The Flow journey

Smoke rising from a genie's lamp, a waterfall, a lava river, a torch flame, a portal ring, a coin fountain. One system: a stream of items travelling through a shaped field you draw on the stage, the whole field bending and breathing slowly over time. The fourth thing this tool designs, beside atmospheric layers, coin flights and win lines.

One system at a time

ChixyFX describes one particle system and the game renders it. The start screen asks which one you are designing, from left to right:

The header badge turns cyan and reads Flow. Start over takes you back to the start screen; nothing is lost until you pick there. A Flow session saves as chixy-fx-settings-flow.chix and opens straight back into this journey, and the game gets its own chixy-fx-effect-flow.zip. The game stacks the systems: the lamp's smoke in one file, the rain behind it in another.

How a flow works

Think of the field as a soft tube lying on the screen. You draw its middle line, the spine, by dragging a few dots on the stage. A curve says how wide the tube is along its length, so it can be a funnel, a bulb or a pear. Items are born on a grid of emitter points inside the tube, usually at its start, and travel along the spine toward its end, at their own speed, until their lifetime runs out. On top of that the whole tube sways, bulges and twists together, slowly, so it never stands still.

[flow_02 - The stage with the Genie smoke preset running and the Paths tab open: the pink-to-violet smoke column with glow bulbs and twinkles, the cyan field outline around it, the node dots on the spine, the white start dot with its "start" label and the travel arrow. About 1350 px wide, no panel.]

Fig 1 - the Genie smoke on the stage: the field's outline, its nodes, the white start dot and the arrow the items travel along.

Three things make it look like smoke rather than a conveyor belt:

Everything about the field is on the Paths tab: Flow.

What an item is

Every item is a very short flight whose path is its trip through the field. Because it is a flight, everything you know from the other journeys rides on it unchanged:

Trails, sparks and hits cost sprites per item, so while any of them is on, Count is capped at 60 in this journey (24 in the Atmospheric one, which usually has hundreds of items). A waterfall or a star river with no layers riding on it goes to 600.

The presets

Every preset is the same system with different numbers. Load one on the Paths tab, drag its start dot to where the effect should come from, then change what you like.

PresetFieldItemsMotion and lifeLook
Genie smoke (the default)a wavy column widening upward like a pear, twist 120, turbulence 110 px, depth split60 puffs x 7 s, born at the base120 px/s up, a lazy swaysmoke puff on Screen, pink to violet along the field, glow bulbs and twinkles riding on it
Waterfalla straight fall widening at the bottom200 streaks x 1.6 s900 px/s down, a light boilstreak, pale blue, turned along its travel
Lava rivera lazy S across the lower screen, behind the top elements60 puffs x 12 s140 px/s, slow turbulenceadditive puffs, white-hot to dark red along the field, embers floating off
Torch flamea short teardrop pointing up60 puffs x 0.9 s320 px/s, fast small turbulenceadditive puffs, white to orange to red, sparks off the top
Portal ringa closed ring 80 px thick, its cross-section turning 40 degrees a second60 glow bulbs, never replaced (Infinite life)260 px/s round and roundcyan bulbs, glints popping off them
Coin fountainan arch up and over, widening where it lands40 coins x 2.6 s900 px/s along the archthe coin flip, spinning
Star rivera wide band across the top, behind the top elements300 glints x 30 s, lots of depth60 px/s, a very slow swaytiny additive glints, big and small
Smoke wipe (once)a wide band across the whole screen80 puffs x 2.4 s1400 px/s, Run once: births for 1.2 s, then it dies downhuge violet puffs, a transition

[flow_03 - A contact sheet, two rows of three, each cell a stage crop of a preset on the same board: Genie smoke, Waterfall, Lava river, Torch flame, Portal ring, Coin fountain. Label each cell with the preset name. About 1350 px wide.]

Fig 2 - six presets. One system, six looks.

The genie lamp, step by step. On the Board tab, press Add element twice: first the game screen (it covers the stage, so it arrives locked; drag its card to the bottom of the stack, under the Board card), then the lamp itself, cut out with transparency (drag its card to sit just above the Board card, between the board and the effect). Pick Flow and keep the Genie smoke. Drag the white start dot onto the lamp's spout and the other dots up where the smoke should rise. With Depth on Split, the far puffs now pass behind the lamp and the near ones in front. Upload your own puff picture on the Item tab (a soft white cloud works best, the tint colours it), and your own bulb and sparkle pictures on the two sparkle layer cards. For a pink fog behind it all, a second Flow or an Atmospheric design with a few huge soft puffs does the job; the game stacks them.

More ideas for a slot game

Placeholder pictures

The presets use pictures the tool draws for itself when it starts: a soft smoke puff and a glow bulb (new with this journey), plus the streak, star glint and coin flip the other journeys use. They are all white so the tints colour them, and they are placeholders. Replace any of them with Upload image(s) on the Item tab or on a layer card. For several different puffs in one field, add them as Variants on the Item tab; Size variance in the Population group keeps them from all being one size.

What the game gets

Export Effect writes chixy-fx-effect-flow.zip: the field (the spine, the width, the twist, the turbulence, the emitter grid, the motion, the population and the cycle), the item and its layers exactly as in the other journeys, and every picture the items that are switched on draw. The tool never knows where in the game the smoke will play, so the spine is written relative to its first dot: the game puts that dot on the lamp's spout, a pot or a symbol and the field follows. Every rule the tool uses is written into the file as notes, including the turbulence, so the game shows the same flow from the same seed.

Everything is exact at any moment. As in the Atmospheric journey there is no simulation underneath: each item's position is worked out from the clock and its seed. Pause, drag the Scrub slider, render any stretch of time - it is always the same flow.