1ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com 28a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com/* 3ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com * Copyright 2011 The Android Open Source Project 48a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com * 5ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com * Use of this source code is governed by a BSD-style license that can be 6ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com * found in the LICENSE file. 78a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com */ 88a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 9ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com 108a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com#ifndef SkDrawLooper_DEFINED 118a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com#define SkDrawLooper_DEFINED 128a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 13daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com#include "SkBlurTypes.h" 148a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com#include "SkFlattenable.h" 15daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com#include "SkPoint.h" 16daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com#include "SkColor.h" 178a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 188a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.comclass SkCanvas; 198a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.comclass SkPaint; 20c73dd5c6880739f26216f198c757028fd28df1a4djsollen@google.comstruct SkRect; 214991b8f23482afc1494fd17647421ce68de53331robertphillips@google.comclass SkString; 228a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 238a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com/** \class SkDrawLooper 248a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com Subclasses of SkDrawLooper can be attached to a SkPaint. Where they are, 258a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com and something is drawn to a canvas with that paint, the looper subclass will 268a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com be called, allowing it to modify the canvas and/or paint for that draw call. 278a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com More than that, via the next() method, the looper can modify the draw to be 288a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com invoked multiple times (hence the name loop-er), allow it to perform effects 298a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com like shadows or frame/fills, that require more than one pass. 308a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com*/ 317ffb1b21abcc7bbed5a0fc711f6dd7b9dbb4f577ctguil@chromium.orgclass SK_API SkDrawLooper : public SkFlattenable { 328a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.compublic: 330456e0b7b85060e9b9597ce414c4c2b19aff4f58robertphillips@google.com SK_DECLARE_INST_COUNT(SkDrawLooper) 340456e0b7b85060e9b9597ce414c4c2b19aff4f58robertphillips@google.com 354e2b3d3fb1288c6dc0f3ea1c0aa4a0d7c603bd7breed@google.com /** 3679fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * Holds state during a draw. Users call next() until it returns false. 3779fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * 3879fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * Subclasses of SkDrawLooper should create a subclass of this object to 3979fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * hold state specific to their subclass. 404e2b3d3fb1288c6dc0f3ea1c0aa4a0d7c603bd7breed@google.com */ 41e3beb6bd7de7fa211681abbb0be58e80b19885e0commit-bot@chromium.org class SK_API Context : ::SkNoncopyable { 4279fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org public: 4379fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org Context() {} 4479fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org virtual ~Context() {} 4579fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org 4679fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org /** 4779fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * Called in a loop on objects returned by SkDrawLooper::createContext(). 4879fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * Each time true is returned, the object is drawn (possibly with a modified 4979fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * canvas and/or paint). When false is finally returned, drawing for the object 5079fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * stops. 5179fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * 5279fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * On each call, the paint will be in its original state, but the 5379fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * canvas will be as it was following the previous call to next() or 5479fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * createContext(). 5579fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * 5679fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * The implementation must ensure that, when next() finally returns 5779fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * false, the canvas has been restored to the state it was 5879fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * initially, before createContext() was first called. 5979fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org */ 6079fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org virtual bool next(SkCanvas* canvas, SkPaint* paint) = 0; 6179fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org }; 624e2b3d3fb1288c6dc0f3ea1c0aa4a0d7c603bd7breed@google.com 634e2b3d3fb1288c6dc0f3ea1c0aa4a0d7c603bd7breed@google.com /** 6479fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * Called right before something is being drawn. Returns a Context 6579fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * whose next() method should be called until it returns false. 6679fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * The caller has to ensure that the storage pointer provides enough 6779fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * memory for the Context. The required size can be queried by calling 6879fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * contextSize(). It is also the caller's responsibility to destroy the 6979fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * object after use. 704e2b3d3fb1288c6dc0f3ea1c0aa4a0d7c603bd7breed@google.com */ 7179fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org virtual Context* createContext(SkCanvas*, void* storage) const = 0; 7279fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org 7379fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org /** 7479fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * Returns the number of bytes needed to store subclasses of Context (belonging to the 7579fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org * corresponding SkDrawLooper subclass). 7679fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org */ 7779fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org virtual size_t contextSize() const = 0; 7879fbb40bca9d815ef79b896b31ba6ee736817e0fcommit-bot@chromium.org 79fbfcd5602128ec010c82cb733c9cdc0a3254f9f3rmistry@google.com 809efd9a048aebaa6681afb76b18e1a7dd642078d3reed@google.com /** 819efd9a048aebaa6681afb76b18e1a7dd642078d3reed@google.com * The fast bounds functions are used to enable the paint to be culled early 829efd9a048aebaa6681afb76b18e1a7dd642078d3reed@google.com * in the drawing pipeline. If a subclass can support this feature it must 839efd9a048aebaa6681afb76b18e1a7dd642078d3reed@google.com * return true for the canComputeFastBounds() function. If that function 849efd9a048aebaa6681afb76b18e1a7dd642078d3reed@google.com * returns false then computeFastBounds behavior is undefined otherwise it 859efd9a048aebaa6681afb76b18e1a7dd642078d3reed@google.com * is expected to have the following behavior. Given the parent paint and 869efd9a048aebaa6681afb76b18e1a7dd642078d3reed@google.com * the parent's bounding rect the subclass must fill in and return the 879efd9a048aebaa6681afb76b18e1a7dd642078d3reed@google.com * storage rect, where the storage rect is with the union of the src rect 889efd9a048aebaa6681afb76b18e1a7dd642078d3reed@google.com * and the looper's bounding rect. 899efd9a048aebaa6681afb76b18e1a7dd642078d3reed@google.com */ 9005d611574ac7dd07c055c9a7426199b804e6061fmtklein bool canComputeFastBounds(const SkPaint& paint) const; 9105d611574ac7dd07c055c9a7426199b804e6061fmtklein void computeFastBounds(const SkPaint& paint, const SkRect& src, SkRect* dst) const; 929efd9a048aebaa6681afb76b18e1a7dd642078d3reed@google.com 93daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com struct BlurShadowRec { 94daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com SkScalar fSigma; 95daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com SkVector fOffset; 96daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com SkColor fColor; 97daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com SkBlurStyle fStyle; 98daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com SkBlurQuality fQuality; 99daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com }; 100daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com /** 101daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com * If this looper can be interpreted as having two layers, such that 102daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com * 1. The first layer (bottom most) just has a blur and translate 103daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com * 2. The second layer has no modifications to either paint or canvas 104daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com * 3. No other layers. 105daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com * then return true, and if not null, fill out the BlurShadowRec). 106daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com * 107daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com * If any of the above are not met, return false and ignore the BlurShadowRec parameter. 108daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com */ 109daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com virtual bool asABlurShadow(BlurShadowRec*) const; 110daaafa6e81860e3dc52660ba019c336f0a43f1e7reed@google.com 1110f10f7bf1fb43ca6346dc220a076773b1f19a367commit-bot@chromium.org SK_TO_STRING_PUREVIRT() 112c0b7e10c6a68f59e1653e6c18e6bc954b3c3f0cfcommit-bot@chromium.org SK_DEFINE_FLATTENABLE_TYPE(SkDrawLooper) 1134991b8f23482afc1494fd17647421ce68de53331robertphillips@google.com 1148a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.comprotected: 1158a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com SkDrawLooper() {} 1168a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 1178a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.comprivate: 1188a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com typedef SkFlattenable INHERITED; 1198a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com}; 1208a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 1218a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com#endif 122