1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/include/core/SkFixed.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,164 @@
1.4 +/*
1.5 + * Copyright 2006 The Android Open Source Project
1.6 + *
1.7 + * Use of this source code is governed by a BSD-style license that can be
1.8 + * found in the LICENSE file.
1.9 + */
1.10 +
1.11 +#ifndef SkFixed_DEFINED
1.12 +#define SkFixed_DEFINED
1.13 +
1.14 +#include "SkTypes.h"
1.15 +
1.16 +/** \file SkFixed.h
1.17 +
1.18 + Types and macros for 16.16 fixed point
1.19 +*/
1.20 +
1.21 +/** 32 bit signed integer used to represent fractions values with 16 bits to the right of the decimal point
1.22 +*/
1.23 +typedef int32_t SkFixed;
1.24 +#define SK_Fixed1 (1 << 16)
1.25 +#define SK_FixedHalf (1 << 15)
1.26 +#define SK_FixedMax (0x7FFFFFFF)
1.27 +#define SK_FixedMin (-SK_FixedMax)
1.28 +#define SK_FixedNaN ((int) 0x80000000)
1.29 +#define SK_FixedPI (0x3243F)
1.30 +#define SK_FixedSqrt2 (92682)
1.31 +#define SK_FixedTanPIOver8 (0x6A0A)
1.32 +#define SK_FixedRoot2Over2 (0xB505)
1.33 +
1.34 +#define SkFixedToFloat(x) ((x) * 1.5258789e-5f)
1.35 +#if 1
1.36 + #define SkFloatToFixed(x) ((SkFixed)((x) * SK_Fixed1))
1.37 +#else
1.38 + // pins over/under flows to max/min int32 (slower than just a cast)
1.39 + static inline SkFixed SkFloatToFixed(float x) {
1.40 + int64_t n = x * SK_Fixed1;
1.41 + return (SkFixed)n;
1.42 + }
1.43 +#endif
1.44 +
1.45 +#ifdef SK_DEBUG
1.46 + static inline SkFixed SkFloatToFixed_Check(float x) {
1.47 + int64_t n64 = (int64_t)(x * SK_Fixed1);
1.48 + SkFixed n32 = (SkFixed)n64;
1.49 + SkASSERT(n64 == n32);
1.50 + return n32;
1.51 + }
1.52 +#else
1.53 + #define SkFloatToFixed_Check(x) SkFloatToFixed(x)
1.54 +#endif
1.55 +
1.56 +#define SkFixedToDouble(x) ((x) * 1.5258789e-5)
1.57 +#define SkDoubleToFixed(x) ((SkFixed)((x) * SK_Fixed1))
1.58 +
1.59 +/** Converts an integer to a SkFixed, asserting that the result does not overflow
1.60 + a 32 bit signed integer
1.61 +*/
1.62 +#ifdef SK_DEBUG
1.63 + inline SkFixed SkIntToFixed(int n)
1.64 + {
1.65 + SkASSERT(n >= -32768 && n <= 32767);
1.66 + return n << 16;
1.67 + }
1.68 +#else
1.69 + // force the cast to SkFixed to ensure that the answer is signed (like the debug version)
1.70 + #define SkIntToFixed(n) (SkFixed)((n) << 16)
1.71 +#endif
1.72 +
1.73 +#define SkFixedRoundToInt(x) (((x) + SK_FixedHalf) >> 16)
1.74 +#define SkFixedCeilToInt(x) (((x) + SK_Fixed1 - 1) >> 16)
1.75 +#define SkFixedFloorToInt(x) ((x) >> 16)
1.76 +
1.77 +#define SkFixedRoundToFixed(x) (((x) + SK_FixedHalf) & 0xFFFF0000)
1.78 +#define SkFixedCeilToFixed(x) (((x) + SK_Fixed1 - 1) & 0xFFFF0000)
1.79 +#define SkFixedFloorToFixed(x) ((x) & 0xFFFF0000)
1.80 +
1.81 +#define SkFixedAbs(x) SkAbs32(x)
1.82 +#define SkFixedAve(a, b) (((a) + (b)) >> 1)
1.83 +
1.84 +SkFixed SkFixedMul_portable(SkFixed, SkFixed);
1.85 +
1.86 +#define SkFixedDiv(numer, denom) SkDivBits(numer, denom, 16)
1.87 +
1.88 +///////////////////////////////////////////////////////////////////////////////
1.89 +// TODO: move fixed sin/cos into SkCosineMapper, as that is the only caller
1.90 +// or rewrite SkCosineMapper to not use it at all
1.91 +
1.92 +SkFixed SkFixedSinCos(SkFixed radians, SkFixed* cosValueOrNull);
1.93 +#define SkFixedSin(radians) SkFixedSinCos(radians, NULL)
1.94 +static inline SkFixed SkFixedCos(SkFixed radians) {
1.95 + SkFixed cosValue;
1.96 + (void)SkFixedSinCos(radians, &cosValue);
1.97 + return cosValue;
1.98 +}
1.99 +
1.100 +//////////////////////////////////////////////////////////////////////////////////////////////////////
1.101 +// Now look for ASM overrides for our portable versions (should consider putting this in its own file)
1.102 +
1.103 +#ifdef SkLONGLONG
1.104 + inline SkFixed SkFixedMul_longlong(SkFixed a, SkFixed b)
1.105 + {
1.106 + return (SkFixed)((int64_t)a * b >> 16);
1.107 + }
1.108 + #define SkFixedMul(a,b) SkFixedMul_longlong(a,b)
1.109 +#endif
1.110 +
1.111 +#if defined(SK_CPU_ARM)
1.112 + /* This guy does not handle NaN or other obscurities, but is faster than
1.113 + than (int)(x*65536)
1.114 + */
1.115 + inline SkFixed SkFloatToFixed_arm(float x)
1.116 + {
1.117 + int32_t y, z;
1.118 + asm("movs %1, %3, lsl #1 \n"
1.119 + "mov %2, #0x8E \n"
1.120 + "sub %1, %2, %1, lsr #24 \n"
1.121 + "mov %2, %3, lsl #8 \n"
1.122 + "orr %2, %2, #0x80000000 \n"
1.123 + "mov %1, %2, lsr %1 \n"
1.124 + "it cs \n"
1.125 + "rsbcs %1, %1, #0 \n"
1.126 + : "=r"(x), "=&r"(y), "=&r"(z)
1.127 + : "r"(x)
1.128 + : "cc"
1.129 + );
1.130 + return y;
1.131 + }
1.132 + inline SkFixed SkFixedMul_arm(SkFixed x, SkFixed y)
1.133 + {
1.134 + int32_t t;
1.135 + asm("smull %0, %2, %1, %3 \n"
1.136 + "mov %0, %0, lsr #16 \n"
1.137 + "orr %0, %0, %2, lsl #16 \n"
1.138 + : "=r"(x), "=&r"(y), "=r"(t)
1.139 + : "r"(x), "1"(y)
1.140 + :
1.141 + );
1.142 + return x;
1.143 + }
1.144 + #undef SkFixedMul
1.145 + #define SkFixedMul(x, y) SkFixedMul_arm(x, y)
1.146 +
1.147 + #undef SkFloatToFixed
1.148 + #define SkFloatToFixed(x) SkFloatToFixed_arm(x)
1.149 +#endif
1.150 +
1.151 +#ifndef SkFixedMul
1.152 + #define SkFixedMul(x, y) SkFixedMul_portable(x, y)
1.153 +#endif
1.154 +
1.155 +///////////////////////////////////////////////////////////////////////////////
1.156 +
1.157 +typedef int64_t SkFixed48;
1.158 +
1.159 +#define SkIntToFixed48(x) ((SkFixed48)(x) << 48)
1.160 +#define SkFixed48ToInt(x) ((int)((x) >> 48))
1.161 +#define SkFixedToFixed48(x) ((SkFixed48)(x) << 32)
1.162 +#define SkFixed48ToFixed(x) ((SkFixed)((x) >> 32))
1.163 +#define SkFloatToFixed48(x) ((SkFixed48)((x) * (65536.0f * 65536.0f * 65536.0f)))
1.164 +
1.165 +#define SkScalarToFixed48(x) SkFloatToFixed48(x)
1.166 +
1.167 +#endif
