEnabled( true );
483 mVertBlurTask.SetClearColor( mBackgroundColor );
484 mVertBlurTask.SetCameraActor(mRenderDownsampledCamera);
485 if(mUserOutputRenderTarget)
487 mVertBlurTask.SetFrameBuffer( mUserOutputRenderTarget );
491 mVertBlurTask.SetFrameBuffer( mRenderTarget1 );
493 if( mRenderOnce || ( mRenderOnce && mBlurUserImage ) )
495 mVertBlurTask.SetRefreshRate(RenderTask::REFRESH_ONCE);
496 mVertBlurTask.FinishedSignal().Connect( this, &GaussianBlurView::OnRenderTaskFinished );
499 // use the completed blur in the first buffer and composite with the original child actors render
502 mCompositeTask = taskList.CreateTask();
503 mCompositeTask.SetSourceActor( mCompositingActor );
504 mCompositeTask.SetExclusive(true);
505 mCompositeTask.SetInputEnabled( false );
507 mCompositeTask.SetCameraActor(mRenderFullSizeCamera);
508 mCompositeTask.SetFrameBuffer( mRenderTargetForRenderingChildren );
512 mCompositeTask.SetRefreshRate(RenderTask::REFRESH_ONCE);
517 void GaussianBlurView::RemoveRenderTasks()
519 RenderTaskList taskList = Stage::GetCurrent().GetRenderTaskList();
521 taskList.RemoveTask(mRenderChildrenTask);
522 taskList.RemoveTask(mHorizBlurTask);
523 taskList.RemoveTask(mVertBlurTask);
524 taskList.RemoveTask(mCompositeTask);
527 void GaussianBlurView::Activate()
531 // make sure resources are allocated and start the render tasks processing
532 Self().Add( mInternalRoot );
539 void GaussianBlurView::ActivateOnce()
546 void GaussianBlurView::Deactivate()
550 // stop render tasks processing
551 // Note: render target resources are automatically freed since we set the Image::Unused flag
552 mInternalRoot.Unparent();
553 mRenderTargetForRenderingChildren.Reset();
554 mRenderTarget1.Reset();
555 mRenderTarget2.Reset();
562 void GaussianBlurView::SetBlurBellCurveWidth(float blurBellCurveWidth)
564 // a value of zero leads to undefined Gaussian weights, do not allow user to do this
565 mBlurBellCurveWidth = std::max( blurBellCurveWidth, 0.001f );
568 float GaussianBlurView::CalcGaussianWeight(float x)
570 return (1.0f / sqrt(2.0f * Math::PI * mBlurBellCurveWidth)) * exp(-(x * x) / (2.0f * mBlurBellCurveWidth * mBlurBellCurveWidth));
573 void GaussianBlurView::SetShaderConstants()
578 float w, totalWeights;
581 uvOffsets = new Vector2[mNumSamples + 1];
582 weights = new float[mNumSamples + 1];
584 totalWeights = weights[0] = CalcGaussianWeight(0);
585 uvOffsets[0].x = 0.0f;
586 uvOffsets[0].y = 0.0f;
588 for(i=0; i<mNumSamples >> 1; i++)
590 w = CalcGaussianWeight((float)(i + 1));
591 weights[(i << 1) + 1] = w;
592 weights[(i << 1) + 2] = w;
593 totalWeights += w * 2.0f;
595 // offset texture lookup to between texels, that way the bilinear filter in the texture hardware will average two samples with one lookup
596 ofs = ((float)(i << 1)) + 1.5f;
598 // get offsets from units of pixels into uv coordinates in [0..1]
599 float ofsX = ofs / mDownsampledWidth;
600 float ofsY = ofs / mDownsampledHeight;
601 uvOffsets[(i << 1) + 1].x = ofsX;
602 uvOffsets[(i << 1) + 1].y = ofsY;
604 uvOffsets[(i << 1) + 2].x = -ofsX;
605 uvOffsets[(i << 1) + 2].y = -ofsY;
608 for(i=0; i<mNumSamples; i++)
610 weights[i] /= totalWeights;
613 // set shader constants
614 Vector2 xAxis(1.0f, 0.0f);
615 Vector2 yAxis(0.0f, 1.0f);
616 for (i = 0; i < mNumSamples; ++i )
618 mHorizBlurActor.RegisterProperty( GetSampleOffsetsPropertyName( i ), uvOffsets[ i ] * xAxis );
619 mHorizBlurActor.RegisterProperty( GetSampleWeightsPropertyName( i ), weights[ i ] );
621 mVertBlurActor.RegisterProperty( GetSampleOffsetsPropertyName( i ), uvOffsets[ i ] * yAxis );
622 mVertBlurActor.RegisterProperty( GetSampleWeightsPropertyName( i ), weights[ i ] );
629 std::string GaussianBlurView::GetSampleOffsetsPropertyName( unsigned int index ) const
631 DALI_ASSERT_ALWAYS( index < mNumSamples );
633 std::ostringstream oss;
634 oss << "uSampleOffsets[" << index << "]";
638 std::string GaussianBlurView::GetSampleWeightsPropertyName( unsigned int index ) const
640 DALI_ASSERT_ALWAYS( index < mNumSamples );
642 std::ostringstream oss;
643 oss << "uSampleWeights[" << index << "]";
647 Dali::Toolkit::GaussianBlurView::GaussianBlurViewSignal& GaussianBlurView::FinishedSignal()
649 return mFinishedSignal;
652 void GaussianBlurView::OnRenderTaskFinished(Dali::RenderTask& renderTask)
654 Toolkit::GaussianBlurView handle( GetOwner() );
655 mFinishedSignal.Emit( handle );
658 } // namespace Internal
659 } // namespace Toolkit