1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/include/effects/SkGradientShader.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,147 @@
1.4 +/*
1.5 + * Copyright 2006 The Android Open Source Project
1.6 + *
1.7 + * Use of this source code is governed by a BSD-style license that can be
1.8 + * found in the LICENSE file.
1.9 + */
1.10 +
1.11 +#ifndef SkGradientShader_DEFINED
1.12 +#define SkGradientShader_DEFINED
1.13 +
1.14 +#include "SkShader.h"
1.15 +
1.16 +class SkUnitMapper;
1.17 +
1.18 +/** \class SkGradientShader
1.19 +
1.20 + SkGradientShader hosts factories for creating subclasses of SkShader that
1.21 + render linear and radial gradients.
1.22 +*/
1.23 +class SK_API SkGradientShader {
1.24 +public:
1.25 + enum Flags {
1.26 + /** By default gradients will interpolate their colors in unpremul space
1.27 + * and then premultiply each of the results. By setting this flag, the
1.28 + * gradients will premultiply their colors first, and then interpolate
1.29 + * between them.
1.30 + */
1.31 + kInterpolateColorsInPremul_Flag = 1 << 0,
1.32 + };
1.33 +
1.34 + /** Returns a shader that generates a linear gradient between the two
1.35 + specified points.
1.36 + <p />
1.37 + CreateLinear returns a shader with a reference count of 1.
1.38 + The caller should decrement the shader's reference count when done with the shader.
1.39 + It is an error for count to be < 2.
1.40 + @param pts The start and end points for the gradient.
1.41 + @param colors The array[count] of colors, to be distributed between the two points
1.42 + @param pos May be NULL. array[count] of SkScalars, or NULL, of the relative position of
1.43 + each corresponding color in the colors array. If this is NULL,
1.44 + the the colors are distributed evenly between the start and end point.
1.45 + If this is not null, the values must begin with 0, end with 1.0, and
1.46 + intermediate values must be strictly increasing.
1.47 + @param count Must be >=2. The number of colors (and pos if not NULL) entries.
1.48 + @param mode The tiling mode
1.49 + @param mapper May be NULL. Callback to modify the spread of the colors.
1.50 + */
1.51 + static SkShader* CreateLinear(const SkPoint pts[2],
1.52 + const SkColor colors[], const SkScalar pos[], int count,
1.53 + SkShader::TileMode mode,
1.54 + SkUnitMapper* mapper = NULL,
1.55 + uint32_t flags = 0);
1.56 +
1.57 + /** Returns a shader that generates a radial gradient given the center and radius.
1.58 + <p />
1.59 + CreateRadial returns a shader with a reference count of 1.
1.60 + The caller should decrement the shader's reference count when done with the shader.
1.61 + It is an error for colorCount to be < 2, or for radius to be <= 0.
1.62 + @param center The center of the circle for this gradient
1.63 + @param radius Must be positive. The radius of the circle for this gradient
1.64 + @param colors The array[count] of colors, to be distributed between the center and edge of the circle
1.65 + @param pos May be NULL. The array[count] of SkScalars, or NULL, of the relative position of
1.66 + each corresponding color in the colors array. If this is NULL,
1.67 + the the colors are distributed evenly between the center and edge of the circle.
1.68 + If this is not null, the values must begin with 0, end with 1.0, and
1.69 + intermediate values must be strictly increasing.
1.70 + @param count Must be >= 2. The number of colors (and pos if not NULL) entries
1.71 + @param mode The tiling mode
1.72 + @param mapper May be NULL. Callback to modify the spread of the colors.
1.73 + */
1.74 + static SkShader* CreateRadial(const SkPoint& center, SkScalar radius,
1.75 + const SkColor colors[], const SkScalar pos[], int count,
1.76 + SkShader::TileMode mode,
1.77 + SkUnitMapper* mapper = NULL,
1.78 + uint32_t flags = 0);
1.79 +
1.80 + /** Returns a shader that generates a radial gradient given the start position, start radius, end position and end radius.
1.81 + <p />
1.82 + CreateTwoPointRadial returns a shader with a reference count of 1.
1.83 + The caller should decrement the shader's reference count when done with the shader.
1.84 + It is an error for colorCount to be < 2, for startRadius or endRadius to be < 0, or for
1.85 + startRadius to be equal to endRadius.
1.86 + @param start The center of the start circle for this gradient
1.87 + @param startRadius Must be positive. The radius of the start circle for this gradient.
1.88 + @param end The center of the end circle for this gradient
1.89 + @param endRadius Must be positive. The radius of the end circle for this gradient.
1.90 + @param colors The array[count] of colors, to be distributed between the center and edge of the circle
1.91 + @param pos May be NULL. The array[count] of SkScalars, or NULL, of the relative position of
1.92 + each corresponding color in the colors array. If this is NULL,
1.93 + the the colors are distributed evenly between the center and edge of the circle.
1.94 + If this is not null, the values must begin with 0, end with 1.0, and
1.95 + intermediate values must be strictly increasing.
1.96 + @param count Must be >= 2. The number of colors (and pos if not NULL) entries
1.97 + @param mode The tiling mode
1.98 + @param mapper May be NULL. Callback to modify the spread of the colors.
1.99 + */
1.100 + static SkShader* CreateTwoPointRadial(const SkPoint& start,
1.101 + SkScalar startRadius,
1.102 + const SkPoint& end,
1.103 + SkScalar endRadius,
1.104 + const SkColor colors[],
1.105 + const SkScalar pos[], int count,
1.106 + SkShader::TileMode mode,
1.107 + SkUnitMapper* mapper = NULL,
1.108 + uint32_t flags = 0);
1.109 +
1.110 + /**
1.111 + * Returns a shader that generates a conical gradient given two circles, or
1.112 + * returns NULL if the inputs are invalid. The gradient interprets the
1.113 + * two circles according to the following HTML spec.
1.114 + * http://dev.w3.org/html5/2dcontext/#dom-context-2d-createradialgradient
1.115 + */
1.116 + static SkShader* CreateTwoPointConical(const SkPoint& start,
1.117 + SkScalar startRadius,
1.118 + const SkPoint& end,
1.119 + SkScalar endRadius,
1.120 + const SkColor colors[],
1.121 + const SkScalar pos[], int count,
1.122 + SkShader::TileMode mode,
1.123 + SkUnitMapper* mapper = NULL,
1.124 + uint32_t flags = 0);
1.125 +
1.126 + /** Returns a shader that generates a sweep gradient given a center.
1.127 + <p />
1.128 + CreateSweep returns a shader with a reference count of 1.
1.129 + The caller should decrement the shader's reference count when done with the shader.
1.130 + It is an error for colorCount to be < 2.
1.131 + @param cx The X coordinate of the center of the sweep
1.132 + @param cx The Y coordinate of the center of the sweep
1.133 + @param colors The array[count] of colors, to be distributed around the center.
1.134 + @param pos May be NULL. The array[count] of SkScalars, or NULL, of the relative position of
1.135 + each corresponding color in the colors array. If this is NULL,
1.136 + the the colors are distributed evenly between the center and edge of the circle.
1.137 + If this is not null, the values must begin with 0, end with 1.0, and
1.138 + intermediate values must be strictly increasing.
1.139 + @param count Must be >= 2. The number of colors (and pos if not NULL) entries
1.140 + @param mapper May be NULL. Callback to modify the spread of the colors.
1.141 + */
1.142 + static SkShader* CreateSweep(SkScalar cx, SkScalar cy,
1.143 + const SkColor colors[], const SkScalar pos[],
1.144 + int count, SkUnitMapper* mapper = NULL,
1.145 + uint32_t flags = 0);
1.146 +
1.147 + SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP()
1.148 +};
1.149 +
1.150 +#endif
