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