1 #ifndef __DALI_TOOLKIT_INTERNAL_GRADIENT_H__
2 #define __DALI_TOOLKIT_INTERNAL_GRADIENT_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/math/matrix3.h>
23 #include <dali/public-api/object/ref-object.h>
24 #include <dali/public-api/common/dali-vector.h>
25 #include <dali/public-api/images/buffer-image.h>
39 * Gradients consist of continuously smooth color transitions along a vector from one color to another,
40 * possibly followed by additional transitions along the same vector to other colors.
42 class Gradient : public RefObject
46 * Defines the coordinate system of the attributes
47 * (start and end position for linear gradient, circle center and radius for radial gradient)
56 * Indicates what happens if the gradient starts or ends inside the bounds of the object being painted by the gradient.
60 PAD, // use the terminal colors of the gradient to fill the remainder of the target region
61 REPEAT, // reflect the gradient pattern start-to-end, end-to-start, start-to-end, etc. continuously until the target rectangle is filled
62 REFLECT // repeat the gradient pattern start-to-end, start-to-end, start-to-end, etc. continuously until the target region is filled
66 * The stop node tells the gradient what color it should be at certain position.
70 GradientStop( float offset, const Vector4& color )
71 : mOffset( offset ), mStopColor( color )
74 bool operator<(const GradientStop& rhs) const
76 return mOffset < rhs.mOffset;
79 float mOffset; // A value ranging from 0 to 1 to indicate where the gradient stop is placed.
80 Vector4 mStopColor; // The color to use at this gradient stop
86 * Add a gradient stop.
88 * @param[in] offset The position to place the stop.
89 * @param[in] color The color to use at this stop.
91 void AddStop(float offset, const Vector4& color);
94 * Set the coordinate system used by the gradient attributes.
95 * @param[in] gradientUnits The the attributes are defined using the current user coordinate system or the bounding box of the shape.
97 void SetGradientUnits( GradientUnits gradientUnits );
100 * Get the coordinate system used by the gradient attributes.
101 * @return USER_SPACE_ON_USE or OBJECT_BOUNDING_BOX
103 GradientUnits GetGradientUnits() const;
106 * Indicates what happens if the gradient starts or ends inside the bounds of the target rectangle.
107 * If not specified, the effect is as if a value of 'pad' were specified
109 * @param[in] spread The method to fill the remainder of target region which is outside the gradient bounds
111 void SetSpreadMethod( SpreadMethod spread );
114 * Get the filling method for the the remainder of target region which is outside the gradient boun.
115 * @return PAD, REFLECT or REPEAT
117 SpreadMethod GetSpreadMethod() const;
120 * Get the transformation matrix to align the vertices with the gradient line/circle
121 * @ return the aligning transformation matrix
123 const Matrix3& GetAlignmentTransform() const;
126 * Generate the lookup texture with the gradient stops.
127 * @return the lookup texture which transit smoothly between stops.
129 BufferImage GenerateLookupTexture();
134 * Estimate the resolution of the lookup texture.
135 * Note: Only call this function after the gradient stops are sorted in order.
137 unsigned int EstimateTextureResolution();
142 * Construct a new Gradient object
143 * Called in the constructor of subclasses
148 * @brief A reference counted object may only be deleted by calling Unreference().
153 Gradient( const Gradient& gradient );
156 Gradient& operator=( const Gradient& handle );
160 Vector<GradientStop> mGradientStops;
161 Matrix3 mAlignmentTransform;
162 GradientUnits mGradientUnits;
163 SpreadMethod mSpreadMethod;
167 } // namespace Internal
169 } // namespace Toolkit
173 #endif /* __DALI_TOOLKIT_INTERNAL_GRADIENT_RENDERER_H__ */