Current File : //usr/local/lib/node_modules/node-sass/src/libsass/src/units.cpp
#include "sass.hpp"
#include <stdexcept>
#include "units.hpp"
#include "error_handling.hpp"
namespace Sass {
/* the conversion matrix can be readed the following way */
/* if you go down, the factor is for the numerator (multiply) */
/* if you go right, the factor is for the denominator (divide) */
/* and yes, we actually use both, not sure why, but why not!? */
const double size_conversion_factors[6][6] =
{
/* in cm pc mm pt px */
/* in */ { 1, 2.54, 6, 25.4, 72, 96, },
/* cm */ { 1.0/2.54, 1, 6.0/2.54, 10, 72.0/2.54, 96.0/2.54 },
/* pc */ { 1.0/6.0, 2.54/6.0, 1, 25.4/6.0, 72.0/6.0, 96.0/6.0 },
/* mm */ { 1.0/25.4, 1.0/10.0, 6.0/25.4, 1, 72.0/25.4, 96.0/25.4 },
/* pt */ { 1.0/72.0, 2.54/72.0, 6.0/72.0, 25.4/72.0, 1, 96.0/72.0 },
/* px */ { 1.0/96.0, 2.54/96.0, 6.0/96.0, 25.4/96.0, 72.0/96.0, 1, }
};
const double angle_conversion_factors[4][4] =
{
/* deg grad rad turn */
/* deg */ { 1, 40.0/36.0, PI/180.0, 1.0/360.0 },
/* grad */ { 36.0/40.0, 1, PI/200.0, 1.0/400.0 },
/* rad */ { 180.0/PI, 200.0/PI, 1, 0.5/PI },
/* turn */ { 360.0, 400.0, 2.0*PI, 1 }
};
const double time_conversion_factors[2][2] =
{
/* s ms */
/* s */ { 1, 1000.0 },
/* ms */ { 1/1000.0, 1 }
};
const double frequency_conversion_factors[2][2] =
{
/* Hz kHz */
/* Hz */ { 1, 1/1000.0 },
/* kHz */ { 1000.0, 1 }
};
const double resolution_conversion_factors[3][3] =
{
/* dpi dpcm dppx */
/* dpi */ { 1, 1/2.54, 1/96.0 },
/* dpcm */ { 2.54, 1, 2.54/96 },
/* dppx */ { 96, 96/2.54, 1 }
};
UnitClass get_unit_type(UnitType unit)
{
switch (unit & 0xFF00)
{
case UnitClass::LENGTH: return UnitClass::LENGTH;
case UnitClass::ANGLE: return UnitClass::ANGLE;
case UnitClass::TIME: return UnitClass::TIME;
case UnitClass::FREQUENCY: return UnitClass::FREQUENCY;
case UnitClass::RESOLUTION: return UnitClass::RESOLUTION;
default: return UnitClass::INCOMMENSURABLE;
}
};
std::string get_unit_class(UnitType unit)
{
switch (unit & 0xFF00)
{
case UnitClass::LENGTH: return "LENGTH";
case UnitClass::ANGLE: return "ANGLE";
case UnitClass::TIME: return "TIME";
case UnitClass::FREQUENCY: return "FREQUENCY";
case UnitClass::RESOLUTION: return "RESOLUTION";
default: return "INCOMMENSURABLE";
}
};
UnitType get_main_unit(const UnitClass unit)
{
switch (unit)
{
case UnitClass::LENGTH: return UnitType::PX;
case UnitClass::ANGLE: return UnitType::DEG;
case UnitClass::TIME: return UnitType::SEC;
case UnitClass::FREQUENCY: return UnitType::HERTZ;
case UnitClass::RESOLUTION: return UnitType::DPI;
default: return UnitType::UNKNOWN;
}
};
UnitType string_to_unit(const std::string& s)
{
// size units
if (s == "px") return UnitType::PX;
else if (s == "pt") return UnitType::PT;
else if (s == "pc") return UnitType::PC;
else if (s == "mm") return UnitType::MM;
else if (s == "cm") return UnitType::CM;
else if (s == "in") return UnitType::IN;
// angle units
else if (s == "deg") return UnitType::DEG;
else if (s == "grad") return UnitType::GRAD;
else if (s == "rad") return UnitType::RAD;
else if (s == "turn") return UnitType::TURN;
// time units
else if (s == "s") return UnitType::SEC;
else if (s == "ms") return UnitType::MSEC;
// frequency units
else if (s == "Hz") return UnitType::HERTZ;
else if (s == "kHz") return UnitType::KHERTZ;
// resolutions units
else if (s == "dpi") return UnitType::DPI;
else if (s == "dpcm") return UnitType::DPCM;
else if (s == "dppx") return UnitType::DPPX;
// for unknown units
else return UnitType::UNKNOWN;
}
const char* unit_to_string(UnitType unit)
{
switch (unit) {
// size units
case UnitType::PX: return "px";
case UnitType::PT: return "pt";
case UnitType::PC: return "pc";
case UnitType::MM: return "mm";
case UnitType::CM: return "cm";
case UnitType::IN: return "in";
// angle units
case UnitType::DEG: return "deg";
case UnitType::GRAD: return "grad";
case UnitType::RAD: return "rad";
case UnitType::TURN: return "turn";
// time units
case UnitType::SEC: return "s";
case UnitType::MSEC: return "ms";
// frequency units
case UnitType::HERTZ: return "Hz";
case UnitType::KHERTZ: return "kHz";
// resolutions units
case UnitType::DPI: return "dpi";
case UnitType::DPCM: return "dpcm";
case UnitType::DPPX: return "dppx";
// for unknown units
default: return "";
}
}
std::string unit_to_class(const std::string& s)
{
if (s == "px") return "LENGTH";
else if (s == "pt") return "LENGTH";
else if (s == "pc") return "LENGTH";
else if (s == "mm") return "LENGTH";
else if (s == "cm") return "LENGTH";
else if (s == "in") return "LENGTH";
// angle units
else if (s == "deg") return "ANGLE";
else if (s == "grad") return "ANGLE";
else if (s == "rad") return "ANGLE";
else if (s == "turn") return "ANGLE";
// time units
else if (s == "s") return "TIME";
else if (s == "ms") return "TIME";
// frequency units
else if (s == "Hz") return "FREQUENCY";
else if (s == "kHz") return "FREQUENCY";
// resolutions units
else if (s == "dpi") return "RESOLUTION";
else if (s == "dpcm") return "RESOLUTION";
else if (s == "dppx") return "RESOLUTION";
// for unknown units
return "CUSTOM:" + s;
}
// throws incompatibleUnits exceptions
double conversion_factor(const std::string& s1, const std::string& s2)
{
// assert for same units
if (s1 == s2) return 1;
// get unit enum from string
UnitType u1 = string_to_unit(s1);
UnitType u2 = string_to_unit(s2);
// query unit group types
UnitClass t1 = get_unit_type(u1);
UnitClass t2 = get_unit_type(u2);
// return the conversion factor
return conversion_factor(u1, u2, t1, t2);
}
// throws incompatibleUnits exceptions
double conversion_factor(UnitType u1, UnitType u2, UnitClass t1, UnitClass t2)
{
// can't convert between groups
if (t1 != t2) return 0;
// get absolute offset
// used for array acces
size_t i1 = u1 - t1;
size_t i2 = u2 - t2;
// process known units
switch (t1) {
case LENGTH:
return size_conversion_factors[i1][i2];
case ANGLE:
return angle_conversion_factors[i1][i2];
case TIME:
return time_conversion_factors[i1][i2];
case FREQUENCY:
return frequency_conversion_factors[i1][i2];
case RESOLUTION:
return resolution_conversion_factors[i1][i2];
case INCOMMENSURABLE:
return 0;
}
// fallback
return 0;
}
double convert_units(const std::string& lhs, const std::string& rhs, int& lhsexp, int& rhsexp)
{
double f = 0;
// do not convert same ones
if (lhs == rhs) return 0;
// skip already canceled out unit
if (lhsexp == 0) return 0;
if (rhsexp == 0) return 0;
// check if it can be converted
UnitType ulhs = string_to_unit(lhs);
UnitType urhs = string_to_unit(rhs);
// skip units we cannot convert
if (ulhs == UNKNOWN) return 0;
if (urhs == UNKNOWN) return 0;
// query unit group types
UnitClass clhs = get_unit_type(ulhs);
UnitClass crhs = get_unit_type(urhs);
// skip units we cannot convert
if (clhs != crhs) return 0;
// if right denominator is bigger than lhs, we want to keep it in rhs unit
if (rhsexp < 0 && lhsexp > 0 && - rhsexp > lhsexp) {
// get the conversion factor for units
f = conversion_factor(urhs, ulhs, clhs, crhs);
// left hand side has been consumned
f = std::pow(f, lhsexp);
rhsexp += lhsexp;
lhsexp = 0;
}
else {
// get the conversion factor for units
f = conversion_factor(ulhs, urhs, clhs, crhs);
// right hand side has been consumned
f = std::pow(f, rhsexp);
lhsexp += rhsexp;
rhsexp = 0;
}
return f;
}
bool Units::operator< (const Units& rhs) const
{
return (numerators < rhs.numerators) &&
(denominators < rhs.denominators);
}
bool Units::operator== (const Units& rhs) const
{
return (numerators == rhs.numerators) &&
(denominators == rhs.denominators);
}
double Units::normalize()
{
size_t iL = numerators.size();
size_t nL = denominators.size();
// the final conversion factor
double factor = 1;
for (size_t i = 0; i < iL; i++) {
std::string &lhs = numerators[i];
UnitType ulhs = string_to_unit(lhs);
if (ulhs == UNKNOWN) continue;
UnitClass clhs = get_unit_type(ulhs);
UnitType umain = get_main_unit(clhs);
if (ulhs == umain) continue;
double f(conversion_factor(umain, ulhs, clhs, clhs));
if (f == 0) throw std::runtime_error("INVALID");
numerators[i] = unit_to_string(umain);
factor /= f;
}
for (size_t n = 0; n < nL; n++) {
std::string &rhs = denominators[n];
UnitType urhs = string_to_unit(rhs);
if (urhs == UNKNOWN) continue;
UnitClass crhs = get_unit_type(urhs);
UnitType umain = get_main_unit(crhs);
if (urhs == umain) continue;
double f(conversion_factor(umain, urhs, crhs, crhs));
if (f == 0) throw std::runtime_error("INVALID");
denominators[n] = unit_to_string(umain);
factor /= f;
}
std::sort (numerators.begin(), numerators.end());
std::sort (denominators.begin(), denominators.end());
// return for conversion
return factor;
}
double Units::reduce()
{
size_t iL = numerators.size();
size_t nL = denominators.size();
// have less than two units?
if (iL + nL < 2) return 1;
// first make sure same units cancel each other out
// it seems that a map table will fit nicely to do this
// we basically construct exponents for each unit
// has the advantage that they will be pre-sorted
std::map<std::string, int> exponents;
// initialize by summing up occurences in unit vectors
// this will already cancel out equivalent units (e.q. px/px)
for (size_t i = 0; i < iL; i ++) exponents[numerators[i]] += 1;
for (size_t n = 0; n < nL; n ++) exponents[denominators[n]] -= 1;
// the final conversion factor
double factor = 1;
// convert between compatible units
for (size_t i = 0; i < iL; i++) {
for (size_t n = 0; n < nL; n++) {
std::string &lhs = numerators[i], &rhs = denominators[n];
int &lhsexp = exponents[lhs], &rhsexp = exponents[rhs];
double f(convert_units(lhs, rhs, lhsexp, rhsexp));
if (f == 0) continue;
factor /= f;
}
}
// now we can build up the new unit arrays
numerators.clear();
denominators.clear();
// recreate sorted units vectors
for (auto exp : exponents) {
int &exponent = exp.second;
while (exponent > 0 && exponent --)
numerators.push_back(exp.first);
while (exponent < 0 && exponent ++)
denominators.push_back(exp.first);
}
// return for conversion
return factor;
}
std::string Units::unit() const
{
std::string u;
size_t iL = numerators.size();
size_t nL = denominators.size();
for (size_t i = 0; i < iL; i += 1) {
if (i) u += '*';
u += numerators[i];
}
if (nL != 0) u += '/';
for (size_t n = 0; n < nL; n += 1) {
if (n) u += '*';
u += denominators[n];
}
return u;
}
bool Units::is_unitless() const
{
return numerators.empty() &&
denominators.empty();
}
bool Units::is_valid_css_unit() const
{
return numerators.size() <= 1 &&
denominators.size() == 0;
}
// this does not cover all cases (multiple prefered units)
double Units::convert_factor(const Units& r) const
{
std::vector<std::string> miss_nums(0);
std::vector<std::string> miss_dens(0);
// create copy since we need these for state keeping
std::vector<std::string> r_nums(r.numerators);
std::vector<std::string> r_dens(r.denominators);
auto l_num_it = numerators.begin();
auto l_num_end = numerators.end();
bool l_unitless = is_unitless();
auto r_unitless = r.is_unitless();
// overall conversion
double factor = 1;
// process all left numerators
while (l_num_it != l_num_end)
{
// get and increment afterwards
const std::string l_num = *(l_num_it ++);
auto r_num_it = r_nums.begin(), r_num_end = r_nums.end();
bool found = false;
// search for compatible numerator
while (r_num_it != r_num_end)
{
// get and increment afterwards
const std::string r_num = *(r_num_it);
// get possible conversion factor for units
double conversion = conversion_factor(l_num, r_num);
// skip incompatible numerator
if (conversion == 0) {
++ r_num_it;
continue;
}
// apply to global factor
factor *= conversion;
// remove item from vector
r_nums.erase(r_num_it);
// found numerator
found = true;
break;
}
// maybe we did not find any
// left numerator is leftover
if (!found) miss_nums.push_back(l_num);
}
auto l_den_it = denominators.begin();
auto l_den_end = denominators.end();
// process all left denominators
while (l_den_it != l_den_end)
{
// get and increment afterwards
const std::string l_den = *(l_den_it ++);
auto r_den_it = r_dens.begin();
auto r_den_end = r_dens.end();
bool found = false;
// search for compatible denominator
while (r_den_it != r_den_end)
{
// get and increment afterwards
const std::string r_den = *(r_den_it);
// get possible converstion factor for units
double conversion = conversion_factor(l_den, r_den);
// skip incompatible denominator
if (conversion == 0) {
++ r_den_it;
continue;
}
// apply to global factor
factor /= conversion;
// remove item from vector
r_dens.erase(r_den_it);
// found denominator
found = true;
break;
}
// maybe we did not find any
// left denominator is leftover
if (!found) miss_dens.push_back(l_den);
}
// check left-overs (ToDo: might cancel out?)
if (miss_nums.size() > 0 && !r_unitless) {
throw Exception::IncompatibleUnits(r, *this);
}
else if (miss_dens.size() > 0 && !r_unitless) {
throw Exception::IncompatibleUnits(r, *this);
}
else if (r_nums.size() > 0 && !l_unitless) {
throw Exception::IncompatibleUnits(r, *this);
}
else if (r_dens.size() > 0 && !l_unitless) {
throw Exception::IncompatibleUnits(r, *this);
}
return factor;
}
}
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