1 #ifndef __DALI_TOOLKIT_OVERLAY_EFFECT_H__
2 #define __DALI_TOOLKIT_OVERLAY_EFFECT_H__
5 * Copyright (c) 2015 Samsung Electronics Co., Ltd.
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
11 * http://www.apache.org/licenses/LICENSE-2.0
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.
22 #include <dali/public-api/images/image.h>
23 #include <dali/public-api/shader-effects/shader-effect.h>
32 * @brief Creates a new OverlayEffect
34 * OverlayEffect is used to apply an overlay image to the actor.
35 * Typically overlay images should be the same size as the main image being viewed, but this isn't essential.
39 * ImageActor actor = ImageActor::New( Image( EXAMPLE_IMAGE_PATH ) );
40 * ShaderEffect overlayEffect = CreateOverlayEffect( Image::New( OVERLAY_IMAGE_PATH ) );
41 * actor.SetShaderEffect( overlayEffect );
43 * @param[in] overlayImage The image to overlay on top of the actor
44 * @return A handle to a newly allocated ShaderEffect
46 inline ShaderEffect CreateOverlayEffect(Image overlayImage)
48 // (Target > 0.5) * (1 - (1-2*(Target-0.5)) * (1-Blend)) + (Target <= 0.5) * ((2*Target) * Blend)
49 const char* OVERLAY_FRAGMENT_SHADER_SOURCE =
52 " lowp vec4 target = texture2D(sTexture, vTexCoord);\n"
53 " lowp vec4 overlay = texture2D(sEffect, vTexCoord);\n"
54 " if ( length( target.rgb ) > 0.5 )\n"
56 " gl_FragColor = vec4( mix( target.rgb, 1.0 - ( 1.0 - 2.0 * ( target.rgb - 0.5 ) ) * ( 1.0 - overlay.rgb ), overlay.a ), min( 1.0, target.a + overlay.a ) );\n"
60 " gl_FragColor = vec4( mix( target.rgb, 2.0 * target.rgb * overlay.rgb, overlay.a ), target.a + overlay.a );\n"
64 ShaderEffect shaderEffect = ShaderEffect::New(
66 OVERLAY_FRAGMENT_SHADER_SOURCE,
67 ShaderEffect::GeometryHints( ShaderEffect::HINT_BLENDING ) );
69 shaderEffect.SetEffectImage( overlayImage );
74 } // namespace Toolkit
78 #endif // __DALI_TOOLKIT_OVERLAY_EFFECT_H__