SkScalar.h revision 1a5e51f94ed8cb01600184119e52bb64bdb3dccc
18a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com/* 2ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com * Copyright 2006 The Android Open Source Project 38a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com * 4ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com * Use of this source code is governed by a BSD-style license that can be 5ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com * found in the LICENSE file. 68a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com */ 78a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 88a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com#ifndef SkScalar_DEFINED 98a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com#define SkScalar_DEFINED 108a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 118a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com#include "SkFixed.h" 1280afbf08eb82a99f8a2eeeb1741eb7ca1ccf957depoger@google.com#include "SkFloatingPoint.h" 138a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 14e1ca705cac4b946993f6cbf798e2a0ba27e739f3reed@google.com//#define SK_SUPPORT_DEPRECATED_SCALARROUND 15e1ca705cac4b946993f6cbf798e2a0ba27e739f3reed@google.com 168f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.comtypedef float SkScalar; 178a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 188f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** SK_Scalar1 is defined to be 1.0 represented as an SkScalar 198a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com*/ 208f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SK_Scalar1 (1.0f) 218f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** SK_Scalar1 is defined to be 1/2 represented as an SkScalar 228f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 238f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SK_ScalarHalf (0.5f) 248f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** SK_ScalarInfinity is defined to be infinity as an SkScalar 258f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 268f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SK_ScalarInfinity SK_FloatInfinity 278f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** SK_ScalarNegativeInfinity is defined to be negative infinity as an SkScalar 288f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 298f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SK_ScalarNegativeInfinity SK_FloatNegativeInfinity 308f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** SK_ScalarMax is defined to be the largest value representable as an SkScalar 318f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 328f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SK_ScalarMax (3.402823466e+38f) 338f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** SK_ScalarMin is defined to be the smallest value representable as an SkScalar 348f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 358f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SK_ScalarMin (-SK_ScalarMax) 368f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** SK_ScalarNaN is defined to be 'Not a Number' as an SkScalar 378f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 388f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SK_ScalarNaN SK_FloatNaN 398f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** SkScalarIsNaN(n) returns true if argument is not a number 408f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 418f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.comstatic inline bool SkScalarIsNaN(float x) { return x != x; } 428f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com 438f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** Returns true if x is not NaN and not infinite */ 448f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.comstatic inline bool SkScalarIsFinite(float x) { 458f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com // We rely on the following behavior of infinities and nans 468f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com // 0 * finite --> 0 478f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com // 0 * infinity --> NaN 488f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com // 0 * NaN --> NaN 498f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com float prod = x * 0; 508f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com // At this point, prod will either be NaN or 0 518f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com // Therefore we can return (prod == prod) or (0 == prod). 528f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com return prod == prod; 538f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com} 548a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 558f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** SkIntToScalar(n) returns its integer argument as an SkScalar 568f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 578f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkIntToScalar(n) ((float)(n)) 588f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** SkFixedToScalar(n) returns its SkFixed argument as an SkScalar 598f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 608f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkFixedToScalar(x) SkFixedToFloat(x) 618f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** SkScalarToFixed(n) returns its SkScalar argument as an SkFixed 628f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 638f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarToFixed(x) SkFloatToFixed(x) 64077910e20cda41d7981084fbd047a108894bc8dfreed@google.com 658f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarToFloat(n) (n) 664b413c8bb123e42ca4b9c7bfa6bc2167283cb84ccommit-bot@chromium.org#ifndef SK_SCALAR_TO_FLOAT_EXCLUDED 678f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkFloatToScalar(n) (n) 684b413c8bb123e42ca4b9c7bfa6bc2167283cb84ccommit-bot@chromium.org#endif 698a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 708f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarToDouble(n) (double)(n) 718f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkDoubleToScalar(n) (float)(n) 721b20280f9b2e95fdcf4a2ee6f7f9d5a92c5b94c2reed@google.com 738f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** SkScalarFraction(x) returns the signed fractional part of the argument 748f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 758f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarFraction(x) sk_float_mod(x, 1.0f) 768a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 778f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarFloorToScalar(x) sk_float_floor(x) 788f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarCeilToScalar(x) sk_float_ceil(x) 798f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarRoundToScalar(x) sk_float_floor((x) + 0.5f) 808a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 818f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarFloorToInt(x) sk_float_floor2int(x) 828f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarCeilToInt(x) sk_float_ceil2int(x) 838f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarRoundToInt(x) sk_float_round2int(x) 848f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarTruncToInt(x) static_cast<int>(x) 85185d3d016d1e493694e9aaf45b070f34ba456983reed@google.com 868f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** Returns the absolute value of the specified SkScalar 878f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 888f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarAbs(x) sk_float_abs(x) 898f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** Return x with the sign of y 908f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com */ 918f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarCopySign(x, y) sk_float_copysign(x, y) 928f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** Returns the value pinned between 0 and max inclusive 938f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 948f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.cominline SkScalar SkScalarClampMax(SkScalar x, SkScalar max) { 958f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com return x < 0 ? 0 : x > max ? max : x; 968f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com} 978f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** Returns the value pinned between min and max inclusive 988f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 998f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.cominline SkScalar SkScalarPin(SkScalar x, SkScalar min, SkScalar max) { 1008f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com return x < min ? min : x > max ? max : x; 1018f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com} 1028f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** Returns the specified SkScalar squared (x*x) 1038f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 1048f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.cominline SkScalar SkScalarSquare(SkScalar x) { return x * x; } 1058f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** Returns the product of two SkScalars 1068f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 1078f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarMul(a, b) ((float)(a) * (b)) 1088f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** Returns the product of two SkScalars plus a third SkScalar 1098f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 1108f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarMulAdd(a, b, c) ((float)(a) * (b) + (c)) 1118f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** Returns the quotient of two SkScalars (a/b) 1128f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 1138f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarDiv(a, b) ((float)(a) / (b)) 1148f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** Returns the mod of two SkScalars (a mod b) 1158f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 1168f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarMod(x,y) sk_float_mod(x,y) 1178f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** Returns the product of the first two arguments, divided by the third argument 1188f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 1198f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarMulDiv(a, b, c) ((float)(a) * (b) / (c)) 1208f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** Returns the multiplicative inverse of the SkScalar (1/x) 1218f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 1228f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarInvert(x) (SK_Scalar1 / (x)) 1238f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarFastInvert(x) (SK_Scalar1 / (x)) 1248f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** Returns the square root of the SkScalar 1258f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 1268f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarSqrt(x) sk_float_sqrt(x) 1278f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** Returns b to the e 1288f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 1298f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarPow(b, e) sk_float_pow(b, e) 1308f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** Returns the average of two SkScalars (a+b)/2 1318f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 1328f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarAve(a, b) (((a) + (b)) * 0.5f) 1338f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com/** Returns one half of the specified SkScalar 1348f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com*/ 1358f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarHalf(a) ((a) * 0.5f) 1368f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com 1378f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SK_ScalarSqrt2 1.41421356f 1388f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SK_ScalarPI 3.14159265f 1398f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SK_ScalarTanPIOver8 0.414213562f 1408f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SK_ScalarRoot2Over2 0.707106781f 1418f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com 1428f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkDegreesToRadians(degrees) ((degrees) * (SK_ScalarPI / 180)) 143c8d732800e1a660fca6d2478fc24d6e6935ef8adcommit-bot@chromium.org#define SkRadiansToDegrees(radians) ((radians) * (180 / SK_ScalarPI)) 1448f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.comfloat SkScalarSinCos(SkScalar radians, SkScalar* cosValue); 1458f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarSin(radians) (float)sk_float_sin(radians) 1468f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarCos(radians) (float)sk_float_cos(radians) 1478f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarTan(radians) (float)sk_float_tan(radians) 1488f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarASin(val) (float)sk_float_asin(val) 1498f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarACos(val) (float)sk_float_acos(val) 1508f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarATan2(y, x) (float)sk_float_atan2(y,x) 1518f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarExp(x) (float)sk_float_exp(x) 1528f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com#define SkScalarLog(x) (float)sk_float_log(x) 1538f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com 1548f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.cominline SkScalar SkMaxScalar(SkScalar a, SkScalar b) { return a > b ? a : b; } 1558f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.cominline SkScalar SkMinScalar(SkScalar a, SkScalar b) { return a < b ? a : b; } 1568f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com 1578f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.comstatic inline bool SkScalarIsInt(SkScalar x) { 1588f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com return x == (float)(int)x; 1598f4d2306fa866a26f9448048ff63f692b2ba43aareed@google.com} 1608a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 1611b20280f9b2e95fdcf4a2ee6f7f9d5a92c5b94c2reed@google.com// DEPRECATED : use ToInt or ToScalar variant 162e1ca705cac4b946993f6cbf798e2a0ba27e739f3reed@google.com#ifdef SK_SUPPORT_DEPRECATED_SCALARROUND 163e1ca705cac4b946993f6cbf798e2a0ba27e739f3reed@google.com# define SkScalarFloor(x) SkScalarFloorToInt(x) 164e1ca705cac4b946993f6cbf798e2a0ba27e739f3reed@google.com# define SkScalarCeil(x) SkScalarCeilToInt(x) 165e1ca705cac4b946993f6cbf798e2a0ba27e739f3reed@google.com# define SkScalarRound(x) SkScalarRoundToInt(x) 166e1ca705cac4b946993f6cbf798e2a0ba27e739f3reed@google.com#endif 1671b20280f9b2e95fdcf4a2ee6f7f9d5a92c5b94c2reed@google.com 168647a804c3dd53b6743091ec97dd12111f90efec3bsalomon@google.com/** 169647a804c3dd53b6743091ec97dd12111f90efec3bsalomon@google.com * Returns -1 || 0 || 1 depending on the sign of value: 170647a804c3dd53b6743091ec97dd12111f90efec3bsalomon@google.com * -1 if x < 0 171647a804c3dd53b6743091ec97dd12111f90efec3bsalomon@google.com * 0 if x == 0 172647a804c3dd53b6743091ec97dd12111f90efec3bsalomon@google.com * 1 if x > 0 173647a804c3dd53b6743091ec97dd12111f90efec3bsalomon@google.com */ 174647a804c3dd53b6743091ec97dd12111f90efec3bsalomon@google.comstatic inline int SkScalarSignAsInt(SkScalar x) { 175647a804c3dd53b6743091ec97dd12111f90efec3bsalomon@google.com return x < 0 ? -1 : (x > 0); 176647a804c3dd53b6743091ec97dd12111f90efec3bsalomon@google.com} 177647a804c3dd53b6743091ec97dd12111f90efec3bsalomon@google.com 178647a804c3dd53b6743091ec97dd12111f90efec3bsalomon@google.com// Scalar result version of above 179647a804c3dd53b6743091ec97dd12111f90efec3bsalomon@google.comstatic inline SkScalar SkScalarSignAsScalar(SkScalar x) { 180647a804c3dd53b6743091ec97dd12111f90efec3bsalomon@google.com return x < 0 ? -SK_Scalar1 : ((x > 0) ? SK_Scalar1 : 0); 181647a804c3dd53b6743091ec97dd12111f90efec3bsalomon@google.com} 1821b20280f9b2e95fdcf4a2ee6f7f9d5a92c5b94c2reed@google.com 1838a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com#define SK_ScalarNearlyZero (SK_Scalar1 / (1 << 12)) 1848a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 185187d5595901d1120d9425851e5afdd773f574502reed@android.comstatic inline bool SkScalarNearlyZero(SkScalar x, 1861fd56dc6e189ea0e94b5df9af959c243573f8883epoger@google.com SkScalar tolerance = SK_ScalarNearlyZero) { 1879b5ca29af81b93faea040daa25a620bee99d6c38reed@google.com SkASSERT(tolerance >= 0); 1889b5ca29af81b93faea040daa25a620bee99d6c38reed@google.com return SkScalarAbs(x) <= tolerance; 1898a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com} 1908a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 1911fd56dc6e189ea0e94b5df9af959c243573f8883epoger@google.comstatic inline bool SkScalarNearlyEqual(SkScalar x, SkScalar y, 1921fd56dc6e189ea0e94b5df9af959c243573f8883epoger@google.com SkScalar tolerance = SK_ScalarNearlyZero) { 1939b5ca29af81b93faea040daa25a620bee99d6c38reed@google.com SkASSERT(tolerance >= 0); 1949b5ca29af81b93faea040daa25a620bee99d6c38reed@google.com return SkScalarAbs(x-y) <= tolerance; 1951fd56dc6e189ea0e94b5df9af959c243573f8883epoger@google.com} 1961fd56dc6e189ea0e94b5df9af959c243573f8883epoger@google.com 1978a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com/** Linearly interpolate between A and B, based on t. 1988a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com If t is 0, return A 1998a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com If t is 1, return B 2008a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com else interpolate. 2018a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com t must be [0..SK_Scalar1] 2028a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com*/ 203187d5595901d1120d9425851e5afdd773f574502reed@android.comstatic inline SkScalar SkScalarInterp(SkScalar A, SkScalar B, SkScalar t) { 2048a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com SkASSERT(t >= 0 && t <= SK_Scalar1); 2051a5e51f94ed8cb01600184119e52bb64bdb3dcccreed@google.com return A + (B - A) * t; 2068a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com} 2078a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 20828be72b63e457c680c192a34fb9f58e1c693363fvandebo@chromium.org/** Interpolate along the function described by (keys[length], values[length]) 20928be72b63e457c680c192a34fb9f58e1c693363fvandebo@chromium.org for the passed searchKey. SearchKeys outside the range keys[0]-keys[Length] 21028be72b63e457c680c192a34fb9f58e1c693363fvandebo@chromium.org clamp to the min or max value. This function was inspired by a desire 21128be72b63e457c680c192a34fb9f58e1c693363fvandebo@chromium.org to change the multiplier for thickness in fakeBold; therefore it assumes 21228be72b63e457c680c192a34fb9f58e1c693363fvandebo@chromium.org the number of pairs (length) will be small, and a linear search is used. 21328be72b63e457c680c192a34fb9f58e1c693363fvandebo@chromium.org Repeated keys are allowed for discontinuous functions (so long as keys is 21428be72b63e457c680c192a34fb9f58e1c693363fvandebo@chromium.org monotonically increasing), and if key is the value of a repeated scalar in 21528be72b63e457c680c192a34fb9f58e1c693363fvandebo@chromium.org keys, the first one will be used. However, that may change if a binary 21628be72b63e457c680c192a34fb9f58e1c693363fvandebo@chromium.org search is used. 21728be72b63e457c680c192a34fb9f58e1c693363fvandebo@chromium.org*/ 21828be72b63e457c680c192a34fb9f58e1c693363fvandebo@chromium.orgSkScalar SkScalarInterpFunc(SkScalar searchKey, const SkScalar keys[], 21928be72b63e457c680c192a34fb9f58e1c693363fvandebo@chromium.org const SkScalar values[], int length); 22028be72b63e457c680c192a34fb9f58e1c693363fvandebo@chromium.org 221e1e7d7a6b55504d97ce9f30202a179b63800093breed@google.com/* 222e1e7d7a6b55504d97ce9f30202a179b63800093breed@google.com * Helper to compare an array of scalars. 223e1e7d7a6b55504d97ce9f30202a179b63800093breed@google.com */ 224e1e7d7a6b55504d97ce9f30202a179b63800093breed@google.comstatic inline bool SkScalarsEqual(const SkScalar a[], const SkScalar b[], int n) { 225e1e7d7a6b55504d97ce9f30202a179b63800093breed@google.com SkASSERT(n >= 0); 226e1e7d7a6b55504d97ce9f30202a179b63800093breed@google.com for (int i = 0; i < n; ++i) { 227e1e7d7a6b55504d97ce9f30202a179b63800093breed@google.com if (a[i] != b[i]) { 228e1e7d7a6b55504d97ce9f30202a179b63800093breed@google.com return false; 229e1e7d7a6b55504d97ce9f30202a179b63800093breed@google.com } 230e1e7d7a6b55504d97ce9f30202a179b63800093breed@google.com } 231e1e7d7a6b55504d97ce9f30202a179b63800093breed@google.com return true; 232e1e7d7a6b55504d97ce9f30202a179b63800093breed@google.com} 233e1e7d7a6b55504d97ce9f30202a179b63800093breed@google.com 2348a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com#endif 235