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/*
* Copyright 2008 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkMathPriv.h"
#include "SkFixed.h"
#include "SkFloatBits.h"
#include "SkFloatingPoint.h"
#include "SkScalar.h"
#define sub_shift(zeros, x, n) \
zeros -= n; \
x >>= n
int SkCLZ_portable(uint32_t x) {
if (x == 0) {
return 32;
}
int zeros = 31;
if (x & 0xFFFF0000) {
sub_shift(zeros, x, 16);
}
if (x & 0xFF00) {
sub_shift(zeros, x, 8);
}
if (x & 0xF0) {
sub_shift(zeros, x, 4);
}
if (x & 0xC) {
sub_shift(zeros, x, 2);
}
if (x & 0x2) {
sub_shift(zeros, x, 1);
}
return zeros;
}
///////////////////////////////////////////////////////////////////////////////
/* www.worldserver.com/turk/computergraphics/FixedSqrt.pdf
*/
int32_t SkSqrtBits(int32_t x, int count) {
SkASSERT(x >= 0 && count > 0 && (unsigned)count <= 30);
uint32_t root = 0;
uint32_t remHi = 0;
uint32_t remLo = x;
do {
root <<= 1;
remHi = (remHi<<2) | (remLo>>30);
remLo <<= 2;
uint32_t testDiv = (root << 1) + 1;
if (remHi >= testDiv) {
remHi -= testDiv;
root++;
}
} while (--count >= 0);
return root;
}
///////////////////////////////////////////////////////////////////////////////
float SkScalarSinCos(float radians, float* cosValue) {
float sinValue = sk_float_sin(radians);
if (cosValue) {
*cosValue = sk_float_cos(radians);
if (SkScalarNearlyZero(*cosValue)) {
*cosValue = 0;
}
}
if (SkScalarNearlyZero(sinValue)) {
sinValue = 0;
}
return sinValue;
}
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