{
/**
- * @brief DissolveEffect is a custom shader effect to achieve Dissolve effects in Image actors.
+ * @brief Set the dissolve central line.
+ *
+ * Use one point (position) and one direction ( displacement ) vector to define this line
+ * As we use the texture coordinate as pixel position to calculate random offset,
+ * the line should passing through rectangle {(0,0),(0,1),(1,0),(1,1)},
+ * so make the position parameter with two component values between 0.0 to 1.0
+ * @param[in] dissolveEffect The shader effect
+ * @param[in] position The point ( locates within rectangle {(0,0),(0,1),(1,0),(1,1)} ) passed through by the central line
+ * @param[in] displacement The direction of the central line
+ */
+inline void DissolveEffectSetCentralLine( ShaderEffect& dissolveEffect, const Vector2& position, const Vector2& displacement )
+{
+ // the line passes through 'position' and has the direction of 'displacement'
+ float coefA, coefB, coefC; //line equation: Ax+By+C=0;
+ coefA = displacement.y;
+ coefB = -displacement.x;
+ coefC = -displacement.y*position.x + displacement.x*position.y;
+
+ float inversedAABB = 1.f / (coefA*coefA+coefB*coefB);
+ float inversedSqrtAABB = sqrtf(inversedAABB);
+ float saddleA;
+
+ //saddle surface(Hyperbolic paraboloid)function, used to calculate the dissolve starting time
+ //z = y*y/a/a - x*x/b/b
+ //with our selection of parameters(a and b), this value for any texture coordinate is between -1.0 and 1.0
+
+ Vector3 saddleParam; // [0]: a*a, [1]: b*b, [2] b
+ Vector2 translation;
+ Vector2 rotation;
+ float toNext = -1.f;
+ if( displacement.x > 0.f || (EqualsZero(displacement.x) && displacement.y > 0.f) )
+ {
+ toNext = 1.f;
+ }
+
+ if( (displacement.y * displacement.x < 0.0f) )
+ {
+ //distance from (0,0) to the line
+ float distanceTopLeft = fabsf(coefC) * inversedSqrtAABB;
+ //distance from (1, 1 ) to the line
+ float distanceBottomRight = fabsf(coefA+coefB+coefC) * inversedSqrtAABB;
+ saddleA = std::max( distanceTopLeft, distanceBottomRight );
+
+ //foot of a perpendicular: (1,0) to the line
+ float footX1 = ( coefB*coefB - coefA*coefC) * inversedAABB;
+ float footY1 = (-coefA*coefB - coefB*coefC) * inversedAABB;
+ //foot of a perpendicular: (0,1) to the line
+ float footX2 = (-coefA*coefB - coefA*coefC) * inversedAABB;
+ float footY2 = ( coefA*coefA - coefB*coefC) * inversedAABB;
+ saddleParam[1] = (footX1-footX2)*(footX1-footX2) + (footY1-footY2)*(footY1-footY2);
+ translation = Vector2(-footX2,-footY2);
+ }
+ else
+ {
+ //distance from(1,0) to the line
+ float distanceTopRight = fabsf(coefA+coefC) * inversedSqrtAABB;
+ //distance from(0,1) to the line
+ float distanceBottomLeft = fabsf(coefB+coefC) * inversedSqrtAABB;
+ saddleA = std::max( distanceTopRight, distanceBottomLeft );
+ //foot of a perpendicular: (0,0) to the line
+ float footX3 = (-coefA*coefC) * inversedAABB;
+ float footY3 = (-coefB*coefC) * inversedAABB;
+ //foot of a perpendicular: (1.0,1.0) to the line
+ float footX4 = ( coefB*coefB - coefA*coefB - coefA*coefC) * inversedAABB;
+ float footY4 = (-coefA*coefB + coefA*coefA- coefB*coefC) * inversedAABB;
+ saddleParam[1] = (footX3-footX4)*(footX3-footX4) + (footY3-footY4)*(footY3-footY4);
+ translation = Vector2(-footX3, -footY3);
+ }
+
+ saddleParam[2] = sqrtf(saddleParam[1]);
+ saddleParam[0] = saddleA*saddleA;
+ rotation = Vector2(-displacement.x, displacement.y);
+ rotation.Normalize();
+
+ dissolveEffect.SetUniform( "uSaddleParam", saddleParam );
+ dissolveEffect.SetUniform( "uTranslation", translation );
+ dissolveEffect.SetUniform( "uRotation", rotation );
+ dissolveEffect.SetUniform( "uToNext", toNext );
+}
+/**
+ * @brief Create a new Dissolve effect
+ *
+ * DissolveEffect is a custom shader effect to achieve Dissolve effects in Image actors.
+ *
+ * Animatable/Constrainable uniforms:
+ * "uPercentage" - This value is proportional to the distortion applied; a value of zero means no distortion.
+ *
+ * @param[in] useHighPrecision True if using high precision in fragment shader for fully random noise, false otherwise
+ * @return A handle to a newly allocated ShaderEffect
*/
-class DALI_IMPORT_API DissolveEffect : public ShaderEffect
+
+inline ShaderEffect CreateDissolveEffect(bool useHighPrecision = true)
{
-public:
-
- /**
- * @brief Create an uninitialized DissolveEffect; this can be initialized with DissolveEffect::New().
- *
- * Calling member functions with an uninitialized Dali::Object is not allowed.
- */
- DissolveEffect();
-
- /**
- * @brief Destructor
- *
- * This is non-virtual since derived Handle types must not contain data or virtual methods.
- */
- ~DissolveEffect();
-
- /**
- * @brief Create an initialized DissolveEffect.
- *
- * @param[in] useHighPrecision True if using high precision in fragment shader for fully random noise, false otherwise
- * @return A handle to a newly allocated Dali resource.
- */
- static DissolveEffect New( bool useHighPrecision = true);
-
- /**
- * @brief Set the dissolve central line.
- *
- * Use one point (position) and one direction ( displacement ) vector to define this line
- * As we use the texture coordinate as pixel position to calculate random offset,
- * the line should passing through rectangle {(0,0),(0,1),(1,0),(1,1)},
- * so make the position parameter with two component values between 0.0 to 1.0
- * @param[in] position The point ( locates within rectangle {(0,0),(0,1),(1,0),(1,1)} ) passed through by the central line
- * @param[in] displacement The direction of the central line
- */
- void SetCentralLine( const Vector2& position, const Vector2& displacement );
-
- /**
- * @brief Sets the distortion applied to the effect texture.
- *
- * This value is proportional to the distortion applied; a value of zero means no distortion.
- * @param [in] distortion The distortion value.
- */
- void SetDistortion( float distortion );
-
- /**
- * @brief Get the name for the distortion property.
- *
- * @return A std::string containing the property name
- */
- const std::string& GetDistortionPropertyName() const;
-
-private: // Not intended for application developers
- DALI_INTERNAL DissolveEffect(ShaderEffect handle);
-};
+ std::string prefixHighPrecision( "precision highp float;\n");
+ std::string prefixMediumPrecision( "precision mediump float;\n" );
+ std::string vertexShader(
+ "uniform float uPercentage;\n"
+ "uniform vec3 uSaddleParam;\n"
+ "uniform vec2 uTranslation;\n"
+ "uniform vec2 uRotation; \n"
+ "uniform float uToNext;\n"
+ "varying float vPercentage;\n"
+ "void main()\n"
+ "{\n"
+ "gl_Position = uProjection * uModelView * vec4(aPosition, 1.0);\n"
+ "vTexCoord = aTexCoord;\n"
+ //Calculate the distortion value given the dissolve central line
+ "vec2 texCoor = vec2( (aTexCoord.s - sTextureRect.s ) / (sTextureRect.p - sTextureRect.s), (aTexCoord.t- sTextureRect.t)/(sTextureRect.q - sTextureRect.t) ); \n"
+ "vec2 value = texCoor + uTranslation; \n"
+ "mat2 rotateMatrix = mat2( uRotation.s, uRotation.t, -uRotation.t, uRotation.s ); \n"
+ "value = rotateMatrix * value; \n"
+ "if(uToNext == 1.0) \n"
+ " value.s = uSaddleParam[2] + value.s; \n"
+ "float delay = value.t*value.t / uSaddleParam[0] - value.s*value.s/uSaddleParam[1];\n"
+ "vPercentage = clamp( uPercentage*2.0 - 0.5*sin(delay*1.571) - 0.5, 0.0, 1.0 ); \n"
+ "}\n");
+ std::string fragmentShader(
+ "varying float vPercentage;\n"
+ "float rand(vec2 co) \n"
+ "{\n"
+ " return fract(sin(dot(co.xy ,vec2(12.9898,78.233))) * 43758.5453); \n"
+ "}\n"
+ "void main()\n"
+ "{\n"
+ //Calculate the randomness
+ "float offsetS = rand( vTexCoord * vPercentage ) * (sTextureRect.p - sTextureRect.s) - vTexCoord.s + sTextureRect.s; \n"
+ "float offsetT = rand( vec2(vTexCoord.t*vPercentage, vTexCoord.s * vPercentage) ) * (sTextureRect.q - sTextureRect.t) - vTexCoord.t + sTextureRect.t; \n"
+ "vec2 lookupCoord = vTexCoord + vec2(offsetS, offsetT) * vPercentage; \n"
+ "gl_FragColor = texture2D( sTexture, lookupCoord ) * uColor; \n"
+ "gl_FragColor.a *= 1.0 - vPercentage; \n"
+ "}" );
+
+ // Create the implementation, temporarily owned on stack,
+ Dali::ShaderEffect shaderEffect;
+ if( useHighPrecision )
+ {
+ shaderEffect = Dali::ShaderEffect::New(
+ prefixHighPrecision+vertexShader, prefixHighPrecision + fragmentShader,
+ GeometryType( GEOMETRY_TYPE_IMAGE),
+ ShaderEffect::GeometryHints( ShaderEffect::HINT_GRID | ShaderEffect::HINT_BLENDING ) );
+ }
+ else
+ {
+ shaderEffect = Dali::ShaderEffect::New(
+ prefixMediumPrecision+vertexShader, prefixMediumPrecision + fragmentShader,
+ GeometryType( GEOMETRY_TYPE_IMAGE),
+ ShaderEffect::GeometryHints( ShaderEffect::HINT_GRID | ShaderEffect::HINT_BLENDING ) );
+ }
+
+ shaderEffect.SetUniform( "uPercentage", 0.0f );
+ shaderEffect.SetProperty( ShaderEffect::Property::GRID_DENSITY, Dali::Property::Value(50.0f) );
+
+ DissolveEffectSetCentralLine( shaderEffect, Vector2(1.0f,0.5f), Vector2(-1.0f, 0.0f) );
+
+ return shaderEffect;
+
+}
} // namespace Toolkit