| /* |
| * Copyright 2019 Google LLC |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef SkImageFilters_DEFINED |
| #define SkImageFilters_DEFINED |
| |
| #include "include/core/SkColor.h" |
| #include "include/core/SkImage.h" |
| #include "include/core/SkImageFilter.h" |
| #include "include/core/SkPicture.h" |
| #include "include/core/SkRect.h" |
| #include "include/core/SkRefCnt.h" |
| #include "include/core/SkScalar.h" |
| #include "include/core/SkShader.h" |
| #include "include/core/SkTileMode.h" |
| #include "include/core/SkTypes.h" |
| |
| #include <cstddef> |
| #include <optional> |
| #include <string_view> |
| #include <utility> |
| |
| class SkBlender; |
| class SkColorFilter; |
| class SkMatrix; |
| class SkRuntimeShaderBuilder; |
| enum class SkBlendMode; |
| struct SkIPoint; |
| struct SkISize; |
| struct SkPoint3; |
| struct SkSamplingOptions; |
| |
| // A set of factory functions providing useful SkImageFilter effects. For image filters that take an |
| // input filter, providing nullptr means it will automatically use the dynamic source image. This |
| // source depends on how the filter is applied, but is either the contents of a saved layer when |
| // drawing with SkCanvas, or an explicit SkImage if using one of the SkImages::MakeWithFilter |
| // factories. |
| class SK_API SkImageFilters { |
| public: |
| // This is just a convenience type to allow passing SkIRects, SkRects, and optional pointers |
| // to those types as a crop rect for the image filter factories. It's not intended to be used |
| // directly. |
| struct CropRect : public std::optional<SkRect> { |
| CropRect() {} |
| // Intentionally not explicit so callers don't have to use this type but can use SkIRect or |
| // SkRect as desired. |
| CropRect(const SkIRect& crop) : std::optional<SkRect>(SkRect::Make(crop)) {} |
| CropRect(const SkRect& crop) : std::optional<SkRect>(crop) {} |
| CropRect(const std::optional<SkRect>& crop) : std::optional<SkRect>(crop) {} |
| CropRect(const std::nullopt_t&) : std::optional<SkRect>() {} |
| |
| // Backwards compatibility for when the APIs used to explicitly accept "const SkRect*" |
| CropRect(std::nullptr_t) {} |
| CropRect(const SkIRect* optionalCrop) { |
| if (optionalCrop) { |
| *this = SkRect::Make(*optionalCrop); |
| } |
| } |
| CropRect(const SkRect* optionalCrop) { |
| if (optionalCrop) { |
| *this = *optionalCrop; |
| } |
| } |
| |
| // std::optional doesn't define == when comparing to another optional... |
| bool operator==(const CropRect& o) const { |
| return this->has_value() == o.has_value() && |
| (!this->has_value() || this->value() == *o); |
| } |
| }; |
| |
| /** |
| * Create a filter that implements a custom blend mode. Each output pixel is the result of |
| * combining the corresponding background and foreground pixels using the 4 coefficients: |
| * k1 * foreground * background + k2 * foreground + k3 * background + k4 |
| * @param k1, k2, k3, k4 The four coefficients used to combine the foreground and background. |
| * @param enforcePMColor If true, the RGB channels will be clamped to the calculated alpha. |
| * @param background The background content, using the source bitmap when this is null. |
| * @param foreground The foreground content, using the source bitmap when this is null. |
| * @param cropRect Optional rectangle that crops the inputs and output. |
| */ |
| static sk_sp<SkImageFilter> Arithmetic(SkScalar k1, SkScalar k2, SkScalar k3, SkScalar k4, |
| bool enforcePMColor, sk_sp<SkImageFilter> background, |
| sk_sp<SkImageFilter> foreground, |
| const CropRect& cropRect = {}); |
| |
| /** |
| * This filter takes an SkBlendMode and uses it to composite the two filters together. |
| * @param mode The blend mode that defines the compositing operation |
| * @param background The Dst pixels used in blending, if null the source bitmap is used. |
| * @param foreground The Src pixels used in blending, if null the source bitmap is used. |
| * @cropRect Optional rectangle to crop input and output. |
| */ |
| static sk_sp<SkImageFilter> Blend(SkBlendMode mode, sk_sp<SkImageFilter> background, |
| sk_sp<SkImageFilter> foreground = nullptr, |
| const CropRect& cropRect = {}); |
| |
| /** |
| * This filter takes an SkBlendMode and uses it to composite the two filters together. |
| * @param blender The blender that defines the compositing operation |
| * @param background The Dst pixels used in blending, if null the source bitmap is used. |
| * @param foreground The Src pixels used in blending, if null the source bitmap is used. |
| * @cropRect Optional rectangle to crop input and output. |
| */ |
| static sk_sp<SkImageFilter> Blend(sk_sp<SkBlender> blender, sk_sp<SkImageFilter> background, |
| sk_sp<SkImageFilter> foreground = nullptr, |
| const CropRect& cropRect = {}); |
| |
| /** |
| * Create a filter that blurs its input by the separate X and Y sigmas. The provided tile mode |
| * is used when the blur kernel goes outside the input image. |
| * @param sigmaX The Gaussian sigma value for blurring along the X axis. |
| * @param sigmaY The Gaussian sigma value for blurring along the Y axis. |
| * @param tileMode The tile mode applied at edges . |
| * TODO (michaelludwig) - kMirror is not supported yet |
| * @param input The input filter that is blurred, uses source bitmap if this is null. |
| * @param cropRect Optional rectangle that crops the input and output. |
| */ |
| static sk_sp<SkImageFilter> Blur(SkScalar sigmaX, SkScalar sigmaY, SkTileMode tileMode, |
| sk_sp<SkImageFilter> input, const CropRect& cropRect = {}); |
| // As above, but defaults to the decal tile mode. |
| static sk_sp<SkImageFilter> Blur(SkScalar sigmaX, SkScalar sigmaY, sk_sp<SkImageFilter> input, |
| const CropRect& cropRect = {}) { |
| return Blur(sigmaX, sigmaY, SkTileMode::kDecal, std::move(input), cropRect); |
| } |
| |
| /** |
| * Create a filter that applies the color filter to the input filter results. |
| * @param cf The color filter that transforms the input image. |
| * @param input The input filter, or uses the source bitmap if this is null. |
| * @param cropRect Optional rectangle that crops the input and output. |
| */ |
| static sk_sp<SkImageFilter> ColorFilter(sk_sp<SkColorFilter> cf, sk_sp<SkImageFilter> input, |
| const CropRect& cropRect = {}); |
| |
| /** |
| * Create a filter that composes 'inner' with 'outer', such that the results of 'inner' are |
| * treated as the source bitmap passed to 'outer', i.e. result = outer(inner(source)). |
| * @param outer The outer filter that evaluates the results of inner. |
| * @param inner The inner filter that produces the input to outer. |
| */ |
| static sk_sp<SkImageFilter> Compose(sk_sp<SkImageFilter> outer, sk_sp<SkImageFilter> inner); |
| |
| /** |
| * Create a filter that applies a crop to the result of the 'input' filter. Pixels within the |
| * crop rectangle are unmodified from what 'input' produced. Pixels outside of crop match the |
| * provided SkTileMode (defaulting to kDecal). |
| * |
| * NOTE: The optional CropRect argument for many of the factories is equivalent to creating the |
| * filter without a CropRect and then wrapping it in ::Crop(rect, kDecal). Explicitly adding |
| * Crop filters lets you control their tiling and use different geometry for the input and the |
| * output of another filter. |
| * |
| * @param rect The cropping geometry |
| * @param tileMode The tilemode applied to pixels *outside* of 'crop' |
| * @param input The input filter that is cropped, uses source image if this is null |
| */ |
| static sk_sp<SkImageFilter> Crop(const SkRect& rect, |
| SkTileMode tileMode, |
| sk_sp<SkImageFilter> input); |
| static sk_sp<SkImageFilter> Crop(const SkRect& rect, sk_sp<SkImageFilter> input) { |
| return Crop(rect, SkTileMode::kDecal, std::move(input)); |
| } |
| |
| /** |
| * Create a filter that moves each pixel in its color input based on an (x,y) vector encoded |
| * in its displacement input filter. Two color components of the displacement image are |
| * mapped into a vector as scale * (color[xChannel], color[yChannel]), where the channel |
| * selectors are one of R, G, B, or A. |
| * @param xChannelSelector RGBA channel that encodes the x displacement per pixel. |
| * @param yChannelSelector RGBA channel that encodes the y displacement per pixel. |
| * @param scale Scale applied to displacement extracted from image. |
| * @param displacement The filter defining the displacement image, or null to use source. |
| * @param color The filter providing the color pixels to be displaced. If null, |
| * it will use the source. |
| * @param cropRect Optional rectangle that crops the color input and output. |
| */ |
| static sk_sp<SkImageFilter> DisplacementMap(SkColorChannel xChannelSelector, |
| SkColorChannel yChannelSelector, |
| SkScalar scale, sk_sp<SkImageFilter> displacement, |
| sk_sp<SkImageFilter> color, |
| const CropRect& cropRect = {}); |
| |
| /** |
| * Create a filter that draws a drop shadow under the input content. This filter produces an |
| * image that includes the inputs' content. |
| * @param dx The X offset of the shadow. |
| * @param dy The Y offset of the shadow. |
| * @param sigmaX The blur radius for the shadow, along the X axis. |
| * @param sigmaY The blur radius for the shadow, along the Y axis. |
| * @param color The color of the drop shadow. |
| * @param input The input filter, or will use the source bitmap if this is null. |
| * @param cropRect Optional rectangle that crops the input and output. |
| */ |
| static sk_sp<SkImageFilter> DropShadow(SkScalar dx, SkScalar dy, |
| SkScalar sigmaX, SkScalar sigmaY, |
| SkColor color, sk_sp<SkImageFilter> input, |
| const CropRect& cropRect = {}); |
| /** |
| * Create a filter that renders a drop shadow, in exactly the same manner as ::DropShadow, |
| * except that the resulting image does not include the input content. This allows the shadow |
| * and input to be composed by a filter DAG in a more flexible manner. |
| * @param dx The X offset of the shadow. |
| * @param dy The Y offset of the shadow. |
| * @param sigmaX The blur radius for the shadow, along the X axis. |
| * @param sigmaY The blur radius for the shadow, along the Y axis. |
| * @param color The color of the drop shadow. |
| * @param input The input filter, or will use the source bitmap if this is null. |
| * @param cropRect Optional rectangle that crops the input and output. |
| */ |
| static sk_sp<SkImageFilter> DropShadowOnly(SkScalar dx, SkScalar dy, |
| SkScalar sigmaX, SkScalar sigmaY, |
| SkColor color, sk_sp<SkImageFilter> input, |
| const CropRect& cropRect = {}); |
| |
| /** |
| * Create a filter that always produces transparent black. |
| */ |
| static sk_sp<SkImageFilter> Empty(); |
| |
| /** |
| * Create a filter that draws the 'srcRect' portion of image into 'dstRect' using the given |
| * filter quality. Similar to SkCanvas::drawImageRect. The returned image filter evaluates |
| * to transparent black if 'image' is null. |
| * |
| * @param image The image that is output by the filter, subset by 'srcRect'. |
| * @param srcRect The source pixels sampled into 'dstRect' |
| * @param dstRect The local rectangle to draw the image into. |
| * @param sampling The sampling to use when drawing the image. |
| */ |
| static sk_sp<SkImageFilter> Image(sk_sp<SkImage> image, const SkRect& srcRect, |
| const SkRect& dstRect, const SkSamplingOptions& sampling); |
| |
| /** |
| * Create a filter that draws the image using the given sampling. |
| * Similar to SkCanvas::drawImage. The returned image filter evaluates to transparent black if |
| * 'image' is null. |
| * |
| * @param image The image that is output by the filter. |
| * @param sampling The sampling to use when drawing the image. |
| */ |
| static sk_sp<SkImageFilter> Image(sk_sp<SkImage> image, const SkSamplingOptions& sampling) { |
| if (image) { |
| SkRect r = SkRect::Make(image->bounds()); |
| return Image(std::move(image), r, r, sampling); |
| } else { |
| return nullptr; |
| } |
| } |
| |
| /** |
| * Create a filter that fills 'lensBounds' with a magnification of the input. |
| * |
| * @param lensBounds The outer bounds of the magnifier effect |
| * @param zoomAmount The amount of magnification applied to the input image |
| * @param inset The size or width of the fish-eye distortion around the magnified content |
| * @param sampling The SkSamplingOptions applied to the input image when magnified |
| * @param input The input filter that is magnified; if null the source bitmap is used |
| * @param cropRect Optional rectangle that crops the input and output. |
| */ |
| static sk_sp<SkImageFilter> Magnifier(const SkRect& lensBounds, |
| SkScalar zoomAmount, |
| SkScalar inset, |
| const SkSamplingOptions& sampling, |
| sk_sp<SkImageFilter> input, |
| const CropRect& cropRect = {}); |
| |
| /** |
| * Create a filter that applies an NxM image processing kernel to the input image. This can be |
| * used to produce effects such as sharpening, blurring, edge detection, etc. |
| * @param kernelSize The kernel size in pixels, in each dimension (N by M). |
| * @param kernel The image processing kernel. Must contain N * M elements, in row order. |
| * @param gain A scale factor applied to each pixel after convolution. This can be |
| * used to normalize the kernel, if it does not already sum to 1. |
| * @param bias A bias factor added to each pixel after convolution. |
| * @param kernelOffset An offset applied to each pixel coordinate before convolution. |
| * This can be used to center the kernel over the image |
| * (e.g., a 3x3 kernel should have an offset of {1, 1}). |
| * @param tileMode How accesses outside the image are treated. |
| * TODO (michaelludwig) - kMirror is not supported yet |
| * @param convolveAlpha If true, all channels are convolved. If false, only the RGB channels |
| * are convolved, and alpha is copied from the source image. |
| * @param input The input image filter, if null the source bitmap is used instead. |
| * @param cropRect Optional rectangle to which the output processing will be limited. |
| */ |
| static sk_sp<SkImageFilter> MatrixConvolution(const SkISize& kernelSize, |
| const SkScalar kernel[], SkScalar gain, |
| SkScalar bias, const SkIPoint& kernelOffset, |
| SkTileMode tileMode, bool convolveAlpha, |
| sk_sp<SkImageFilter> input, |
| const CropRect& cropRect = {}); |
| |
| /** |
| * Create a filter that transforms the input image by 'matrix'. This matrix transforms the |
| * local space, which means it effectively happens prior to any transformation coming from the |
| * SkCanvas initiating the filtering. |
| * @param matrix The matrix to apply to the original content. |
| * @param sampling How the image will be sampled when it is transformed |
| * @param input The image filter to transform, or null to use the source image. |
| */ |
| static sk_sp<SkImageFilter> MatrixTransform(const SkMatrix& matrix, |
| const SkSamplingOptions& sampling, |
| sk_sp<SkImageFilter> input); |
| |
| /** |
| * Create a filter that merges the 'count' filters together by drawing their results in order |
| * with src-over blending. |
| * @param filters The input filter array to merge, which must have 'count' elements. Any null |
| * filter pointers will use the source bitmap instead. |
| * @param count The number of input filters to be merged. |
| * @param cropRect Optional rectangle that crops all input filters and the output. |
| */ |
| static sk_sp<SkImageFilter> Merge(sk_sp<SkImageFilter>* const filters, int count, |
| const CropRect& cropRect = {}); |
| /** |
| * Create a filter that merges the results of the two filters together with src-over blending. |
| * @param first The first input filter, or the source bitmap if this is null. |
| * @param second The second input filter, or the source bitmap if this null. |
| * @param cropRect Optional rectangle that crops the inputs and output. |
| */ |
| static sk_sp<SkImageFilter> Merge(sk_sp<SkImageFilter> first, sk_sp<SkImageFilter> second, |
| const CropRect& cropRect = {}) { |
| sk_sp<SkImageFilter> array[] = { std::move(first), std::move(second) }; |
| return Merge(array, 2, cropRect); |
| } |
| |
| /** |
| * Create a filter that offsets the input filter by the given vector. |
| * @param dx The x offset in local space that the image is shifted. |
| * @param dy The y offset in local space that the image is shifted. |
| * @param input The input that will be moved, if null the source bitmap is used instead. |
| * @param cropRect Optional rectangle to crop the input and output. |
| */ |
| static sk_sp<SkImageFilter> Offset(SkScalar dx, SkScalar dy, sk_sp<SkImageFilter> input, |
| const CropRect& cropRect = {}); |
| |
| /** |
| * Create a filter that produces the SkPicture as its output, clipped to both 'targetRect' and |
| * the picture's internal cull rect. |
| * |
| * If 'pic' is null, the returned image filter produces transparent black. |
| * |
| * @param pic The picture that is drawn for the filter output. |
| * @param targetRect The drawing region for the picture. |
| */ |
| static sk_sp<SkImageFilter> Picture(sk_sp<SkPicture> pic, const SkRect& targetRect); |
| // As above, but uses SkPicture::cullRect for the drawing region. |
| static sk_sp<SkImageFilter> Picture(sk_sp<SkPicture> pic) { |
| SkRect target = pic ? pic->cullRect() : SkRect::MakeEmpty(); |
| return Picture(std::move(pic), target); |
| } |
| |
| /** |
| * Create a filter that fills the output with the per-pixel evaluation of the SkShader produced |
| * by the SkRuntimeShaderBuilder. The shader is defined in the image filter's local coordinate |
| * system, so it will automatically be affected by SkCanvas' transform. |
| * |
| * This variant assumes that the runtime shader samples 'childShaderName' with the same input |
| * coordinate passed to to shader. |
| * |
| * This requires a GPU backend or SkSL to be compiled in. |
| * |
| * @param builder The builder used to produce the runtime shader, that will in turn |
| * fill the result image |
| * @param childShaderName The name of the child shader defined in the builder that will be |
| * bound to the input param (or the source image if the input param |
| * is null). If empty, the builder can have exactly one child shader, |
| * which automatically binds the input param. |
| * @param input The image filter that will be provided as input to the runtime |
| * shader. If null the implicit source image is used instead |
| */ |
| static sk_sp<SkImageFilter> RuntimeShader(const SkRuntimeShaderBuilder& builder, |
| std::string_view childShaderName, |
| sk_sp<SkImageFilter> input) { |
| return RuntimeShader(builder, /*sampleRadius=*/0.f, childShaderName, std::move(input)); |
| } |
| |
| /** |
| * As above, but 'sampleRadius' defines the sampling radius of 'childShaderName' relative to |
| * the runtime shader produced by 'builder'. If greater than 0, the coordinate passed to |
| * childShader.eval() will be up to 'sampleRadius' away (maximum absolute offset in 'x' or 'y') |
| * from the coordinate passed into the runtime shader. |
| * |
| * This allows Skia to provide sampleable values for the image filter without worrying about |
| * boundary conditions. |
| * |
| * This requires a GPU backend or SkSL to be compiled in. |
| */ |
| static sk_sp<SkImageFilter> RuntimeShader(const SkRuntimeShaderBuilder& builder, |
| SkScalar sampleRadius, |
| std::string_view childShaderName, |
| sk_sp<SkImageFilter> input); |
| |
| /** |
| * Create a filter that fills the output with the per-pixel evaluation of the SkShader produced |
| * by the SkRuntimeShaderBuilder. The shader is defined in the image filter's local coordinate |
| * system, so it will automatically be affected by SkCanvas' transform. |
| * |
| * This requires a GPU backend or SkSL to be compiled in. |
| * |
| * @param builder The builder used to produce the runtime shader, that will in turn |
| * fill the result image |
| * @param childShaderNames The names of the child shaders defined in the builder that will be |
| * bound to the input params (or the source image if the input param |
| * is null). If any name is null, or appears more than once, factory |
| * fails and returns nullptr. |
| * @param inputs The image filters that will be provided as input to the runtime |
| * shader. If any are null, the implicit source image is used instead. |
| * @param inputCount How many entries are present in 'childShaderNames' and 'inputs'. |
| */ |
| static sk_sp<SkImageFilter> RuntimeShader(const SkRuntimeShaderBuilder& builder, |
| std::string_view childShaderNames[], |
| const sk_sp<SkImageFilter> inputs[], |
| int inputCount) { |
| return RuntimeShader(builder, /*maxSampleRadius=*/0.f, childShaderNames, |
| inputs, inputCount); |
| } |
| |
| /** |
| * As above, but 'maxSampleRadius' defines the sampling limit on coordinates provided to all |
| * child shaders. Like the single-child variant with a sample radius, this can be used to |
| * inform Skia that the runtime shader guarantees that all dynamic children (defined in |
| * childShaderNames) will be evaluated with coordinates at most 'maxSampleRadius' away from the |
| * coordinate provided to the runtime shader itself. |
| * |
| * This requires a GPU backend or SkSL to be compiled in. |
| */ |
| static sk_sp<SkImageFilter> RuntimeShader(const SkRuntimeShaderBuilder& builder, |
| SkScalar maxSampleRadius, |
| std::string_view childShaderNames[], |
| const sk_sp<SkImageFilter> inputs[], |
| int inputCount); |
| |
| enum class Dither : bool { |
| kNo = false, |
| kYes = true |
| }; |
| |
| /** |
| * Create a filter that fills the output with the per-pixel evaluation of the SkShader. The |
| * shader is defined in the image filter's local coordinate system, so will automatically |
| * be affected by SkCanvas' transform. |
| * |
| * Like Image() and Picture(), this is a leaf filter that can be used to introduce inputs to |
| * a complex filter graph, but should generally be combined with a filter that as at least |
| * one null input to use the implicit source image. |
| * |
| * Returns an image filter that evaluates to transparent black if 'shader' is null. |
| * |
| * @param shader The shader that fills the result image |
| */ |
| static sk_sp<SkImageFilter> Shader(sk_sp<SkShader> shader, const CropRect& cropRect = {}) { |
| return Shader(std::move(shader), Dither::kNo, cropRect); |
| } |
| static sk_sp<SkImageFilter> Shader(sk_sp<SkShader> shader, Dither dither, |
| const CropRect& cropRect = {}); |
| |
| /** |
| * Create a tile image filter. |
| * @param src Defines the pixels to tile |
| * @param dst Defines the pixel region that the tiles will be drawn to |
| * @param input The input that will be tiled, if null the source bitmap is used instead. |
| */ |
| static sk_sp<SkImageFilter> Tile(const SkRect& src, const SkRect& dst, |
| sk_sp<SkImageFilter> input); |
| |
| // Morphology filter effects |
| |
| /** |
| * Create a filter that dilates each input pixel's channel values to the max value within the |
| * given radii along the x and y axes. |
| * @param radiusX The distance to dilate along the x axis to either side of each pixel. |
| * @param radiusY The distance to dilate along the y axis to either side of each pixel. |
| * @param input The image filter that is dilated, using source bitmap if this is null. |
| * @param cropRect Optional rectangle that crops the input and output. |
| */ |
| static sk_sp<SkImageFilter> Dilate(SkScalar radiusX, SkScalar radiusY, |
| sk_sp<SkImageFilter> input, |
| const CropRect& cropRect = {}); |
| |
| /** |
| * Create a filter that erodes each input pixel's channel values to the minimum channel value |
| * within the given radii along the x and y axes. |
| * @param radiusX The distance to erode along the x axis to either side of each pixel. |
| * @param radiusY The distance to erode along the y axis to either side of each pixel. |
| * @param input The image filter that is eroded, using source bitmap if this is null. |
| * @param cropRect Optional rectangle that crops the input and output. |
| */ |
| static sk_sp<SkImageFilter> Erode(SkScalar radiusX, SkScalar radiusY, |
| sk_sp<SkImageFilter> input, |
| const CropRect& cropRect = {}); |
| |
| // Lighting filter effects |
| |
| /** |
| * Create a filter that calculates the diffuse illumination from a distant light source, |
| * interpreting the alpha channel of the input as the height profile of the surface (to |
| * approximate normal vectors). |
| * @param direction The direction to the distance light. |
| * @param lightColor The color of the diffuse light source. |
| * @param surfaceScale Scale factor to transform from alpha values to physical height. |
| * @param kd Diffuse reflectance coefficient. |
| * @param input The input filter that defines surface normals (as alpha), or uses the |
| * source bitmap when null. |
| * @param cropRect Optional rectangle that crops the input and output. |
| */ |
| static sk_sp<SkImageFilter> DistantLitDiffuse(const SkPoint3& direction, SkColor lightColor, |
| SkScalar surfaceScale, SkScalar kd, |
| sk_sp<SkImageFilter> input, |
| const CropRect& cropRect = {}); |
| /** |
| * Create a filter that calculates the diffuse illumination from a point light source, using |
| * alpha channel of the input as the height profile of the surface (to approximate normal |
| * vectors). |
| * @param location The location of the point light. |
| * @param lightColor The color of the diffuse light source. |
| * @param surfaceScale Scale factor to transform from alpha values to physical height. |
| * @param kd Diffuse reflectance coefficient. |
| * @param input The input filter that defines surface normals (as alpha), or uses the |
| * source bitmap when null. |
| * @param cropRect Optional rectangle that crops the input and output. |
| */ |
| static sk_sp<SkImageFilter> PointLitDiffuse(const SkPoint3& location, SkColor lightColor, |
| SkScalar surfaceScale, SkScalar kd, |
| sk_sp<SkImageFilter> input, |
| const CropRect& cropRect = {}); |
| /** |
| * Create a filter that calculates the diffuse illumination from a spot light source, using |
| * alpha channel of the input as the height profile of the surface (to approximate normal |
| * vectors). The spot light is restricted to be within 'cutoffAngle' of the vector between |
| * the location and target. |
| * @param location The location of the spot light. |
| * @param target The location that the spot light is point towards |
| * @param falloffExponent Exponential falloff parameter for illumination outside of cutoffAngle |
| * @param cutoffAngle Maximum angle from lighting direction that receives full light |
| * @param lightColor The color of the diffuse light source. |
| * @param surfaceScale Scale factor to transform from alpha values to physical height. |
| * @param kd Diffuse reflectance coefficient. |
| * @param input The input filter that defines surface normals (as alpha), or uses the |
| * source bitmap when null. |
| * @param cropRect Optional rectangle that crops the input and output. |
| */ |
| static sk_sp<SkImageFilter> SpotLitDiffuse(const SkPoint3& location, const SkPoint3& target, |
| SkScalar falloffExponent, SkScalar cutoffAngle, |
| SkColor lightColor, SkScalar surfaceScale, |
| SkScalar kd, sk_sp<SkImageFilter> input, |
| const CropRect& cropRect = {}); |
| |
| /** |
| * Create a filter that calculates the specular illumination from a distant light source, |
| * interpreting the alpha channel of the input as the height profile of the surface (to |
| * approximate normal vectors). |
| * @param direction The direction to the distance light. |
| * @param lightColor The color of the specular light source. |
| * @param surfaceScale Scale factor to transform from alpha values to physical height. |
| * @param ks Specular reflectance coefficient. |
| * @param shininess The specular exponent determining how shiny the surface is. |
| * @param input The input filter that defines surface normals (as alpha), or uses the |
| * source bitmap when null. |
| * @param cropRect Optional rectangle that crops the input and output. |
| */ |
| static sk_sp<SkImageFilter> DistantLitSpecular(const SkPoint3& direction, SkColor lightColor, |
| SkScalar surfaceScale, SkScalar ks, |
| SkScalar shininess, sk_sp<SkImageFilter> input, |
| const CropRect& cropRect = {}); |
| /** |
| * Create a filter that calculates the specular illumination from a point light source, using |
| * alpha channel of the input as the height profile of the surface (to approximate normal |
| * vectors). |
| * @param location The location of the point light. |
| * @param lightColor The color of the specular light source. |
| * @param surfaceScale Scale factor to transform from alpha values to physical height. |
| * @param ks Specular reflectance coefficient. |
| * @param shininess The specular exponent determining how shiny the surface is. |
| * @param input The input filter that defines surface normals (as alpha), or uses the |
| * source bitmap when null. |
| * @param cropRect Optional rectangle that crops the input and output. |
| */ |
| static sk_sp<SkImageFilter> PointLitSpecular(const SkPoint3& location, SkColor lightColor, |
| SkScalar surfaceScale, SkScalar ks, |
| SkScalar shininess, sk_sp<SkImageFilter> input, |
| const CropRect& cropRect = {}); |
| /** |
| * Create a filter that calculates the specular illumination from a spot light source, using |
| * alpha channel of the input as the height profile of the surface (to approximate normal |
| * vectors). The spot light is restricted to be within 'cutoffAngle' of the vector between |
| * the location and target. |
| * @param location The location of the spot light. |
| * @param target The location that the spot light is point towards |
| * @param falloffExponent Exponential falloff parameter for illumination outside of cutoffAngle |
| * @param cutoffAngle Maximum angle from lighting direction that receives full light |
| * @param lightColor The color of the specular light source. |
| * @param surfaceScale Scale factor to transform from alpha values to physical height. |
| * @param ks Specular reflectance coefficient. |
| * @param shininess The specular exponent determining how shiny the surface is. |
| * @param input The input filter that defines surface normals (as alpha), or uses the |
| * source bitmap when null. |
| * @param cropRect Optional rectangle that crops the input and output. |
| */ |
| static sk_sp<SkImageFilter> SpotLitSpecular(const SkPoint3& location, const SkPoint3& target, |
| SkScalar falloffExponent, SkScalar cutoffAngle, |
| SkColor lightColor, SkScalar surfaceScale, |
| SkScalar ks, SkScalar shininess, |
| sk_sp<SkImageFilter> input, |
| const CropRect& cropRect = {}); |
| |
| private: |
| SkImageFilters() = delete; |
| }; |
| |
| #endif // SkImageFilters_DEFINED |
