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      1 /*
      2  * Copyright 2016 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #include "SkCanvas.h"
      9 #include "SkData.h"
     10 #include "SkDrawFilter.h"
     11 #include "SkDrawShadowInfo.h"
     12 #include "SkImage.h"
     13 #include "SkImageFilter.h"
     14 #include "SkLiteDL.h"
     15 #include "SkMath.h"
     16 #include "SkPicture.h"
     17 #include "SkRegion.h"
     18 #include "SkRSXform.h"
     19 #include "SkTextBlob.h"
     20 #include "SkVertices.h"
     21 
     22 #ifndef SKLITEDL_PAGE
     23     #define SKLITEDL_PAGE 4096
     24 #endif
     25 
     26 // A stand-in for an optional SkRect which was not set, e.g. bounds for a saveLayer().
     27 static const SkRect kUnset = { SK_ScalarInfinity, 0,0,0};
     28 static const SkRect* maybe_unset(const SkRect& r) {
     29     return r.left() == SK_ScalarInfinity ? nullptr : &r;
     30 }
     31 
     32 // copy_v(dst, src,n, src,n, ...) copies an arbitrary number of typed srcs into dst.
     33 static void copy_v(void* dst) {}
     34 
     35 template <typename S, typename... Rest>
     36 static void copy_v(void* dst, const S* src, int n, Rest&&... rest) {
     37     SkASSERTF(((uintptr_t)dst & (alignof(S)-1)) == 0,
     38               "Expected %p to be aligned for at least %zu bytes.", dst, alignof(S));
     39     sk_careful_memcpy(dst, src, n*sizeof(S));
     40     copy_v(SkTAddOffset<void>(dst, n*sizeof(S)), std::forward<Rest>(rest)...);
     41 }
     42 
     43 // Helper for getting back at arrays which have been copy_v'd together after an Op.
     44 template <typename D, typename T>
     45 static const D* pod(const T* op, size_t offset = 0) {
     46     return SkTAddOffset<const D>(op+1, offset);
     47 }
     48 
     49 namespace {
     50 #define TYPES(M)                                                               \
     51     M(SetDrawFilter) M(Flush) M(Save) M(Restore) M(SaveLayer)                   \
     52     M(Concat) M(SetMatrix) M(Translate)                                         \
     53     M(ClipPath) M(ClipRect) M(ClipRRect) M(ClipRegion)                          \
     54     M(DrawPaint) M(DrawPath) M(DrawRect) M(DrawRegion) M(DrawOval) M(DrawArc)   \
     55     M(DrawRRect) M(DrawDRRect) M(DrawAnnotation) M(DrawDrawable) M(DrawPicture) \
     56     M(DrawImage) M(DrawImageNine) M(DrawImageRect) M(DrawImageLattice)          \
     57     M(DrawText) M(DrawPosText) M(DrawPosTextH)                                  \
     58     M(DrawTextOnPath) M(DrawTextRSXform) M(DrawTextBlob)                        \
     59     M(DrawPatch) M(DrawPoints) M(DrawVertices) M(DrawAtlas) M(DrawShadowRec)
     60 
     61 #define M(T) T,
     62     enum class Type : uint8_t { TYPES(M) };
     63 #undef M
     64 
     65     struct Op {
     66         uint32_t type :  8;
     67         uint32_t skip : 24;
     68     };
     69     static_assert(sizeof(Op) == 4, "");
     70 
     71     struct SetDrawFilter final : Op {
     72 #ifdef SK_SUPPORT_LEGACY_DRAWFILTER
     73         static const auto kType = Type::SetDrawFilter;
     74         SetDrawFilter(SkDrawFilter* df) : drawFilter(sk_ref_sp(df)) {}
     75         sk_sp<SkDrawFilter> drawFilter;
     76 #endif
     77         void draw(SkCanvas* c, const SkMatrix&) const {
     78 #ifdef SK_SUPPORT_LEGACY_DRAWFILTER
     79             c->setDrawFilter(drawFilter.get());
     80 #endif
     81         }
     82     };
     83 
     84     struct Flush final : Op {
     85         static const auto kType = Type::Flush;
     86         void draw(SkCanvas* c, const SkMatrix&) const { c->flush(); }
     87     };
     88 
     89     struct Save final : Op {
     90         static const auto kType = Type::Save;
     91         void draw(SkCanvas* c, const SkMatrix&) const { c->save(); }
     92     };
     93     struct Restore final : Op {
     94         static const auto kType = Type::Restore;
     95         void draw(SkCanvas* c, const SkMatrix&) const { c->restore(); }
     96     };
     97     struct SaveLayer final : Op {
     98         static const auto kType = Type::SaveLayer;
     99         SaveLayer(const SkRect* bounds, const SkPaint* paint,
    100                   const SkImageFilter* backdrop, const SkImage* clipMask,
    101                   const SkMatrix* clipMatrix, SkCanvas::SaveLayerFlags flags) {
    102             if (bounds) { this->bounds = *bounds; }
    103             if (paint)  { this->paint  = *paint;  }
    104             this->backdrop = sk_ref_sp(backdrop);
    105             this->clipMask = sk_ref_sp(clipMask);
    106             this->clipMatrix = clipMatrix ? *clipMatrix : SkMatrix::I();
    107             this->flags = flags;
    108         }
    109         SkRect                     bounds = kUnset;
    110         SkPaint                    paint;
    111         sk_sp<const SkImageFilter> backdrop;
    112         sk_sp<const SkImage>       clipMask;
    113         SkMatrix                   clipMatrix;
    114         SkCanvas::SaveLayerFlags   flags;
    115         void draw(SkCanvas* c, const SkMatrix&) const {
    116             c->saveLayer({ maybe_unset(bounds), &paint, backdrop.get(), clipMask.get(),
    117                            clipMatrix.isIdentity() ? nullptr : &clipMatrix, flags });
    118         }
    119     };
    120 
    121     struct Concat final : Op {
    122         static const auto kType = Type::Concat;
    123         Concat(const SkMatrix& matrix) : matrix(matrix) {}
    124         SkMatrix matrix;
    125         void draw(SkCanvas* c, const SkMatrix&) const { c->concat(matrix); }
    126     };
    127     struct SetMatrix final : Op {
    128         static const auto kType = Type::SetMatrix;
    129         SetMatrix(const SkMatrix& matrix) : matrix(matrix) {}
    130         SkMatrix matrix;
    131         void draw(SkCanvas* c, const SkMatrix& original) const {
    132             c->setMatrix(SkMatrix::Concat(original, matrix));
    133         }
    134     };
    135     struct Translate final : Op {
    136         static const auto kType = Type::Translate;
    137         Translate(SkScalar dx, SkScalar dy) : dx(dx), dy(dy) {}
    138         SkScalar dx,dy;
    139         void draw(SkCanvas* c, const SkMatrix&) const {
    140             c->translate(dx, dy);
    141         }
    142     };
    143 
    144     struct ClipPath final : Op {
    145         static const auto kType = Type::ClipPath;
    146         ClipPath(const SkPath& path, SkClipOp op, bool aa) : path(path), op(op), aa(aa) {}
    147         SkPath   path;
    148         SkClipOp op;
    149         bool     aa;
    150         void draw(SkCanvas* c, const SkMatrix&) const { c->clipPath(path, op, aa); }
    151     };
    152     struct ClipRect final : Op {
    153         static const auto kType = Type::ClipRect;
    154         ClipRect(const SkRect& rect, SkClipOp op, bool aa) : rect(rect), op(op), aa(aa) {}
    155         SkRect   rect;
    156         SkClipOp op;
    157         bool     aa;
    158         void draw(SkCanvas* c, const SkMatrix&) const { c->clipRect(rect, op, aa); }
    159     };
    160     struct ClipRRect final : Op {
    161         static const auto kType = Type::ClipRRect;
    162         ClipRRect(const SkRRect& rrect, SkClipOp op, bool aa) : rrect(rrect), op(op), aa(aa) {}
    163         SkRRect  rrect;
    164         SkClipOp op;
    165         bool     aa;
    166         void draw(SkCanvas* c, const SkMatrix&) const { c->clipRRect(rrect, op, aa); }
    167     };
    168     struct ClipRegion final : Op {
    169         static const auto kType = Type::ClipRegion;
    170         ClipRegion(const SkRegion& region, SkClipOp op) : region(region), op(op) {}
    171         SkRegion region;
    172         SkClipOp op;
    173         void draw(SkCanvas* c, const SkMatrix&) const { c->clipRegion(region, op); }
    174     };
    175 
    176     struct DrawPaint final : Op {
    177         static const auto kType = Type::DrawPaint;
    178         DrawPaint(const SkPaint& paint) : paint(paint) {}
    179         SkPaint paint;
    180         void draw(SkCanvas* c, const SkMatrix&) const { c->drawPaint(paint); }
    181     };
    182     struct DrawPath final : Op {
    183         static const auto kType = Type::DrawPath;
    184         DrawPath(const SkPath& path, const SkPaint& paint) : path(path), paint(paint) {}
    185         SkPath  path;
    186         SkPaint paint;
    187         void draw(SkCanvas* c, const SkMatrix&) const { c->drawPath(path, paint); }
    188     };
    189     struct DrawRect final : Op {
    190         static const auto kType = Type::DrawRect;
    191         DrawRect(const SkRect& rect, const SkPaint& paint) : rect(rect), paint(paint) {}
    192         SkRect  rect;
    193         SkPaint paint;
    194         void draw(SkCanvas* c, const SkMatrix&) const { c->drawRect(rect, paint); }
    195     };
    196     struct DrawRegion final : Op {
    197         static const auto kType = Type::DrawRegion;
    198         DrawRegion(const SkRegion& region, const SkPaint& paint) : region(region), paint(paint) {}
    199         SkRegion region;
    200         SkPaint  paint;
    201         void draw(SkCanvas* c, const SkMatrix&) const { c->drawRegion(region, paint); }
    202     };
    203     struct DrawOval final : Op {
    204         static const auto kType = Type::DrawOval;
    205         DrawOval(const SkRect& oval, const SkPaint& paint) : oval(oval), paint(paint) {}
    206         SkRect  oval;
    207         SkPaint paint;
    208         void draw(SkCanvas* c, const SkMatrix&) const { c->drawOval(oval, paint); }
    209     };
    210     struct DrawArc final : Op {
    211         static const auto kType = Type::DrawArc;
    212         DrawArc(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool useCenter,
    213                 const SkPaint& paint)
    214             : oval(oval), startAngle(startAngle), sweepAngle(sweepAngle), useCenter(useCenter)
    215             , paint(paint) {}
    216         SkRect  oval;
    217         SkScalar startAngle;
    218         SkScalar sweepAngle;
    219         bool useCenter;
    220         SkPaint paint;
    221         void draw(SkCanvas* c, const SkMatrix&) const { c->drawArc(oval, startAngle, sweepAngle,
    222                                                                    useCenter, paint); }
    223     };
    224     struct DrawRRect final : Op {
    225         static const auto kType = Type::DrawRRect;
    226         DrawRRect(const SkRRect& rrect, const SkPaint& paint) : rrect(rrect), paint(paint) {}
    227         SkRRect rrect;
    228         SkPaint paint;
    229         void draw(SkCanvas* c, const SkMatrix&) const { c->drawRRect(rrect, paint); }
    230     };
    231     struct DrawDRRect final : Op {
    232         static const auto kType = Type::DrawDRRect;
    233         DrawDRRect(const SkRRect& outer, const SkRRect& inner, const SkPaint& paint)
    234             : outer(outer), inner(inner), paint(paint) {}
    235         SkRRect outer, inner;
    236         SkPaint paint;
    237         void draw(SkCanvas* c, const SkMatrix&) const { c->drawDRRect(outer, inner, paint); }
    238     };
    239 
    240     struct DrawAnnotation final : Op {
    241         static const auto kType = Type::DrawAnnotation;
    242         DrawAnnotation(const SkRect& rect, SkData* value) : rect(rect), value(sk_ref_sp(value)) {}
    243         SkRect        rect;
    244         sk_sp<SkData> value;
    245         void draw(SkCanvas* c, const SkMatrix&) const {
    246             c->drawAnnotation(rect, pod<char>(this), value.get());
    247         }
    248     };
    249     struct DrawDrawable final : Op {
    250         static const auto kType = Type::DrawDrawable;
    251         DrawDrawable(SkDrawable* drawable, const SkMatrix* matrix) : drawable(sk_ref_sp(drawable)) {
    252             if (matrix) { this->matrix = *matrix; }
    253         }
    254         sk_sp<SkDrawable> drawable;
    255         SkMatrix          matrix = SkMatrix::I();
    256         void draw(SkCanvas* c, const SkMatrix&) const {
    257             c->drawDrawable(drawable.get(), &matrix);
    258         }
    259     };
    260     struct DrawPicture final : Op {
    261         static const auto kType = Type::DrawPicture;
    262         DrawPicture(const SkPicture* picture, const SkMatrix* matrix, const SkPaint* paint)
    263             : picture(sk_ref_sp(picture)) {
    264             if (matrix) { this->matrix = *matrix; }
    265             if (paint)  { this->paint  = *paint; has_paint = true; }
    266         }
    267         sk_sp<const SkPicture> picture;
    268         SkMatrix               matrix = SkMatrix::I();
    269         SkPaint                paint;
    270         bool                   has_paint = false;  // TODO: why is a default paint not the same?
    271         void draw(SkCanvas* c, const SkMatrix&) const {
    272             c->drawPicture(picture.get(), &matrix, has_paint ? &paint : nullptr);
    273         }
    274     };
    275 
    276     struct DrawImage final : Op {
    277         static const auto kType = Type::DrawImage;
    278         DrawImage(sk_sp<const SkImage>&& image, SkScalar x, SkScalar y, const SkPaint* paint)
    279             : image(std::move(image)), x(x), y(y) {
    280             if (paint) { this->paint = *paint; }
    281         }
    282         sk_sp<const SkImage> image;
    283         SkScalar x,y;
    284         SkPaint paint;
    285         void draw(SkCanvas* c, const SkMatrix&) const { c->drawImage(image.get(), x,y, &paint); }
    286     };
    287     struct DrawImageNine final : Op {
    288         static const auto kType = Type::DrawImageNine;
    289         DrawImageNine(sk_sp<const SkImage>&& image,
    290                       const SkIRect& center, const SkRect& dst, const SkPaint* paint)
    291             : image(std::move(image)), center(center), dst(dst) {
    292             if (paint) { this->paint = *paint; }
    293         }
    294         sk_sp<const SkImage> image;
    295         SkIRect center;
    296         SkRect  dst;
    297         SkPaint paint;
    298         void draw(SkCanvas* c, const SkMatrix&) const {
    299             c->drawImageNine(image.get(), center, dst, &paint);
    300         }
    301     };
    302     struct DrawImageRect final : Op {
    303         static const auto kType = Type::DrawImageRect;
    304         DrawImageRect(sk_sp<const SkImage>&& image, const SkRect* src, const SkRect& dst,
    305                       const SkPaint* paint, SkCanvas::SrcRectConstraint constraint)
    306             : image(std::move(image)), dst(dst), constraint(constraint) {
    307             this->src = src ? *src : SkRect::MakeIWH(image->width(), image->height());
    308             if (paint) { this->paint = *paint; }
    309         }
    310         sk_sp<const SkImage> image;
    311         SkRect src, dst;
    312         SkPaint paint;
    313         SkCanvas::SrcRectConstraint constraint;
    314         void draw(SkCanvas* c, const SkMatrix&) const {
    315             c->drawImageRect(image.get(), src, dst, &paint, constraint);
    316         }
    317     };
    318     struct DrawImageLattice final : Op {
    319         static const auto kType = Type::DrawImageLattice;
    320         DrawImageLattice(sk_sp<const SkImage>&& image, int xs, int ys, int fs,
    321                          const SkIRect& src, const SkRect& dst, const SkPaint* paint)
    322             : image(std::move(image)), xs(xs), ys(ys), fs(fs), src(src), dst(dst) {
    323             if (paint) { this->paint = *paint; }
    324         }
    325         sk_sp<const SkImage> image;
    326         int                  xs, ys, fs;
    327         SkIRect              src;
    328         SkRect               dst;
    329         SkPaint              paint;
    330         void draw(SkCanvas* c, const SkMatrix&) const {
    331             auto xdivs = pod<int>(this, 0),
    332                  ydivs = pod<int>(this, xs*sizeof(int));
    333             auto colors = (0 == fs) ? nullptr :
    334                           pod<SkColor>(this, (xs+ys)*sizeof(int));
    335             auto flags = (0 == fs) ? nullptr :
    336                          pod<SkCanvas::Lattice::RectType>(this, (xs+ys)*sizeof(int)+
    337                                                           fs*sizeof(SkColor));
    338             c->drawImageLattice(image.get(), {xdivs, ydivs, flags, xs, ys, &src, colors}, dst,
    339                                 &paint);
    340         }
    341     };
    342 
    343     struct DrawText final : Op {
    344         static const auto kType = Type::DrawText;
    345         DrawText(size_t bytes, SkScalar x, SkScalar y, const SkPaint& paint)
    346             : bytes(bytes), x(x), y(y), paint(paint) {}
    347         size_t bytes;
    348         SkScalar x,y;
    349         SkPaint paint;
    350         void draw(SkCanvas* c, const SkMatrix&) const {
    351             c->drawText(pod<void>(this), bytes, x,y, paint);
    352         }
    353     };
    354     struct DrawPosText final : Op {
    355         static const auto kType = Type::DrawPosText;
    356         DrawPosText(size_t bytes, const SkPaint& paint, int n)
    357             : bytes(bytes), paint(paint), n(n) {}
    358         size_t bytes;
    359         SkPaint paint;
    360         int n;
    361         void draw(SkCanvas* c, const SkMatrix&) const {
    362             auto points = pod<SkPoint>(this);
    363             auto text   = pod<void>(this, n*sizeof(SkPoint));
    364             c->drawPosText(text, bytes, points, paint);
    365         }
    366     };
    367     struct DrawPosTextH final : Op {
    368         static const auto kType = Type::DrawPosTextH;
    369         DrawPosTextH(size_t bytes, SkScalar y, const SkPaint& paint, int n)
    370             : bytes(bytes), y(y), paint(paint), n(n) {}
    371         size_t   bytes;
    372         SkScalar y;
    373         SkPaint  paint;
    374         int n;
    375         void draw(SkCanvas* c, const SkMatrix&) const {
    376             auto xs   = pod<SkScalar>(this);
    377             auto text = pod<void>(this, n*sizeof(SkScalar));
    378             c->drawPosTextH(text, bytes, xs, y, paint);
    379         }
    380     };
    381     struct DrawTextOnPath final : Op {
    382         static const auto kType = Type::DrawTextOnPath;
    383         DrawTextOnPath(size_t bytes, const SkPath& path,
    384                        const SkMatrix* matrix, const SkPaint& paint)
    385             : bytes(bytes), path(path), paint(paint) {
    386             if (matrix) { this->matrix = *matrix; }
    387         }
    388         size_t   bytes;
    389         SkPath   path;
    390         SkMatrix matrix = SkMatrix::I();
    391         SkPaint  paint;
    392         void draw(SkCanvas* c, const SkMatrix&) const {
    393             c->drawTextOnPath(pod<void>(this), bytes, path, &matrix, paint);
    394         }
    395     };
    396     struct DrawTextRSXform final : Op {
    397         static const auto kType = Type::DrawTextRSXform;
    398         DrawTextRSXform(size_t bytes, int xforms, const SkRect* cull, const SkPaint& paint)
    399             : bytes(bytes), xforms(xforms), paint(paint) {
    400             if (cull) { this->cull = *cull; }
    401         }
    402         size_t  bytes;
    403         int     xforms;
    404         SkRect  cull = kUnset;
    405         SkPaint paint;
    406         void draw(SkCanvas* c, const SkMatrix&) const {
    407             // For alignment, the SkRSXforms are first in the pod section, followed by the text.
    408             c->drawTextRSXform(pod<void>(this,xforms*sizeof(SkRSXform)),
    409                                bytes,
    410                                pod<SkRSXform>(this),
    411                                maybe_unset(cull),
    412                                paint);
    413         }
    414     };
    415     struct DrawTextBlob final : Op {
    416         static const auto kType = Type::DrawTextBlob;
    417         DrawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y, const SkPaint& paint)
    418             : blob(sk_ref_sp(blob)), x(x), y(y), paint(paint) {}
    419         sk_sp<const SkTextBlob> blob;
    420         SkScalar x,y;
    421         SkPaint paint;
    422         void draw(SkCanvas* c, const SkMatrix&) const {
    423             c->drawTextBlob(blob.get(), x,y, paint);
    424         }
    425     };
    426 
    427     struct DrawPatch final : Op {
    428         static const auto kType = Type::DrawPatch;
    429         DrawPatch(const SkPoint cubics[12], const SkColor colors[4], const SkPoint texs[4],
    430                   SkBlendMode bmode, const SkPaint& paint)
    431             : xfermode(bmode), paint(paint)
    432         {
    433             copy_v(this->cubics, cubics, 12);
    434             if (colors) { copy_v(this->colors, colors, 4); has_colors = true; }
    435             if (texs  ) { copy_v(this->texs  , texs  , 4); has_texs   = true; }
    436         }
    437         SkPoint           cubics[12];
    438         SkColor           colors[4];
    439         SkPoint           texs[4];
    440         SkBlendMode       xfermode;
    441         SkPaint           paint;
    442         bool              has_colors = false;
    443         bool              has_texs   = false;
    444         void draw(SkCanvas* c, const SkMatrix&) const {
    445             c->drawPatch(cubics, has_colors ? colors : nullptr, has_texs ? texs : nullptr,
    446                          xfermode, paint);
    447         }
    448     };
    449     struct DrawPoints final : Op {
    450         static const auto kType = Type::DrawPoints;
    451         DrawPoints(SkCanvas::PointMode mode, size_t count, const SkPaint& paint)
    452             : mode(mode), count(count), paint(paint) {}
    453         SkCanvas::PointMode mode;
    454         size_t              count;
    455         SkPaint             paint;
    456         void draw(SkCanvas* c, const SkMatrix&) const {
    457             c->drawPoints(mode, count, pod<SkPoint>(this), paint);
    458         }
    459     };
    460     struct DrawVertices final : Op {
    461         static const auto kType = Type::DrawVertices;
    462         DrawVertices(const SkVertices* v, SkBlendMode m, const SkPaint& p)
    463             : vertices(sk_ref_sp(const_cast<SkVertices*>(v))), mode(m), paint(p) {}
    464         sk_sp<SkVertices> vertices;
    465         SkBlendMode mode;
    466         SkPaint paint;
    467         void draw(SkCanvas* c, const SkMatrix&) const {
    468             c->drawVertices(vertices, mode, paint);
    469         }
    470     };
    471     struct DrawAtlas final : Op {
    472         static const auto kType = Type::DrawAtlas;
    473         DrawAtlas(const SkImage* atlas, int count, SkBlendMode xfermode,
    474                   const SkRect* cull, const SkPaint* paint, bool has_colors)
    475             : atlas(sk_ref_sp(atlas)), count(count), xfermode(xfermode), has_colors(has_colors) {
    476             if (cull)  { this->cull  = *cull; }
    477             if (paint) { this->paint = *paint; }
    478         }
    479         sk_sp<const SkImage> atlas;
    480         int                  count;
    481         SkBlendMode          xfermode;
    482         SkRect               cull = kUnset;
    483         SkPaint              paint;
    484         bool                 has_colors;
    485         void draw(SkCanvas* c, const SkMatrix&) const {
    486             auto xforms = pod<SkRSXform>(this, 0);
    487             auto   texs = pod<SkRect>(this, count*sizeof(SkRSXform));
    488             auto colors = has_colors
    489                 ? pod<SkColor>(this, count*(sizeof(SkRSXform) + sizeof(SkRect)))
    490                 : nullptr;
    491             c->drawAtlas(atlas.get(), xforms, texs, colors, count, xfermode,
    492                          maybe_unset(cull), &paint);
    493         }
    494     };
    495     struct DrawShadowRec final : Op {
    496         static const auto kType = Type::DrawShadowRec;
    497         DrawShadowRec(const SkPath& path, const SkDrawShadowRec& rec)
    498             : fPath(path), fRec(rec)
    499         {}
    500         SkPath          fPath;
    501         SkDrawShadowRec fRec;
    502         void draw(SkCanvas* c, const SkMatrix&) const {
    503             c->private_draw_shadow_rec(fPath, fRec);
    504         }
    505     };
    506 }
    507 
    508 template <typename T, typename... Args>
    509 void* SkLiteDL::push(size_t pod, Args&&... args) {
    510     size_t skip = SkAlignPtr(sizeof(T) + pod);
    511     SkASSERT(skip < (1<<24));
    512     if (fUsed + skip > fReserved) {
    513         static_assert(SkIsPow2(SKLITEDL_PAGE), "This math needs updating for non-pow2.");
    514         // Next greater multiple of SKLITEDL_PAGE.
    515         fReserved = (fUsed + skip + SKLITEDL_PAGE) & ~(SKLITEDL_PAGE-1);
    516         fBytes.realloc(fReserved);
    517     }
    518     SkASSERT(fUsed + skip <= fReserved);
    519     auto op = (T*)(fBytes.get() + fUsed);
    520     fUsed += skip;
    521     new (op) T{ std::forward<Args>(args)... };
    522     op->type = (uint32_t)T::kType;
    523     op->skip = skip;
    524     return op+1;
    525 }
    526 
    527 template <typename Fn, typename... Args>
    528 inline void SkLiteDL::map(const Fn fns[], Args... args) const {
    529     auto end = fBytes.get() + fUsed;
    530     for (const uint8_t* ptr = fBytes.get(); ptr < end; ) {
    531         auto op = (const Op*)ptr;
    532         auto type = op->type;
    533         auto skip = op->skip;
    534         if (auto fn = fns[type]) {  // We replace no-op functions with nullptrs
    535             fn(op, args...);        // to avoid the overhead of a pointless call.
    536         }
    537         ptr += skip;
    538     }
    539 }
    540 
    541 #ifdef SK_SUPPORT_LEGACY_DRAWFILTER
    542 void SkLiteDL::setDrawFilter(SkDrawFilter* df) {
    543     this->push<SetDrawFilter>(0, df);
    544 }
    545 #endif
    546 
    547 void SkLiteDL::flush() { this->push<Flush>(0); }
    548 
    549 void SkLiteDL::   save() { this->push   <Save>(0); }
    550 void SkLiteDL::restore() { this->push<Restore>(0); }
    551 void SkLiteDL::saveLayer(const SkRect* bounds, const SkPaint* paint,
    552                          const SkImageFilter* backdrop, const SkImage* clipMask,
    553                          const SkMatrix* clipMatrix, SkCanvas::SaveLayerFlags flags) {
    554     this->push<SaveLayer>(0, bounds, paint, backdrop, clipMask, clipMatrix, flags);
    555 }
    556 
    557 void SkLiteDL::   concat(const SkMatrix& matrix)   { this->push   <Concat>(0, matrix); }
    558 void SkLiteDL::setMatrix(const SkMatrix& matrix)   { this->push<SetMatrix>(0, matrix); }
    559 void SkLiteDL::translate(SkScalar dx, SkScalar dy) { this->push<Translate>(0, dx, dy); }
    560 
    561 void SkLiteDL::clipPath(const SkPath& path, SkClipOp op, bool aa) {
    562     this->push<ClipPath>(0, path, op, aa);
    563 }
    564 void SkLiteDL::clipRect(const SkRect& rect, SkClipOp op, bool aa) {
    565     this->push<ClipRect>(0, rect, op, aa);
    566 }
    567 void SkLiteDL::clipRRect(const SkRRect& rrect, SkClipOp op, bool aa) {
    568     this->push<ClipRRect>(0, rrect, op, aa);
    569 }
    570 void SkLiteDL::clipRegion(const SkRegion& region, SkClipOp op) {
    571     this->push<ClipRegion>(0, region, op);
    572 }
    573 
    574 void SkLiteDL::drawPaint(const SkPaint& paint) {
    575     this->push<DrawPaint>(0, paint);
    576 }
    577 void SkLiteDL::drawPath(const SkPath& path, const SkPaint& paint) {
    578     this->push<DrawPath>(0, path, paint);
    579 }
    580 void SkLiteDL::drawRect(const SkRect& rect, const SkPaint& paint) {
    581     this->push<DrawRect>(0, rect, paint);
    582 }
    583 void SkLiteDL::drawRegion(const SkRegion& region, const SkPaint& paint) {
    584     this->push<DrawRegion>(0, region, paint);
    585 }
    586 void SkLiteDL::drawOval(const SkRect& oval, const SkPaint& paint) {
    587     this->push<DrawOval>(0, oval, paint);
    588 }
    589 void SkLiteDL::drawArc(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool useCenter,
    590                        const SkPaint& paint) {
    591     this->push<DrawArc>(0, oval, startAngle, sweepAngle, useCenter, paint);
    592 }
    593 void SkLiteDL::drawRRect(const SkRRect& rrect, const SkPaint& paint) {
    594     this->push<DrawRRect>(0, rrect, paint);
    595 }
    596 void SkLiteDL::drawDRRect(const SkRRect& outer, const SkRRect& inner, const SkPaint& paint) {
    597     this->push<DrawDRRect>(0, outer, inner, paint);
    598 }
    599 
    600 void SkLiteDL::drawAnnotation(const SkRect& rect, const char* key, SkData* value) {
    601     size_t bytes = strlen(key)+1;
    602     void* pod = this->push<DrawAnnotation>(bytes, rect, value);
    603     copy_v(pod, key,bytes);
    604 }
    605 void SkLiteDL::drawDrawable(SkDrawable* drawable, const SkMatrix* matrix) {
    606     this->push<DrawDrawable>(0, drawable, matrix);
    607 }
    608 void SkLiteDL::drawPicture(const SkPicture* picture,
    609                            const SkMatrix* matrix, const SkPaint* paint) {
    610     this->push<DrawPicture>(0, picture, matrix, paint);
    611 }
    612 void SkLiteDL::drawImage(sk_sp<const SkImage> image, SkScalar x, SkScalar y, const SkPaint* paint) {
    613     this->push<DrawImage>(0, std::move(image), x,y, paint);
    614 }
    615 void SkLiteDL::drawImageNine(sk_sp<const SkImage> image, const SkIRect& center,
    616                              const SkRect& dst, const SkPaint* paint) {
    617     this->push<DrawImageNine>(0, std::move(image), center, dst, paint);
    618 }
    619 void SkLiteDL::drawImageRect(sk_sp<const SkImage> image, const SkRect* src, const SkRect& dst,
    620                              const SkPaint* paint, SkCanvas::SrcRectConstraint constraint) {
    621     this->push<DrawImageRect>(0, std::move(image), src, dst, paint, constraint);
    622 }
    623 void SkLiteDL::drawImageLattice(sk_sp<const SkImage> image, const SkCanvas::Lattice& lattice,
    624                                 const SkRect& dst, const SkPaint* paint) {
    625     int xs = lattice.fXCount, ys = lattice.fYCount;
    626     int fs = lattice.fRectTypes ? (xs + 1) * (ys + 1) : 0;
    627     size_t bytes = (xs + ys) * sizeof(int) + fs * sizeof(SkCanvas::Lattice::RectType)
    628                    + fs * sizeof(SkColor);
    629     SkASSERT(lattice.fBounds);
    630     void* pod = this->push<DrawImageLattice>(bytes, std::move(image), xs, ys, fs, *lattice.fBounds,
    631                                              dst, paint);
    632     copy_v(pod, lattice.fXDivs, xs,
    633                 lattice.fYDivs, ys,
    634                 lattice.fColors, fs,
    635                 lattice.fRectTypes, fs);
    636 }
    637 
    638 void SkLiteDL::drawText(const void* text, size_t bytes,
    639                         SkScalar x, SkScalar y, const SkPaint& paint) {
    640     void* pod = this->push<DrawText>(bytes, bytes, x, y, paint);
    641     copy_v(pod, (const char*)text,bytes);
    642 }
    643 void SkLiteDL::drawPosText(const void* text, size_t bytes,
    644                            const SkPoint pos[], const SkPaint& paint) {
    645     int n = paint.countText(text, bytes);
    646     void* pod = this->push<DrawPosText>(n*sizeof(SkPoint)+bytes, bytes, paint, n);
    647     copy_v(pod, pos,n, (const char*)text,bytes);
    648 }
    649 void SkLiteDL::drawPosTextH(const void* text, size_t bytes,
    650                            const SkScalar xs[], SkScalar y, const SkPaint& paint) {
    651     int n = paint.countText(text, bytes);
    652     void* pod = this->push<DrawPosTextH>(n*sizeof(SkScalar)+bytes, bytes, y, paint, n);
    653     copy_v(pod, xs,n, (const char*)text,bytes);
    654 }
    655 void SkLiteDL::drawTextOnPath(const void* text, size_t bytes,
    656                               const SkPath& path, const SkMatrix* matrix, const SkPaint& paint) {
    657     void* pod = this->push<DrawTextOnPath>(bytes, bytes, path, matrix, paint);
    658     copy_v(pod, (const char*)text,bytes);
    659 }
    660 void SkLiteDL::drawTextRSXform(const void* text, size_t bytes,
    661                                const SkRSXform xforms[], const SkRect* cull, const SkPaint& paint) {
    662     int n = paint.countText(text, bytes);
    663     void* pod = this->push<DrawTextRSXform>(bytes+n*sizeof(SkRSXform), bytes, n, cull, paint);
    664     copy_v(pod, xforms,n, (const char*)text,bytes);
    665 }
    666 void SkLiteDL::drawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y, const SkPaint& paint) {
    667     this->push<DrawTextBlob>(0, blob, x,y, paint);
    668 }
    669 
    670 void SkLiteDL::drawPatch(const SkPoint points[12], const SkColor colors[4], const SkPoint texs[4],
    671                          SkBlendMode bmode, const SkPaint& paint) {
    672     this->push<DrawPatch>(0, points, colors, texs, bmode, paint);
    673 }
    674 void SkLiteDL::drawPoints(SkCanvas::PointMode mode, size_t count, const SkPoint points[],
    675                           const SkPaint& paint) {
    676     void* pod = this->push<DrawPoints>(count*sizeof(SkPoint), mode, count, paint);
    677     copy_v(pod, points,count);
    678 }
    679 void SkLiteDL::drawVertices(const SkVertices* vertices, SkBlendMode mode, const SkPaint& paint) {
    680     this->push<DrawVertices>(0, vertices, mode, paint);
    681 }
    682 void SkLiteDL::drawAtlas(const SkImage* atlas, const SkRSXform xforms[], const SkRect texs[],
    683                          const SkColor colors[], int count, SkBlendMode xfermode,
    684                          const SkRect* cull, const SkPaint* paint) {
    685     size_t bytes = count*(sizeof(SkRSXform) + sizeof(SkRect));
    686     if (colors) {
    687         bytes += count*sizeof(SkColor);
    688     }
    689     void* pod = this->push<DrawAtlas>(bytes,
    690                                       atlas, count, xfermode, cull, paint, colors != nullptr);
    691     copy_v(pod, xforms, count,
    692                   texs, count,
    693                 colors, colors ? count : 0);
    694 }
    695 void SkLiteDL::drawShadowRec(const SkPath& path, const SkDrawShadowRec& rec) {
    696     this->push<DrawShadowRec>(0, path, rec);
    697 }
    698 
    699 typedef void(*draw_fn)(const void*,  SkCanvas*, const SkMatrix&);
    700 typedef void(*void_fn)(const void*);
    701 
    702 // All ops implement draw().
    703 #define M(T) [](const void* op, SkCanvas* c, const SkMatrix& original) { \
    704     ((const T*)op)->draw(c, original);                                         \
    705 },
    706 static const draw_fn draw_fns[] = { TYPES(M) };
    707 #undef M
    708 
    709 // Older libstdc++ has pre-standard std::has_trivial_destructor.
    710 #if defined(__GLIBCXX__) && (__GLIBCXX__ < 20130000)
    711     template <typename T> using can_skip_destructor = std::has_trivial_destructor<T>;
    712 #else
    713     template <typename T> using can_skip_destructor = std::is_trivially_destructible<T>;
    714 #endif
    715 
    716 // Most state ops (matrix, clip, save, restore) have a trivial destructor.
    717 #define M(T) !can_skip_destructor<T>::value ? [](const void* op) { ((const T*)op)->~T(); } \
    718                                             : (void_fn)nullptr,
    719 static const void_fn dtor_fns[] = { TYPES(M) };
    720 #undef M
    721 
    722 void SkLiteDL::draw(SkCanvas* canvas) const {
    723     SkAutoCanvasRestore acr(canvas, false);
    724     this->map(draw_fns, canvas, canvas->getTotalMatrix());
    725 }
    726 
    727 SkLiteDL::~SkLiteDL() {
    728     this->reset();
    729 }
    730 
    731 void SkLiteDL::reset() {
    732     this->map(dtor_fns);
    733 
    734     // Leave fBytes and fReserved alone.
    735     fUsed   = 0;
    736 }
    737