1 #ifndef SkLineClipper_DEFINED 2 #define SkLineClipper_DEFINED 3 4 #include "SkRect.h" 5 #include "SkPoint.h" 6 7 class SkLineClipper { 8 public: 9 enum { 10 kMaxPoints = 4 11 }; 12 13 /* Clip the line pts[0]...pts[1] against clip, ignoring segments that 14 lie completely above or below the clip. For portions to the left or 15 right, turn those into vertical line segments that are aligned to the 16 edge of the clip. 17 18 Return the number of line segments that result, and store the end-points 19 of those segments sequentially in lines as follows: 20 1st segment: lines[0]..lines[1] 21 2nd segment: lines[1]..lines[2] 22 3rd segment: lines[2]..lines[3] 23 */ 24 static int ClipLine(const SkPoint pts[2], const SkRect& clip, 25 SkPoint lines[kMaxPoints]); 26 27 /* Intersect the line segment against the rect. If there is a non-empty 28 resulting segment, return true and set dst[] to that segment. If not, 29 return false and ignore dst[]. 30 31 ClipLine is specialized for scan-conversion, as it adds vertical 32 segments on the sides to show where the line extended beyond the 33 left or right sides. IntersectLine does not. 34 */ 35 static bool IntersectLine(const SkPoint src[2], const SkRect& clip, 36 SkPoint dst[2]); 37 }; 38 39 #endif 40 41