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