42/42_INT_09_piscine_cpp
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transformation float en fixed par deplacement pa au point

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hugogogo
2022-02-14 10:31:51 +01:00
parent 2fcc6782c4
commit 051936c06e
3 changed files with 52 additions and 4 deletions
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49
d02/ex01/Fixed.cpp
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@@ -10,12 +10,10 @@ std::string printBitsInt(int num)
{ {
int i = 0; int i = 0;
std::cout << " ";
for (unsigned int mask = 1U << (sizeof(int) *8 -1); mask; mask >>= 1) for (unsigned int mask = 1U << (sizeof(int) *8 -1); mask; mask >>= 1)
{ {
std::cout << ((num & mask) != 0); std::cout << ((num & mask) != 0);
i++; i++;
// if (i % 8 == 0 && i < 32)
if (i == 1 || i == 9 || i == 24) if (i == 1 || i == 9 || i == 24)
std::cout << ' '; std::cout << ' ';
} }
@@ -31,7 +29,7 @@ std::string printBitsFloat(float num)
{ {
std::cout << ((*p & mask) != 0); std::cout << ((*p & mask) != 0);
i++; i++;
if (i == 1 || i == 9) if (i == 1 || i == 9 || i == 24)
std::cout << ' '; std::cout << ' ';
} }
return ""; return "";
@@ -84,6 +82,7 @@ Fixed::Fixed(int integer) {
} }
std::cout << "integer : " << printBitsInt(integer) << " (" << integer << ")\n"; std::cout << "integer : " << printBitsInt(integer) << " (" << integer << ")\n";
this->_value = integer << this->_frac; this->_value = integer << this->_frac;
std::cout << "_value : " << printBitsInt(this->_value) << " (" << this->_value << ")\n";
} }
Fixed::Fixed(float const floater) { Fixed::Fixed(float const floater) {
@@ -95,6 +94,50 @@ Fixed::Fixed(float const floater) {
return; return;
} }
std::cout << "floater : " << printBitsFloat(floater) << " (" << floater << ")\n"; std::cout << "floater : " << printBitsFloat(floater) << " (" << floater << ")\n";
this->_value = floater * (1 << this->_frac);
std::cout << "_value : " << printBitsInt(this->_value) << " (" << this->_value << ")\n";
this->_value = *((int *)&floater); // cast floater into int
std::cout << "_value : " << printBitsInt(this->_value) << " (" << this->_value << ")\n";
int sign = this->_value & (1 << 31); // set most left bits to sign
std::cout << "sign : " << printBitsInt(sign) << " (" << sign << ")\n";
int exponent = ((unsigned int)(this->_value << 1) >> 24) - 127; // extract exponent value
std::cout << "exponent: " << printBitsInt(exponent) << " (" << exponent << ")\n";
int decimal = (this->_value << (9));
std::cout << "decimal : " << printBitsInt(decimal) << " (" << decimal << ")\n";
decimal = (this->_value << (9 + exponent));
std::cout << "decimal : " << printBitsInt(decimal) << " (" << decimal << ")\n";
int integer = (this->_value << 8) | (1 << 31); // add left 1 to integer part
std::cout << "left 1 : " << printBitsInt(integer) << " (" << integer << ")\n";
if (sign != 0)
integer = ~integer; // reverse for negatif
std::cout << "reverse : " << printBitsInt(integer) << " (" << integer << ")\n";
integer = ((unsigned int)integer >> 1) | sign; // add sign to integer part
std::cout << "left +/-: " << printBitsInt(integer) << " (" << integer << ")\n";
integer >>= (30 - exponent); // extract integer part
std::cout << "integer : " << printBitsInt(integer) << " (" << integer << ")\n";
// this->_value = (unsigned int)(this->_value << 8); // shift to left to erase exponent part
// this->_value |= 1 << 31; // add the missing left 1
//std::cout << "to left : " << printBitsInt(this->_value) << " (" << this->_value << ")\n";
// this->_value = (unsigned int)this->_value >> 1;
//std::cout << "to right: " << printBitsInt(this->_value) << " (" << this->_value << ")\n";
// this->_value |= sign;
//std::cout << "sign : " << printBitsInt(this->_value) << " (" << this->_value << ")\n";
// this->_value = this->_value >> (30 - exponent - this->_frac); // shift to right untill fixed point
//std::cout << "_value : " << printBitsInt(this->_value) << " (" << this->_value << ")\n";
//// int decimal = (unsigned int)(this->_value << (24)) >> 24; // extract decimal
////std::cout << "decimal : " << printBitsInt(decimal) << " (" << decimal << ")\n";
// this->_value >>= this->_frac;
//std::cout << "int valu: " << printBitsInt(this->_value) << " (" << this->_value << ")\n";
//// this->_value += (unsigned int)sign >> 31;
////std::cout << "val sign: " << printBitsInt(this->_value) << " (" << this->_value << ")\n";
// this->_value = (this->_value << this->_frac);
//std::cout << "val sign: " << printBitsInt(this->_value) << " (" << this->_value << ")\n";
} }

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d02/ex01/fixed
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7
d02/ex01/main.cpp
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@@ -3,7 +3,12 @@
int main( void ) { int main( void ) {
Fixed a(1105979538); // Fixed a(1105979538);
Fixed a(1105979);
std::cout << '\n';
Fixed b(1000.5979f);
std::cout << '\n';
Fixed c(-1105.979f);
// Fixed a; // Fixed a;
// Fixed const b( 10 ); // Fixed const b( 10 );