164 lines
9.2 KiB
C++
164 lines
9.2 KiB
C++
/*
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* Copyright 2006 The Android Open Source Project
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#ifndef SkGradientShader_DEFINED
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#define SkGradientShader_DEFINED
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#include "SkShader.h"
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/** \class SkGradientShader
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SkGradientShader hosts factories for creating subclasses of SkShader that
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render linear and radial gradients.
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*/
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class SK_API SkGradientShader {
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public:
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enum Flags {
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/** By default gradients will interpolate their colors in unpremul space
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* and then premultiply each of the results. By setting this flag, the
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* gradients will premultiply their colors first, and then interpolate
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* between them.
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*/
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kInterpolateColorsInPremul_Flag = 1 << 0,
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};
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/** Returns a shader that generates a linear gradient between the two
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specified points.
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<p />
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CreateLinear returns a shader with a reference count of 1.
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The caller should decrement the shader's reference count when done with the shader.
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It is an error for count to be < 2.
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@param pts The start and end points for the gradient.
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@param colors The array[count] of colors, to be distributed between the two points
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@param pos May be NULL. array[count] of SkScalars, or NULL, of the relative position of
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each corresponding color in the colors array. If this is NULL,
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the the colors are distributed evenly between the start and end point.
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If this is not null, the values must begin with 0, end with 1.0, and
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intermediate values must be strictly increasing.
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@param count Must be >=2. The number of colors (and pos if not NULL) entries.
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@param mode The tiling mode
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*/
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static SkShader* CreateLinear(const SkPoint pts[2],
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const SkColor colors[], const SkScalar pos[], int count,
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SkShader::TileMode mode,
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uint32_t flags, const SkMatrix* localMatrix);
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static SkShader* CreateLinear(const SkPoint pts[2],
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const SkColor colors[], const SkScalar pos[], int count,
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SkShader::TileMode mode) {
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return CreateLinear(pts, colors, pos, count, mode, 0, NULL);
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}
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/** Returns a shader that generates a radial gradient given the center and radius.
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<p />
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CreateRadial returns a shader with a reference count of 1.
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The caller should decrement the shader's reference count when done with the shader.
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It is an error for colorCount to be < 2, or for radius to be <= 0.
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@param center The center of the circle for this gradient
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@param radius Must be positive. The radius of the circle for this gradient
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@param colors The array[count] of colors, to be distributed between the center and edge of the circle
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@param pos May be NULL. The array[count] of SkScalars, or NULL, of the relative position of
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each corresponding color in the colors array. If this is NULL,
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the the colors are distributed evenly between the center and edge of the circle.
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If this is not null, the values must begin with 0, end with 1.0, and
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intermediate values must be strictly increasing.
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@param count Must be >= 2. The number of colors (and pos if not NULL) entries
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@param mode The tiling mode
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*/
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static SkShader* CreateRadial(const SkPoint& center, SkScalar radius,
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const SkColor colors[], const SkScalar pos[], int count,
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SkShader::TileMode mode,
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uint32_t flags, const SkMatrix* localMatrix);
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static SkShader* CreateRadial(const SkPoint& center, SkScalar radius,
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const SkColor colors[], const SkScalar pos[], int count,
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SkShader::TileMode mode) {
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return CreateRadial(center, radius, colors, pos, count, mode, 0, NULL);
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}
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/** Returns a shader that generates a radial gradient given the start position, start radius, end position and end radius.
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<p />
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CreateTwoPointRadial returns a shader with a reference count of 1.
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The caller should decrement the shader's reference count when done with the shader.
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It is an error for colorCount to be < 2, for startRadius or endRadius to be < 0, or for
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startRadius to be equal to endRadius.
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@param start The center of the start circle for this gradient
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@param startRadius Must be positive. The radius of the start circle for this gradient.
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@param end The center of the end circle for this gradient
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@param endRadius Must be positive. The radius of the end circle for this gradient.
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@param colors The array[count] of colors, to be distributed between the center and edge of the circle
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@param pos May be NULL. The array[count] of SkScalars, or NULL, of the relative position of
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each corresponding color in the colors array. If this is NULL,
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the the colors are distributed evenly between the center and edge of the circle.
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If this is not null, the values must begin with 0, end with 1.0, and
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intermediate values must be strictly increasing.
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@param count Must be >= 2. The number of colors (and pos if not NULL) entries
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@param mode The tiling mode
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*/
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static SkShader* CreateTwoPointRadial(const SkPoint& start, SkScalar startRadius,
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const SkPoint& end, SkScalar endRadius,
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const SkColor colors[], const SkScalar pos[], int count,
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SkShader::TileMode mode,
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uint32_t flags, const SkMatrix* localMatrix);
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static SkShader* CreateTwoPointRadial(const SkPoint& start, SkScalar startRadius,
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const SkPoint& end, SkScalar endRadius,
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const SkColor colors[], const SkScalar pos[], int count,
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SkShader::TileMode mode) {
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return CreateTwoPointRadial(start, startRadius, end, endRadius, colors, pos, count, mode,
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0, NULL);
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}
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/**
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* Returns a shader that generates a conical gradient given two circles, or
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* returns NULL if the inputs are invalid. The gradient interprets the
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* two circles according to the following HTML spec.
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* http://dev.w3.org/html5/2dcontext/#dom-context-2d-createradialgradient
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*/
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static SkShader* CreateTwoPointConical(const SkPoint& start, SkScalar startRadius,
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const SkPoint& end, SkScalar endRadius,
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const SkColor colors[], const SkScalar pos[], int count,
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SkShader::TileMode mode,
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uint32_t flags, const SkMatrix* localMatrix);
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static SkShader* CreateTwoPointConical(const SkPoint& start, SkScalar startRadius,
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const SkPoint& end, SkScalar endRadius,
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const SkColor colors[], const SkScalar pos[], int count,
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SkShader::TileMode mode) {
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return CreateTwoPointConical(start, startRadius, end, endRadius, colors, pos, count, mode,
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0, NULL);
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}
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/** Returns a shader that generates a sweep gradient given a center.
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<p />
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CreateSweep returns a shader with a reference count of 1.
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The caller should decrement the shader's reference count when done with the shader.
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It is an error for colorCount to be < 2.
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@param cx The X coordinate of the center of the sweep
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@param cx The Y coordinate of the center of the sweep
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@param colors The array[count] of colors, to be distributed around the center.
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@param pos May be NULL. The array[count] of SkScalars, or NULL, of the relative position of
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each corresponding color in the colors array. If this is NULL,
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the the colors are distributed evenly between the center and edge of the circle.
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If this is not null, the values must begin with 0, end with 1.0, and
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intermediate values must be strictly increasing.
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@param count Must be >= 2. The number of colors (and pos if not NULL) entries
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*/
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static SkShader* CreateSweep(SkScalar cx, SkScalar cy,
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const SkColor colors[], const SkScalar pos[], int count,
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uint32_t flags, const SkMatrix* localMatrix);
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static SkShader* CreateSweep(SkScalar cx, SkScalar cy,
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const SkColor colors[], const SkScalar pos[], int count) {
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return CreateSweep(cx, cy, colors, pos, count, 0, NULL);
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}
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SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP()
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};
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#endif
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