michael@0: 
michael@0: /*
michael@0:  * Copyright 2011 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: 
michael@0: #ifndef SkClampRange_DEFINED
michael@0: #define SkClampRange_DEFINED
michael@0: 
michael@0: #include "SkFixed.h"
michael@0: 
michael@0: /**
michael@0:  *  Iteration fixed fx by dx, clamping as you go to [0..0xFFFF], this class
michael@0:  *  computes the (up to) 3 spans there are:
michael@0:  *
michael@0:  *  range0: use constant value V0
michael@0:  *  range1: iterate as usual fx += dx
michael@0:  *  range2: use constant value V1
michael@0:  */
michael@0: struct SkClampRange {
michael@0:     int fCount0;    // count for fV0
michael@0:     int fCount1;    // count for interpolating (fV0...fV1)
michael@0:     int fCount2;    // count for fV1
michael@0:     SkFixed fFx1;   // initial fx value for the fCount1 range.
michael@0:                     // only valid if fCount1 > 0
michael@0:     int fV0, fV1;
michael@0:     bool fOverflowed;   // true if we had to clamp due to numerical overflow
michael@0: 
michael@0:     void init(SkFixed fx, SkFixed dx, int count, int v0, int v1);
michael@0: 
michael@0: private:
michael@0:     void initFor1(SkFixed fx);
michael@0: };
michael@0: 
michael@0: #endif