1 #ifndef __DALI_TOOLKIT_IMAGE_REGION_EFFECT_H__
2 #define __DALI_TOOLKIT_IMAGE_REGION_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/shader-effects/shader-effect.h>
31 * @brief Creates a new ImageRegionEffect
33 * ImageRegionEffect is a custom shader effect to show only a region of an Image actor.
35 * Animatable/Constrainable uniforms:
36 * "uTopLeft" - The top-left corner of the image region. The coordinates are in percentage,
37 * (0,0) being the top-left and (1,1) the bottom right of the original image
38 * "uBottomRight" - The bottom-right corner of the image region. The coordinates are in percentage,
39 * (0,0) being the top-left and (1,1) the bottom right of the original image
41 * @return A handle to a newly allocated ShaderEffect
43 inline ShaderEffect CreateImageRegionEffect()
45 std::string vertexShader(
46 "uniform mediump vec2 uTopLeft;\n"
47 "uniform mediump vec2 uBottomRight;\n"
50 " mediump vec4 position = vec4(aPosition,1.0);\n"
51 " gl_Position = uMvpMatrix * position;\n"
52 // The line below is doing the same as the following commented lines:
53 //" vec2 imageSize = sTextureRect.zw - sTextureRect.xy;\n"
54 //" vec2 topLeft = sTextureRect.xy + uTopLeft * imageSize;\n"
55 //" vec2 bottomRight = sTextureRect.xy + uBottomRight * imageSize;\n"
56 //" vec2 texCoord = (aTexCoord - sTextureRect.xy) / imageSize;\n"
57 //" vTexCoord = topLeft + texCoord * ( bottomRight - topLeft );\n"
58 " vTexCoord = sTextureRect.xy + uTopLeft * ( sTextureRect.zw - sTextureRect.xy ) + ( aTexCoord - sTextureRect.xy ) * ( uBottomRight - uTopLeft );\n"
62 Dali::ShaderEffect shaderEffect = Dali::ShaderEffect::New( vertexShader, "" );
63 shaderEffect.SetUniform( "uTopLeft", Vector2( 0.f, 0.f ) );
64 shaderEffect.SetUniform( "uBottomRight", Vector2( 1.f, 1.f ) );
69 } // namespace Toolkit
73 #endif // __DALI_TOOLKIT_IMAGE_REGION_EFFECT_H__