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

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