AL_BUILD_CAMERA_TRANSFORM(3)

💅 NAME 💅

okay bestie, so this is al_build_camera_transform — it's literally part of the Allegro 5 API and it's the glow-up your 3D camera deserves ✨

---

🎀 SYNOPSIS 🎀

#include <allegro5/allegro.h>

void al_build_camera_transform(ALLEGRO_TRANSFORM *trans,
   float position_x, float position_y, float position_z,
   float look_x, float look_y, float look_z,
   float up_x, float up_y, float up_z)

no cap, that's the whole signature — one transform pointer and then three lil triplets of floats 🫶

---

✨ DESCRIPTION ✨

okay so here's the vibe: this function builds a transformation that you can use to transform 3D coordinates from world space into camera space. it's giving translate-plus-rotate, because that's literally what it does — translation and a rotation, together, iconic 💅

the way it works is it wants three coordinate triplets from you:

• the camera's position 🎯
• the position the camera is looking at 👀
• an up vector ⬆️

and bestie listen — the up vector does not need to be of unit length, and it also does not need to be perpendicular to the view direction. normally you can literally just hand it the world up direction, which is most commonly 0/1/0. so chill, it's not that deep 💖

---

🌸 example time 🌸

al_build_camera_transform(&t,
    1, 1, 1,
    5, 5, 5,
    0, 1, 0);

that one creates a transformation for a camera standing at 1/1/1 and looking towards 5/5/5. slay 💅

⚠️ note: if the position and look parameters are identical, or if the up direction is parallel to the view direction, an identity matrix is created. no drama, it just kinda gives up and hands you identity 🫠

---

another example, and this one will simply re-create the identity matrix (yes bestie, that's the whole personality of this call):

al_build_camera_transform(&t,
    0, 0, 0,
    0, 0, -1,
    0, 1, 0);

---

and here's one where the up vector will cause the camera to lean (roll) by 45 degrees — tumblr era camera, we love a tilt 🔥

al_build_camera_transform(&t,
    1, 1, 1,
    5, 5, 5,
    1, 1, 0);

---

since 5.1.9 🦋 — so if you're on anything older, this function simply does not exist for you, sorry babe 😭

---

👑 SEE ALSO 👑

• al_translate_transform_3d(3)
• al_rotate_transform_3d(3)
• al_scale_transform_3d(3)
• al_compose_transform(3)
• al_use_transform(3)

---

and that's the page, bestie 🎀✨ this little gem comes to you straight from the Allegro reference manual — go forth, build those camera transforms, and remember: identity matrix is still a valid answer 💜🫶