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senso edited this page Jun 22, 2026 · 2 revisions

Utility Functions Reference

#sdk #reference #functions #color #geometry #math #audio

Helper functions for color conversion, geometry, and numeric operations.

Defined in: sdk/UserUtils.h

Constants

Constant Value Description
PI 3.14159265... Pi (std::atan(1.0f)*4)
COEFF_TO_DB_MIN -200 Minimum dB value for coefficient conversion
GAIN_MIN -80 Minimum gain in dB
LN10S20 0.115129254f ln(10)/20, used in dB conversion
MID_NOTE_ON 144 MIDI Note On message byte
MID_VOL_RANGE 127 MIDI volume range

Color Conversion Functions

Between Color Spaces

Function Input Output Description
sdkColorArgbToColorAhsl(TColorArgb) ARGB floats TColorAhsl ARGB to AHSL conversion
sdkColorAhslToColorArgb(TColorAhsl) AHSL floats TColorArgb AHSL to ARGB conversion
sdkColorArgbToAlphaColor(TColorArgb) ARGB floats TUsineColor ARGB to packed color
sdkAlphaColorToColorArgb(TUsineColor) Packed color TColorArgb Packed color to ARGB
sdkColorAhslToAlphaColor(TColorAhsl) AHSL floats TUsineColor AHSL to packed color
sdkAlphaColorToColorAhsl(TUsineColor) Packed color TColorAhsl Packed color to AHSL

Color Constructors

Function Description
sdkColorAgrb(float r, g, b, a) Create TColorArgb from floats (0.0-1.0)
sdkColorAhsl(float h, s, l, a) Create TColorAhsl (h: 0-360, s/l/a: 0-1)
sdkAlphaColor(float r, g, b, a) Create TUsineColor from floats (0.0-1.0)
sdkAlphaColor(int r, g, b, a) Create TUsineColor from ints (0-255)

Pixel Conversion

Function Description
sdkColorToPixel(TUsineColor) Convert color to video pixel (TUsinePixel)
sdkPixelToColor(TUsinePixel) Convert video pixel to color (TUsineColor)

Usage

// Create a semi-transparent red
TUsineColor red = sdkAlphaColor(1.0f, 0.0f, 0.0f, 0.5f);

// Convert to HSL, modify hue, convert back
TColorAhsl hsl = sdkAlphaColorToColorAhsl(red);
hsl.h += 120.0f;  // shift to green
TUsineColor green = sdkColorAhslToAlphaColor(hsl);

Example: See VideoDimmer for color conversion in practice.

Geometry Functions

Point Construction

TPointF sdkPointF(float x, float y);

Create a TPointF from x, y coordinates.

Point-in-Rectangle Tests

Function Parameters Description
sdkPointInRect(int X, Y, TPointI LeftTop, RightBottom) Integer coords Test if point is inside rectangle
sdkPointInRect(TPointI Coords, TPointI LeftTop, RightBottom) Integer points Test with TPointI
sdkPointInRect(float X, Y, TRectF rect) Float coords Test with TRectF

Bezier Interpolation

// Bezier interpolation with 4 control points
TPointF sdkBezier4(TPointF p1, p2, p3, p4, float mu);  // Returns 2D point
float   sdkBezier4(float p1, p2, p3, p4, float mu);     // Returns float value

mu is the interpolation parameter (0.0 to 1.0).

Numeric Functions

Audio dB Conversion

float sdkCoeffToDb(float coeff);  // Linear coefficient to decibels
float sdkDbToCoeff(float dB);     // Decibels to linear coefficient

Formulas:

  • sdkCoeffToDb: Returns 20 * log10(coeff), clamped to COEFF_TO_DB_MIN (-200 dB)
  • sdkDbToCoeff: Returns 10^(dB/20), returns 0 if dB <= GAIN_MIN (-80 dB)

Example: See AudioVolume for dB conversion usage.

Math

float sqr(float x);  // Returns x * x (square)

String Conversion

std::string sdkFloatToString(float value, int precision, int width);
std::string sdkIntToString(int value);

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