X-Git-Url: http://review.tizen.org/git/?p=platform%2Fcore%2Fuifw%2Fdali-toolkit.git;a=blobdiff_plain;f=dali-toolkit%2Fdevel-api%2Fshader-effects%2Fmotion-stretch-effect.h;h=22aa71972d00eac9e7623065365b0adfad79964d;hp=5cc7bcf882ae7187958f8228578a1e60a1306c3a;hb=1c5674a11a51310ee689d6daf4e6b7d94dec607e;hpb=5f6e04b26996da4c06716ce044bdfdb0e7e2e61b diff --git a/dali-toolkit/devel-api/shader-effects/motion-stretch-effect.h b/dali-toolkit/devel-api/shader-effects/motion-stretch-effect.h index 5cc7bcf..22aa719 100644 --- a/dali-toolkit/devel-api/shader-effects/motion-stretch-effect.h +++ b/dali-toolkit/devel-api/shader-effects/motion-stretch-effect.h @@ -19,7 +19,7 @@ */ // EXTERNAL INCLUDES -#include +#include #include namespace Dali @@ -29,136 +29,180 @@ namespace Toolkit { /** + * @brief Creates a new MotionStretchEffect * - * Class for motion stretch shader that works on a per object basis. Objects will stretch in the direction of motion when they move, or if the camera moves. Can be applied + * Motion stretch shader works on a per object basis. Objects will stretch in the direction of motion when they move, or if the camera moves. Can be applied * to ImageActor or TextActor only. * * Usage example:- * * // Create shader used for doing motion stretch\n - * MotionStretchEffect MotionStretchEffect = MotionStretchEffect::New(); + * ShaderEffect MotionStretchEffect = CreateMotionStretchEffect(); * * // set actor shader to the stretch one\n - * Actor Actor = Actor::New( ... );\n - * Actor.SetShaderEffect( MotionStretchEffect ); + * Actor actor = Actor::New( ... );\n + * actor.SetShaderEffect( MotionStretchEffect ); * + * // Constrain "uModelLastFrame" to be the same as the actor's world matrix\n + * Dali::Property::Index uModelProperty = MotionBlurEffect.GetPropertyIndex( "uModelLastFrame" ); + * Constraint constraint = Constraint::New( MotionBlurEffect, uModelProperty, EqualToConstraint() );\n + * constraint.AddSource( Source( actor , Actor::Property::WORLD_MATRIX ) );\n + * constraint.Apply();\n + * + * Animatable/Constrainable uniforms: + * "uGeometryStretchFactor" - This scales the amount the geometry stretches along the motion velocity vector. + * A smaller value means the geometry stretches less, larger it stretches more. Default 0.5. + * "uSpeedScalingFactor" - This value is used to control how much to fade the actor near the edges, based on the + * speed the actor is moving. When the actor is at rest this is not applied. Default 0.5. + * "uObjectFadeStart" - The displacement from the centre of the actor that the actor will start to fade towards + * its edges. This is used to prevent an unsightly hard edge between the stretched actor and + * the scene. Depends on the values of the vertices in the vertex stream. When the actor is at + * rest this is not applied. Default Vector2(0.25, 0.25), which is half way towards the edge for + * an ImageRenderer::QUAD. + * "uObjectFadeEnd" - The displacement from the centre of the actor that the actor will finish fading towards its edges. + * This is used to prevent an unsightly hard edge between the stretched actor and the scene. Depends + * on the values of the vertices in the vertex stream. When the actor is at rest this is not applied. + * Default 0.5, which is all the way towards the edge for an ImageRenderer::QUAD. + * "uAlphaScale" - Global scaler applied to the alpha of the actor. Used to make the stretched actor a bit more subtle + * and reveal a bit of the background behind it as it moves. When the actor is at rest this is not + * applied. Default 0.75. + * "uModelLastFrame" - The model to world space transformation matrix of the actor in the previous frame. + * + * @return A handle to a newly allocated ShaderEffect */ -class DALI_IMPORT_API MotionStretchEffect : public ShaderEffect +inline ShaderEffect CreateMotionStretchEffect() { - -public: - - /** - * Create an uninitialized MotionStretchEffect; this can be initialized with MotionStretchEffect::New() - * Calling member functions with an uninitialized Dali::Object is not allowed. - */ - MotionStretchEffect(); - - /** - * @brief Destructor - * - * This is non-virtual since derived Handle types must not contain data or virtual methods. - */ - ~MotionStretchEffect(); - - /** - * Create an initialized MotionStretchEffect - * @return A handle to a newly allocated Dali resource. - */ - static MotionStretchEffect New(); - - /** - * Create a MotionStretchEffect and attach it to the specified actor - * @param renderable actor to apply the effect to - * @return A handle to a newly allocated Dali resource. - */ - static MotionStretchEffect Apply( RenderableActor renderable ); - - /** - * Set geometry stretch factor property. This scales the amount the geometry - * stretches along the motion velocity vector. A smaller value means the geometry - * stretches less, larger it stretches more. Default 0.5. - * @param scalingFactor The scaling factor that extrudes the geometry forwards along the motion velocity vector. - */ - void SetGeometryStretchFactor( float scalingFactor ); - - /** - * Set speed scaling factor property. This value is used to control how much - * to fade the actor near the edges, based on the speed the actor is moving. - * When the actor is at rest this is not applied. Default 0.5. - * @param scalingFactor The scaling factor that controls the edge fade of the actor. - */ - void SetSpeedScalingFactor( float scalingFactor ); - - /** - * Set the displacement from the centre of the actor that the actor will start to - * fade towards its edges. This is used to prevent an unsightly hard edge - * between the stretched actor and the scene. Depends on the values of the - * vertices in the vertex stream. When the actor is at rest this is not applied. - * Default Vector2(0.25, 0.25), which is half way towards the edge for an ImageRenderer::QUAD. - * @param displacement The displacement from the centre of the actor that the actor will start to edge fade. - */ - void SetObjectFadeStart( Vector2 displacement ); - - /** - * Set the displacement from the centre of the actor that the actor will - * finish fading towards its edges. This is used to prevent an unsightly hard - * edge between the stretched actor and the scene. Depends on the values of - * the vertices in the vertex stream. When the actor is at rest this is not applied. - * Default 0.5, which is all the way towards the edge for an ImageRenderer::QUAD. - * @param displacement The displacement from the centre of the actor that the actor will finish edge fading. - */ - void SetObjectFadeEnd( Vector2 displacement ); - - /** - * Set a global scaler applied to the alpha of the actor. Used to make the - * stretched actor a bit more subtle and reveal a bit of the background behind - * it as it moves. When the actor is at rest this is not applied. Default 0.75. - * @param alphaScale The scaling factor which multiplies the alpha of each pixel of the actor. - */ - void SetAlphaScale( float alphaScale ); - - - /** - * Get the name for the texcoord scale property. Useful for animation. - * @return A std::string containing the property name - */ - const std::string& GetTexcoordScalePropertyName() const; - - /** - * Get the name for the geometry stretching property. Useful for animation. - * @return A std::string containing the property name - */ - const std::string& GetGeometryStretchFactorPropertyName() const; - - /** - * Get the name for the speed scaling property. Useful for animation. - * @return A std::string containing the property name - */ - const std::string& GetSpeedScalingFactorPropertyName() const; - - /** - * Get the name for the fade start X property. Useful for animation. - * @return A std::string containing the property name - */ - const std::string& GetObjectFadeStartPropertyName() const; - - /** - * Get the name for the fade end X property. Useful for animation. - * @return A std::string containing the property name - */ - const std::string& GetObjectFadeEndPropertyName() const; - - /** - * Get the name for the alpha scale property. Useful for animation. - * @return A std::string containing the property name - */ - const std::string& GetAlphaScalePropertyName() const; - -private: - // Not intended for application developers - DALI_INTERNAL MotionStretchEffect( ShaderEffect handle ); -}; + // Dali vertexSource prefix for reference: + // precision highp float; + // attribute vec3 aPosition; + // attribute vec2 aTexCoord; + // uniform mat4 uMvpMatrix; + // uniform mat4 uModelView; + // uniform mat3 uNormalMatrix; + // uniform mat4 uProjection; + // uniform vec4 uColor; + // varying vec2 vTexCoord; + std::string vertexSource; + vertexSource = + "precision mediump float;\n" + "uniform mat4 uModelLastFrame;\n" + "uniform float uTimeDelta;\n" + + "uniform float uGeometryStretchFactor;\n" + "uniform float uSpeedScalingFactor;\n" + + // outputs + "varying vec2 vModelSpaceCenterToPos;\n" + "varying vec2 vScreenSpaceVelocityVector;\n" + "varying float vSpeed;\n" + + "void main()\n" + "{\n" + // get view space position of vertex this frame and last frame + " vec4 vertex = vec4(aPosition, 1.0);\n" + " vec4 viewSpaceVertex = uModelView * vertex;\n" + " vec4 viewSpaceVertexLastFrame = uViewMatrix * uModelLastFrame * vertex;\n" + + // work out vertex's last movement in view space + " vec3 viewSpacePosDelta = viewSpaceVertex.xyz - viewSpaceVertexLastFrame.xyz;\n" + " float reciprocalTimeDelta = 1.0 / ((uTimeDelta > 0.0) ? uTimeDelta : 0.01);\n" + + // get clip space position of vertex this frame and last frame + " vec4 clipSpaceVertex = uMvpMatrix * vertex;\n" + " vec4 clipSpaceVertexLastFrame = uProjection * viewSpaceVertexLastFrame;\n" + + // decide how much this vertex is 'trailing', i.e. at the back of the object relative to its direction of motion. We do this + // by assuming the objects model space origin is at its center and taking the dot product of the vector from center to vertex with the motion direction + " float t = 0.0;\n" + " float posDeltaLength = length(viewSpacePosDelta);\n" + " if(posDeltaLength > 0.001)\n" // avoid div by 0 if object has barely moved + " {\n" + " vec4 viewSpaceCenterToPos = uModelView * vec4(aPosition, 0.0);\n" + " float centerToVertexDist = length(viewSpaceCenterToPos);\n" + " if(centerToVertexDist > 0.001)\n" // avoid div by 0 if object has vertex at model space origin + " {\n" + " vec3 viewSpacePosDeltaNormalised = viewSpacePosDelta / posDeltaLength;\n" + " vec3 viewSpaceCenterToPosNormalised = viewSpaceCenterToPos.xyz / centerToVertexDist;\n" + " t = (dot(viewSpacePosDeltaNormalised, viewSpaceCenterToPosNormalised) * 0.5 ) + 0.5;\n" // scale and bias from [-1..1] to [0..1] + " }\n" + " }\n" + // output vertex position lerped with its last position, based on how much it is trailing, + // this stretches the geom back along where it has just been, giving a warping effect + // We raise t to a power in order that non-trailing vertices are effected much more than trailing ones + // Note: we must take account of time delta to convert position delta into a velocity, so changes are smooth (take into account frame time correctly) + " gl_Position = mix(clipSpaceVertexLastFrame, clipSpaceVertex, t * t * t * uGeometryStretchFactor * reciprocalTimeDelta);\n" + + // work out vertex's last movement in normalised device coordinates [-1..1] space, i.e. perspective divide + " vec2 ndcVertex = clipSpaceVertex.xy / clipSpaceVertex.w;\n" + " vec2 ndcVertexLastFrame = clipSpaceVertexLastFrame.xy / clipSpaceVertexLastFrame.w;\n" + // scale and bias so that a value of 1.0 corresponds to screen size (NDC is [-1..1] = 2) + " vScreenSpaceVelocityVector = ((ndcVertex - ndcVertexLastFrame) * 0.5 * reciprocalTimeDelta);\n" + " vScreenSpaceVelocityVector.y = -vScreenSpaceVelocityVector.y;\n" // TODO negated due to y being inverted in our coordinate system? + // calculate a scaling factor proportional to velocity, which we can use to tweak how things look + " vSpeed = length(vScreenSpaceVelocityVector) * uSpeedScalingFactor;\n" + " vSpeed = clamp(vSpeed, 0.0, 1.0);\n" + + // provide fragment shader with vector from center of object to pixel (assumes the objects model space origin is at its center and verts have same z) + " vModelSpaceCenterToPos = aPosition.xy;\n" + + " vTexCoord = aTexCoord;\n" + "}\n"; + + + // Dali fragmentSource prefix for reference: + // precision highp float; + // uniform sampler2D sTexture; + // uniform sampler2D sEffect; + // uniform vec4 uColor; + // varying vec2 vTexCoord; + std::string fragmentSource; + fragmentSource = + "precision mediump float;\n" + + "uniform vec2 uObjectFadeStart;\n" + "uniform vec2 uObjectFadeEnd;\n" + "uniform float uAlphaScale;\n" + + // inputs + "varying vec2 vModelSpaceCenterToPos;\n" + "varying vec2 vScreenSpaceVelocityVector;\n" + "varying float vSpeed;\n" + + "void main()\n" + "{\n" + // calculate an alpha value that will fade the object towards its extremities, we need this to avoid an unsightly hard edge between color values of + // the stretched object and the background. Use smoothstep also to hide any hard edges (discontinuities) in rate of change of this alpha gradient + " vec2 centerToPixel = abs( vModelSpaceCenterToPos );\n" + " vec2 fadeToEdges = smoothstep(0.0, 1.0, 1.0 - ((centerToPixel - uObjectFadeStart) / (uObjectFadeEnd - uObjectFadeStart)));\n" + " float fadeToEdgesScale = fadeToEdges.x * fadeToEdges.y * uAlphaScale;\n" // apply global scaler + " fadeToEdgesScale = mix(1.0, fadeToEdgesScale, vSpeed);\n" // fade proportional to speed, so opaque when at rest + + // standard actor texel + " vec4 colActor = texture2D(sTexture, vTexCoord);\n" + " gl_FragColor = colActor;\n" + " gl_FragColor.a *= fadeToEdgesScale;\n" // fade actor to its edges based on speed of motion + " gl_FragColor *= uColor;\n" + "}"; + + // NOTE: we must turn on alpha blending for the actor (HINT_BLENDING) + ShaderEffect shaderEffect = ShaderEffect::New( + vertexSource, fragmentSource, GeometryType( GEOMETRY_TYPE_IMAGE ), + ShaderEffect::GeometryHints( ShaderEffect::HINT_BLENDING | ShaderEffect::HINT_GRID ) ); + + + ////////////////////////////////////// + // Register uniform properties + // + // + shaderEffect.SetUniform( "uGeometryStretchFactor", 0.5f ); + shaderEffect.SetUniform( "uSpeedScalingFactor", 0.5f ); + shaderEffect.SetUniform( "uObjectFadeStart", Vector2( 0.25f, 0.25f ) ); + shaderEffect.SetUniform( "uObjectFadeEnd", Vector2( 0.5f, 0.5f ) ); + shaderEffect.SetUniform( "uAlphaScale", 0.75f ); + shaderEffect.SetUniform( "uModelLastFrame", Matrix::IDENTITY ); + + return shaderEffect; +} }