SkFloat.h revision 8a1c16ff38322f0210116fa7293eb8817c7e477e 
1/*
2 * Copyright (C) 2006-2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef SkFloat_DEFINED
18#define SkFloat_DEFINED
19
20#include "SkFixed.h"
21
22class SkFloat {
23public:
24    SkFloat() {}
25
26    void    setZero() { fPacked = 0; }
27//  void    setShift(int value, int shift) { fPacked = SetShift(value, shift); }
28    void    setInt(int value) { fPacked = SetShift(value, 0); }
29    void    setFixed(SkFixed value) { fPacked = SetShift(value, -16); }
30    void    setFract(SkFract value) { fPacked = SetShift(value, -30); }
31
32//  int     getShift(int shift) const { return GetShift(fPacked, shift); }
33    int     getInt() const { return GetShift(fPacked, 0); }
34    SkFixed getFixed() const { return GetShift(fPacked, -16); }
35    SkFract getFract() const { return GetShift(fPacked, -30); }
36
37    void    abs() { fPacked = Abs(fPacked); }
38    void    negate() { fPacked = Neg(fPacked); }
39
40    void    shiftLeft(int bits) { fPacked = Shift(fPacked, bits); }
41    void    setShiftLeft(const SkFloat& a, int bits) { fPacked = Shift(a.fPacked, bits); }
42
43    void    shiftRight(int bits) { fPacked = Shift(fPacked, -bits); }
44    void    setShiftRight(const SkFloat& a, int bits) { fPacked = Shift(a.fPacked, -bits); }
45
46    void    add(const SkFloat& a) { fPacked = Add(fPacked, a.fPacked); }
47    void    setAdd(const SkFloat& a, const SkFloat& b) { fPacked = Add(a.fPacked, b.fPacked); }
48
49    void    sub(const SkFloat& a) { fPacked = Add(fPacked, Neg(a.fPacked)); }
50    void    setSub(const SkFloat& a, const SkFloat& b) { fPacked = Add(a.fPacked, Neg(b.fPacked)); }
51
52    void    mul(const SkFloat& a) { fPacked = Mul(fPacked, a.fPacked); }
53    void    setMul(const SkFloat& a, const SkFloat& b) { fPacked = Mul(a.fPacked, b.fPacked); }
54
55    void    div(const SkFloat& a) { fPacked = Div(fPacked, a.fPacked); }
56    void    setDiv(const SkFloat& a, const SkFloat& b) { fPacked = Div(a.fPacked, b.fPacked); }
57
58    void    sqrt() { fPacked = Sqrt(fPacked); }
59    void    setSqrt(const SkFloat& a) { fPacked = Sqrt(a.fPacked); }
60    void    cubeRoot() { fPacked = CubeRoot(fPacked); }
61    void    setCubeRoot(const SkFloat& a) { fPacked = CubeRoot(a.fPacked); }
62
63    friend bool operator==(const SkFloat& a, const SkFloat& b) { return a.fPacked == b.fPacked; }
64    friend bool operator!=(const SkFloat& a, const SkFloat& b) { return a.fPacked != b.fPacked; }
65    friend bool operator<(const SkFloat& a, const SkFloat& b) { return Cmp(a.fPacked, b.fPacked) < 0; }
66    friend bool operator<=(const SkFloat& a, const SkFloat& b) { return Cmp(a.fPacked, b.fPacked) <= 0; }
67    friend bool operator>(const SkFloat& a, const SkFloat& b) { return Cmp(a.fPacked, b.fPacked) > 0; }
68    friend bool operator>=(const SkFloat& a, const SkFloat& b) { return Cmp(a.fPacked, b.fPacked) >= 0; }
69
70#ifdef SK_DEBUG
71    static void UnitTest();
72
73    void assertEquals(float f, int tolerance = 0)
74    {
75        union {
76            float   fFloat;
77            int32_t fPacked;
78        } tmp;
79
80        tmp.fFloat = f;
81        int d = tmp.fPacked - fPacked;
82        SkASSERT(SkAbs32(d) <= tolerance);
83    }
84    float getFloat() const
85    {
86        union {
87            float   fFloat;
88            int32_t fPacked;
89        } tmp;
90
91        tmp.fPacked = fPacked;
92        return tmp.fFloat;
93    }
94#endif
95
96private:
97    int32_t fPacked;
98
99    SkFloat(int32_t packed) : fPacked(fPacked) {}
100
101public:
102    static int GetShift(int32_t packed, int shift);
103    static int32_t SetShift(int value, int shift);
104    static int32_t Neg(int32_t);
105    static int32_t Abs(int32_t packed) { return (uint32_t)(packed << 1) >> 1; }
106    static int32_t Shift(int32_t, int bits);
107    static int32_t Add(int32_t, int32_t);
108    static int32_t Mul(int32_t, int32_t);
109    static int32_t MulInt(int32_t, int);
110    static int32_t Div(int32_t, int32_t);
111    static int32_t DivInt(int32_t, int);
112    static int32_t Invert(int32_t);
113    static int32_t Sqrt(int32_t);
114    static int32_t CubeRoot(int32_t);
115    static int Cmp(int32_t, int32_t);
116};
117
118#endif
119