1 #ifndef __DALI_TOOLKIT_IMAGE_REGION_EFFECT_H__
2 #define __DALI_TOOLKIT_IMAGE_REGION_EFFECT_H__
5 * Copyright (c) 2017 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/object/property-map.h>
25 #include <dali-toolkit/public-api/visuals/visual-properties.h>
34 * @brief Creates a new ImageRegionEffect
36 * ImageRegionEffect is a custom shader effect to show only a region of an Image actor.
38 * Animatable/Constrainable uniforms:
39 * "uTopLeft" - The top-left corner of the image region. The coordinates are in percentage,
40 * (0,0) being the top-left and (1,1) the bottom right of the original image
41 * "uBottomRight" - The bottom-right corner of the image region. The coordinates are in percentage,
42 * (0,0) being the top-left and (1,1) the bottom right of the original image
44 * @return A property map of the required shader
46 inline Property::Map CreateImageRegionEffect()
48 std::string vertexShader(
49 "attribute mediump vec2 aPosition;\n"
51 "uniform mediump mat4 uMvpMatrix;\n"
52 "uniform vec3 uSize;\n"
53 "uniform vec4 uTextureRect;"
55 "varying vec2 vTexCoord;\n"
57 "uniform mediump vec2 uTopLeft;\n"
58 "uniform mediump vec2 uBottomRight;\n"
61 " mediump vec4 position = vec4(aPosition, 0.0, 1.0);\n"
62 " position.xyz *= uSize;\n"
63 " gl_Position = uMvpMatrix * position;\n"
64 // The line below is doing the same as the following commented lines:
65 //" vec2 imageSize = uTextureRect.zw - uTextureRect.xy;\n"
66 //" vec2 topLeft = uTextureRect.xy + uTopLeft * imageSize;\n"
67 //" vec2 bottomRight = uTextureRect.xy + uBottomRight * imageSize;\n"
68 //" vec2 texCoord = (aTexCoord - uTextureRect.xy) / imageSize;\n"
69 //" vTexCoord = topLeft + texCoord * ( bottomRight - topLeft );\n"
71 " vec2 texCoord = aPosition + vec2(0.5);\n"
72 " vTexCoord = uTextureRect.xy + uTopLeft * ( uTextureRect.zw - uTextureRect.xy ) + ( texCoord - uTextureRect.xy ) * ( uBottomRight - uTopLeft );\n"
78 Property::Map customShader;
79 customShader[ Visual::Shader::Property::VERTEX_SHADER ] = vertexShader;
81 map[ Toolkit::Visual::Property::SHADER ] = customShader;
85 } // namespace Toolkit
89 #endif // __DALI_TOOLKIT_IMAGE_REGION_EFFECT_H__