1 #ifndef __DALI_TOOLKIT_SHADER_EFFECT_MOTION_BLUR_H__
2 #define __DALI_TOOLKIT_SHADER_EFFECT_MOTION_BLUR_H__
5 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
24 #include <dali/dali.h>
26 namespace Dali DALI_IMPORT_API
34 * Class for motion blur shader that works on a per object basis. Objects will
35 * blur when they move, or if the camera moves. Can be applied to ImageActor or
40 * // Create shader used for doing motion blur\n
41 * MotionBlurEffect MotionBlurEffect = MotionBlurEffect::New();
43 * // set actor shader to the blur one\n
44 * Actor Actor = Actor::New( ... );\n
45 * Actor.SetShaderEffect( MotionBlurEffect );
48 class MotionBlurEffect : public ShaderEffect
54 * Create an uninitialized MotionBlurEffect; this can be initialized with MotionBlurEffect::New()
55 * Calling member functions with an uninitialized Dali::Object is not allowed.
62 * This is non-virtual since derived Handle types must not contain data or virtual methods.
67 * Create an initialized MotionBlurEffect
68 * The number of texture samples taken along the motion velocity vector of the
69 * actor, producing the blur, is set to a default of 8.
70 * @return A handle to a newly allocated Dali resource.
72 static MotionBlurEffect New();
75 * Create a MotionBlurEffect and attach it to the specified actor
76 * The number of texture samples taken along the motion velocity vector of the
77 * actor, producing the blur, is set to a default of 8.
78 * @param renderable actor to apply the effect to
79 * @return A handle to a newly allocated Dali resource.
81 static MotionBlurEffect Apply( RenderableActor renderable );
84 * Create an initialized MotionBlurEffect
85 * @param numBlurSamples The number of texture samples taken along the motion
86 * velocity vector of the actor, producing the blur. A higher number gives a
87 * smoother blur but costs more in terms of performance.
88 * @param numBlurSamples to have
89 * @return A handle to a newly allocated Dali resource.
91 static MotionBlurEffect New( unsigned int numBlurSamples );
94 * Set texcoord scale property. This scales the offset for texture samples
95 * along the motion velocity vector. A smaller value means the samples will
96 * be spaced closer, larger value further apart. User should use this to get
97 * the blur to look contiguous, i.e. the blur texels should not be too widely
98 * spread, with gaps in between. Default 0.125.
99 * @param texcoordScale The scaling factor that multiplies the motion velocity vector for texture lookups.
101 void SetTexcoordScale( float texcoordScale );
104 * Set geometry stretch factor property. This scales the amount the
105 * geometry stretches backwards along the motion velocity vector. A smaller
106 * value means the geometry stretches less, larger it stretches more. User
107 * should use this to get the blur to 'bleed' into areas outside the physical
108 * bounds of the actor. We need this as the blur is only applied inside the
109 * bounds of the actor, but you would expect motion blur trails where the
110 * actor was previously but is there no longer. Default 0.05.
111 * @param scalingFactor The scaling factor that extrudes the geometry backwards along the motion velocity vector.
113 void SetGeometryStretchFactor( float scalingFactor );
116 * Set speed scaling factor property. This takes the magnitude of the motion
117 * velocity vector and scales it to produce a value which is used to fade the
118 * blur in / out with the speed that the actor is moving. As the blur fades
119 * in, more of the blur is visible and less of the original actor, and vice
121 * This value is also used to control how much to fade the actor near the
122 * edges, based on the speed the actor is moving. When the actor is at rest
123 * this is not applied. Default 0.5.
124 * @param scalingFactor The scaling factor that controls the edge fade / blur fade of the actor.
126 void SetSpeedScalingFactor( float scalingFactor );
129 * Set the displacement from the centre of the actor that the actor will start
130 * to fade towards its edges. This is used to prevent an unsightly hard edge
131 * between the blurred actor and the scene. Depends on the values of the
132 * vertices in the vertex stream. When the actor is at rest this is not applied.
133 * Default 0.25, which is half way towards the edge for an ImageRenderer::QUAD.
134 * @param displacement The displacement from the centre of the actor that the actor will start to edge fade.
136 void SetObjectFadeStart( Vector2 displacement );
139 * Set the displacement from the centre of the actor that the actor will
140 * finish fading towards its edges. This is used to prevent an unsightly hard
141 * edge between the blurred actor and the scene. Depends on the values of the
142 * vertices in the vertex stream. When the actor is at rest this is not applied.
143 * Default 0.5, which is all the way towards the edge for an ImageRenderer::QUAD.
144 * @param displacement The displacement from the centre of the actor that the actor will finish edge fading.
146 void SetObjectFadeEnd( Vector2 displacement );
149 * Set a global scaler applied to the alpha of the actor. Used to make the
150 * blurred actor a bit more subtle (helps to hide discontinuities due to
151 * limited number of texture samples) and reveal a bit of the background
152 * behind it as it moves. When the actor is at rest this is not applied. Default 0.75.
153 * @param alphaScale The scaling factor which multiplies the alpha of each pixel of the actor.
155 void SetAlphaScale( float alphaScale );
158 * Set the number of texture samples to be taken. Increasing the number of
159 * samples provides better quality at the cost of performance.
160 * @param numSamples The number of texture samples to be taken. Default is 8.
162 void SetNumSamples( int numSamples );
165 * Get the name for the texcoord scale property. Useful for animation.
166 * @return A std::string containing the property name
168 const std::string& GetTexcoordScalePropertyName() const;
171 * Get the name for the geometry stretching property. Useful for animation.
172 * @return A std::string containing the property name
174 const std::string& GetGeometryStretchFactorPropertyName() const;
177 * Get the name for the speed scaling property. Useful for animation.
178 * @return A std::string containing the property name
180 const std::string& GetSpeedScalingFactorPropertyName() const;
183 * Get the name for the fade start property. Useful for animation.
184 * @return A std::string containing the property name
186 const std::string& GetObjectFadeStartPropertyName() const;
189 * Get the name for the fade end property. Useful for animation.
190 * @return A std::string containing the property name
192 const std::string& GetObjectFadeEndPropertyName() const;
195 * Get the name for the alpha scale property. Useful for animation.
196 * @return A std::string containing the property name
198 const std::string& GetAlphaScalePropertyName() const;
201 * Downcast an ShaderEffect handle to MotionBlurEffect handle. If handle points to a MotionBlurEffect object the
202 * downcast produces valid handle. If not the returned handle is left uninitialized.
203 * @param[in] handle to a ShaderEffect
204 * @return handle to a MotionBlurEffect object or an uninitialized handle
206 static MotionBlurEffect DownCast( ShaderEffect handle );
209 // Not intended for application developers
210 MotionBlurEffect( ShaderEffect handle );
217 #endif //#ifndef __DALI_TOOLKIT_SHADER_EFFECT_MOTION_BLUR_H__