Assets

All visual assets live in the assets/ directory, organized into categorized subdirectories. Sprites are PNG files loaded by raylib and sounds are WAV files in assets/sounds/, generated by tools/gen_sounds.py. Text uses raylib’s built-in font, so there is no font directory.

assets/
├── sounds/                 ← Generated WAV files (see Sounds page)
│   ├── collectibles/
│   ├── entities/
│   ├── hazards/
│   ├── levels/
│   ├── player/
│   ├── screens/
│   └── surfaces/
└── sprites/                ← PNG sprite sheets and textures
    ├── backgrounds/        ← Parallax background layers
    ├── collectibles/       ← Coins, stars
    ├── entities/           ← Enemy sprites
    ├── foregrounds/        ← Fog, water, lava, clouds
    ├── hazards/            ← Spike, saw, flame sprites
    ├── levels/             ← Level tilesets and themes
    ├── player/             ← Player sprite sheet
    ├── screens/            ← HUD, menu assets
    ├── surfaces/           ← Platforms, bridges, vines, etc.
    └── unused/             ← Reserve assets for future use

Coordinate note: All game objects use logical space (400x300). The raylib render target scales to the 800×600 OS window at 2×. A 48×48 sprite appears as 96×96 physical pixels on screen.

Per-Level Asset Configuration

Several visual elements are configurable per TOML level file, allowing different themes without changing code:

Floor Tile

floor_tile_path = "assets/sprites/levels/grass_tileset.png"

Any 48×48 PNG tile can be substituted here. The engine 9-slice renders it across FLOOR_Y to form the ground.

Parallax Background Layers

[[background_layers]]
path  = "assets/sprites/backgrounds/sky_blue.png"
speed = 0.0

[[background_layers]]
path  = "assets/sprites/backgrounds/glacial_mountains.png"
speed = 0.2

Layers are TOML array-of-tables and are drawn in array order (first = furthest back). speed is the parallax scroll factor: 0.0 = static sky, 1.0 = locks to camera, 0.1–0.5 = typical mid-ground parallax. Up to 8 layers are supported. See Level Design for the full list of available background images and suggested speeds.

Foreground Strip and Fog Layers

foreground_layers currently select the level foreground strip texture used by the water/lava renderer; the active runtime takes the last valid configured path. Atmospheric overlays are configured separately with fog_layers and loaded into the fog system.

[[foreground_layers]]
path  = "assets/sprites/foregrounds/water.png"
speed = 0.0

[[fog_layers]]
path = "assets/sprites/foregrounds/fog_1.png"

[[fog_layers]]
path = "assets/sprites/foregrounds/fog_2.png"

Asset Reference

These tables include runtime resources and available theme variants; being bundled does not mean a current level references a file. Asset Inventory is the generated size/budget record. Asset Provenance records attribution and unresolved license evidence.

Backgrounds — assets/sprites/backgrounds/

Foregrounds — assets/sprites/foregrounds/

fog.c loads a level’s fog_layers paths into fog->textures[] in array order (up to MAX_FOG_TEXTURES).

Player — assets/sprites/player/

Entities — assets/sprites/entities/

Collectibles — assets/sprites/collectibles/

Hazards — assets/sprites/hazards/

Surfaces — assets/sprites/surfaces/

Levels — assets/sprites/levels/

Screens — assets/sprites/screens/

Text font

The HUD, menus, overlays and editor draw text with raylib’s built-in default font through src/shared/text.c. It is a 10 px bitmap font compiled into raylib (zlib license), drawn at exactly TEXT_FONT_SIZE (10) with point filtering so each font pixel maps to one canvas pixel. It covers ASCII and Latin-1; other characters draw as ?. No font file ships with the game.

Player Sprite Sheet – player.png

Sheet dimensions: 192 x 288 px Grid: 4 columns x 6 rows Frame size: 48 x 48 px

Animation Row Map

Frame Source Rect Formula

frame.x = anim_frame_index * FRAME_W;   // column x 48
frame.y = ANIM_ROW[anim_state] * FRAME_H; // row x 48

Horizontal Flipping

When player->facing_left == 1, sprite_draw uses SPRITE_FLIP_X, expressed as a negative source width in raylib’s DrawTexturePro. The same right-facing animation frames serve both directions.

Unused Assets

The following asset is stored in assets/sprites/unused/ and is not loaded by the game. It is available as a reserve for future use.

Additional background variants are stored alongside used backgrounds in assets/sprites/backgrounds/; no current level references them, but they ship as playable theme options:

Additional tilesets are stored in assets/sprites/levels/; the stone variants are already used by the volcanic campaign levels:

Sprite Sheet Analysis

To inspect any sprite sheet’s exact dimensions and pixel layout:

python3 tools/analyze_sprite.py assets/sprites/<category>/<sprite>.png

The tool requires Python and Pillow. Supply explicit frame dimensions when known, for example:

python3 tools/analyze_sprite.py assets/sprites/entities/spider.png 64 48

Without explicit dimensions, the analyzer looks for transparent gutters. Verify its result against the image: sheet width and height must divide into whole frame columns and rows. Frames are zero-indexed; transparent padding is not part of the visible art or collision hitbox. Measure the art bounds before setting ART_X/Y/W/H or hitbox padding, and check rows separately when their usable frame counts differ.

Theme Variants

Match an existing asset’s dimensions, frame grid, and silhouette before making a theme variant. Palette-only variants preserve pixel positions and transparency; use a limited palette and inspect silhouettes at game scale. Check 9-slice tilesets tiled together for seams.

tools/gen_fire_sprites.py retains the fire-palette generation utility:

python3 tools/gen_fire_sprites.py

It also requires Pillow and resolves assets relative to the repository, not the working directory. Running it writes 13 background/foreground PNGs under assets/sprites/; run it only when intentionally regenerating those assets and review the resulting diff.

Frame Math Reference

Sheet width  = cols x frame_w
Sheet height = rows x frame_h

source_x = (frame_index % cols) * frame_w
source_y = (frame_index / cols) * frame_h

Generated Sounds

Every WAV under assets/sounds/ is synthesized by tools/gen_sounds.py, which needs only the Python standard library. The file doubles as a short synthesis lesson: oscillators with a phase accumulator, exponential pitch sweeps, ADSR and exponential envelopes, seeded noise, one-pole low/high/band-pass filters, peak normalization and seamless loop crossfades.

make sounds                          # rewrite WAVs that changed beyond 1 LSB
python3 tools/gen_sounds.py --check  # exit 1 if a committed WAV drifts

Output is mono 16-bit PCM at 22050 Hz and byte-identical on every run on the same platform, because each recipe draws noise from its own fixed random.Random seed. make docs-drift runs --check, which requires identical WAV headers and frame counts but lets each sample differ by 1 LSB, because math.sin/math.exp come from the platform C library and may round differently on macOS and Linux. make sounds applies the same tolerance and reports such files as unchanged instead of rewriting them, so regenerating on another OS only touches sounds whose recipe actually changed. --check also rejects WAV files the generator does not produce; make test runs tests/gen_sounds_test.py (format, determinism, fade outs, loop seams, the 1-LSB tolerance, unchanged-file skips and a 2 MiB sound budget). To change a sound, edit its recipe and seed/peak entry in the SOUNDS table, run make sounds, then listen and commit the regenerated files with the recipe. To add one, add a recipe and table row first; the C side then loads it as described on the Sounds page.

Loading an Asset

// In game_init or an entity's init function:
Texture2D *tex = texture_load("assets/sprites/collectibles/coin.png");
if (!tex) {
    fprintf(stderr, "Failed to load assets/sprites/collectibles/coin.png\n");
    return -1;
}

// At cleanup (reverse init order):
texture_unload(tex); tex = NULL;