| /* |
| * Copyright (C) 2006 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef SkFixed_DEFINED |
| #define SkFixed_DEFINED |
| |
| #include "SkMath.h" |
| |
| /** \file SkFixed.h |
| |
| Types and macros for 16.16 fixed point |
| */ |
| |
| /** 32 bit signed integer used to represent fractions values with 16 bits to the right of the decimal point |
| */ |
| typedef int32_t SkFixed; |
| #define SK_Fixed1 (1 << 16) |
| #define SK_FixedHalf (1 << 15) |
| #define SK_FixedMax (0x7FFFFFFF) |
| #define SK_FixedMin (-SK_FixedMax) |
| #define SK_FixedNaN ((int) 0x80000000) |
| #define SK_FixedPI (0x3243F) |
| #define SK_FixedSqrt2 (92682) |
| #define SK_FixedTanPIOver8 (0x6A0A) |
| #define SK_FixedRoot2Over2 (0xB505) |
| |
| #ifdef SK_CAN_USE_FLOAT |
| #define SkFixedToFloat(x) ((x) * 1.5258789e-5f) |
| #if 1 |
| #define SkFloatToFixed(x) ((SkFixed)((x) * SK_Fixed1)) |
| #else |
| // pins over/under flows to max/min int32 (slower than just a cast) |
| static inline SkFixed SkFloatToFixed(float x) { |
| int64_t n = x * SK_Fixed1; |
| return (SkFixed)n; |
| } |
| #endif |
| |
| #define SkFixedToDouble(x) ((x) * 1.5258789e-5) |
| #define SkDoubleToFixed(x) ((SkFixed)((x) * SK_Fixed1)) |
| #endif |
| |
| /** 32 bit signed integer used to represent fractions values with 30 bits to the right of the decimal point |
| */ |
| typedef int32_t SkFract; |
| #define SK_Fract1 (1 << 30) |
| #define Sk_FracHalf (1 << 29) |
| #define SK_FractPIOver180 (0x11DF46A) |
| |
| #ifdef SK_CAN_USE_FLOAT |
| #define SkFractToFloat(x) ((float)(x) * 0.00000000093132257f) |
| #define SkFloatToFract(x) ((SkFract)((x) * SK_Fract1)) |
| #endif |
| |
| /** Converts an integer to a SkFixed, asserting that the result does not overflow |
| a 32 bit signed integer |
| */ |
| #ifdef SK_DEBUG |
| inline SkFixed SkIntToFixed(int n) |
| { |
| SkASSERT(n >= -32768 && n <= 32767); |
| return n << 16; |
| } |
| #else |
| // force the cast to SkFixed to ensure that the answer is signed (like the debug version) |
| #define SkIntToFixed(n) (SkFixed)((n) << 16) |
| #endif |
| |
| /** Converts a SkFixed to a SkFract, asserting that the result does not overflow |
| a 32 bit signed integer |
| */ |
| #ifdef SK_DEBUG |
| inline SkFract SkFixedToFract(SkFixed x) |
| { |
| SkASSERT(x >= (-2 << 16) && x <= (2 << 16) - 1); |
| return x << 14; |
| } |
| #else |
| #define SkFixedToFract(x) ((x) << 14) |
| #endif |
| |
| /** Returns the signed fraction of a SkFixed |
| */ |
| inline SkFixed SkFixedFraction(SkFixed x) |
| { |
| SkFixed mask = x >> 31 << 16; |
| return (x & 0xFFFF) | mask; |
| } |
| |
| /** Converts a SkFract to a SkFixed |
| */ |
| #define SkFractToFixed(x) ((x) >> 14) |
| /** Round a SkFixed to an integer |
| */ |
| #define SkFixedRound(x) (((x) + SK_FixedHalf) >> 16) |
| #define SkFixedCeil(x) (((x) + SK_Fixed1 - 1) >> 16) |
| #define SkFixedFloor(x) ((x) >> 16) |
| #define SkFixedAbs(x) SkAbs32(x) |
| #define SkFixedAve(a, b) (((a) + (b)) >> 1) |
| |
| // The same as SkIntToFixed(SkFixedFloor(x)) |
| #define SkFixedFloorToFixed(x) ((x) & ~0xFFFF) |
| |
| SkFixed SkFixedMul_portable(SkFixed, SkFixed); |
| SkFract SkFractMul_portable(SkFract, SkFract); |
| inline SkFixed SkFixedSquare_portable(SkFixed value) |
| { |
| uint32_t a = SkAbs32(value); |
| uint32_t ah = a >> 16; |
| uint32_t al = a & 0xFFFF; |
| SkFixed result = ah * a + al * ah + (al * al >> 16); |
| if (result >= 0) |
| return result; |
| else // Overflow. |
| return SK_FixedMax; |
| } |
| |
| #define SkFixedDiv(numer, denom) SkDivBits(numer, denom, 16) |
| SkFixed SkFixedDivInt(int32_t numer, int32_t denom); |
| SkFixed SkFixedMod(SkFixed numer, SkFixed denom); |
| #define SkFixedInvert(n) SkDivBits(SK_Fixed1, n, 16) |
| SkFixed SkFixedFastInvert(SkFixed n); |
| #define SkFixedSqrt(n) SkSqrtBits(n, 23) |
| SkFixed SkFixedMean(SkFixed a, SkFixed b); //*< returns sqrt(x*y) |
| int SkFixedMulCommon(SkFixed, int , int bias); // internal used by SkFixedMulFloor, SkFixedMulCeil, SkFixedMulRound |
| |
| #define SkFractDiv(numer, denom) SkDivBits(numer, denom, 30) |
| #define SkFractSqrt(n) SkSqrtBits(n, 30) |
| |
| SkFixed SkFixedSinCos(SkFixed radians, SkFixed* cosValueOrNull); |
| #define SkFixedSin(radians) SkFixedSinCos(radians, NULL) |
| inline SkFixed SkFixedCos(SkFixed radians) |
| { |
| SkFixed cosValue; |
| (void)SkFixedSinCos(radians, &cosValue); |
| return cosValue; |
| } |
| SkFixed SkFixedTan(SkFixed radians); |
| SkFixed SkFixedASin(SkFixed); |
| SkFixed SkFixedACos(SkFixed); |
| SkFixed SkFixedATan2(SkFixed y, SkFixed x); |
| SkFixed SkFixedExp(SkFixed); |
| SkFixed SkFixedLog(SkFixed); |
| |
| #define SK_FixedNearlyZero (SK_Fixed1 >> 12) |
| |
| inline bool SkFixedNearlyZero(SkFixed x, SkFixed tolerance = SK_FixedNearlyZero) |
| { |
| SkASSERT(tolerance > 0); |
| return SkAbs32(x) < tolerance; |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////////////////////////////// |
| // Now look for ASM overrides for our portable versions (should consider putting this in its own file) |
| |
| #ifdef SkLONGLONG |
| inline SkFixed SkFixedMul_longlong(SkFixed a, SkFixed b) |
| { |
| return (SkFixed)((SkLONGLONG)a * b >> 16); |
| } |
| inline SkFract SkFractMul_longlong(SkFract a, SkFract b) |
| { |
| return (SkFixed)((SkLONGLONG)a * b >> 30); |
| } |
| inline SkFixed SkFixedSquare_longlong(SkFixed value) |
| { |
| return (SkFixed)((SkLONGLONG)value * value >> 16); |
| } |
| #define SkFixedMul(a,b) SkFixedMul_longlong(a,b) |
| #define SkFractMul(a,b) SkFractMul_longlong(a,b) |
| #define SkFixedSquare(a) SkFixedSquare_longlong(a) |
| #endif |
| |
| #if defined(__arm__) && !defined(__thumb__) |
| /* This guy does not handle NaN or other obscurities, but is faster than |
| than (int)(x*65536) when we only have software floats |
| */ |
| inline SkFixed SkFloatToFixed_arm(float x) |
| { |
| register int32_t y, z; |
| asm("movs %1, %3, lsl #1 \n" |
| "mov %2, #0x8E \n" |
| "sub %1, %2, %1, lsr #24 \n" |
| "mov %2, %3, lsl #8 \n" |
| "orr %2, %2, #0x80000000 \n" |
| "mov %1, %2, lsr %1 \n" |
| "rsbcs %1, %1, #0 \n" |
| : "=r"(x), "=&r"(y), "=&r"(z) |
| : "r"(x) |
| : "cc" |
| ); |
| return y; |
| } |
| inline SkFixed SkFixedMul_arm(SkFixed x, SkFixed y) |
| { |
| register int32_t t; |
| asm("smull %0, %2, %1, %3 \n" |
| "mov %0, %0, lsr #16 \n" |
| "orr %0, %0, %2, lsl #16 \n" |
| : "=r"(x), "=&r"(y), "=r"(t) |
| : "r"(x), "1"(y) |
| : |
| ); |
| return x; |
| } |
| inline SkFixed SkFixedMulAdd_arm(SkFixed x, SkFixed y, SkFixed a) |
| { |
| register int32_t t; |
| asm("smull %0, %3, %1, %4 \n" |
| "add %0, %2, %0, lsr #16 \n" |
| "add %0, %0, %3, lsl #16 \n" |
| : "=r"(x), "=&r"(y), "=&r"(a), "=r"(t) |
| : "%r"(x), "1"(y), "2"(a) |
| : |
| ); |
| return x; |
| } |
| inline SkFixed SkFractMul_arm(SkFixed x, SkFixed y) |
| { |
| register int32_t t; |
| asm("smull %0, %2, %1, %3 \n" |
| "mov %0, %0, lsr #30 \n" |
| "orr %0, %0, %2, lsl #2 \n" |
| : "=r"(x), "=&r"(y), "=r"(t) |
| : "r"(x), "1"(y) |
| : |
| ); |
| return x; |
| } |
| #undef SkFixedMul |
| #undef SkFractMul |
| #define SkFixedMul(x, y) SkFixedMul_arm(x, y) |
| #define SkFractMul(x, y) SkFractMul_arm(x, y) |
| #define SkFixedMulAdd(x, y, a) SkFixedMulAdd_arm(x, y, a) |
| |
| #undef SkFloatToFixed |
| #define SkFloatToFixed(x) SkFloatToFixed_arm(x) |
| #endif |
| |
| /////////////////////// Now define our macros to the portable versions if they weren't overridden |
| |
| #ifndef SkFixedSquare |
| #define SkFixedSquare(x) SkFixedSquare_portable(x) |
| #endif |
| #ifndef SkFixedMul |
| #define SkFixedMul(x, y) SkFixedMul_portable(x, y) |
| #endif |
| #ifndef SkFractMul |
| #define SkFractMul(x, y) SkFractMul_portable(x, y) |
| #endif |
| #ifndef SkFixedMulAdd |
| #define SkFixedMulAdd(x, y, a) (SkFixedMul(x, y) + (a)) |
| #endif |
| |
| #endif |
