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] position The point ( locates within rectangle {(0,0),(0,1),(1,0),(1,1)} ) passed through by the central line
39 * @param[in] displacement The direction of the central line
40 * @param[in] initialProgress, the normalised initial progress of the shader
42 inline void DissolveEffectSetCentralLine( Actor& actor, const Vector2& position, const Vector2& displacement, float initialProgress )
44 // the line passes through 'position' and has the direction of 'displacement'
45 float coefA, coefB, coefC; //line equation: Ax+By+C=0;
46 coefA = displacement.y;
47 coefB = -displacement.x;
48 coefC = -displacement.y*position.x + displacement.x*position.y;
50 float inversedAABB = 1.f / (coefA*coefA+coefB*coefB);
51 float inversedSqrtAABB = sqrtf(inversedAABB);
54 //saddle surface(Hyperbolic paraboloid)function, used to calculate the dissolve starting time
55 //z = y*y/a/a - x*x/b/b
56 //with our selection of parameters(a and b), this value for any texture coordinate is between -1.0 and 1.0
58 Vector3 saddleParam; // [0]: a*a, [1]: b*b, [2] b
62 if( displacement.x > 0.f || (EqualsZero(displacement.x) && displacement.y > 0.f) )
67 if( (displacement.y * displacement.x < 0.0f) )
69 //distance from (0,0) to the line
70 float distanceTopLeft = fabsf(coefC) * inversedSqrtAABB;
71 //distance from (1, 1 ) to the line
72 float distanceBottomRight = fabsf(coefA+coefB+coefC) * inversedSqrtAABB;
73 saddleA = std::max( distanceTopLeft, distanceBottomRight );
75 //foot of a perpendicular: (1,0) to the line
76 float footX1 = ( coefB*coefB - coefA*coefC) * inversedAABB;
77 float footY1 = (-coefA*coefB - coefB*coefC) * inversedAABB;
78 //foot of a perpendicular: (0,1) to the line
79 float footX2 = (-coefA*coefB - coefA*coefC) * inversedAABB;
80 float footY2 = ( coefA*coefA - coefB*coefC) * inversedAABB;
81 saddleParam[1] = (footX1-footX2)*(footX1-footX2) + (footY1-footY2)*(footY1-footY2);
82 translation = Vector2(-footX2,-footY2);
86 //distance from(1,0) to the line
87 float distanceTopRight = fabsf(coefA+coefC) * inversedSqrtAABB;
88 //distance from(0,1) to the line
89 float distanceBottomLeft = fabsf(coefB+coefC) * inversedSqrtAABB;
90 saddleA = std::max( distanceTopRight, distanceBottomLeft );
91 //foot of a perpendicular: (0,0) to the line
92 float footX3 = (-coefA*coefC) * inversedAABB;
93 float footY3 = (-coefB*coefC) * inversedAABB;
94 //foot of a perpendicular: (1.0,1.0) to the line
95 float footX4 = ( coefB*coefB - coefA*coefB - coefA*coefC) * inversedAABB;
96 float footY4 = (-coefA*coefB + coefA*coefA- coefB*coefC) * inversedAABB;
97 saddleParam[1] = (footX3-footX4)*(footX3-footX4) + (footY3-footY4)*(footY3-footY4);
98 translation = Vector2(-footX3, -footY3);
101 saddleParam[2] = sqrtf(saddleParam[1]);
102 saddleParam[0] = saddleA*saddleA;
103 rotation = Vector2(-displacement.x, displacement.y);
104 rotation.Normalize();
106 actor.RegisterProperty( "uSaddleParam", saddleParam );
107 actor.RegisterProperty( "uTranslation", translation );
108 actor.RegisterProperty( "uRotation", rotation );
109 actor.RegisterProperty( "uToNext", toNext );
110 actor.RegisterProperty( "uPercentage", initialProgress, Dali::Property::ANIMATABLE );
113 * @brief Create a new Dissolve effect
115 * DissolveEffect is a custom shader effect to achieve Dissolve effects in Image actors.
117 * Animatable/Constrainable uniforms:
118 * "uPercentage" - This value is proportional to the distortion applied; a value of zero means no distortion.
120 * @param[in] useHighPrecision True if using high precision in fragment shader for fully random noise, false otherwise
121 * @return The newly created Property::Map with the dissolve effect
124 inline Property::Map CreateDissolveEffect( bool useHighPrecision = true )
126 const char* prefixHighPrecision( "precision highp float;\n");
127 const char* prefixMediumPrecision( "precision mediump float;\n" );
129 const char* vertexShader( DALI_COMPOSE_SHADER(
130 attribute mediump vec2 aPosition;\n
132 uniform mediump mat4 uMvpMatrix;\n
133 uniform vec3 uSize;\n
134 uniform vec4 uTextureRect;
136 uniform float uPercentage;\n
137 uniform vec3 uSaddleParam;\n
138 uniform vec2 uTranslation;\n
139 uniform vec2 uRotation; \n
140 uniform float uToNext;\n
142 varying float vPercentage;\n
143 varying vec2 vTexCoord;\n
147 mediump vec4 vertexPosition = vec4(aPosition, 0.0, 1.0);\n
148 vertexPosition.xyz *= uSize;\n
149 vertexPosition = uMvpMatrix * vertexPosition;\n
150 gl_Position = vertexPosition;\n
152 vec2 texCoord = aPosition + vec2(0.5);
153 vTexCoord = texCoord;\n
154 //Calculate the distortion value given the dissolve central line
155 vec2 value = texCoord + uTranslation; \n
156 mat2 rotateMatrix = mat2( uRotation.s, uRotation.t, -uRotation.t, uRotation.s ); \n
157 value = rotateMatrix * value; \n
158 if(uToNext == 1.0) \n
159 value.s = uSaddleParam[2] + value.s; \n
160 float delay = value.t*value.t / uSaddleParam[0] - value.s*value.s/uSaddleParam[1];\n
161 vPercentage = clamp( uPercentage*2.0 - 0.5*sin(delay*1.571) - 0.5, 0.0, 1.0 ); \n
165 const char* fragmentShader( DALI_COMPOSE_SHADER(
166 varying float vPercentage;\n
167 varying mediump vec2 vTexCoord;\n
169 uniform sampler2D sTexture;\n
170 uniform lowp vec4 uColor;\n
171 uniform vec4 uTextureRect;
173 float rand(vec2 co) \n
175 return fract(sin(dot(co.xy ,vec2(12.9898,78.233))) * 43758.5453); \n
181 //Calculate the randomness
182 float offsetS = rand( vTexCoord * vPercentage ) - vTexCoord.s; \n
183 float offsetT = rand( vec2(vTexCoord.t*vPercentage, vTexCoord.s * vPercentage) ) - vTexCoord.t; \n
184 vec2 lookupCoord = vTexCoord + vec2(offsetS, offsetT) * vPercentage; \n
185 gl_FragColor = texture2D( sTexture, lookupCoord ) * uColor; \n
186 gl_FragColor.a *= 1.0 - vPercentage; \n
192 Property::Map customShader;
194 std::string vertexShaderString;
195 std::string fragmentShaderString;
196 if( useHighPrecision )
198 vertexShaderString.reserve(strlen( prefixHighPrecision ) + strlen( vertexShader ));
199 vertexShaderString.append( prefixHighPrecision );
201 fragmentShaderString.reserve(strlen( prefixHighPrecision ) + strlen( fragmentShader ));
202 fragmentShaderString.append( prefixHighPrecision );
206 vertexShaderString.reserve(strlen( prefixMediumPrecision ) + strlen( vertexShader ));
207 vertexShaderString.append( prefixMediumPrecision );
209 fragmentShaderString.reserve(strlen( prefixMediumPrecision ) + strlen( fragmentShader ));
210 fragmentShaderString.append( prefixMediumPrecision );
213 vertexShaderString.append( vertexShader );
214 fragmentShaderString.append( fragmentShader );
216 customShader[ "vertexShader" ] = vertexShaderString;
217 customShader[ "fragmentShader" ] = fragmentShaderString;
219 customShader[ "subdivideGridX" ] = 20;
220 customShader[ "subdivideGridY" ] = 20;
222 customShader[ "hints" ] = "outputIsTransparent";
224 map[ "shader" ] = customShader;
228 } // namespace Toolkit
232 #endif // __DALI_TOOLKIT_SHADER_EFFECT_DISSOLVE_H__