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      1 
      2 /*
      3  * Copyright 2006 The Android Open Source Project
      4  *
      5  * Use of this source code is governed by a BSD-style license that can be
      6  * found in the LICENSE file.
      7  */
      8 
      9 
     10 #ifndef SkDraw_DEFINED
     11 #define SkDraw_DEFINED
     12 
     13 #include "SkCanvas.h"
     14 #include "SkMask.h"
     15 #include "SkPaint.h"
     16 
     17 class SkBitmap;
     18 class SkClipStack;
     19 class SkBaseDevice;
     20 class SkBlitter;
     21 class SkMatrix;
     22 class SkPath;
     23 class SkRegion;
     24 class SkRasterClip;
     25 struct SkDrawProcs;
     26 struct SkRect;
     27 class SkRRect;
     28 
     29 class SkDraw {
     30 public:
     31     SkDraw();
     32     SkDraw(const SkDraw& src);
     33 
     34     void    drawPaint(const SkPaint&) const;
     35     void    drawPoints(SkCanvas::PointMode, size_t count, const SkPoint[],
     36                        const SkPaint&, bool forceUseDevice = false) const;
     37     void    drawRect(const SkRect& prePaintRect, const SkPaint&, const SkMatrix* paintMatrix,
     38                      const SkRect* postPaintRect) const;
     39     void    drawRect(const SkRect& rect, const SkPaint& paint) const {
     40         this->drawRect(rect, paint, NULL, NULL);
     41     }
     42     void    drawRRect(const SkRRect&, const SkPaint&) const;
     43     /**
     44      *  To save on mallocs, we allow a flag that tells us that srcPath is
     45      *  mutable, so that we don't have to make copies of it as we transform it.
     46      *
     47      *  If prePathMatrix is not null, it should logically be applied before any
     48      *  stroking or other effects. If there are no effects on the paint that
     49      *  affect the geometry/rasterization, then the pre matrix can just be
     50      *  pre-concated with the current matrix.
     51      */
     52     void    drawPath(const SkPath& path, const SkPaint& paint,
     53                      const SkMatrix* prePathMatrix, bool pathIsMutable) const {
     54         this->drawPath(path, paint, prePathMatrix, pathIsMutable, false);
     55     }
     56 
     57     void drawPath(const SkPath& path, const SkPaint& paint,
     58                   SkBlitter* customBlitter = NULL) const {
     59         this->drawPath(path, paint, NULL, false, false, customBlitter);
     60     }
     61 
     62     /* If dstOrNull is null, computes a dst by mapping the bitmap's bounds through the matrix. */
     63     void    drawBitmap(const SkBitmap&, const SkMatrix&, const SkRect* dstOrNull,
     64                        const SkPaint&) const;
     65     void    drawSprite(const SkBitmap&, int x, int y, const SkPaint&) const;
     66     void    drawText(const char text[], size_t byteLength, SkScalar x,
     67                      SkScalar y, const SkPaint& paint) const;
     68     void    drawPosText(const char text[], size_t byteLength,
     69                         const SkScalar pos[], int scalarsPerPosition,
     70                         const SkPoint& offset, const SkPaint& paint) const;
     71     void    drawVertices(SkCanvas::VertexMode mode, int count,
     72                          const SkPoint vertices[], const SkPoint textures[],
     73                          const SkColor colors[], SkXfermode* xmode,
     74                          const uint16_t indices[], int ptCount,
     75                          const SkPaint& paint) const;
     76 
     77     /**
     78      *  Overwrite the target with the path's coverage (i.e. its mask).
     79      *  Will overwrite the entire device, so it need not be zero'd first.
     80      *
     81      *  Only device A8 is supported right now.
     82      */
     83     void drawPathCoverage(const SkPath& src, const SkPaint& paint,
     84                           SkBlitter* customBlitter = NULL) const {
     85         this->drawPath(src, paint, NULL, false, true, customBlitter);
     86     }
     87 
     88     /** Helper function that creates a mask from a path and an optional maskfilter.
     89         Note however, that the resulting mask will not have been actually filtered,
     90         that must be done afterwards (by calling filterMask). The maskfilter is provided
     91         solely to assist in computing the mask's bounds (if the mode requests that).
     92     */
     93     static bool DrawToMask(const SkPath& devPath, const SkIRect* clipBounds,
     94                            const SkMaskFilter*, const SkMatrix* filterMatrix,
     95                            SkMask* mask, SkMask::CreateMode mode,
     96                            SkPaint::Style style);
     97 
     98     enum RectType {
     99         kHair_RectType,
    100         kFill_RectType,
    101         kStroke_RectType,
    102         kPath_RectType
    103     };
    104 
    105     /**
    106      *  Based on the paint's style, strokeWidth, and the matrix, classify how
    107      *  to draw the rect. If no special-case is available, returns
    108      *  kPath_RectType.
    109      *
    110      *  Iff RectType == kStroke_RectType, then strokeSize is set to the device
    111      *  width and height of the stroke.
    112      */
    113     static RectType ComputeRectType(const SkPaint&, const SkMatrix&,
    114                                     SkPoint* strokeSize);
    115 
    116     static bool ShouldDrawTextAsPaths(const SkPaint&, const SkMatrix&);
    117     void        drawText_asPaths(const char text[], size_t byteLength,
    118                                  SkScalar x, SkScalar y, const SkPaint&) const;
    119     void        drawPosText_asPaths(const char text[], size_t byteLength,
    120                                     const SkScalar pos[], int scalarsPerPosition,
    121                                     const SkPoint& offset, const SkPaint&) const;
    122 
    123 private:
    124     void    drawDevMask(const SkMask& mask, const SkPaint&) const;
    125     void    drawBitmapAsMask(const SkBitmap&, const SkPaint&) const;
    126 
    127     void    drawPath(const SkPath&, const SkPaint&, const SkMatrix* preMatrix,
    128                      bool pathIsMutable, bool drawCoverage,
    129                      SkBlitter* customBlitter = NULL) const;
    130 
    131     /**
    132      *  Return the current clip bounds, in local coordinates, with slop to account
    133      *  for antialiasing or hairlines (i.e. device-bounds outset by 1, and then
    134      *  run through the inverse of the matrix).
    135      *
    136      *  If the matrix cannot be inverted, or the current clip is empty, return
    137      *  false and ignore bounds parameter.
    138      */
    139     bool SK_WARN_UNUSED_RESULT
    140     computeConservativeLocalClipBounds(SkRect* bounds) const;
    141 
    142 public:
    143     const SkBitmap* fBitmap;        // required
    144     const SkMatrix* fMatrix;        // required
    145     const SkRegion* fClip;          // DEPRECATED
    146     const SkRasterClip* fRC;        // required
    147 
    148     const SkClipStack* fClipStack;  // optional
    149     SkBaseDevice*   fDevice;        // optional
    150     SkDrawProcs*    fProcs;         // optional
    151 
    152 #ifdef SK_DEBUG
    153     void validate() const;
    154 #else
    155     void validate() const {}
    156 #endif
    157 };
    158 
    159 #endif
    160