Gates¶

The gates' tunnels, which ships jump through (wgate.cpp, 0x0041DD70 to 0x00423228). A Coalition gate stands with a tunnel open in it from the start, and Fixed Gate Open grows one at any object, a nav point among them. A ship goes out through a tunnel with Fixed Gate Jump Out, the player's riding the worm, and comes in through another with Fixed Gate Jump In; Fixed Gate Close shrinks a tunnel away, and Fixed Gate Collapse brings a gate down.

In OpenReliant¶

game/wgate.zig holds the gates' state, their records and the five orders; game/wgate/tunnel.zig builds, shapes and colours the tunnels and the jumps' flashes, and game/wgate/worm.zig the worm. create.gateMade sets the Coalition's gates up (game/create.zig). A mission's start lets every tunnel go.

game/wgate/warp.zig implements Warp In and Warp Out, with their independent tunnels, projector beams and particles.

Not ported: the Boridin's projection (kind 3, order 38) (#30); the Krasny's split in missions 16 and 66 (#407); and the collapse's second passes on the parts of models a gate carries, which the game's walk of its nodes reaches too (#540). No shipped gate carries a model.

Improvements, which --original turns off:

• A tunnel is built four times as finely round and along, its rings a quarter as far apart so that it keeps its length. Its radii and depths follow the game's curves between the game's rings, so that it is round and its rings' wave smooth; its sway and its colours run between the game's vertices', as the game's are drawn between them.
• The ride through the worm has its chance to rumble once for each of the simulation's steps, 25 a second, rather than each frame, so that it rumbles as often whatever the frame rate: as the game does at 25 frames a second.

Fixes, each marked so in the code:

• Where an order names an object with no tunnel, the game reads the record before the first as one, whatever it holds; OpenReliant logs it and ends the order.
• Jump Out cuts the ship by the portal of the tunnel it goes through. The game cuts it by the portal of the gate its order names, which Jump In goes through next.
• The game turns a ship being drawn down the tunnel toward the angles of a matrix it never fills, whatever the stack holds there; OpenReliant leaves it turned as it is.
• The game makes the worm anew for each of the player's jumps out and never lets the last go; OpenReliant lets it go.
• The collapse's fireballs go off at the points of the hull's cut list by number, and the game reads past the list's end where a number lies beyond it, as the advanced gate's OuterRing does for its 55 fireballs; OpenReliant counts on from the list's start again.
• The collapse's burn and fade write each colour to the vertex before its own, lighting the last vertex of the mouth's black rim and blacking out one of the ring before the last; OpenReliant writes each vertex's own.

Improvement: the sines and cosines come from std.math rather than the engine's tables, and a segment's turn round the axis from std.math.tau over the segments, where the game multiplies by 6.2831855 (0x004DC3EC) and by one over the segments (0x0051D130).

Time¶

The gates count their time in thousandths of the timer's ticks (0x004DC418): a tick is a hundredth of a second, so that a rate of 1 runs from 0 to 1 in 10 seconds. Open and Close count from the tunnel's last frame (+0x0C), the jumps from the order's last update (+0x08). The ticks since a record's tick are taken unsigned, those since an order's update signed.

The records¶

0x0051D1A4 holds 32 records, each flagged in use in 0x0051D224 and allocated 0x88 bytes by 0x0041FE60:

0x00420920 finds the first record at an object; 0x00420830 lets a record go. The gates' start with each attempt at a mission (0x0041E280, from 0x004AD0A0) takes the grid by the options' detail and the textures, and clears the records; their end (0x0041E4A0, from 0x004AD260) lets them go.

The tunnel¶

A tunnel (0x0041DD70, Wgate_Mesh) is a funnel of rings round its Z axis, each a ring of vertices after a centre vertex, two triangles for each segment between two rings:

A gate's tunnel is 344 or so times its size across at the mouth, each ring a sixth narrower than the last: 80 * 1.2^(8 - ring) times the size, 70 for a proto gate's tunnel and 40 for an advanced gate's, 70 again in mission 8. The game works it out as 10 * 8 * 1.2^8 / (1.2^rings * rings) times 1.2^(rings - ring) * rings * size, in double precision.

It is drawn with warp128 (ddwarp128 without a hardware renderer), added, by coordinates of its own: u a unit along for eight rings, and v the vertex's height across a warp's tunnel's radius in thousandths. A hardware renderer draws all but its last band in two passes, the second a highlight texture by its normals, 7 for a proto gate's and 0 for an advanced gate's. Its object takes colours of its own (0x0041D7D0): its mouth's ring and its last are black and clear, and the ring before the last its deep colour; between them a hardware renderer's run in a straight line from the mouth's colour to the middle's over the first 0.3 of the rings, then to the end's by the square root:

A software renderer's run from white to black, the ring before the last a mid grey.

Each frame the gates' frame (0x00420A00), which shield_bubbles_draw runs before the bubbles, works on each record of a fixed gate:

1. Each ring stands ring * 1500 + sin(ring + time) * 300 deep, its time since it was made.
2. Each vertex stands at its ring's radius and depth, the last ring at the depth of the one before, and the record's 0x1C deeper (0x0041FA50). At the high detail each sways across and down by up to 41.7 times the segments, at its own pace by the frame's tick.
3. Its normals, its bounds and its radius follow.
4. Its portal goes into the world's layer, and the tunnel too, unless the player's ship rides the worm.

As it is drawn, its texture scrolls by its time, 3.5 across and 0.6 along (0x00420950, its object's hook at +0x170).

OpenReliant places the tunnel and its portal from where the gate's object is drawn, where the game hangs their frames from it.

Warps¶

Warp Out (5) and Warp In (4) use an independent tunnel for each ship, rather than a fixed gate's tunnel. Their shared order state stores the step at 0x04, an orientation at 0x0C and the saved position at 0x3C.

Warp Out (0x0041E550, 0x0041E710) clears the steering controls and uncloaks player slots. The ship aligns with its target. The player faces it immediately and marks objects in a 500000-unit corridor ahead as jumping; other ships steer until their inputs and turn rates are within 0.05. The projection sound plays and the player's camera takes view 9.

The order creates a kind-0 record, saves the departure frame and freezes the ship. Four beams connect its warp projectors to two counter-rotating endpoint frames. The original supplies red vertex colours, but the unlit material draws the texture's own colour. Point group 10 supplies the origins; the Yamato uses four points on Yam_Warp_Proj_3. Without projector points, the origin is 300 units ahead of the ship. Each beam has a cap and three blades, 110 units wide on either side. Its endpoints stream particles with a 120-tick life.

The opening depth follows square-root easing. Ring spacing is 900 units for ships without components and 4000 for ships with them. Rings start updating once the depth exceeds 800. Their radii grow from five percent of the ship type's warp size to its full size. The extension then moves the rings along the tunnel. At entry, the portal clips the ship, the departure sound plays and the player's camera holds view 10. The ship moves forward while the tunnel fades. Fighters stretch along their drawn Z axis between progress 0.2 and 0.6, without changing their flight orientation. The order hides the ship and queues Warp In at its target, keeping the sequence number. A self-targeted departure ends without an arrival.

Warp In (0x0041E5C0, 0x0041F260) stops the ship and uses the target's orientation. The sequence spreads arrivals along the target's X axis: 0, -3000, +3000, -6000, +6000. It reuses the departure record where one exists, resets its colours and reverses the tunnel. The player takes camera view 11, clears jumping flags and updates the environment. The arrival sound plays. At high detail the ship starts 20000 units behind its arrival point, hidden (15000 units at lower detail), and becomes visible at progress 0.4. Other ships accelerate at throttle 2; the Yamato moves explicitly while frozen. After the emergence and final wait, the tunnel is freed, collision and motion flags are restored, the player returns to the cockpit and JumpedIn is posted.

The existing fine-tunnel setting applies to warps too. --original uses the original grid. Fix: a missing record or allocation failure ends the order and releases its frozen flags instead of leaving the ship stuck.

The Coalition's gates¶

create_object sets the Coalition's gates up (0x00467D2B, 0x0046823A). A prototype (type 0x6D) has a proto gate's tunnel at the middle of the first two points of the door list of its part 1, where that part stands from the one it hangs from; its power core (Protogate Power core) burns for good with steady rays alone, and each of its parts plays its Rotate End track. An advanced gate (type 0x6E) has an advanced gate's tunnel at its part 6's, and each part plays Rotate Inner at four times the pace, then Rotate End.

The portal¶

A jump sets the portal up (0x0041FDF0): it faces along the tunnel's axis, at ring rings - 5 as the tunnel stands then. A ship going through is cut by it (node_tree_clip, 0x004ADEE0): only what lies on the tunnel's mouth side of the portal shows.

Open and close¶

Fixed Gate Open (28) makes a tunnel at the object (0x004218A0), an advanced gate's where one is among the objects and a proto gate's otherwise, and it is heard (gateopen). It grows from 0.0001 of its size, easing in and out, over 1.1 seconds (0x00421940), then the order ends.

Fixed Gate Close (29) is heard (gateclos, 0x00421920), shrinks the tunnel likewise, then lets it go (0x00421A00).

Jump in¶

Fixed Gate Jump In (25, 0x00420B80) brings the ship in through the tunnel at the object its order names. It comes from 18000 deep and 2000 above the axis for the player's ship, 26000 deep for the rest, to 53000 out beyond the mouth for a friend, 25000 for the rest, turned about the axis by 0.3 for each step of the spread (0x004E3F68). The spread starts at -2 and runs on to 2, then back to -2, passing over 0 but for the player's ship, which sets it to 0. The ship faces the way it goes, its lights' sprites hidden (0x00423050), unpowered, frozen and untargetable, colliding with nothing where it lists no components, and goes in a straight line.

Its update (0x00420FD0) waits while another ship comes through the tunnel, save for the player's ship. Then it holds the tunnel, the flashes stand at the portal's ring, and the ship starts where it comes from, heard (warpin); for the player's ship the mission's space takes on what its script asked of it (environment_update). It goes to where it goes over 5 seconds, letting the tunnel go half way. Over the first fifth of the way, while the player's ship does not ride the worm, the flashes show (warpin3, 25000 across): the first shrinking from 12500 either way as it brightens, the second growing to it as it dims, each by the square of how far through. Then the ship is powered, collides and can be targeted again, its lights' sprites show, the portal lets it go, and the order ends; its FixedGateJumpedIn is posted with the gate's ship (event_fixed_gate_jumped_in, 0x0045ABD0).

In missions 16 and 66 the Krasny (type 0x9A) comes out straight ahead, leaving the spread as it is, at 0.13 rather than 2, with no flashes.

Jump out¶

Fixed Gate Jump Out (26, 0x00420DD0) takes the ship out through the nearest gate's tunnel, whatever its order names: its inputs, its rates and its speed at nothing, colliding with nothing, frozen, unpowered and untargetable, going to 12000 down the tunnel for the player's ship and 26000 for the rest. The player's ship's worm is made.

Its update (0x00421510) waits while another ship goes out, then the ship is drawn toward where it goes, a growing share of the rest of the way each frame, until it is within 400. Then it is gone to its slot times a million along X and 25 million back along Z. The player's ship rides the worm (0x0051D13E), which stands where it does, turned as it is, and the screen flashes. While it rides, the worm sways, its texture scrolls, and each frame, one time in 40, the view shakes and flashes and the ride rumbles (sound 10 of bank_stdsmp, as loud as 2000 times the ship's radius). The ride lasts 4 seconds. Then the player's ship leaves the worm, flashing and shaking, the tunnels are free, the ship is powered and collides again, the portal lets it go, and its order gives way to Fixed Gate Jump In through the gate it named.

The worm (0x00422700, Worm_Mesh) is a tube of 31 rings, 16 segments round, 10000 across and 200000 apart, drawn solid with the gates' texture, with a highlight added by its normals, coloured as a proto gate's tunnel over its rings (0x00422AD0). As the ship rides it sways by up to 2000 (0x004229B0), and its texture scrolls 10.5 along it and 0.5 across.

Collapse¶

Fixed Gate Collapse (31, 0x00421AC0) is logged ">>>>>>Starting gate collapse at %d"; a proto gate's hull (Protogate) burns with flickering rays alone, for a while, and the screen flashes. Its update (0x00421B80), counting from the tunnel's last frame:

1. Over 10 seconds, 55 fireballs go off at the points of the hull's cut list in turn (Protogate, or OuterRing for any other gate), each 5500 to 8500 across and lit, every seventh heard (explosion02). Past the end of the list, OpenReliant counts on from its start again. Each frame the second passes of the gate's type's meshes go off at random, 0.3 of the frames (0x00422680). Then they go off for good, and the screen flashes.
2. Over the first fifth, its rings slow to a stop: a proto gate's forcering from 1, an advanced gate's InnerRing from 4 and Tube11 from 1. One frame in 20 a fireball 3500 to 4500 across goes off at a random point among the first 56 of the cut list, counted on from its start again past its end. The tunnel burns out (0x00422380): a flickering share of its vertices take a dull red, the ring before the last blue, brightest where the share has just reached them. The gate shakes by 15 along each axis at random, unpowered. A proto gate's step lasts 20 seconds, any other's 40, its tunnel burning twice as fast.
3. The tunnel fades (0x004221E0) over 1.7 seconds: its vertices take a pale grey, the ring before the last green, by the same reach.
4. It is logged ">>>>>>Gate fully collapsed at %d"; any gate but a proto gate lets its tunnel go, an advanced gate losing its hull (object_hull_lost), and a gate's forcefield is hidden.

The wipes reach a share of the vertices counted from the tunnel's first ring. The game writes each colour to the vertex before its own; OpenReliant writes each vertex's own.