arospdf/splash/SplashXPathScanner.h

   1 //========================================================================
   2 //
   3 // SplashXPathScanner.h
   4 //
   5 //========================================================================
   6
   7 #ifndef SPLASHXPATHSCANNER_H
   8 #define SPLASHXPATHSCANNER_H
   9
  10 #include <aconf.h>
  11
  12 #ifdef USE_GCC_PRAGMAS
  13 #pragma interface
  14 #endif
  15
  16 #include "SplashTypes.h"
  17
  18 class SplashXPath;
  19 class SplashBitmap;
  20 struct SplashIntersect;
  21
  22 //------------------------------------------------------------------------
  23 // SplashXPathScanner
  24 //------------------------------------------------------------------------
  25
  26 class SplashXPathScanner {
  27 public:
  28
  29   // Create a new SplashXPathScanner object.  <xPathA> must be sorted.
  30   SplashXPathScanner(SplashXPath *xPathA, GBool eoA);
  31
  32   ~SplashXPathScanner();
  33
  34   // Return the path's bounding box.
  35   void getBBox(int *xMinA, int *yMinA, int *xMaxA, int *yMaxA)
  36     { *xMinA = xMin; *yMinA = yMin; *xMaxA = xMax; *yMaxA = yMax; }
  37
  38   // Return the path's bounding box.
  39   void getBBoxAA(int *xMinA, int *yMinA, int *xMaxA, int *yMaxA);
  40
  41   // Return the min/max x values for the span at <y>.
  42   void getSpanBounds(int y, int *spanXMin, int *spanXMax);
  43
  44   // Returns true if (<x>,<y>) is inside the path.
  45   GBool test(int x, int y);
  46
  47   // Returns true if the entire span ([<x0>,<x1>], <y>) is inside the
  48   // path.
  49   GBool testSpan(int x0, int x1, int y);
  50
  51   // Returns the next span inside the path at <y>.  If <y> is
  52   // different than the previous call to getNextSpan, this returns the
  53   // first span at <y>; otherwise it returns the next span (relative
  54   // to the previous call to getNextSpan).  Returns false if there are
  55   // no more spans at <y>.
  56   GBool getNextSpan(int y, int *x0, int *x1);
  57
  58   // Renders one anti-aliased line into <aaBuf>.  Returns the min and
  59   // max x coordinates with non-zero pixels in <x0> and <x1>.
  60   void renderAALine(SplashBitmap *aaBuf, int *x0, int *x1, int y);
  61
  62   // Clips an anti-aliased line by setting pixels to zero.  On entry,
  63   // all non-zero pixels are between <x0> and <x1>.  This function
  64   // will update <x0> and <x1>.
  65   void clipAALine(SplashBitmap *aaBuf, int *x0, int *x1, int y);
  66
  67 private:
  68
  69   void computeIntersections(int y);
  70
  71   SplashXPath *xPath;
  72   GBool eo;
  73   int xMin, yMin, xMax, yMax;
  74
  75   int interY;                   // current y value
  76   int interIdx;                 // current index into <inter> - used by
  77                                 //   getNextSpan
  78   int interCount;               // current EO/NZWN counter - used by
  79                                 //   getNextSpan
  80   int xPathIdx;                 // current index into <xPath> - used by
  81                                 //   computeIntersections
  82   SplashIntersect *inter;       // intersections array for <interY>
  83   int interLen;                 // number of intersections in <inter>
  84   int interSize;                // size of the <inter> array
  85 };
  86
  87 #endif