miniRT

✅ Status: Completed
🏫 School: 42 – miniRT
🏅 Score: 100/100

miniRT is an educational ray tracer (42 school project): it parses .rt scenes, ray-traces basic primitives (sphere/plane/cylinder), computes lighting & shadows, and displays the result using MiniLibX (X11/Linux).

Repository: https://github.com/tigran-sargsyan-w/miniRT

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Gallery (render results)

Showcase #1 — Base objects

Showcase #2 — Multiple objects

Showcase #3 — Selection

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Features

• Parse scene from .rt file
• Primitives:
  • sp — sphere
  • pl — plane
  • cy — cylinder (including caps)
• Lights:
  • A — ambient light
  • L — point light
• C — camera (position / direction / FOV)
• Shadows (shadow rays / occlusion)
• Rendering via MiniLibX (window + image buffer)
• Feature: Runtime Transform (Translate / Rotate / Scale) — interactively transform objects while the program is running
• Feature: OOP-like design in C (interface / polymorphism via function pointers) — a unified object “interface” implemented by each primitive

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Controls (Runtime Transform)

Object selection

• LMB (Left Mouse Click) — select an object
• ESC — cancel selection (unselect)
• Window close button [X] — quit
• ESC — quit (when nothing is selected / depending on your logic)

Translate — WASDQE

• W / S — forward / backward
• A / D — left / right
• Q / E — down / up

Rotate — J I L K U O

• J / L — rotate around Y (yaw)
• I / K — rotate around X (pitch)
• U / O — rotate around Z (roll)

Scale

• ← / → — uniform scale (scale up / down)
• ↑ / ↓ — height scale (scale height)

Note: height scale is especially useful for cylinders, but can be applied to any object depending on the implementation.

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Architecture: “Interface” & Polymorphism in C

This project uses an OOP-like approach in pure C:

• t_object is the base abstraction
• each primitive “implements” the same operations (intersection + transforms)
• the implementation is plugged in using function pointers (like a vtable)

1) The “interface” (function pointers)

File: include/object.h

struct s_object contains pointers to operations:

• intersect_func — ray/object intersection
• translate — move
• rotate_euler — Euler rotation (rx, ry, rz)
• scale_uniform — uniform scale
• scale_height — height scale

typedef int  (*t_intersect_func)(const t_object *object, t_ray ray,
                                 t_range range, t_hit *hit_result);
typedef void (*t_translate_func)(t_object *object, t_vector3 delta);
typedef void (*t_rotate_euler_func)(t_object *object, double rx, double ry, double rz);
typedef void (*t_scale_func)(t_object *object, double factor);
typedef void (*t_scale_height_func)(t_object *object, double factor);

typedef struct s_object
{
    t_object_type         type;
    t_material            material;

    t_intersect_func      intersect_func;
    t_translate_func      translate;
    t_rotate_euler_func   rotate_euler;
    t_scale_func          scale_uniform;
    t_scale_height_func   scale_height;
} t_object;

2) Abstraction: base object initializer

File: src/scene_utils/object.c

A single object_init() binds a concrete implementation (set of functions) to the object:

void object_init(t_object *object, t_object_type type,
                 t_material material, t_object_funcs funcs)
{
    object->type = type;
    object->material = material;
    object->intersect_func = funcs.intersect;
    object->translate = funcs.translate;
    object->rotate_euler = funcs.rotate_euler;
    object->scale_uniform = funcs.scale_uniform;
    object->scale_height = funcs.scale_height;
}

3) Concrete implementations: primitives “implement the interface”

Example: src/objects/plane.c (similar in sphere.c, cylinder.c)

funcs.intersect = &intersect_plane;
funcs.translate = &plane_translate;
funcs.rotate_euler = &plane_rotate;
funcs.scale_uniform = &plane_scale_uniform;
funcs.scale_height = &plane_scale_height;

object_init(&plane->base, PLANE, material, funcs);

This lets the renderer & event system work with t_object* without knowing the concrete shape type.

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Quick Start

1) Clone

git clone --recursive https://github.com/tigran-sargsyan-w/miniRT.git
cd miniRT

If you already cloned without --recursive:

git submodule update --init --recursive

2) Dependencies (Linux)

MiniLibX on Linux requires X11. Typical packages:

• Debian/Ubuntu:

  sudo apt-get install -y build-essential libx11-dev libxext-dev zlib1g-dev libbsd-dev

• Arch:

  sudo pacman -S --needed base-devel libx11 libxext zlib libbsd

3) Build

make

Clean:

make clean
make fclean
make re

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Run

./miniRT scenes/colored_room_with_sphere.rt

Scenes: scenes/

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.rt scene format (brief)

A 0.15 255,255,255
C 0,8,-30 0,0,1 65
L -5,18,-5 0.8 255,255,255

pl 0,0,0   0,1,0   0,0,255
sp 0,5,35  10      220,220,220

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Leak check (Valgrind)

valgrind --leak-check=full --show-leak-kinds=all --track-origins=yes \
  ./miniRT scenes/valgrind_check.rt

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miniRT — Leak Check Scenarios

Use this checklist to systematically test memory leak paths.
In the Status column you can mark ✅ / ❌ or add a short note.

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Category 1 — Command line arguments

#	Scenario	What to do / expected behavior	Status
1	No arguments	Run ./miniRT with no args. Should print error/usage and exit cleanly (no leaks).	✅
2	Too many arguments	Run ./miniRT scene1.rt scene2.rt. Should print error and exit cleanly.	✅
3	Invalid file extension	Run ./miniRT scene.txt. Should detect invalid format and exit cleanly.	✅
4	Path is a directory	Run ./miniRT scenes/ (where scenes/ is a folder). Should fail to open as file and exit cleanly.	✅

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Category 2 — File I/O errors

#	Scenario	What to do / expected behavior	Status
5	File does not exist	./miniRT scenes/not_found.rt. Should report open error and free everything.	✅
6	No read permission	chmod 000 scenes/no_read.rt → ./miniRT scenes/no_read.rt. Should report access error and exit cleanly.	✅
7	Empty file	./miniRT scenes/empty.rt. Should fail validation (missing required elements) and free resources.	✅
8	Only spaces/newlines/comments	./miniRT scenes/spaces_only.rt (blank lines/spaces/# only). Scene invalid, exit cleanly.	✅

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Category 3 — Parser errors

#	Scenario	What to do / expected behavior	Status
9	Error in the first line	err_first_line.rt: invalid identifier/format. Parser must stop and free everything.	✅
10	Error in the middle	err_middle_object.rt: valid start, then broken line. Must free the whole scene.	✅
11	Error in the last line	err_last_line.rt: many valid objects + invalid last line. Must free everything.	✅
12	Missing camera	err_no_camera.rt: no C. Validation fails and everything is freed.	✅
13	Multiple cameras (if forbidden)	err_multi_camera.rt: 2+ C lines. Config error and full cleanup.	✅
14	Bad numeric values	err_bad_number.rt: invalid coords/color/normal (e.g. abc, overflow). Clean exit.	✅
15	Unknown identifier	err_unknown_id.rt: unknown type (e.g. XX). Error + full cleanup.	✅

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Category 4 — Graphics initialization (mlx / window / image)

For these tests it’s convenient to temporarily inject forced failures in a debug build after a successful parse.

#	Scenario	What to do / expected behavior	Status
16	Failure in init_mlx	After parse_scene, force init_mlx to fail. Must run global cleanup with no leaks.	✅
17	Window creation failure	mlx initialized but window creation fails. All resources freed.	✅
18	Image/buffer creation failure	Window exists but mlx_new_image (or equivalent) fails. Cleanup and exit.	✅
19	Hooks/events setup failure	Window+image OK, but hooks setup fails. Must free scene/window/image.	✅

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Category 5 — Normal run & all exit paths

#	Scenario	What to do / expected behavior	Status
20	Start → do nothing → ESC	Open window, press ESC. Cleanup must run.	✅
21	Start → close via [X]	Close the window using [X]. Cleanup must match ESC path.	✅
22	Select/transform object → ESC	Select object, translate/rotate/scale, then exit. No leaks.	✅
23	Select/transform object → [X]	Same as 22 but exit via [X]. No leaks.	✅

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Category 6 — Long run & “drip” leaks

#	Scenario	What to do / expected behavior	Status
24	Long session	Run under Valgrind, keep window open for minutes, select and transform objects, then exit. Loop leaks should appear here.	✅
25	Stress test	Rapidly select objects and apply many transforms, then exit. Should catch rare leak branches.	✅