2 // Copyright (c) 2014 Samsung Electronics Co., Ltd.
4 // Licensed under the Flora License, Version 1.0 (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://floralicense.org/license/
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.
17 #include <dali-toolkit/public-api/shader-effects/dissolve-effect.h>
28 const std::string DISTORTION_PROPERTY_NAME( "uPercentage" );
32 DissolveEffect::DissolveEffect()
36 //Call the Parent copy constructor to add reference to the implementation for this object
37 DissolveEffect::DissolveEffect(ShaderEffect handle)
42 DissolveEffect::~DissolveEffect()
47 DissolveEffect DissolveEffect::New( bool useHighPrecision )
49 std::string prefixHighPrecision( "precision highp float;\n");
50 std::string prefixMediumPrecision( "precision mediump float;\n" );
51 std::string vertexShader(
52 "uniform float uPercentage;\n"
53 "uniform vec3 uSaddleParam;\n"
54 "uniform vec2 uTranslation;\n"
55 "uniform vec2 uRotation; \n"
56 "uniform float uToNext;\n"
57 "varying float vPercentage;\n"
60 "gl_Position = uProjection * uModelView * vec4(aPosition, 1.0);\n"
61 "vTexCoord = aTexCoord;\n"
62 //Calculate the distortion value given the dissolve central line
63 "vec2 texCoor = vec2( (aTexCoord.s - sTextureRect.s ) / (sTextureRect.p - sTextureRect.s), (aTexCoord.t- sTextureRect.t)/(sTextureRect.q - sTextureRect.t) ); \n"
64 "vec2 value = texCoor + uTranslation; \n"
65 "mat2 rotateMatrix = mat2( uRotation.s, uRotation.t, -uRotation.t, uRotation.s ); \n"
66 "value = rotateMatrix * value; \n"
67 "if(uToNext == 1.0) \n"
68 " value.s = uSaddleParam[2] + value.s; \n"
69 "float delay = value.t*value.t / uSaddleParam[0] - value.s*value.s/uSaddleParam[1];\n"
70 "vPercentage = clamp( uPercentage*2.0 - 0.5*sin(delay*1.571) - 0.5, 0.0, 1.0 ); \n"
72 std::string fragmentShader(
73 "varying float vPercentage;\n"
74 "float rand(vec2 co) \n"
76 " return fract(sin(dot(co.xy ,vec2(12.9898,78.233))) * 43758.5453); \n"
80 //Calculate the randomness
81 "float offsetS = rand( vTexCoord * vPercentage ) * (sTextureRect.p - sTextureRect.s) - vTexCoord.s + sTextureRect.s; \n"
82 "float offsetT = rand( vec2(vTexCoord.t*vPercentage, vTexCoord.s * vPercentage) ) * (sTextureRect.q - sTextureRect.t) - vTexCoord.t + sTextureRect.t; \n"
83 "vec2 lookupCoord = vTexCoord + vec2(offsetS, offsetT) * vPercentage; \n"
84 "gl_FragColor = texture2D( sTexture, lookupCoord ) * uColor; \n"
85 "gl_FragColor.a *= 1.0 - vPercentage; \n"
88 // Create the implementation, temporarily owned on stack,
89 Dali::ShaderEffect shaderEffectCustom;
90 if( useHighPrecision )
92 shaderEffectCustom = Dali::ShaderEffect::New( vertexShader, prefixHighPrecision + fragmentShader,
93 GeometryType( GEOMETRY_TYPE_IMAGE),
94 ShaderEffect::GeometryHints( ShaderEffect::HINT_GRID | ShaderEffect::HINT_BLENDING ) );
98 shaderEffectCustom = Dali::ShaderEffect::New( vertexShader, prefixMediumPrecision + fragmentShader,
99 GeometryType( GEOMETRY_TYPE_IMAGE),
100 ShaderEffect::GeometryHints( ShaderEffect::HINT_GRID | ShaderEffect::HINT_BLENDING ) );
103 /* Pass ownership to DissolveEffect through overloaded constructor, So that it now has access to the
104 Dali::ShaderEffect implementation */
105 Dali::Toolkit::DissolveEffect handle( shaderEffectCustom );
107 handle.SetUniform( DISTORTION_PROPERTY_NAME, 0.0f );
108 handle.SetProperty( ShaderEffect::GRID_DENSITY, Property::Value(50.0f) );
110 handle.SetCentralLine( Vector2(1.0f,0.5f), Vector2(-1.0f, 0.0f) );
115 void DissolveEffect::SetCentralLine( const Vector2& position, const Vector2& displacement )
117 // the line passes through 'position' and has the direction of 'displacement'
118 float coefA, coefB, coefC; //line equation: Ax+By+C=0;
119 coefA = displacement.y;
120 coefB = -displacement.x;
121 coefC = -displacement.y*position.x + displacement.x*position.y;
123 float inversedAABB = 1.f / (coefA*coefA+coefB*coefB);
124 float inversedSqrtAABB = sqrtf(inversedAABB);
127 //saddle surface(Hyperbolic paraboloid)function, used to calculate the dissolve starting time
128 //z = y*y/a/a - x*x/b/b
129 //with our selection of parameters(a and b), this value for any texture coordinate is between -1.0 and 1.0
131 Vector3 saddleParam; // [0]: a*a, [1]: b*b, [2] b
135 if( displacement.x > 0.f || (EqualsZero(displacement.x) && displacement.y > 0.f) )
140 if( (displacement.y * displacement.x < 0.0f) )
142 //distance from (0,0) to the line
143 float distanceTopLeft = fabsf(coefC) * inversedSqrtAABB;
144 //distance from (1, 1 ) to the line
145 float distanceBottomRight = fabsf(coefA+coefB+coefC) * inversedSqrtAABB;
146 saddleA = std::max( distanceTopLeft, distanceBottomRight );
148 //foot of a perpendicular: (1,0) to the line
149 float footX1 = ( coefB*coefB - coefA*coefC) * inversedAABB;
150 float footY1 = (-coefA*coefB - coefB*coefC) * inversedAABB;
151 //foot of a perpendicular: (0,1) to the line
152 float footX2 = (-coefA*coefB - coefA*coefC) * inversedAABB;
153 float footY2 = ( coefA*coefA - coefB*coefC) * inversedAABB;
154 saddleParam[1] = (footX1-footX2)*(footX1-footX2) + (footY1-footY2)*(footY1-footY2);
155 translation = Vector2(-footX2,-footY2);
159 //distance from(1,0) to the line
160 float distanceTopRight = fabsf(coefA+coefC) * inversedSqrtAABB;
161 //distance from(0,1) to the line
162 float distanceBottomLeft = fabsf(coefB+coefC) * inversedSqrtAABB;
163 saddleA = std::max( distanceTopRight, distanceBottomLeft );
164 //foot of a perpendicular: (0,0) to the line
165 float footX3 = (-coefA*coefC) * inversedAABB;
166 float footY3 = (-coefB*coefC) * inversedAABB;
167 //foot of a perpendicular: (1.0,1.0) to the line
168 float footX4 = ( coefB*coefB - coefA*coefB - coefA*coefC) * inversedAABB;
169 float footY4 = (-coefA*coefB + coefA*coefA- coefB*coefC) * inversedAABB;
170 saddleParam[1] = (footX3-footX4)*(footX3-footX4) + (footY3-footY4)*(footY3-footY4);
171 translation = Vector2(-footX3, -footY3);
174 saddleParam[2] = sqrtf(saddleParam[1]);
175 saddleParam[0] = saddleA*saddleA;
176 rotation = Vector2(-displacement.x, displacement.y);
177 rotation.Normalize();
179 SetUniform( "uSaddleParam", saddleParam );
180 SetUniform( "uTranslation", translation );
181 SetUniform( "uRotation", rotation );
182 SetUniform( "uToNext", toNext );
186 void DissolveEffect::SetDistortion( float distortion )
188 SetUniform( DISTORTION_PROPERTY_NAME, distortion );
191 const std::string& DissolveEffect::GetDistortionPropertyName() const
193 return DISTORTION_PROPERTY_NAME;
196 } // namespace Toolkit