al_calculate_spline(3alleg5)

💖 al_calculate_spline — NAME, bestie 💖

okay so <pink>al_calculate_spline</pink> is the Allegro 5 API girlie who does the math for you, no cap ✨

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✨ SYNOPSIS ✨

#include <allegro5/allegro_primitives.h>

void al_calculate_spline(float* dest, int stride, const float points[8],
   float thickness, int num_segments)

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🎀 DESCRIPTION 🎀

so like, this function calculates a Bézier spline based on 4 control points. iconic behavior fr fr 💅

here's the tea tho, because the math has opinions:

• If thickness <= 0, then you need num_segments points in the destination buffer.
• Otherwise (i.e. thickness is a real one), you need twice as many points. the way that ribbon needs double the points… it's giving main character energy 😭

and the destination buffer? it should be made of regularly spaced doublets of floats — spaced apart by stride bytes, bestie — and each doublet is literally just the x and y coordinates of a vertex. simple as that 🌸

🫶 Parameters 🫶

• dest — the destination buffer, aka where the magic gets written 💖
• stride — distance, in bytes, between the starts of successive pairs of coordinates. yes it's bytes. read it again. bytes 🧚
• points — an array of 4 pairs of coordinates, aka the 4 control points, aka the whole personality of this spline 👑
• thickness — the thickness of the spline ribbon. set it <= 0 and you get a plain line vibe, set it thicc and you get a ribbon 🔥
• num_segments — the number of points to calculate ✨

ngl bestie, watch that stride situation closely — it's in bytes, not in floats, and mixing those two up is a classic 😭 moment.

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🌈 SEE ALSO 🌈

• al_draw_spline(3alleg5)
• al_calculate_arc(3alleg5)
• al_calculate_ribbon(3alleg5)

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periodt. that's the whole page, and it came straight out of the Allegro reference manual for al_calculate_spline(3alleg5) — go forth and draw some iconic curves, bestie 🦋💜⭐