Road assault

What it does

A game is a list of rallies, each a section of a road-data road file with a checkpoint marker halfway and a rally point near the end. There is no race clock: fuel is the clock. A main and a reserve tank burn by the second, so dawdling runs you dry. Green globes on the road add fuel, enemies blasted from far enough away drop red ones, the checkpoint restores the main tank to its level at the start of the rally, and the rally point pays reserve fuel by the rally's score. A crash costs fuel and the special weapon, and when both tanks are dry you continue or the game ends.

Enemy cars are driven by road-pursuit's target driving, so they cruise, swerve round each other, block and take a shove; a role only decides what each one aims for. Racers overtake, blockers are armoured and can be immune to gunfire, jeeps ride the verge and then cut across and brake, weavers cross the lanes, packs arrive together and some throw spikers back at you. Gun turrets beside the road fire leading shells, minefields switch on a warning light, and boulders and toxic spills that spin the car wait on the road.

The cannon repeats while the button is held, and an accuracy multiplier rises with each kill by a shot and falls with each miss. A support jet swoops in at set points in a rally and drops a pod to catch: a rapid-fire cannon, a shield, a nitro or a cruise missile, each with a limited number of uses. Everything is deterministic with snapshot and restore, and scene() hands the whole race to road-view-pseudo3d to draw.

Features

• Rallies on any road file — a standing start, a checkpoint and a rally point per section, with a top speed, starting fuel and an enemy roster each.
• Two fuel tanks — main and reserve, burning by the second, with green and red globes, a checkpoint refill, reserve by score, fuel lost in a crash and a low-fuel light.
• Enemy roles — racers, armoured blockers, verge-riding jeeps and weavers, arriving ahead, behind or both, in packs, some throwing spikers.
• Turrets and hazards — roadside turrets firing leading shells, minefields with a warning light, boulders and toxic spills.
• An accuracy multiplier — up with each kill, down with each miss, with its own start, limits and crash reset.
• A support jet — swoops in at fractions of a rally and drops a pod: rapid-fire cannon, shield, nitro or cruise missile.
• A start screen — starting rallies with bonuses paid on finishing them, and continues.
• Difficulty — Easy, Normal and Arcade, scaling fuel burn, road density and turret fire.
• Presenter-ready — field groups for enemies, turrets, shells, hazards, globes, shots, the pod and effects, and a scene for the road view.

Good for

• Combat rally racers in the style of the 1987 arcade RoadBlasters, fifty rallies across twelve regions.
• Convoy raids, a single long rally against armoured trucks with no support jet.
• Fuel-only survival runs, with no checkpoint refill, no reserve and red globes as the only fuel.
• Getaway shoot-outs and wasteland runs between depots on any road someone drew.
• Endless arcade modes, with generated rallies and a rising number of enemies on the road.
• Bike combat games, on a motorbike handling model and narrow roads.

Make it yours

Every field of the config is data, and the presets are starting points. Each rally sets its road entry, region, top speed, starting fuel, enemy roster by weight, the most on the road and the seconds between arrivals by difficulty, turrets, minefields, boulders and globe rows per kilometre, spikers, when the jet comes and which weapons it brings. Enemy kinds set their size, points, armour, role, speeds, where they come from, packs and whether they give a red globe. Fuel burn, globe values, the checkpoint rule, reserve by score, the multiplier, the cannon, each weapon (or none), the jet's timing, continues and the final bonus are all settings.

Two quite different games ship as presets. roadBlastersPreset is fifty rallies with a start screen of three skill levels, unlimited continues until the last rally and a million-point finish. nightStrikePreset is an original configuration on its own road file with its own camera and enemies. Beyond those, a desert convoy raid, a fuel-only survival run or a hundred-rally endless mode are changes to the same config.

A quick look

A game from the preset, the frame loop and the scene for the road view:

const RA = game.roadAssault;
const a = RA.createAssault(RA.roadBlastersPreset({ difficulty: "normal" }));
a.start();                                        // the start screen (ROOKIE, VETERAN, EXPERT)
a.tick(dt, { throttle, brake, steer, fire, special, start, select });   // presses are latched
for (const e of a.drain()) present(e);            // rally, kill, miss, globe, checkpoint, jet, catch, rally-point ...
view.draw(a.scene());                             // road-view-pseudo3d, camera RA.ROAD_BLASTERS_CAMERA

Works with

• road-racer — required: the car, the road, crashes into scenery and distance scoring underneath each rally.
• road-pursuit — required: the target driving every enemy car uses.
• road-data — required: the road files the rallies run on.
• vehicle-handling, pseudo-road and scaled-depth — required: the car's handling, the road and the field objects every hit is tested on.
• road-view-pseudo3d — draws the scene.
• road-combat — for a top-down road shooter instead.

Good to know

• One player car; enemy cars do not shoot (only turrets do) and do not collide with each other.
• Rallies are single road sections without forks, and roadside furniture is laid from the seed per rally.
• The cruise missile clears a stretch of road ahead at once and leaves toxic spills, which are road surface.
• There is no invulnerability after a respawn, so an enemy still in the way can strike again.
• Fuel burn, globe values, enemy speeds and densities in the preset are estimates where no source gives them.