Scaling Functions

Detailed Description

Fast, efficient 8-bit scaling functions specifically designed for high-performance LED programming.

Because of the AVR(Arduino) and ARM assembly language implementations provided, using these functions often results in smaller and faster code than the equivalent program using plain "C" arithmetic and logic.

Collaboration diagram for Scaling Functions:

Topics
	Scaling Functions that Leave R1 Dirty
	These functions are more efficient for scaling multiple bytes at once, but require calling cleanup_R1() afterwards.

Functions
LIB8STATIC void	nscale8x2 (uint8_t &i, uint8_t &j, fract8 scale)
	Scale two one-byte values by a third one, which is treated as the numerator of a fraction whose demominator is 256.
LIB8STATIC void	nscale8x2_video (uint8_t &i, uint8_t &j, fract8 scale)
	Scale two one-byte values by a third one, which is treated as the numerator of a fraction whose demominator is 256.
LIB8STATIC void	nscale8x3 (uint8_t &r, uint8_t &g, uint8_t &b, fract8 scale)
	Scale three one-byte values by a fourth one, which is treated as the numerator of a fraction whose demominator is 256.
LIB8STATIC void	nscale8x3_video (uint8_t &r, uint8_t &g, uint8_t &b, fract8 scale)
	Scale three one-byte values by a fourth one, which is treated as the numerator of a fraction whose demominator is 256.
LIB8STATIC uint16_t	scale16 (uint16_t i, fract16 scale)
	Scale a 16-bit unsigned value by an 16-bit value, which is treated as the numerator of a fraction whose denominator is 65536.
LIB8STATIC_ALWAYS_INLINE uint16_t	scale16by8 (uint16_t i, fract8 scale)
	Scale a 16-bit unsigned value by an 8-bit value, which is treated as the numerator of a fraction whose denominator is 256.
LIB8STATIC_ALWAYS_INLINE uint8_t	scale8 (uint8_t i, fract8 scale)
	Scale one byte by a second one, which is treated as the numerator of a fraction whose denominator is 256.
constexpr uint8_t	scale8_constexpr (uint8_t i, fract8 scale)
LIB8STATIC_ALWAYS_INLINE uint8_t	scale8_video (uint8_t i, fract8 scale)
	The "video" version of scale8() guarantees that the output will be only be zero if one or both of the inputs are zero.