| /* |
| * Copyright (C) 2006 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef SkGradientShader_DEFINED |
| #define SkGradientShader_DEFINED |
| |
| #include "SkShader.h" |
| |
| class SkUnitMapper; |
| |
| /** \class SkGradientShader |
| |
| SkGradientShader hosts factories for creating subclasses of SkShader that |
| render linear and radial gradients. |
| */ |
| class SkGradientShader { |
| public: |
| /** Returns a shader that generates a linear gradient between the two |
| specified points. |
| <p /> |
| CreateLinear returns a shader with a reference count of 1. |
| The caller should decrement the shader's reference count when done with the shader. |
| It is an error for count to be < 2. |
| @param pts The start and end points for the gradient. |
| @param colors The array[count] of colors, to be distributed between the two points |
| @param pos May be NULL. array[count] of SkScalars, or NULL, of the relative position of |
| each corresponding color in the colors array. If this is NULL, |
| the the colors are distributed evenly between the start and end point. |
| If this is not null, the values must begin with 0, end with 1.0, and |
| intermediate values must be strictly increasing. |
| @param count Must be >=2. The number of colors (and pos if not NULL) entries. |
| @param mode The tiling mode |
| @param mapper May be NULL. Callback to modify the spread of the colors. |
| */ |
| static SkShader* CreateLinear( const SkPoint pts[2], |
| const SkColor colors[], const SkScalar pos[], int count, |
| SkShader::TileMode mode, |
| SkUnitMapper* mapper = NULL); |
| |
| /** Returns a shader that generates a radial gradient given the center and radius. |
| <p /> |
| CreateRadial returns a shader with a reference count of 1. |
| The caller should decrement the shader's reference count when done with the shader. |
| It is an error for colorCount to be < 2, or for radius to be <= 0. |
| @param center The center of the circle for this gradient |
| @param radius Must be positive. The radius of the circle for this gradient |
| @param colors The array[count] of colors, to be distributed between the center and edge of the circle |
| @param pos May be NULL. The array[count] of SkScalars, or NULL, of the relative position of |
| each corresponding color in the colors array. If this is NULL, |
| the the colors are distributed evenly between the center and edge of the circle. |
| If this is not null, the values must begin with 0, end with 1.0, and |
| intermediate values must be strictly increasing. |
| @param count Must be >= 2. The number of colors (and pos if not NULL) entries |
| @param mode The tiling mode |
| @param mapper May be NULL. Callback to modify the spread of the colors. |
| */ |
| static SkShader* CreateRadial( const SkPoint& center, SkScalar radius, |
| const SkColor colors[], const SkScalar pos[], int count, |
| SkShader::TileMode mode, |
| SkUnitMapper* mapper = NULL); |
| |
| /** Returns a shader that generates a sweep gradient given a center. |
| <p /> |
| CreateRadial returns a shader with a reference count of 1. |
| The caller should decrement the shader's reference count when done with the shader. |
| It is an error for colorCount to be < 2. |
| @param cx The X coordinate of the center of the sweep |
| @param cx The Y coordinate of the center of the sweep |
| @param colors The array[count] of colors, to be distributed around the center. |
| @param pos May be NULL. The array[count] of SkScalars, or NULL, of the relative position of |
| each corresponding color in the colors array. If this is NULL, |
| the the colors are distributed evenly between the center and edge of the circle. |
| If this is not null, the values must begin with 0, end with 1.0, and |
| intermediate values must be strictly increasing. |
| @param count Must be >= 2. The number of colors (and pos if not NULL) entries |
| @param mapper May be NULL. Callback to modify the spread of the colors. |
| */ |
| static SkShader* CreateSweep(SkScalar cx, SkScalar cy, |
| const SkColor colors[], const SkScalar pos[], |
| int count, SkUnitMapper* mapper = NULL); |
| }; |
| |
| #endif |
| |