/home/runner/work/FastLED/FastLED/src/fl/math/intmap.h

Generic integer scaling between different integer sizes.

Generic integer scaling between different integer sizes.

Template Parameters

INT_FROM	Input integer type (must be explicitly specified)
INT_TO	Output integer type (uint8_t, int8_t, uint16_t, int16_t, uint32_t, int32_t)

Parameters

x	The input value to scale

Returns

The scaled value preserving relative position in range

Requires explicit specification of BOTH input and output types to prevent implicit type conversions that could mask bugs. Uses bit replication for scaling up (8→16, 8→32, 16→32) and right-shift with rounding for scaling down (16→8, 32→16, 32→8).

Supports all combinations of 8-bit, 16-bit, and 32-bit signed/unsigned types. Compile-time error for unsupported type conversions.

uint16_t y = fl::int_scale<uint8_t, uint16_t>(102);   // Explicit: 8→16
int32_t z = fl::int_scale<int8_t, int32_t>(64);       // Explicit: 8→32
uint8_t w = fl::int_scale<uint32_t, uint8_t>(0x80000000);  // Explicit: 32→8
uint8_t noop = fl::int_scale<uint8_t, uint8_t>(255);   // Identity: no scaling

 
#pragma once
 
#include "platforms/intmap.h"
#include "fl/math/math.h"
#include "fl/stl/noexcept.h"
 
namespace fl {


 
// Deprecated legacy unsigned functions that delegate to the new int_scale<FROM, TO>() template
 
inline u16 map8_to_16(u8 x) FL_NO_EXCEPT {
    return fl::int_scale<u8, u16>(x);
}

 
inline u32 map8_to_32(u8 x) FL_NO_EXCEPT {
    return fl::int_scale<u8, u32>(x);
}

 
inline u32 map16_to_32(u16 x) FL_NO_EXCEPT {
    return fl::int_scale<u16, u32>(x);
}

 
inline u8 map16_to_8(u16 x) FL_NO_EXCEPT {
    return fl::int_scale<u16, u8>(x);
}

 
inline u16 map32_to_16(u32 x) FL_NO_EXCEPT {
    return fl::int_scale<u32, u16>(x);
}

inline u8 map32_to_8(u32 x) FL_NO_EXCEPT {
    return fl::int_scale<u32, u8>(x);
}
 
// New signed functions that delegate to int_scale
inline i16 smap8_to_16(i8 x) FL_NO_EXCEPT {
    return fl::int_scale<i8, i16>(x);
}

inline i32 smap8_to_32(i8 x) FL_NO_EXCEPT {
    return fl::int_scale<i8, i32>(x);
}

inline i32 smap16_to_32(i16 x) FL_NO_EXCEPT {
    return fl::int_scale<i16, i32>(x);
}

inline i8 smap16_to_8(i16 x) FL_NO_EXCEPT {
    return fl::int_scale<i16, i8>(x);
}

inline i16 smap32_to_16(i32 x) FL_NO_EXCEPT {
    return fl::int_scale<i32, i16>(x);
}

inline i8 smap32_to_8(i32 x) FL_NO_EXCEPT {
    return fl::int_scale<i32, i8>(x);
}

}  // namespace fl