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