The SHIP_CANISTER (Ship blueprints M) variable - Elite on the BBC Micro and NES

       Name: SHIP_CANISTER                                           [Show more]
       Type: Variable
   Category: Drawing ships
    Summary: Ship blueprint for a cargo canister
  Deep dive: Ship blueprints
    Context: See this variable in context in the source code
 Variations: See code variations for this variable in the different versions
 References: This variable is used as follows:
             * XX21 uses SHIP_CANISTER


.SHIP_CANISTER

 EQUB 0                 \ Max. canisters on demise = 0
 EQUW 20 * 20           \ Targetable area          = 20 * 20

 EQUB LO(SHIP_CANISTER_EDGES - SHIP_CANISTER)      \ Edges data offset (low)
 EQUB LO(SHIP_CANISTER_FACES - SHIP_CANISTER)      \ Faces data offset (low)

 EQUB 49                \ Max. edge count          = (49 - 1) / 4 = 12
 EQUB 0                 \ Gun vertex               = 0
 EQUB 18                \ Explosion count          = 3, as (4 * n) + 6 = 18
 EQUB 60                \ Number of vertices       = 60 / 6 = 10
 EQUB 15                \ Number of edges          = 15
 EQUW 0                 \ Bounty                   = 0
 EQUB 28                \ Number of faces          = 28 / 4 = 7
 EQUB 12                \ Visibility distance      = 12
 EQUB 17                \ Max. energy              = 17
 EQUB 15                \ Max. speed               = 15

 EQUB HI(SHIP_CANISTER_EDGES - SHIP_CANISTER)      \ Edges data offset (high)
 EQUB HI(SHIP_CANISTER_FACES - SHIP_CANISTER)      \ Faces data offset (high)

 EQUB 2                 \ Normals are scaled by    = 2^2 = 4
 EQUB %00000000         \ Laser power              = 0
                        \ Missiles                 = 0

.SHIP_CANISTER_VERTICES

      \    x,    y,    z, face1, face2, face3, face4, visibility
 VERTEX   24,   16,    0,     0,      1,    5,     5,         31    \ Vertex 0
 VERTEX   24,    5,   15,     0,      1,    2,     2,         31    \ Vertex 1
 VERTEX   24,  -13,    9,     0,      2,    3,     3,         31    \ Vertex 2
 VERTEX   24,  -13,   -9,     0,      3,    4,     4,         31    \ Vertex 3
 VERTEX   24,    5,  -15,     0,      4,    5,     5,         31    \ Vertex 4
 VERTEX  -24,   16,    0,     1,      5,    6,     6,         31    \ Vertex 5
 VERTEX  -24,    5,   15,     1,      2,    6,     6,         31    \ Vertex 6
 VERTEX  -24,  -13,    9,     2,      3,    6,     6,         31    \ Vertex 7
 VERTEX  -24,  -13,   -9,     3,      4,    6,     6,         31    \ Vertex 8
 VERTEX  -24,    5,  -15,     4,      5,    6,     6,         31    \ Vertex 9

.SHIP_CANISTER_EDGES

    \ vertex1, vertex2, face1, face2, visibility
 EDGE       0,       1,     0,     1,         31    \ Edge 0
 EDGE       1,       2,     0,     2,         31    \ Edge 1
 EDGE       2,       3,     0,     3,         31    \ Edge 2
 EDGE       3,       4,     0,     4,         31    \ Edge 3
 EDGE       0,       4,     0,     5,         31    \ Edge 4
 EDGE       0,       5,     1,     5,         31    \ Edge 5
 EDGE       1,       6,     1,     2,         31    \ Edge 6
 EDGE       2,       7,     2,     3,         31    \ Edge 7
 EDGE       3,       8,     3,     4,         31    \ Edge 8
 EDGE       4,       9,     4,     5,         31    \ Edge 9
 EDGE       5,       6,     1,     6,         31    \ Edge 10
 EDGE       6,       7,     2,     6,         31    \ Edge 11
 EDGE       7,       8,     3,     6,         31    \ Edge 12
 EDGE       8,       9,     4,     6,         31    \ Edge 13
 EDGE       9,       5,     5,     6,         31    \ Edge 14

.SHIP_CANISTER_FACES

    \ normal_x, normal_y, normal_z, visibility
 FACE       96,        0,        0,         31    \ Face 0
 FACE        0,       41,       30,         31    \ Face 1
 FACE        0,      -18,       48,         31    \ Face 2
 FACE        0,      -51,        0,         31    \ Face 3
 FACE        0,      -18,      -48,         31    \ Face 4
 FACE        0,       41,      -30,         31    \ Face 5
 FACE      -96,        0,        0,         31    \ Face 6

[X]

Macro EDGE (category: Drawing ships)

Macro definition for adding edges to ship blueprints

[X]

Macro FACE (category: Drawing ships)

Macro definition for adding faces to ship blueprints

[X]

Variable SHIP_CANISTER (category: Drawing ships)

Ship blueprint for a cargo canister

[X]

Label SHIP_CANISTER_EDGES is local to this routine

[X]

Label SHIP_CANISTER_FACES is local to this routine

[X]

Macro VERTEX (category: Drawing ships)

Macro definition for adding vertices to ship blueprints

Drawing ships: SHIP_CANISTER

[BBC Micro disc version, Ship blueprints M]