Colconv(3NCARG)

💖 Colconv — the NCAR GRAPHICS color-model glow-up 💖

okay bestie, welcome to Colconv (that's Colconv(3NCARG), the NCAR GRAPHICS one). this is the routine that lets you convert a color spec between the color models RGB, HSV, HLS, and YIQ. that's literally it, that's the whole vibe. she converts. she slays. periodt. 💅

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✨ NAME ✨

Colconv — Allows a user to convert among the color models RGB, HSV, HLS, and YIQ. 🎨🦋

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🌸 SYNOPSIS 🌸

okay so there's a whole lil squad here, one function per conversion. no cap, they all do exactly what their name says:

• HLSRGB — Converts a color specification given as Hue, Lightness, and Saturation (HLS) values to Red, Green, and Blue (RGB) intensity values in the RGB color space.
• HSVRGB — Converts a color specification given in the Hue, Saturation, and Value (HSV) color space to color values in the Red, Green, Blue (RGB) color space.
• RGBHLS — Converts a color specification given in the Red, Green, Blue (RGB) color space to color values in the Hue, Lightness, Saturation (HLS) color space.
• RGBHSV — Converts a color specification given in the Red, Green, Blue (RGB) color space to color values in the Hue, Saturation, and Value (HSV) color space.
• RGBYIQ — Converts a color specification given in the RGB Red, Green, Blue, (RGB) color space to a color specification in the YIQ color space.
• YIQRGB — Converts a color specification given in the YIQ color space to the equivalent color specification in the Red, Green, Blue (RGB) color space.

it's giving "one job, done flawlessly." 👑

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🌈 C-BINDING SYNOPSIS 🌈

for my C girls, you get lowercase lil versions of everybody. first, obviously:

#include <ncarg/ncargC.h>

and then the cast, in order:

c_hlsrgb
c_hsvrgb
c_rgbhls
c_rgbhsv
c_rgbyiq
c_yiqrgb

💀 yes bestie, c_hlsrgb goes from HLS to RGB even though the letters read the other way. that's just how she is. we don't question the icon.

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🎀 ACCESS 🎀

To use Colconv or the c_colconv routines, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c — preferably in that order. (the order matters, don't be chaotic about it, i'm begging 🙈)

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🚨 MESSAGES 🚨

When error conditions are detected, the support routine SETER is called in such a way that it writes a message to the standard error file (as defined by I1MACH(4)) and then terminates execution. like, that's it, that's the end of the run. no gentle warning arc. 😭

so here's the full list of possible error messages, and what each one means:

• HLSRGB - L out of range — Lightness is less than 0. or greater than 100.
• HLSRGB - S out of range — Saturation is less than 0. or greater than 100.
• HSVRGB - S out of range — Saturation is less than 0. or greater than 1.
• HSVRGB - V out of range — Value of input color is less than 0. or greater than 1.
• RGBHLS - R out of range — Value of red intensity component is less than 0. or greater than 1.
• RGBHLS - G out of range — Value of green intensity component is less than 0. or greater than 1.
• RGBHLS - B out of range — Value of blue intensity component is less than 0. or greater than 1.
• RGBHSV - R out of range — Value of red intensity component is less than 0. or greater than 1.
• RGBHSV - G out of range — Value of green intensity component is less than 0. or greater than 1.
• RGBHSV - B out of range — Value of blue intensity component is less than 0. or greater than 1.

⚠️ bestie. check your ranges. i'm not even being dramatic, SETER will literally end your whole program over a 1.5. vibe check your inputs before you hand them over. 🫶

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👀 SEE ALSO 👀

• Online: hlsrgb, hsvrgb, rgbhls, rgbhsv, rgbyiq, yiqrgb, ncarg_cbind.
• Hardcopy: NCAR Graphics Fundamentals, UNIX Version

go read the friends, they're all in the same friend group. iykyk. 💜

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📜 COPYRIGHT 📜

Copyright (C) 1987-2009 University Corporation for Atmospheric Research The use of this Software is governed by a License Agreement.

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that's the whole page bestie, you ate it, every last flag and range and legal line intact, no crumbs left. 🍓✨

kisses from the UNIX manual page, dated March 1993, titled Colconv(3NCARG) — mwah 💋