1 #ifndef __DALI_TOOLKIT_SHADER_EFFECT_DISSOLVE_H__
2 #define __DALI_TOOLKIT_SHADER_EFFECT_DISSOLVE_H__
5 * Copyright (c) 2015 Samsung Electronics Co., Ltd.
7 * Licensed under the Apache License, Version 2.0 (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://www.apache.org/licenses/LICENSE-2.0
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/devel-api/rendering/shader.h>
32 * @brief Set the dissolve central line.
34 * Use one point (position) and one direction ( displacement ) vector to define this line
35 * As we use the texture coordinate as pixel position to calculate random offset,
36 * the line should passing through rectangle {(0,0),(0,1),(1,0),(1,1)},
37 * so make the position parameter with two component values between 0.0 to 1.0
38 * @param[in] actor The actor that registers the uniform properties
39 * @param[in] position The point ( locates within rectangle {(0,0),(0,1),(1,0),(1,1)} ) passed through by the central line
40 * @param[in] displacement The direction of the central line
41 * @param[in] initialProgress The normalised initial progress of the shader
43 inline void DissolveEffectSetCentralLine( Actor& actor, const Vector2& position, const Vector2& displacement, float initialProgress )
45 // the line passes through 'position' and has the direction of 'displacement'
46 float coefA, coefB, coefC; //line equation: Ax+By+C=0;
47 coefA = displacement.y;
48 coefB = -displacement.x;
49 coefC = -displacement.y*position.x + displacement.x*position.y;
51 float inversedAABB = 1.f / (coefA*coefA+coefB*coefB);
52 float inversedSqrtAABB = sqrtf(inversedAABB);
55 //saddle surface(Hyperbolic paraboloid)function, used to calculate the dissolve starting time
56 //z = y*y/a/a - x*x/b/b
57 //with our selection of parameters(a and b), this value for any texture coordinate is between -1.0 and 1.0
59 Vector3 saddleParam; // [0]: a*a, [1]: b*b, [2] b
63 if( displacement.x > 0.f || (EqualsZero(displacement.x) && displacement.y > 0.f) )
68 if( (displacement.y * displacement.x < 0.0f) )
70 //distance from (0,0) to the line
71 float distanceTopLeft = fabsf(coefC) * inversedSqrtAABB;
72 //distance from (1, 1 ) to the line
73 float distanceBottomRight = fabsf(coefA+coefB+coefC) * inversedSqrtAABB;
74 saddleA = std::max( distanceTopLeft, distanceBottomRight );
76 //foot of a perpendicular: (1,0) to the line
77 float footX1 = ( coefB*coefB - coefA*coefC) * inversedAABB;
78 float footY1 = (-coefA*coefB - coefB*coefC) * inversedAABB;
79 //foot of a perpendicular: (0,1) to the line
80 float footX2 = (-coefA*coefB - coefA*coefC) * inversedAABB;
81 float footY2 = ( coefA*coefA - coefB*coefC) * inversedAABB;
82 saddleParam[1] = (footX1-footX2)*(footX1-footX2) + (footY1-footY2)*(footY1-footY2);
83 translation = Vector2(-footX2,-footY2);
87 //distance from(1,0) to the line
88 float distanceTopRight = fabsf(coefA+coefC) * inversedSqrtAABB;
89 //distance from(0,1) to the line
90 float distanceBottomLeft = fabsf(coefB+coefC) * inversedSqrtAABB;
91 saddleA = std::max( distanceTopRight, distanceBottomLeft );
92 //foot of a perpendicular: (0,0) to the line
93 float footX3 = (-coefA*coefC) * inversedAABB;
94 float footY3 = (-coefB*coefC) * inversedAABB;
95 //foot of a perpendicular: (1.0,1.0) to the line
96 float footX4 = ( coefB*coefB - coefA*coefB - coefA*coefC) * inversedAABB;
97 float footY4 = (-coefA*coefB + coefA*coefA- coefB*coefC) * inversedAABB;
98 saddleParam[1] = (footX3-footX4)*(footX3-footX4) + (footY3-footY4)*(footY3-footY4);
99 translation = Vector2(-footX3, -footY3);
102 saddleParam[2] = sqrtf(saddleParam[1]);
103 saddleParam[0] = saddleA*saddleA;
104 rotation = Vector2(-displacement.x, displacement.y);
105 rotation.Normalize();
107 actor.RegisterProperty( "uSaddleParam", saddleParam );
108 actor.RegisterProperty( "uTranslation", translation );
109 actor.RegisterProperty( "uRotation", rotation );
110 actor.RegisterProperty( "uToNext", toNext );
111 actor.RegisterProperty( "uPercentage", initialProgress, Dali::Property::ANIMATABLE );
114 * @brief Create a new Dissolve effect
116 * DissolveEffect is a custom shader effect to achieve Dissolve effects in Image actors.
118 * Animatable/Constrainable uniforms:
119 * "uPercentage" - This value is proportional to the distortion applied; a value of zero means no distortion.
121 * @param[in] useHighPrecision True if using high precision in fragment shader for fully random noise, false otherwise
122 * @return The newly created Property::Map with the dissolve effect
125 inline Property::Map CreateDissolveEffect( bool useHighPrecision = true )
127 const char* prefixHighPrecision( "precision highp float;\n");
128 const char* prefixMediumPrecision( "precision mediump float;\n" );
130 const char* vertexShader( DALI_COMPOSE_SHADER(
131 attribute mediump vec2 aPosition;\n
133 uniform mediump mat4 uMvpMatrix;\n
134 uniform vec3 uSize;\n
135 uniform vec4 uTextureRect;
137 uniform float uPercentage;\n
138 uniform vec3 uSaddleParam;\n
139 uniform vec2 uTranslation;\n
140 uniform vec2 uRotation; \n
141 uniform float uToNext;\n
143 varying float vPercentage;\n
144 varying vec2 vTexCoord;\n
148 mediump vec4 vertexPosition = vec4(aPosition, 0.0, 1.0);\n
149 vertexPosition.xyz *= uSize;\n
150 vertexPosition = uMvpMatrix * vertexPosition;\n
151 gl_Position = vertexPosition;\n
153 vec2 texCoord = aPosition + vec2(0.5);
154 vTexCoord = texCoord;\n
155 //Calculate the distortion value given the dissolve central line
156 vec2 value = texCoord + uTranslation; \n
157 mat2 rotateMatrix = mat2( uRotation.s, uRotation.t, -uRotation.t, uRotation.s ); \n
158 value = rotateMatrix * value; \n
159 if(uToNext == 1.0) \n
160 value.s = uSaddleParam[2] + value.s; \n
161 float delay = value.t*value.t / uSaddleParam[0] - value.s*value.s/uSaddleParam[1];\n
162 vPercentage = clamp( uPercentage*2.0 - 0.5*sin(delay*1.571) - 0.5, 0.0, 1.0 ); \n
166 const char* fragmentShader( DALI_COMPOSE_SHADER(
167 varying float vPercentage;\n
168 varying mediump vec2 vTexCoord;\n
170 uniform sampler2D sTexture;\n
171 uniform lowp vec4 uColor;\n
172 uniform vec4 uTextureRect;
174 float rand(vec2 co) \n
176 return fract(sin(dot(co.xy ,vec2(12.9898,78.233))) * 43758.5453); \n
182 //Calculate the randomness
183 float offsetS = rand( vTexCoord * vPercentage ) - vTexCoord.s; \n
184 float offsetT = rand( vec2(vTexCoord.t*vPercentage, vTexCoord.s * vPercentage) ) - vTexCoord.t; \n
185 vec2 lookupCoord = vTexCoord + vec2(offsetS, offsetT) * vPercentage; \n
186 gl_FragColor = texture2D( sTexture, lookupCoord ) * uColor; \n
187 gl_FragColor.a *= 1.0 - vPercentage; \n
193 Property::Map customShader;
195 std::string vertexShaderString;
196 std::string fragmentShaderString;
197 if( useHighPrecision )
199 vertexShaderString.reserve(strlen( prefixHighPrecision ) + strlen( vertexShader ));
200 vertexShaderString.append( prefixHighPrecision );
202 fragmentShaderString.reserve(strlen( prefixHighPrecision ) + strlen( fragmentShader ));
203 fragmentShaderString.append( prefixHighPrecision );
207 vertexShaderString.reserve(strlen( prefixMediumPrecision ) + strlen( vertexShader ));
208 vertexShaderString.append( prefixMediumPrecision );
210 fragmentShaderString.reserve(strlen( prefixMediumPrecision ) + strlen( fragmentShader ));
211 fragmentShaderString.append( prefixMediumPrecision );
214 vertexShaderString.append( vertexShader );
215 fragmentShaderString.append( fragmentShader );
217 customShader[ "vertexShader" ] = vertexShaderString;
218 customShader[ "fragmentShader" ] = fragmentShaderString;
220 customShader[ "subdivideGridX" ] = 20;
221 customShader[ "subdivideGridY" ] = 20;
223 customShader[ "hints" ] = "outputIsTransparent";
225 map[ "shader" ] = customShader;
229 } // namespace Toolkit
233 #endif // __DALI_TOOLKIT_SHADER_EFFECT_DISSOLVE_H__