1
2/*
3 * Copyright 2011 Google Inc.
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 SkClampRange_DEFINED
11#define SkClampRange_DEFINED
12
13#include "SkFixed.h"
14
15/**
16 *  Iteration fixed fx by dx, clamping as you go to [0..0xFFFF], this class
17 *  computes the (up to) 3 spans there are:
18 *
19 *  range0: use constant value V0
20 *  range1: iterate as usual fx += dx
21 *  range2: use constant value V1
22 */
23struct SkClampRange {
24    int fCount0;    // count for fV0
25    int fCount1;    // count for interpolating (fV0...fV1)
26    int fCount2;    // count for fV1
27    SkFixed fFx1;   // initial fx value for the fCount1 range.
28                    // only valid if fCount1 > 0
29    int fV0, fV1;
30
31    void init(SkFixed fx, SkFixed dx, int count, int v0, int v1);
32
33private:
34    void initFor1(SkFixed fx);
35};
36
37#endif
38