skyway-blog
Beginning
I read a lot of advice for gamedev that says things like: “You should write dev logs for your work”. Well, here we go! I’m a bit late, writing this retroactively - I didn’t think of writing the blog until just now. (The editor is mostly complete as of writing).
I’ve been through many random prototypes, but ran into various stumbling points. I wanted to actually get something done, so I racked through my brain to think of a project I know from start-to-finish, I won’t run into weird issues or rather annoying maths.
And there, at the back of my mind. A flash game I played in my childhood.
(Skywire, by Nitrome games)
You’re in a little cable car, and your goal is to bring your three passengers to the end. Well, this seems like it’d fit the Playdate fantastically. The crank might make for a great method to control the cablecar! I loved the game as a kid, but I won’t be replaying it before making this game. I want it to be an inspiration, not a clone, or rip off, or whatever you’d call it.
Alright, let’s get started!
Engine choice
Well, there’s not much choice in this field. The Playdate is pretty simple, and to my knowledge there’s one ‘engine’ available for Lua - Noble Engine. There’s also some small other utility libraries available, but Noble Engine covers most of the stuff that I don’t want to deal with - scene management, settings/savegames, and, handily, comes with a font that supports japanese.
(Japanese text example. Input prompts are from the Kenney 1-bit input prompts pack)
Noble engine comes with a project template, featuring a couple of example scenes, and a demo of how to use the menu system.
Initial commit
Let’s start by getting in the two most important things: The player, and the cable.
Our track
For the cable, this is pretty simple! The Playdate has the playdate.geometry library, which has handy things like line segments and arcs. So we’ll be composing those together to form our cable.
For this, I opted to plonk some simple objects into a list. Because it’s Lua, we can go for a simple, quick design:
local ARC <const> = 1
local LINE <const> = 2
function DebugPath()
return {
{
Type = LINE,
Line = playdate.geometry.lineSegment.new(5,100,100,100)
-- x1, y1, x2, y2
},
{
Type = ARC,
Arc = playdate.geometry.arc.new(100,150,50,0,90)
-- x, y, radius, startAngle, endAngle
},
{
Type = LINE,
Line = playdate.geometry.lineSegment.new(150,150,150,200)
},
}
end
and then when we want to draw our path, it’s as simple as:
for _, value in ipairs(array) do
if value.Type == ARC then
gfx.drawArc(value.Arc)
elseif value.Type == LINE then
gfx.drawLine(value.Line)
end
end
and that gets us this!
The player
Next up, lets get ourselves a player onto the game. The playdate has a sprite library, CoreLibs/sprites, which Noble Engine extends further. We’ll be using that, along with the Playdate’s simple object-orientation system.
import "CoreLibs/object"
class("Player").extends(NobleSprite)
function Player:init()
Player.super.init(self, "assets/images/spr_cablecar")
self:setCenter(0.5,0)
end
To do our regular ol’ drawing functions alongside sprites, we need to either draw them to a sprite ourselves, or use the convenience setBackgroundDrawingCallback. We’ll be going with the latter, as we want the cable to draw behind our player anyway.
(At this point, I’ve also set the line width to 2, so we have a thicker cable. We’re using for our player sprite an edit of the cablecar from Kenney’s Tiny Ski assets.)
Next up: More player movement stuff!