dali-toolkit/internal/shader-effects/page-turn-effect-impl.cpp

   1 //
   2 // Copyright (c) 2014 Samsung Electronics Co., Ltd.
   3 //
   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
   7 //
   8 //     http://floralicense.org/license/
   9 //
  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.
  15 //
  16
  17 // CLASS HEADER
  18 #include "page-turn-effect-impl.h"
  19
  20 // EXTERNAL HEADERS
  21 #include <sstream>
  22
  23
  24 namespace Dali
  25 {
  26
  27 namespace Toolkit
  28 {
  29
  30 namespace Internal
  31 {
  32
  33 namespace
  34 {
  35 #define MAKE_STRING(A)#A
  36
  37 const std::string CURRENT_CENTER_PROPERTY_NAME("uCurrentCenter");
  38 const std::string ORIGINAL_CENTER_PROPERTY_NAME("uOriginalCenter");
  39 const std::string PAGE_SIZE_PROPERTY_NAME("uPageSize");
  40 const std::string IS_TURNING_BACK_PROPERTY_NAME("uIsTurningBack");
  41 const std::string SHADOW_WIDTH_PROPERTY_NAME("uShadowWidth");
  42 const std::string SPINE_SHADOW_PARAMETER_PROPERTY_NAME("uSpineShadowParameter");
  43
  44 // fake shadow is used to enhance the effect, with its default maximum width to be pageSize * 0.15
  45 const float DEFAULT_SHADOW_WIDTH(0.15f);
  46
  47 // the major&minor radius (in pixels) to form an ellipse shape
  48 // the top-left quarter of this ellipse is used to calculate spine normal for simulating shadow
  49 const Vector2 DEFAULT_SPINE_SHADOW_PARAMETER(50.0f, 20.0f);
  50
  51 // when the vanishing point is very far away(pageHeight*THRESHOLD), make it infinitely, in this case, the page bent horizontally
  52 const float THRESHOLD(20.0);
  53
  54 struct CommonParametersConstraint
  55 {
  56   Matrix operator()( const Matrix& current,
  57                      const PropertyInput& originalCenterProperty,
  58                      const PropertyInput& currentCenterProperty,
  59                      const PropertyInput& pageSizeProperty)
  60   {
  61     const Vector2& originalCenter = originalCenterProperty.GetVector2();
  62     Vector2 currentCenter = currentCenterProperty.GetVector2();
  63     const Vector2& pageSize = pageSizeProperty.GetVector2();
  64
  65     // calculate the curve direction and the vanishing point
  66     // here, the vanishing point is the intersection of spine with the line passing through original center and vertical to curve direction
  67     Vector2 curveDirection( currentCenter - originalCenter );
  68     curveDirection.Normalize();
  69     if( fabs(curveDirection.y) < 0.01f) // eliminate the possibility of division by zero in the next step
  70     {
  71       curveDirection.y = 0.01f;
  72     }
  73     float vanishingPointY = originalCenter.y + curveDirection.x * originalCenter.x / curveDirection.y;
  74
  75     float curveEndY, cosTheta ,sinTheta ,translateX, translateY;
  76     // when the vanishing point is very far away, make it infinitely, in this case, the page bent horizontally
  77     if( fabs(vanishingPointY-pageSize.y*0.5f) >= pageSize.y*THRESHOLD )
  78     {
  79       curveDirection = Vector2(-1.f,0.f);
  80       currentCenter.y = originalCenter.y;
  81
  82       curveEndY = originalCenter.y;
  83       cosTheta = 1.f;
  84       sinTheta = 0.f;
  85       translateX = currentCenter.x - originalCenter.x;
  86       translateY = vanishingPointY;
  87     }
  88     else
  89     {
  90       curveEndY = currentCenter.y - curveDirection.y * (currentCenter.x/curveDirection.x) ;
  91       Vector2 v1( currentCenter.x, currentCenter.y - vanishingPointY );
  92       v1.Normalize();
  93       Vector2 v2( originalCenter.x, originalCenter.y - vanishingPointY );
  94       v2.Normalize();
  95       cosTheta = v1.x*v2.x + v1.y*v2.y;
  96       sinTheta = ( vanishingPointY > pageSize.y*0.5f ) ? sqrt(1.0-cosTheta*cosTheta) : -sqrt(1.0-cosTheta*cosTheta);
  97       translateX = currentCenter.x - cosTheta*originalCenter.x - sinTheta*( originalCenter.y-vanishingPointY );
  98       translateY = currentCenter.y + sinTheta*originalCenter.x - cosTheta*( originalCenter.y-vanishingPointY );
  99     }
 100
 101     float originalLength = fabs(originalCenter.x/curveDirection.x);
 102     float currentLength = fabs(currentCenter.x/curveDirection.x);
 103     float curveHeight = 0.45f*sqrt(originalLength*originalLength - currentLength*currentLength);
 104
 105     Matrix commonParameters( false );
 106     float* parameterArray = commonParameters.AsFloat();
 107     parameterArray[0] = cosTheta;
 108     parameterArray[1] = -sinTheta;
 109     parameterArray[2] = originalCenter.x;
 110     parameterArray[3] = originalCenter.y;
 111     parameterArray[4] = sinTheta;
 112     parameterArray[5] = cosTheta;
 113     parameterArray[6] = currentCenter.x;
 114     parameterArray[7] = currentCenter.y;
 115     parameterArray[8] = translateX;
 116     parameterArray[9] = translateY;
 117     parameterArray[10] = vanishingPointY;
 118     parameterArray[11] = curveEndY;
 119     parameterArray[12] = curveDirection.x;
 120     parameterArray[13] = curveDirection.y;
 121     parameterArray[14] = curveHeight;
 122     parameterArray[15] = currentLength;
 123
 124     return commonParameters;
 125   }
 126 };
 127
 128 }//namespace
 129
 130 PageTurnEffect::PageTurnEffect()
 131 {
 132 }
 133
 134 PageTurnEffect::~PageTurnEffect()
 135 {
 136 }
 137
 138 Toolkit::PageTurnEffect PageTurnEffect::CreateShaderEffect( bool enableBlending )
 139 {
 140   std::string vertexShader = MAKE_STRING(
 141     /*
 142      * The common parameters for all the vertices, calculate in CPU then pass into the shader as uniforms
 143      *
 144      *  first part of the page, (outside the the line passing through original center and vertical to curve direction)
 145      * no Z change, only 2D rotation and translation
 146      * ([0][0],[0][1],[1][0],[1][1]) mat2 rotateMatrix
 147      * ([2][0],[2][1]) vec2 translationVector
 148      *
 149      * ([0][2],[0][3]) vec2 originalCenter: Typically the press down position of the Pan Gesture
 150      * ([1][2],[1][3]) vec2 currentCenter: Typically the current position of the Pan Gesture
 151      * ([3][0],[3][1]) vec2 curveDirection: The normalized vector pointing from original center to current center
 152      * ([2][2]) float vanishingPointY: The Y coordinate of the intersection of the spine
 153      *                                 and the line which goes through the original center and is vertical to the curveDirection
 154      * ([2][3]) float curveEndY: The Y coordinate of intersection of the spine and the line through both original and current center
 155      * ([3][2]) float curveHeight: The height of the interpolated hermite curve.
 156      * ([3][3]) float currentLength: The length from the current center to the curveEnd.
 157      */
 158     uniform mat4 uCommonParameters;\n
 159     \n
 160     uniform vec2 uPageSize;\n
 161     uniform float uIsTurningBack;\n
 162     uniform float uShadowWidth;\n
 163     varying vec3 vNormal;\n
 164     varying vec4 vPosition;\n
 165     varying float vEdgeShadow;\n
 166     \n
 167     void main()\n
 168     {\n
 169       vec4 position = vec4( aPosition.xy, 0.0, 1.0);\n
 170       vec2 currentCenter = vec2( uCommonParameters[1][2], uCommonParameters[1][3]);\n
 171       vec2 originalCenter = vec2( uCommonParameters[0][2], uCommonParameters[0][3]);\n
 172       vec3 normal = vec3(0.0,0.0,1.0);\n
 173       \n
 174       if(currentCenter.x < originalCenter.x)\n
 175       {\n
 176         // change the coordinate origin from the center of the page to its top-left
 177         position.xy += uPageSize * 0.5;\n
 178         vec2 curveDirection = vec2( uCommonParameters[3]);\n
 179         vec3 vanishingPoint = vec3(0.0, uCommonParameters[2][2], 0.0);\n
 180         // first part of the page, (outside the the line passing through original center and vertical to curve direction)
 181         //no Z change, only 2D rotation and translation
 182         if( dot(curveDirection, position.xy - originalCenter) < 0.0 )
 183         {\n
 184           position.y -= vanishingPoint.y;\n
 185           position.xy = mat2(uCommonParameters)*position.xy + vec2( uCommonParameters[2]);\n
 186         }\n
 187          // second part of the page, bent as a ruled surface
 188         else\n
 189         {\n
 190           // calculate on the flat plane, between
 191           // the first line passing through current vertex and vanishing point
 192           // the second line passing through original center and current center
 193           vec2 curveEnd = vec2( 0.0, uCommonParameters[2][3] );\n
 194           vec2 curFlatDirection = vec2(0.0,1.0);\n
 195           float lengthFromCurve = position.y - originalCenter.y;\n
 196           float lengthOnCurve = position.x;\n
 197           if(currentCenter.y != originalCenter.y)\n
 198           {\n
 199             curFlatDirection = normalize(position.xy - vanishingPoint.xy);\n
 200             lengthFromCurve = (curveEnd.x*curveDirection.y-curveEnd.y*curveDirection.x-position.x*curveDirection.y+position.y*curveDirection.x)
 201                             / (curFlatDirection.x*curveDirection.y-curFlatDirection.y*curveDirection.x);\n
 202             lengthOnCurve = length(position.xy+lengthFromCurve*curFlatDirection-curveEnd);\n
 203           }\n
 204           \n
 205           // define the control points of hermite curve, composed with two segments
 206           // calulation is carried out on the 2D plane which is passing through both current and original center and vertical to the image plane
 207           float currentLength = uCommonParameters[3][3];\n
 208           float originalLength =  abs(originalCenter.x/curveDirection.x);\n
 209           float height = uCommonParameters[3][2];\n
 210           float percentage = currentLength/originalLength;\n
 211           //vec2 SegmentOneControlPoint0 = vec2(0.0, 0.0);
 212           vec2 SegmentOneControlPoint1 = vec2((0.65*percentage - 0.15)*originalLength, (0.8 + 0.2 * percentage)*height); \n
 213           vec2 SegmentTwoControlPoint0 = SegmentOneControlPoint1;\n
 214           vec2 SegmentTwoControlPoint1 = vec2(currentLength, 0.0); \n
 215           vec2 SegmentOneTangentVector0 = SegmentOneControlPoint1;\n
 216           vec2 SegmentOneTangentVector1 = vec2(0.5*originalLength,0.0);\n
 217           vec2 SegmentTwoTangentVector0 = SegmentOneTangentVector1;\n
 218           vec2 SegmentTwoTangentVector1 = SegmentOneTangentVector1;\n
 219           \n
 220           // calulate the corresponding curve point position and its tangent vector
 221           // it is a linear mapping onto nonlinear curves, might cause some unwanted deformation
 222           // but as there are no analytical method to calculate the curve length on arbitrary segment
 223           // no efficient way to solve this nonlinear mapping, Numerical approximation would cost too much computation in shader
 224           vec2 curvePoint2D;\n
 225           vec2 tangent;\n
 226           float t0 = lengthOnCurve / originalLength;\n
 227           if(t0<=0.5)\n
 228           {\n
 229             float t = 2.0*t0;\n
 230             float t_2 = t*t;\n
 231             float t_3 = t*t_2;\n
 232             curvePoint2D = (-2.0*t_3+3.0*t_2)*SegmentOneControlPoint1
 233                          + (t_3-2.0*t_2+t)*SegmentOneTangentVector0 + (t_3-t_2)*SegmentOneTangentVector1;\n
 234             tangent = (-6.0*t_2+6.0*t)*SegmentOneControlPoint1
 235                     + (3.0*t_2-4.0*t+1.0)*SegmentOneTangentVector0 + (3.0*t_2-2.0*t)*SegmentOneTangentVector1;\n
 236           }\n
 237           else\n
 238           {\n
 239             float t = 2.0*t0-1.0;\n
 240             float t_2 = t*t;\n
 241             float t_3 = t*t_2;\n
 242             curvePoint2D = (2.0*t_3-3.0*t_2+1.0)*SegmentTwoControlPoint0 + (-2.0*t_3+3.0*t_2)*SegmentTwoControlPoint1
 243                          + (t_3-2.0*t_2+t)*SegmentTwoTangentVector0 + (t_3-t_2)*SegmentTwoTangentVector1;\n
 244             tangent = (6.0*t_2-6.0*t)*SegmentTwoControlPoint0 + (-6.0*t_2+6.0*t)*SegmentTwoControlPoint1
 245                     + (3.0*t_2-4.0*t+1.0)*SegmentTwoTangentVector0 + (3.0*t_2-2.0*t)*SegmentTwoTangentVector1;\n
 246             // a trick to eliminate some optical illusion caused by the gradient matter of normal in per-fragment shading
 247             // which is caused by linear interpolation of normal vs. nonlinear lighting
 248             // will notice some artifact in the areas with dramatically normal changes, so compress the normal differences here
 249             tangent.y *=  min(1.0, length(position.xyz - vanishingPoint) / uPageSize.y ); \n
 250           }\n
 251           vec3 curvePoint = vec3(curveEnd - curvePoint2D.x*curveDirection,max(0.0,curvePoint2D.y));\n
 252           vec3 tangentVector = vec3(-tangent.x*curveDirection,tangent.y);\n
 253           \n
 254           // locate the new vertex position on the line passing through both vanishing point and the calculated curve point position
 255           vec3 curLiftDirection = vec3(0.0,-1.0,0.0);\n
 256           if(currentCenter.y != originalCenter.y)\n
 257           {\n
 258             curLiftDirection = normalize(curvePoint - vanishingPoint);\n
 259             tangentVector *= (curveDirection.y > 0.0) ? -1.0 : 1.0;\n
 260           // an heuristic adjustment here, to compensate the linear parameter mapping onto the nonlinear curve
 261             float Y0 = position.y - curveDirection.y * (position.x/curveDirection.x); \n
 262             float proportion;
 263             float refLength;\n
 264             if(abs(Y0-vanishingPoint.y) > abs(curveEnd.y-vanishingPoint.y)) \n
 265             {\n
 266               proportion = abs(curveEnd.y - Y0) / (abs(curveEnd.y-Y0)+abs(curveEnd.y - vanishingPoint.y)); \n
 267               refLength = proportion*length(originalCenter-vanishingPoint.xy) / (proportion-1.0); \n
 268             }\n
 269             else\n
 270             {\n
 271               proportion = abs(curveEnd.y - Y0) / abs(curveEnd.y - vanishingPoint.y);\n
 272               refLength = proportion*length(originalCenter-vanishingPoint.xy); \n
 273             }\n
 274             float Y1 = currentCenter.y - (normalize(currentCenter-vanishingPoint.xy)).y * refLength; \n
 275             position.y = mix(Y0, Y1, t0); \n
 276           }\n
 277           position.xz = curvePoint.xz - lengthFromCurve*curLiftDirection.xz;\n
 278           // calculate the normal vector, will be used for lighting
 279           normal = cross(curLiftDirection, normalize(tangentVector));\n
 280           // the signature of Z is decided by the page turning direction:
 281           // from left to right(negative); from right to left (positive)
 282           position.z *= -uIsTurningBack;\n
 283           normal.xy *= -uIsTurningBack;\n
 284         }\n
 285         // change the coordinate origin from the top-left of the page to its center
 286         position.xy -= uPageSize * 0.5; \n
 287       }\n
 288       position.z += aPosition.z;\n
 289       gl_Position = uMvpMatrix * position;\n
 290      // varying parameters for fragment shader
 291       vTexCoord = aTexCoord;
 292       vNormal = uNormalMatrix*normal;\n
 293       vPosition = uModelView * position;\n
 294   );
 295
 296   std::string vertexShaderWithFakedShadow = MAKE_STRING(
 297       // display shadow, the fake shadow value is calculated according to the height and the distance from page edge
 298       vTexCoord.x = (aTexCoord.x-sTextureRect.s) /( 1.0 - uShadowWidth ) + sTextureRect.s;\n
 299       vTexCoord.y = ( aTexCoord.y-sTextureRect.t-0.5*uShadowWidth*(sTextureRect.q-sTextureRect.t) )/( 1.0 - uShadowWidth ) + sTextureRect.t;\n
 300       float heightCoef = (1.0 + position.z*uIsTurningBack*3.0 / uPageSize.x) * 0.6;
 301       vEdgeShadow = clamp(0.9 - heightCoef, 0.0, 0.9 ); \n
 302       if( vTexCoord.y >= sTextureRect.q || vTexCoord.y <= sTextureRect.t || vTexCoord.x >= sTextureRect.p  )\n
 303       {\n
 304         float inversedShadowWidth = (1.0-uShadowWidth) / uShadowWidth ;\n
 305         float alpha1 = (vTexCoord.x-sTextureRect.p) * inversedShadowWidth / (sTextureRect.p - sTextureRect.s);\n
 306         inversedShadowWidth = 2.0 * inversedShadowWidth  / (sTextureRect.q - sTextureRect.t); \n
 307         float alpha2 = (vTexCoord.y-sTextureRect.q) * inversedShadowWidth;\n
 308         float alpha3 = (sTextureRect.t-vTexCoord.y) * inversedShadowWidth;\n
 309         float alpha;\n
 310         if(alpha1 > 0.0 && alpha2 > 0.0) alpha = sqrt(alpha2*alpha2+alpha1*alpha1)/sqrt(1.0 + max(alpha1,alpha2)*max(alpha1,alpha2));\n //bottom-right corner
 311         else if(alpha1 > 0.0 && alpha3 > 0.0) alpha = sqrt(alpha3*alpha3+alpha1*alpha1)/sqrt(1.0+max(alpha1,alpha3)*max(alpha1,alpha3));\n //top-right corner
 312         else alpha = max(alpha1,max(alpha2,alpha3)); \n
 313         alpha = 0.9 - alpha*0.9;\n
 314         vEdgeShadow = clamp(alpha - heightCoef, 0.0, 0.9 ); \n
 315       }\n
 316   );
 317
 318   std::string vertexShaderEnd("}");
 319
 320   std::string fragmentShaderPartOne = MAKE_STRING(
 321     uniform vec2 uPageSize;\n
 322     uniform vec2 uSpineShadowParameter;\n
 323     varying vec3 vNormal;\n
 324     varying vec4 vPosition;\n
 325     varying float vEdgeShadow;\n
 326     \n
 327     void main()\n
 328     {\n
 329       // need to re-normalize the interpolated normal
 330       vec3 normal = normalize(vNormal);\n
 331       vec4 texel;\n
 332       float spineShadowCoef = 1.0; \n
 333    );
 334
 335   std::string fragmentShaderWithFakedShadow = MAKE_STRING(
 336       if( vTexCoord.y > sTextureRect.q || vTexCoord.y < sTextureRect.t || vTexCoord.x > sTextureRect.p  )\n
 337          texel = vec4(0.0,0.0,0.0,vEdgeShadow);
 338       else \n
 339   );
 340
 341   std::string fragmentShaderPartTwo = MAKE_STRING(
 342       { \n
 343         // display page content
 344         // display back image of the page, flip the texture
 345         if(  dot(vPosition.xyz, normal) > 0.0 ) texel = texture2D( sTexture, vec2( sTextureRect.p+sTextureRect.s-vTexCoord.x, vTexCoord.y ) );\n
 346         // display front image of the page
 347         else texel = texture2D( sTexture, vTexCoord );\n
 348         // display book spine, a stripe of shadowed texture
 349         float pixelPos = (vTexCoord.x-sTextureRect.s)*uPageSize.x; \n
 350         if(pixelPos < uSpineShadowParameter.x) \n
 351         {\n
 352           float x = pixelPos - uSpineShadowParameter.x;\n
 353           float y = sqrt( uSpineShadowParameter.x*uSpineShadowParameter.x - x*x);\n
 354           spineShadowCoef = normalize( vec2( uSpineShadowParameter.y*x/uSpineShadowParameter.x, y ) ).y;\n
 355         }\n
 356       }\n
 357     // calculate the lighting
 358     // set the ambient color as vec3(0.4);
 359       float lightColor = abs( normal.z ) * 0.6 + 0.4;\n
 360       gl_FragColor = vec4( ( spineShadowCoef* lightColor)* texel.rgb , texel.a ) * uColor;\n
 361     }
 362   );
 363
 364   // Create the implementation, temporarily owned on stack,
 365   Dali::ShaderEffect shaderEffectCustom;
 366   std::ostringstream vertexShaderStringStream;
 367   std::ostringstream fragmentShaderStringStream;
 368   if( enableBlending )
 369   {
 370     vertexShaderStringStream<< vertexShader << vertexShaderWithFakedShadow << vertexShaderEnd;
 371     fragmentShaderStringStream<< fragmentShaderPartOne << fragmentShaderWithFakedShadow << fragmentShaderPartTwo;
 372     shaderEffectCustom = Dali::ShaderEffect::New( vertexShaderStringStream.str(), fragmentShaderStringStream.str(), GeometryType( GEOMETRY_TYPE_IMAGE ),
 373             ShaderEffect::GeometryHints( ShaderEffect::HINT_GRID | ShaderEffect::HINT_DEPTH_BUFFER | ShaderEffect::HINT_BLENDING) );
 374   }
 375   else
 376   {
 377     vertexShaderStringStream<< vertexShader << vertexShaderEnd;
 378     fragmentShaderStringStream<< fragmentShaderPartOne << fragmentShaderPartTwo;
 379     shaderEffectCustom = Dali::ShaderEffect::New( vertexShaderStringStream.str(), fragmentShaderStringStream.str(), GeometryType( GEOMETRY_TYPE_IMAGE ),
 380             ShaderEffect::GeometryHints( ShaderEffect::HINT_GRID | ShaderEffect::HINT_DEPTH_BUFFER ) );
 381   }
 382
 383   PageTurnEffect* shaderImpl = new PageTurnEffect();
 384   Dali::Toolkit::PageTurnEffect handle = Toolkit::PageTurnEffect( shaderEffectCustom, shaderImpl );
 385
 386   shaderImpl->Initialize( handle );
 387
 388   Vector2 defaultPageSize = Dali::Stage::GetCurrent().GetSize();
 389   Matrix zeroMatrix(true);
 390   handle.SetUniform( "uCommonParameters", zeroMatrix );
 391   handle.SetUniform( PAGE_SIZE_PROPERTY_NAME, defaultPageSize/(1.f-DEFAULT_SHADOW_WIDTH) );
 392   handle.SetUniform( SHADOW_WIDTH_PROPERTY_NAME, DEFAULT_SHADOW_WIDTH );
 393   handle.SetUniform( SPINE_SHADOW_PARAMETER_PROPERTY_NAME, DEFAULT_SPINE_SHADOW_PARAMETER );
 394
 395   shaderImpl->mOriginalCenterPropertyIndex = handle.RegisterProperty( ORIGINAL_CENTER_PROPERTY_NAME, Vector2( defaultPageSize[0], defaultPageSize[1]*0.5f ) );
 396   shaderImpl->mCurrentCenterPropertyIndex = handle.RegisterProperty( CURRENT_CENTER_PROPERTY_NAME, Vector2( defaultPageSize[0], defaultPageSize[1]*0.5f ) );
 397   shaderImpl->mInternalConstraint = Constraint::New<Matrix>( handle.GetPropertyIndex( "uCommonParameters" ),
 398                                                         LocalSource( shaderImpl->mOriginalCenterPropertyIndex ),
 399                                                         LocalSource( shaderImpl->mCurrentCenterPropertyIndex ),
 400                                                         LocalSource( handle.GetPropertyIndex( PAGE_SIZE_PROPERTY_NAME ) ),
 401                                                         CommonParametersConstraint() );
 402   handle.ApplyConstraint( shaderImpl->mInternalConstraint );
 403
 404   // setting isTurningBack to -1.0f here means turning page forward
 405   handle.SetUniform( IS_TURNING_BACK_PROPERTY_NAME, -1.0f );
 406
 407   return handle;
 408 }
 409
 410 void PageTurnEffect::SetPageSize(const Vector2& pageSize)
 411 {
 412   mShaderEffect.SetUniform(PAGE_SIZE_PROPERTY_NAME, pageSize);
 413 }
 414
 415 void PageTurnEffect::SetOriginalCenter(const Vector2& originalCenter)
 416 {
 417   mShaderEffect.SetProperty( mOriginalCenterPropertyIndex, originalCenter );
 418 }
 419
 420 void PageTurnEffect::SetCurrentCenter(const Vector2& currentCenter)
 421 {
 422   mShaderEffect.SetProperty( mCurrentCenterPropertyIndex, currentCenter );
 423 }
 424
 425 void PageTurnEffect::SetIsTurningBack(bool isTurningBack)
 426 {
 427   float direction = isTurningBack ? 1.0f : -1.0f;
 428   mShaderEffect.SetUniform(IS_TURNING_BACK_PROPERTY_NAME, direction);
 429 }
 430
 431 void PageTurnEffect::SetShadowWidth(float shadowWidth)
 432 {
 433   mShaderEffect.SetUniform( SHADOW_WIDTH_PROPERTY_NAME, shadowWidth );
 434 }
 435
 436 void PageTurnEffect::SetSpineShadowParameter(const Vector2& spineShadowParameter)
 437 {
 438   mShaderEffect.SetUniform( SPINE_SHADOW_PARAMETER_PROPERTY_NAME, spineShadowParameter);
 439 }
 440
 441 void PageTurnEffect::ApplyInternalConstraint()
 442 {
 443   mShaderEffect.ApplyConstraint( mInternalConstraint );
 444 }
 445
 446 const std::string& PageTurnEffect::GetPageSizePropertyName() const
 447 {
 448   return PAGE_SIZE_PROPERTY_NAME;
 449 }
 450
 451 const std::string& PageTurnEffect::GetOriginalCenterPropertyName() const
 452 {
 453   return ORIGINAL_CENTER_PROPERTY_NAME;
 454 }
 455
 456 const std::string& PageTurnEffect::GetCurrentCenterPropertyName() const
 457 {
 458   return CURRENT_CENTER_PROPERTY_NAME;
 459 }
 460
 461 void PageTurnEffect::Initialize( Dali::ShaderEffect shaderEffect )
 462 {
 463   // Save a reference to the shader handle
 464   mShaderEffect = shaderEffect;
 465 }
 466
 467 } // namespace Internal
 468
 469 } // namespace Toolkit
 470
 471 } // namespace Dali