blob: 8b2df0e640b2eaf374c39290f18ee5176eee3fe6 [file] [log] [blame]
/*
* 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 "include/core/SkScalar.h"
#include "include/private/SkFixed.h"
#include "include/private/SkFloatBits.h"
#include "include/private/SkFloatingPoint.h"
#include "src/core/SkMathPriv.h"
#include "src/core/SkSafeMath.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;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
size_t SkSafeMath::Add(size_t x, size_t y) {
SkSafeMath tmp;
size_t sum = tmp.add(x, y);
return tmp.ok() ? sum : SIZE_MAX;
}
size_t SkSafeMath::Mul(size_t x, size_t y) {
SkSafeMath tmp;
size_t prod = tmp.mul(x, y);
return tmp.ok() ? prod : SIZE_MAX;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
bool sk_floats_are_unit(const float array[], size_t count) {
bool is_unit = true;
for (size_t i = 0; i < count; ++i) {
is_unit &= (array[i] >= 0) & (array[i] <= 1);
}
return is_unit;
}