create_light_table(3alleg4)

💖 create_light_table — bestie edition 💖

okay so you're deep in the Allegro manual, page create_light_table(3alleg4), and this is the Allegro game programming library we're talking about. no big deal. just your fave little function that fills a color mapping table so your sprites can get all glowy and moody. ✨

🌈 SYNOPSIS 🌈

#include <allegro.h>

void create_light_table(COLOR_MAP *table, const PALETTE pal, int r, g, b,
                        void (*callback)(int pos));

✨ DESCRIPTION ✨

so basically, this function fills the color mapping table you hand it (table) with all the lookup data it needs to do lighting effects using the palette you also hand it (pal). 🎀

here's the tea on how the lookup actually works. when you combine two colors — call them c1 and c2 — using this table, c1 gets treated as a light level from 0-255. so:

• at light level 255, the table spits out c2 completely unchanged, like nothing happened, main character untouched 💅
• at light level 0, it spits out the r, g, b values you specified when you called this function
• at every level in between? it gives you a color that's somewhere between those two extremes. a lil gradient moment. 🦋

and the r, g, and b values you pass in live in the range 0-63. not 0-255, bestie. sixty-three. don't forget. 🫶

this function will also take advantage of the global rgb_ap variable to speed up color conversions — lowkey iconic of it honestly.

if the callback function is not NULL, it gets called 256 times during the calculation, which is your moment to show off a progress indicator and let the people know you're working. 🎀

example time:

COLOR_MAP light_table;
...
/* Build a color lookup table for lighting effects. */
create_light_table(&light_table, pal, 0, 0, 0, NULL);

👀 SEE ALSO 👀

• color_map(3alleg4)
• create_trans_table(3alleg4)
• create_color_table(3alleg4)
• create_blender_table(3alleg4)
• draw_trans_sprite(3alleg4)
• draw_lit_sprite(3alleg4)
• draw_gouraud_sprite(3alleg4)
• rgb_map(3alleg4)
• ex3d(3alleg4)
• exshade(3alleg4)
• extrans(3alleg4)

and that's the whole page, bestie!! this was Allegro, version 4.4.3, and the page itself is create_light_table(3alleg4). go build something gorgeous with it. no cap. 💖🌈💅