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 Flora License, Version 1.0 (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://floralicense.org/license/
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.
23 #include <dali/dali.h>
25 namespace Dali DALI_IMPORT_API
33 * Class for motion blur shader that works on a per object basis. Objects will
34 * blur when they move, or if the camera moves. Can be applied to ImageActor or
39 * // Create shader used for doing motion blur\n
40 * MotionBlurEffect MotionBlurEffect = MotionBlurEffect::New();
42 * // set actor shader to the blur one\n
43 * Actor Actor = Actor::New( ... );\n
44 * Actor.SetShaderEffect( MotionBlurEffect );
47 class MotionBlurEffect : public ShaderEffect
53 * Create an uninitialized MotionBlurEffect; this can be initialized with MotionBlurEffect::New()
54 * Calling member functions with an uninitialized Dali::Object is not allowed.
61 virtual ~MotionBlurEffect();
64 * Create an initialized MotionBlurEffect
65 * The number of texture samples taken along the motion velocity vector of the
66 * actor, producing the blur, is set to a default of 8.
67 * @return A handle to a newly allocated Dali resource.
69 static MotionBlurEffect New();
72 * Create a MotionBlurEffect and attach it to the specified actor
73 * The number of texture samples taken along the motion velocity vector of the
74 * actor, producing the blur, is set to a default of 8.
75 * @return A handle to a newly allocated Dali resource.
77 static MotionBlurEffect Apply( Actor handle );
80 * Create an initialized MotionBlurEffect
81 * @param numBlurSamples The number of texture samples taken along the motion
82 * velocity vector of the actor, producing the blur. A higher number gives a
83 * smoother blur but costs more in terms of performance.
84 * @return A handle to a newly allocated Dali resource.
86 static MotionBlurEffect New( const unsigned int numBlurSamples );
89 * Set texcoord scale property. This scales the offset for texture samples
90 * along the motion velocity vector. A smaller value means the samples will
91 * be spaced closer, larger value further apart. User should use this to get
92 * the blur to look contiguous, i.e. the blur texels should not be too widely
93 * spread, with gaps in between. Default 0.125.
94 * @param texcoordScale The scaling factor that multiplies the motion velocity vector for texture lookups.
96 void SetTexcoordScale( float texcoordScale );
99 * Set geometry stretch factor property. This scales the amount the
100 * geometry stretches backwards along the motion velocity vector. A smaller
101 * value means the geometry stretches less, larger it stretches more. User
102 * should use this to get the blur to 'bleed' into areas outside the physical
103 * bounds of the actor. We need this as the blur is only applied inside the
104 * bounds of the actor, but you would expect motion blur trails where the
105 * actor was previously but is there no longer. Default 0.05.
106 * @param scalingFactor The scaling factor that extrudes the geometry backwards along the motion velocity vector.
108 void SetGeometryStretchFactor( float scalingFactor );
111 * Set speed scaling factor property. This takes the magnitude of the motion
112 * velocity vector and scales it to produce a value which is used to fade the
113 * blur in / out with the speed that the actor is moving. As the blur fades
114 * in, more of the blur is visible and less of the original actor, and vice
116 * This value is also used to control how much to fade the actor near the
117 * edges, based on the speed the actor is moving. When the actor is at rest
118 * this is not applied. Default 0.5.
119 * @param scalingFactor The scaling factor that controls the edge fade / blur fade of the actor.
121 void SetSpeedScalingFactor( float scalingFactor );
124 * Set the displacement from the centre of the actor that the actor will start
125 * to fade towards its edges. This is used to prevent an unsightly hard edge
126 * between the blurred actor and the scene. Depends on the values of the
127 * vertices in the vertex stream. When the actor is at rest this is not applied.
128 * Default 0.25, which is half way towards the edge for an ImageRenderer::QUAD.
129 * @param displacement The displacement from the centre of the actor that the actor will start to edge fade.
131 void SetObjectFadeStart( Vector2 displacement );
134 * Set the displacement from the centre of the actor that the actor will
135 * finish fading towards its edges. This is used to prevent an unsightly hard
136 * edge between the blurred actor and the scene. Depends on the values of the
137 * vertices in the vertex stream. When the actor is at rest this is not applied.
138 * Default 0.5, which is all the way towards the edge for an ImageRenderer::QUAD.
139 * @param displacement The displacement from the centre of the actor that the actor will finish edge fading.
141 void SetObjectFadeEnd( Vector2 displacement );
144 * Set a global scaler applied to the alpha of the actor. Used to make the
145 * blurred actor a bit more subtle (helps to hide discontinuities due to
146 * limited number of texture samples) and reveal a bit of the background
147 * behind it as it moves. When the actor is at rest this is not applied. Default 0.75.
148 * @param alphaScale The scaling factor which multiplies the alpha of each pixel of the actor.
150 void SetAlphaScale( float alphaScale );
153 * Set the number of texture samples to be taken. Increasing the number of
154 * samples provides better quality at the cost of performance.
155 * @param numSamples The number of texture samples to be taken. Default is 8.
157 void SetNumSamples( int numSamples );
160 * Get the name for the texcoord scale property. Useful for animation.
161 * @return A std::string containing the property name
163 const std::string& GetTexcoordScalePropertyName() const;
166 * Get the name for the geometry stretching property. Useful for animation.
167 * @return A std::string containing the property name
169 const std::string& GetGeometryStretchFactorPropertyName() const;
172 * Get the name for the speed scaling property. Useful for animation.
173 * @return A std::string containing the property name
175 const std::string& GetSpeedScalingFactorPropertyName() const;
178 * Get the name for the fade start property. Useful for animation.
179 * @return A std::string containing the property name
181 const std::string& GetObjectFadeStartPropertyName() const;
184 * Get the name for the fade end property. Useful for animation.
185 * @return A std::string containing the property name
187 const std::string& GetObjectFadeEndPropertyName() const;
190 * Get the name for the alpha scale property. Useful for animation.
191 * @return A std::string containing the property name
193 const std::string& GetAlphaScalePropertyName() const;
196 * Downcast an ShaderEffect handle to MotionBlurEffect handle. If handle points to a MotionBlurEffect object the
197 * downcast produces valid handle. If not the returned handle is left uninitialized.
198 * @param[in] handle to a ShaderEffect
199 * @return handle to a MotionBlurEffect object or an uninitialized handle
201 static MotionBlurEffect DownCast( ShaderEffect handle );
204 // Not intended for application developers
205 MotionBlurEffect( ShaderEffect handle );
212 #endif //#ifndef __DALI_TOOLKIT_SHADER_EFFECT_MOTION_BLUR_H__