Level Data Format

This document describes the level data formats used in the original Vangers game.

struct LevelConfig {
    width: Power,
    height: Power,
    geo: Power,
    section: Power,
}

VPR

This file contains information about the flood levels.

let flood_size = 1 << (level.height - level.section);
let net_size = 1 << (level.width + level.height - 2 * level.geo);

Type	Description
[u32; 2]	?
[u32; 1+4+4]	?
[u16; net_size]	?
[u32; 2*level.geo]	?
[u32; 2*level.geo*flood_size]	?
[u32; flood_size]	flood level per vertical line

VMC

This file contains the level geometry. Each texel has 2 associated values:

• altitude (uint): how high the texel is above the ground level. Scale?
• meta (uint): encoding shadow/double-level flags and the terrain type

Type	Description
[i32; 1<<level.height]	compressed lines offsets
[i16; 1<<level.height]	compressed lines sizes
[i32; 0x200]	Huffman tree for the altitude stream
[i32; 0x200]	Huffman tree for the meta stream
blob	Compressed binary blob accessed using the offsets/sizes given per height line. Each line decompresses 0x800 altitudes first, and then 0x800 meta markers.

Meta format:

• bits 0-1: levels delta, interleaved (DELTA_MASK)
• bit 2: object shadow flag? This shadow occluder is assumed to be placed at 50 height
• bits 3-5: terrain type
• bit 6: double level flag (DOUBLE_LEVEL)
• bit 7: shadow flag

Interleaved data for double levels

If Mask[i] & DOUBLE_LEVEL != 0 then:

• 0 .. Altitude[i & !1] is below the ground level
• Altitude[i & !1] .. Altitude[i & !1] + Delta is the empty space underground
  • Delta = ((Mask[i & !1] & DELTA_MASK) << 2 + Mask[i|1]) << 3
• Altitude[i & !1] + Delta .. Altitude[i | 1] is inside the upper level
• Altitude[i | 1] .. is above the ground

else:

• Altitude[i] is the height of the single ground level

Terrain type and texel color

Each level supports up to 8 different terrain types with different characteristics. File world.ini of the corresponding level contains info for each terrain type, such as: used range from the .pal file (color palette), shadow offset for coloring shadowed texels, color animation, etc. Factors that affect the final color of a texel are as follows:

• altitude of the texel
• color animation properties (if any)
• whether texel is shadowed or not

PAL

This file contains the color palette for a level. Note: main worlds use multiple palettes depending on the bunch, so the level's associated palette only makes sense for the offshore worlds.

Type	Description
[[u8; 3]; 0x100]	RGB* components of 256 palette colors

Note that stored components need to be multiplied by 4 before written to the framebuffer.