optional/dali-toolkit/public-api/shader-effects/nine-patch-mask-effect.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 <dali-toolkit/public-api/shader-effects/nine-patch-mask-effect.h>
  20
  21 // EXTERNAL INCLUDES
  22 #include <dali/public-api/shader-effects/shader-effect.h>
  23
  24 namespace Dali
  25 {
  26
  27 namespace Toolkit
  28 {
  29
  30 namespace NinePatchMaskEffect
  31 {
  32
  33 struct NinePatchMaskEffectSizeConstraint
  34 {
  35   Vector2 operator()( const Vector2& current, const PropertyInput& property )
  36   {
  37     const Vector3& actorSize = property.GetVector3();
  38     return Vector2( actorSize.x, actorSize.y );
  39   }
  40 };
  41
  42 static void DoApply( ImageActor actor, const std::string& maskImage, const Vector2& maskSize, Vector4 maskBorder )
  43 {
  44   const char* ALPHA_MASK_VERTEX_SHADER_SOURCE =
  45   "precision mediump float;\n"
  46   "uniform vec2 uImageSize;                                                       \n"
  47   "uniform vec2 uMaskSize;                                                        \n"
  48   "varying vec2 vMaskTexCoord;                                                    \n"
  49   "                                                                               \n"
  50   "void main()                                                                    \n"
  51   "{                                                                              \n"
  52   "  gl_Position = uMvpMatrix * vec4(aPosition, 1.0);                             \n"
  53   "                                                                               \n"
  54   "  // Ignore mask UVs for image                                                 \n"
  55   "                                                                               \n"
  56   "  highp vec2 halfImageSize = uImageSize * 0.5;                                 \n"
  57   "  vTexCoord = (aPosition.xy + halfImageSize) / uImageSize;                     \n"
  58   "                                                                               \n"
  59   "  // UVs were calculated for image size, so convert for mask size              \n"
  60   "                                                                               \n"
  61   "  highp vec2 halfMaskSize  = uMaskSize * 0.5;                                  \n"
  62   "  highp vec2 halfSizeDelta = halfImageSize - halfMaskSize;                     \n"
  63   "                                                                               \n"
  64   "  highp vec2 maskPosition = aPosition.xy;                                      \n"
  65   "  maskPosition.x -= halfSizeDelta.x * sign(aPosition.x);                       \n"
  66   "  maskPosition.y -= halfSizeDelta.y * sign(aPosition.y);                       \n"
  67   "                                                                               \n"
  68   "  vMaskTexCoord = (maskPosition + halfMaskSize) / uMaskSize;                   \n"
  69   "}                                                                              \n";
  70
  71   const char* ALPHA_MASK_FRAGMENT_SHADER_SOURCE =
  72   "varying mediump vec2 vMaskTexCoord;                                            \n"
  73   "                                                                               \n"
  74   "void main()                                                                    \n"
  75   "{                                                                              \n"
  76   "  highp vec4 mask = texture2D(sEffect, vMaskTexCoord);                         \n"
  77   "  gl_FragColor = texture2D(sTexture, vTexCoord) * uColor * vec4(1,1,1,mask.a); \n"
  78   "}                                                                              \n";
  79
  80   ShaderEffect maskEffect = ShaderEffect::New(
  81     ALPHA_MASK_VERTEX_SHADER_SOURCE,
  82     ALPHA_MASK_FRAGMENT_SHADER_SOURCE,
  83     GeometryType( GEOMETRY_TYPE_IMAGE ),
  84     ShaderEffect::GeometryHints( ShaderEffect::HINT_BLENDING ) );
  85
  86   maskEffect.SetEffectImage( Image::New( maskImage ) );
  87
  88   maskEffect.SetUniform( "uImageSize", Vector2(0,0) /*Constrained to actor size*/ );
  89   maskEffect.ApplyConstraint( Constraint::New<Vector2>( maskEffect.GetPropertyIndex("uImageSize"),
  90                                                         Source(actor, Actor::SIZE),
  91                                                         NinePatchMaskEffectSizeConstraint() ) );
  92
  93   maskEffect.SetUniform( "uMaskSize", maskSize );
  94
  95   // Actor must provide nine-patch style geometry for this effect to work
  96   actor.SetStyle( ImageActor::STYLE_NINE_PATCH );
  97   actor.SetNinePatchBorder( maskBorder );
  98
  99   actor.SetShaderEffect( maskEffect );
 100 }
 101
 102 void Apply( ImageActor actor, const std::string& maskImage )
 103 {
 104   Vector2 maskSize = Image::GetImageSize( maskImage );
 105
 106   const float leftRight = (maskSize.width  - 1.0f) * 0.5f;
 107   const float topBottom = (maskSize.height - 1.0f) * 0.5f;
 108
 109   DoApply( actor, maskImage, maskSize, Vector4( leftRight, topBottom, leftRight, topBottom ) );
 110 }
 111
 112 void Apply( ImageActor actor, const std::string& maskImage, const Vector4& maskBorder )
 113 {
 114   Vector2 maskSize = Image::GetImageSize( maskImage );
 115
 116   DoApply( actor, maskImage, maskSize, maskBorder );
 117 }
 118
 119 } // namespace NinePatchMaskEffect
 120
 121 } // namespace Toolkit
 122
 123 } // namespace Dali