dali-toolkit/devel-api/shader-effects/iris-effect.h

   1 #ifndef __DALI_TOOLKIT_SHADER_EFFECT_IRIS_H__
   2 #define __DALI_TOOLKIT_SHADER_EFFECT_IRIS_H__
   3
   4 /*
   5  * Copyright (c) 2015 Samsung Electronics Co., Ltd.
   6  *
   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
  10  *
  11  * http://www.apache.org/licenses/LICENSE-2.0
  12  *
  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.
  18  *
  19  */
  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 /**
  31  * @brief Creates a new IrisEffect
  32  *
  33  * IrisEffect is a custom shader effect to achieve iris effects in Image actors
  34  *
  35  * Animatable/Constrainable uniforms:
  36  *
  37  *  "uRadius"       - The radius of the iris effect in texture coordinate distance,
  38  *                    i.e. 0.0 (no circle) to 1.0 (complete circle), to > 1.0 (extending outside of texture).
  39  *                    @note For Atlas Textures results may be unpredictable.
  40  *
  41  *  "uBlendFactor"  - The blend factor of the iris effect. The lower the value, the larger the blending portion
  42  *                    (between Opaque & Transparent). Blending will account for 1 / blendFactor of the radius
  43  *                    of the texture.
  44  *
  45  *  "uCenter"       - The center point of the iris (in texture coordinates)
  46  *
  47  * @return A handle to a newly allocated ShaderEffect
  48  */
  49 inline ShaderEffect CreateIrisEffect()
  50 {
  51   // append the default version
  52   std::string vertexShader(
  53       "uniform mediump vec2 uCenter;\n"
  54       "varying mediump vec2 vRelativePosition;\n"
  55       "\n"
  56       "void main()\n"
  57       "{\n"
  58       "    mediump vec4 world = uModelView * vec4(aPosition, 1.0);\n"
  59       "    gl_Position = uProjection * world;\n"
  60       "    \n"
  61       "    vTexCoord = mix( sTextureRect.xy, sTextureRect.zw, aTexCoord );\n"
  62       "    vRelativePosition = vTexCoord - uCenter;\n"
  63       "}\n");
  64
  65   std::string fragmentShader(
  66       "uniform mediump float uRadius;                                                           \n"
  67       "uniform mediump float uBlendFactor;                                                      \n"
  68       "varying mediump vec2 vRelativePosition;                                                  \n"
  69       "void main()                                                                      \n"
  70       "{                                                                                \n"
  71       "   mediump float delta = (length(vRelativePosition) - uRadius);                          \n"
  72       "   delta = clamp(0.0 - delta * uBlendFactor, 0.0, 1.0);                          \n"
  73       "   gl_FragColor = texture2D(sTexture, vTexCoord) * uColor;                       \n"
  74       "   gl_FragColor.a *= delta;                                                      \n"
  75       "}                                                                                \n"
  76   );
  77
  78   Dali::ShaderEffect shaderEffect =  Dali::ShaderEffect::New(
  79       vertexShader,
  80       fragmentShader,
  81       ShaderEffect::GeometryHints( ShaderEffect::HINT_BLENDING ));
  82
  83   shaderEffect.SetUniform( "uRadius", 0.0f );
  84   shaderEffect.SetUniform( "uBlendFactor", 100.0f );
  85   shaderEffect.SetUniform( "uCenter", Vector2(0.5f, 0.5f) );
  86
  87   return shaderEffect;
  88 }
  89
  90 }
  91 }
  92
  93 #endif