CPCHCL(3NCARG)

💖 CPCHCL — bestie edition 💖

okay so real talk, this is a page from the NCAR GRAPHICS manual, section 3NCARG, and it's about a lil routine called CPCHCL. she's not like other routines. she's a hook. 🪝✨

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🌸 NAME 🌸

CPCHCL — she gets called by the Conpack routines CPCLDM and CPCLDR. the default version? does absolutely nothing, she's just vibing. 🧘 but you can write your own version and swap it in so you get control as contour lines are being drawn. main character energy tbh. 👑

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✨ SYNOPSIS ✨

CALL CPCHCL (IFLG)

that's it. one argument. we love a low-effort queen. 💅

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🦋 DESCRIPTION 🦋

• IFLG (INTEGER, input) — it's +1 if a line is about to be drawn, and -1 if a line has just been drawn. so basically she's telling you "hey bestie, we're going in 😤" or "okay we're done here 💀".

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🎀 USAGE 🎀

not me — this is the important part — CPCHCL is not to be called by the user. do not call her. she calls you. she's booked and busy. 😤

She's called by the Conpack routines CPCLDM and CPCLDR just before and just after the contour lines at each level are drawn. The default version of CPCHCL does nothing. A user-supplied replacement may change attributes such as color and line width — by calling the SPPS routine SETUSV or the appropriate GKS routines. like, glow her up. 💅🌈

so here's the tea on the extra calls, fr fr:

• If the element of the parameter array 'CLU' corresponding to 'PAI' = -1 has been set non-zero to request the drawing of the edge of the grid, then CPCHCL will be called before and after that is done.
• Similarly, if the element of 'CLU' corresponding to 'PAI' = -2 has been set non-zero, then CPCHCL will be called before and after the drawing of the edges of the special-value areas.
• And if the element of 'CLU' corresponding to 'PAI' = -3 has been set non-zero, then CPCHCL will be called before and after the drawing of the edges of the out-of-range areas.

When CPCHCL is called, the parameter 'PAI' will have been set to the index of the appropriate contour level (between 1 and 'NCL') or to one of the values -1, -2, or -3. By retrieving the value of 'PAI', CPCHCL can find out what line is being drawn — iykyk 🔍 — and also, a CPGETx call to retrieve an element of a parameter array like 'CLD' will automatically get the correct one for the line being drawn. automatic slay. ⭐

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👑 ACCESS 👑

To use CPCHCL, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c — preferably in that order. order matters bestie, don't fight it. 🫶

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🌈 SEE ALSO 🌈

Online, go read these too, they're all part of the same friend group:

conpack, cpback, cpchcf, cpchhl, cpchil, cpchll, cpcica, cpclam, cpcldm, cpcldr, cpcltr, cpcnrc, cpdrpl, cpezct, cpgetc, cpgeti, cpgetr, cplbam, cplbdr, cpmpxy, cpmviw, cpmvrw, cppkcl, cppklb, cprect, cprset, cpscae, cpsetc, cpseti, cpsetr, cpsps1, cpsps2, ncarg_cbind

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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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and that's the whole page bestie, no notes. 🎀 this one was written by the fine folks at NCAR Graphics and dated March 1993, which is genuinely iconic of them — like, they were doing documentation before it was cool. periodt. 💅✨🌸🦋