| reed@google.com | 5c3d147 | 2011-02-22 19:12:23 +0000 | [diff] [blame^] | 1 | #include "SkClipStack.h" |
| 2 | #include "SkPath.h" |
| 3 | #include <new> |
| 4 | |
| 5 | struct SkClipStack::Rec { |
| 6 | enum State { |
| 7 | kEmpty_State, |
| 8 | kRect_State, |
| 9 | kPath_State |
| 10 | }; |
| 11 | |
| 12 | SkPath fPath; |
| 13 | SkRect fRect; |
| 14 | int fSaveCount; |
| 15 | SkRegion::Op fOp; |
| 16 | State fState; |
| 17 | |
| 18 | Rec(int saveCount, const SkRect& rect, SkRegion::Op op) : fRect(rect) { |
| 19 | fSaveCount = saveCount; |
| 20 | fOp = op; |
| 21 | fState = kRect_State; |
| 22 | } |
| 23 | |
| 24 | Rec(int saveCount, const SkPath& path, SkRegion::Op op) : fPath(path) { |
| 25 | fSaveCount = saveCount; |
| 26 | fOp = op; |
| 27 | fState = kPath_State; |
| 28 | } |
| 29 | |
| 30 | /** |
| 31 | * Returns true if this Rec can be intersected in place with a new clip |
| 32 | */ |
| 33 | bool canBeIntersected(int saveCount, SkRegion::Op op) const { |
| 34 | if (kEmpty_State == fState) { |
| 35 | return true; |
| 36 | } |
| 37 | return fSaveCount == saveCount && |
| 38 | SkRegion::kIntersect_Op == fOp && |
| 39 | SkRegion::kIntersect_Op == op; |
| 40 | } |
| 41 | }; |
| 42 | |
| 43 | SkClipStack::SkClipStack() : fDeque(sizeof(Rec)) { |
| 44 | fSaveCount = 0; |
| 45 | } |
| 46 | |
| 47 | void SkClipStack::reset() { |
| 48 | // don't have a reset() on SkDeque, so fake it here |
| 49 | fDeque.~SkDeque(); |
| 50 | new (&fDeque) SkDeque(sizeof(Rec)); |
| 51 | |
| 52 | fSaveCount = 0; |
| 53 | } |
| 54 | |
| 55 | void SkClipStack::save() { |
| 56 | fSaveCount += 1; |
| 57 | } |
| 58 | |
| 59 | void SkClipStack::restore() { |
| 60 | fSaveCount -= 1; |
| 61 | while (!fDeque.empty()) { |
| 62 | Rec* rec = (Rec*)fDeque.back(); |
| 63 | if (rec->fSaveCount <= fSaveCount) { |
| 64 | break; |
| 65 | } |
| 66 | rec->~Rec(); |
| 67 | fDeque.pop_back(); |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | void SkClipStack::clipDevRect(const SkRect& rect, SkRegion::Op op) { |
| 72 | Rec* rec = (Rec*)fDeque.back(); |
| 73 | if (rec && rec->canBeIntersected(fSaveCount, op)) { |
| 74 | switch (rec->fState) { |
| 75 | case Rec::kEmpty_State: |
| 76 | return; |
| 77 | case Rec::kRect_State: |
| 78 | if (!rec->fRect.intersect(rect)) { |
| 79 | rec->fState = Rec::kEmpty_State; |
| 80 | } |
| 81 | return; |
| 82 | case Rec::kPath_State: |
| 83 | if (!SkRect::Intersects(rec->fPath.getBounds(), rect)) { |
| 84 | rec->fState = Rec::kEmpty_State; |
| 85 | return; |
| 86 | } |
| 87 | break; |
| 88 | } |
| 89 | } |
| 90 | new (fDeque.push_back()) Rec(fSaveCount, rect, op); |
| 91 | } |
| 92 | |
| 93 | void SkClipStack::clipDevPath(const SkPath& path, SkRegion::Op op) { |
| 94 | Rec* rec = (Rec*)fDeque.back(); |
| 95 | if (rec && rec->canBeIntersected(fSaveCount, op)) { |
| 96 | const SkRect& pathBounds = path.getBounds(); |
| 97 | switch (rec->fState) { |
| 98 | case Rec::kEmpty_State: |
| 99 | return; |
| 100 | case Rec::kRect_State: |
| 101 | if (!SkRect::Intersects(rec->fRect, pathBounds)) { |
| 102 | rec->fState = Rec::kEmpty_State; |
| 103 | return; |
| 104 | } |
| 105 | break; |
| 106 | case Rec::kPath_State: |
| 107 | if (!SkRect::Intersects(rec->fPath.getBounds(), pathBounds)) { |
| 108 | rec->fState = Rec::kEmpty_State; |
| 109 | return; |
| 110 | } |
| 111 | break; |
| 112 | } |
| 113 | } |
| 114 | new (fDeque.push_back()) Rec(fSaveCount, path, op); |
| 115 | } |
| 116 | |
| 117 | /////////////////////////////////////////////////////////////////////////////// |
| 118 | |
| 119 | SkClipStack::B2FIter::B2FIter(const SkClipStack& stack) : fIter(stack.fDeque) { |
| 120 | } |
| 121 | |
| 122 | const SkClipStack::B2FIter::Clip* SkClipStack::B2FIter::next() { |
| 123 | const SkClipStack::Rec* rec = (const SkClipStack::Rec*)fIter.next(); |
| 124 | if (NULL == rec) { |
| 125 | return NULL; |
| 126 | } |
| 127 | |
| 128 | switch (rec->fState) { |
| 129 | case SkClipStack::Rec::kEmpty_State: |
| 130 | fClip.fRect = NULL; |
| 131 | fClip.fPath = NULL; |
| 132 | break; |
| 133 | case SkClipStack::Rec::kRect_State: |
| 134 | fClip.fRect = &rec->fRect; |
| 135 | fClip.fPath = NULL; |
| 136 | break; |
| 137 | case SkClipStack::Rec::kPath_State: |
| 138 | fClip.fRect = NULL; |
| 139 | fClip.fPath = &rec->fPath; |
| 140 | break; |
| 141 | } |
| 142 | fClip.fOp = rec->fOp; |
| 143 | return &fClip; |
| 144 | } |