Mot [Lexaloffle Blog Feed]

Feature suggestion - Enhanced controller input

Tue, 17 Aug 2021 12:48:22 UTC

Just a suggestion, but for modern controllers it would be really nice if the extra controls could be mapped like:

Right trigger = X
Left trigger = O
Right thumbstick = Mouse

That would allow FPS games like Poom, Sorcerer to be played like a twin stick shooter on capable input devices, without actually changing Pico-8's input model.

Variable inspector (debugging)

Mon, 26 Jul 2021 07:12:46 UTC

This is a cut down version of the variable inspector I wrote a while ago. It's a bit more limited, but a lot more light weight. And there's a way to use it even if you have no tokens to spare (described below).

You use it to view Lua table variables:

Run your game
Press Esc to break into it
Type: dinsp(variable)

Then use the mouse to expand values and scroll wheel to scroll up/down.

Code snippet follows (for some reason I can't use the code formatting tags):

poke(0x5f2d,3)cursor()pal()clip()function dadd(n,v,i,p)add(lines,{n=n,v=v,x=type(v)=="table"and"+"or" ",i=i},p) end function dexp(l,p)if l.x=="+" then for n,v in pairs(l.v) do p+=1 dadd(n,v,l.i.." ",p)end l.x="-"end end

function dinp()local x,y,b,w=stat(32),stat(33),stat(34),stat(36)line(x,y,x,y+2,10)if btnp(❎) then local i=(y-10)\6+1 local p=s+i local l=lines[p]if l and (x-10)\4==#l.i then dexp(l,p)end end s=max(min(s-stat(36),#lines-18),0)end

function dui()while true do rectfill(10,10,118,118,1)for i=1,18 do local l=lines[i+s]if l then print(l.i..l.x..l.n..":"..tostr(l.v),10,(i-1)*6+10,7)end end dinp()flip() end end function dinsp(v)lines,s={},0 dadd("value",v,"",#lines+1)dui()end

The snippet is 246 tokens.
If you don't have 246 spare tokens, you can still use it as follows:

Run your game
Press Esc to break into it
Paste in each of the 3 snippet lines one at a time, pressing enter after each.
Type: dinsp(variable)

The snippet must be entered as 3 separate lines because Pico-8 has a 255 character limit for lines in immediate mode.

Feature request: Metronome in sfx editor

Sun, 18 Jul 2021 08:41:58 UTC

This is a suggestion, not a bug obviously.

The ability to toggle on a metronome tick/beep every 4 beats in the sfx editor would be quite helpful for composing tunes.

Trial of the Sorcerer

Fri, 16 Jul 2021 05:45:28 UTC

Trial of the Sorcerer

by Mot

[Click to Play]

Grab your magic staff and venture deep into the demon realm to defeat Bahmott and his evil servants!

Trial of the Sorcerer is a procedurally generated 3D first person shooter inspired by Wolfenstein 3D and Catacomb Abyss.

Shoot monsters, collect loot, find keys to unlock doors, and try to find the exit to the next level.
And don't forget to pickup the power crystals to level-up your magic staff along the way.

Input

Arrows = Move
X = Shoot
Z = Hold to strafe

Or use player 2 controls (E,S,D,F) to move/strafe and player 1 controls to turn.

Mouse input can be enabled via the pause menu (once in game), but only when playing via the Pico-8 application as mouse locking doesn't currently work in the browser version.

Tips

Doors with a small black keyhole require keys.
Each door requires a specific key, so if one won't open it means you don't have the right key yet.

UPDATED (based on feedback):

Swapped green and yellow staff
Decreased green staff cooldown slightly
Player recovers 5 points of health between levels
Made some enemies more visible in dark areas

UPDATE 2

In game music. (Can turn it off in the pause menu.)
Shows gold collected and enemies destroyed after each level and when game completed
Enemies slide off obstacles - don't get stuck as often
Removed range limitation from flame staff (yellow staff). Swapped back with green staff.

UPDATE 3

Fix crash in procgen code

UPDATE 4

Ctrl+C from "Level Done!" screen copies level seed.
Added "Quick Level" option to quickly play a random level.

Crypts of Mot

Tue, 29 Jun 2021 09:35:21 UTC

Crypts of Mot

by Mot

[Click to Play]

Still needs quite a bit of finishing off.
I'm posting it now mainly so I can play it on my phone :-)

Levels are randomly generated. Shoot monsters, collect loot, find keys to unlock doors and reach the exit.

Formula 1 practice lap

Sun, 14 Feb 2021 03:01:03 UTC

mot_formula1

by Mot

[Click to Play]

Strap into one of the world's fastest race cars and blast around the legendary Bronzerock circuit like it's 1988!
...or something - there's not a lot of physical or historical accuracy in this game :)

Z/X=accelerate/brake
Left/right=steering

Driving off road slows you down. Driving too fast around corners causes you to slide.

You can use the pause menu to view your last/best lap times (my best so far is 1:43.23)

This is work-in-progress, so some caveats:

There are no other cars yet.
Lots of things need tweaking/adjusting.

F1 racing game

Fri, 05 Feb 2021 21:12:03 UTC

F1 racing game

by Mot

[Click to Play]

This is very unfinished and I wasn't planning to release this just yet, but somebody asked to play it so here it is :-)

Z/X accel/brake
Left/right to steer

Eventually there will be consequences for leaving the road and crashing into things.

Mot's Wolf3D engine

Fri, 29 Jan 2021 07:19:44 UTC

Mot's Wolf-3D engine

by Mot

[Click to Play]

This isn't really a game - unless you consider it a short "Walking simulator" - it's more of a tech demo.

The engine is a basic Wolfenstein-3D like 3D engine. It has floor and ceiling textures and render reasonably sized and complex rooms at 60 frames-per-second, in a 128x96 viewport.

Arrow keys = move
X = toggle map mode

If anyone feels like something out of it, it's fairly easy to get started with (details below).

Flight simmy

Fri, 27 Nov 2020 07:47:28 UTC

mot_flight

by Mot

[Click to Play]

A little arcady "flight sim" I started writing.
Buzz past randomly generated islands in a wrap-around ocean.

I will probably add stuff to blow up eventually :)

There is no throttle! Just steer with arrows.

Mot's 8-Ball Pool

Thu, 08 Oct 2020 08:05:51 UTC

Pool

by Mot

[Click to Play]

This is Mot's 8-Ball Pool, a little pool simulation inspired by 3D pool on the C64 and Amiga.
Shoot a round of pool against a friend, or one of the 7 different AI characters.

UI

The UI at the bottom of the screen shows how each player is progressing.
The player's name flashes when it is their turn.
The color they must sink is displayed next to their name, and the balls already sunk are displayed above.
A white ball indicates they have a free ball.

When player fouls, the reason for the foul is displayed in a scrolling message along the bottom of the screen.

Rules

I'll assume you know the basic rules of 8-ball pool, so I'll just describe how the rules have been implemented.
The game uses a simplified set of rules:

The game ends when the black ball is sunk.
If you sink it (legally) after sinking all your colored balls, you win. Otherwise you forfeit and your opponent wins.
The first ball sunk becomes that player's color.
A legal shot involves hitting a ball of your color first, and not sinking the wrong color, white ball or black ball (except when you're supposed to).
A free ball is awarded to the other player after a "foul". A free ball means you get a free second shot even if you don't sink a ball - as long as your shot was legal.

Hope you enjoy it.
If you're curious, you can see the development progress in this Twitter thread.

Still Movin'

Sun, 20 Sep 2020 04:27:06 UTC

[sfx]

I felt like transcribing a little tune I made in Caustic to Pico8.
Could use a bit more work (instruments, balancing, is pattern 14 off key?) but I'm happy enough with it.

Pool

Mon, 31 Aug 2020 11:55:35 UTC

Pool

by Mot

[Click to Play]

A work-in-progress 3D pool table simulation.

smap - sspr for maps

Wed, 22 Jul 2020 05:44:11 UTC

Not sure if anyone has posted a smap() yet, but it's reasonably straightforward to implement with tline, so here's mine.

Parameters are:
cx,cy,cw,ch Specify a region in the tile map. Measured in tiles.
sx,sy,sw,sh Region on the screen to map to.
flipx,flipy Whether to flip horizontally and/or vertically.
layers Layer flags. Same as for map().

You need to supply at least the c and s parameters.

function smap(cx,cy,cw,ch,sx,sy,sw,sh,flipx,flipy,layers)

 -- negative screen sizes
 if(sw<0)flipx=not flipx sx+=sw
 if(sh<0)flipy=not flipy sy+=sh
 sw,sh=abs(sw),abs(sh)

 -- delta
 local dx,dy=cw/sw,ch/sh

 -- apply flip
 if flipx then
  cx+=cw
  dx=-dx
 end
 if flipy then
  cy+=ch
  dy=-dy
 end

 -- clip
 if(sx<0)cx-=sx*dx sx=0
 if(sy<0)cy-=sy*dy sy=0
 if(sw>128)sw=128
 if(sh>128)sh=128

 -- render with tlines
 -- pick direction that results
 -- in fewest tline calls
 if sh<sw then
  -- horizontal lines
  for y=sy,sy+sh-1 do
   tline(sx,y,sx+sw-1,y,cx,cy,dx,0,layers)
   cy+=dy
  end
 else
  -- vertical lines
  for x=sx,sx+sw-1 do
   tline(x,sy,x,sy+sh-1,cx,cy,0,dy,layers)
   cx+=dx
  end   
 end
end

mot_smap

by Mot

[Click to Play]

Mot's Animation System

Sun, 12 Jul 2020 00:44:07 UTC

Mot's Animation System

Mot's Animation System

by Mot

[Click to Play]

Mot's Animation System is a visual editor for creating 2D animations.

You start by sequencing sprites and/or tilemaps together to create the basic components. Then combine them using timelines and key-frames to make animations. Or combine them again to make bigger, more complex animations.

Animations can trigger sounds and music, and call back into to your main program, e.g. to trigger game play events.

You could use it for:

Character animations, like run cycles
Larger multi-sprite animated characters
Cutscenes
Animated birthday cards

Animations can be loaded and played in your own carts (the loading and playback code is 1836 tokens). They can either be stored in Lua strings or loaded from a separate cart.

Disclaimer

This is all very much in Beta at the moment!. And some corners had to be cut to fit everything into the token limit. In particular the editor doesn't prevent you from shooting yourself in the foot by:

Creating self referencing animations (infinite recursion)
Creating animation files larger than 0x4300 bytes (about 17K) that won't save properly.

It lacks any sort of undo/redo logic, so if you use this, please take frequent backups of your saved animations.

And also, because the animation code is 1836 tokens and the animation data can be several kilobytes, it's not the best fit for every program.

Feel free to @ me if you need any help.

Overview and basic navigation

Creating animations

Importing graphics

Clearing animations

Saving and loading

Sprite animations

Sprite (and tile map) animations are the building blocks of all animated sequences.
Create a sprite animation by clicking the hamburger icon and selecting "NEW SPRITE ANIM".
To edit the animation, make sure the "Properties" section is expanded.

This UI allows you to define a sequence of frames, each of which displays a sprite.
The frames of the animation are displayed horizontally.

Click on a frame to select it.
If the animation has more than 5 frames, click the rightmost frame to scroll right and the leftmost to scroll left.

The "+" and "-" buttons add and delete frames respectively. Adding always creates a new frame at the end of the animation. Alternatively you can insert a new frame immediately after the selected frame by clicking "Ins".

The bottom of the editor shows the available sprites.

As in Pico-8 itself, sprites are grouped into 4 pages, with page number "tabs" at the top right.
To set the sprite for a particular frame, first click on the frame, and then click on the sprite in the sprites area.
The sprite for the current frame is displayed with a white rectangle.

You can also flip a frame horizontally or vertically by ticking "Flip X" and "Flip Y" respectively while the frame is selected.

Information and settings

Click the I icon on the "Properties" bar to display the sprite animation information and settings.

The Name allows you to give your animation a name, so you can find it more easily in the animation chooser.
You should try to choose short names in order to save space and so that they display properly in the animation list. (Ideally the editor would enforce this but it doesn't have enough spare tokens.)
The name is also used to fetch animations when rendering them in your own carts, so it is a good idea to give each animation a unique one.

The Type allows you to choose between a sprite or tile map based animation. (Tile map animations are described in the next section.)

FPS is the frames-per-second speed of the animation.
The value is set using a "number editor" box. Click and drag left/right to decrease/increase the value. Click and drag with the right mouse button to decrease/increase 10x faster.

Size is the horizontal (left box) and vertical (right box) size of each frame in sprites (or tile map tiles, if using a tile map animation).

The Origin defines the origin point of the animation. If the animation is rendered at coordinates X,Y then the origin is the part of the animation that will align with that position on screen. It is also the part of the animation that stays in the same place if you scale it larger or smaller. It's stored as two values ranging from 0 to 1, representing the fraction of the animation's width and height. So (0,0) sets the top left corner as the origin. (1,1) sets the bottom right corner. (0.5,0.5) sets the center.

Hover the mouse over the animation preview area to see the origin point (displayed as a gray cross)

Tile map animations

Timeline animations

This is the main feature of the animation system: the ability to create animations defined by key frames on a timeline.
Timeline animations are built from other animations, which are often sprite animations but can be other timeline animations as well. In this section we will refer to the other animations as "child animations".
The key frames specify which animations to play at which positions, plus other attributes like scale and flip flags. The animation system interpolates between these values based to create the animation.

Create a timeline animation by clicking the hamburger icon and selecting "NEW TIMELINE ANIM".

The timeline animation UI has two main areas.

Timelines and key frames

The left area contains the timelines and key frames.

The blue top line is for triggering events, like sound effects. This is covered later on.

The gray lines are timelines. Each one displays a single "child" animation. You can include more child animations by creating more timelines, using the buttons at the bottom.

The + and - buttons add and delete timelines respectively.
Use the up and down arrows to re-order the timelines. This controls the order that the child animations are drawn on screen. Timelines are drawn from top to bottom, so the topmost timeline's animation will appear behind the others, and the bottom timeline's animation will appear in front.

The purple dots on the timeline are key frames.
These can be added and deleted with the key frame buttons:

To insert a key frame, first click on the timeline at the position corresponding to the desired time. Then click +.
Note: If key frames are close together it may be difficult or impossible to click on the timeline between them without selecting one of the existing ones. The work around is to click + to create the new key frame anyway, then move it to the desired time.

To delete a key frame, click on it to select it, then click -.

Key frame properties

The right hand side displays the properties of the selected key frame.

Use the number box at the top to set the key frame time on the timeline (drag left/right with the mouse).
(I would have preferred to implement this as dragging the key frame along the timeline, but you know... tokens.)

The key frame properties are grouped into two tabs, which are accesed by clicking the icons to the right of the number box.

The first tab () has the following properties:

Anm selects which child animation to play. Click on the animation name to select it from the list. The child animation will play from this key frame onward. If "None" is selected, the key frame will not change the child animation.

Loop indicates whether the child animation will loop. If not it will stop once it has played to the end (or start if playing backwards).

T and Spd set the time and speed of the child animation. You can use these to start the child animation half way through, or play it in reverse, or double speed etc.
T and Spd are optional properties. This means you can choose not to specify them on a particular key frame, which is useful if you want to add a key frame to change a different property (say the on-screen position). Optional properties are controlled by a tick box on the right hand side which must be ticked in order to enter a value.
For T and Spd there is only one tick box, as you must either set them both, or none at all.

Visible indicates whether the child animation is visible from this key frame onward.

Click the icon to display the second tab.

It has the following properties:

Pos sets the position of the child animation as a X and Y coordinates, relative to the center of the current time line animation. If you render the animation in the center of the screen (like the editor does by default), then 0,0 will position the child animation there.
Pos is an optional property.
It is also an interpolated property. As the animation plays the position will be linearly interpolated between the values supplied on the key frames, so that the child animation moves smoothly from one position to the next.

Sca sets the horizontal and vertical scale factor of the child animation. A value of 1 means no scaling.
Sca is an optional interpolated property.

Flp flips the child animation horizontally and/or vertically from the current key frame onward.

Note: The Visible property is also available on this tab page. It is the same property as on the other page.

Information and settings

As with sprite animations you can click the I icon to display the information and settings.

Refer to the sprite animation section regarding the Name property.

The Duration allows you to specify the animation duration in seconds.

Storyboard animations

Animation events

Playing animations in your own carts

Loading and playback code

Loading from an external cart

Rendering an animation

Drawing text

Handling animation events

Embedding animations as Lua strings

Instead of loading animation data from an external cart, you can embed it directly into your Lua source as hexidecimal strings, to create a single self-contained cart.

For example, here's the demo animation embedded into a cart as a Lua string:

Mot's Animation System - Demo animation

by Mot

[Click to Play]

You will need enough free space to fit the strings in without exceeding the compressed size limit however.

To generate the Lua strings you must run Pico-8 in console mode.
Load your animation in the editor, then click the hamburger icon and select "EXPORT ANIMS".

The editor will write a table of hexidecimal strings to the console window. This looks like (on Windows anyway):

INFO: {
INFO:  "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",
INFO:  "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",
INFO:  "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",
INFO:  "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",
INFO:  "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",
INFO:  "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",
INFO:  "ff0c540100080700000b11ffffffff000064000c320002fdff00000c670002ffff00000c960002010000000cc80002ffffffff0c0e0102fcff0d000c720100080700000b2e0000efff000064000c3f00020100f1ff0c7100020000efff0ca00002fffff1ff0cc800020000efff0c0e0102edffe7ff0c7c01000c0232000373667802009600037366780200020774682d6d616b65c800010100000b2f0000000090019cff0400020774682d77616c6bc800010100000b2f00000000000064000c00020774722d626974735e01060200000b38e0ffe6ff000064000c640000080400000b330000fbff000064000c6400020000fbff0ca0000aefffeaff000000000c2c0100080400000b1600001300000064000c640002000013000ca000021e0009000cfa0000080400000b1800001500000064000c640002000015000ca0000209001c000c130100080700000f151500130056006400000064000c320002150019000c190002110016000c4b0002180016000c640002150013000ca000022b002d000ce10000080700000b15f0ff1900000064000c320002f0ff13000c190002f3ff16000c4b0002edff16000c640002f0ff19000ca00002ddff28000cc800000800020874722d626f6479321400010200000b1300000000000064000c0a0002000001000c00020774722d6c6f6e67e803060100000b3124000a000000000004",
INFO:  "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",
INFO:  "",
INFO:  "",
INFO:  "",
INFO:  "",
INFO:  "",
INFO:  "",
INFO:  "",
INFO:  "",
INFO:  ""}

You will need to copy it from the console window and remove the "INFO: " line prefixes. You can optionally remove any blank strings at the end of the table.

Then add it to your code, assigning it to a variable. For example:

animdata={
"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",
"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",
"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",
"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",
"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",
"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",
"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",
"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"
}

You can now use the following code to load the animations:

    -- load animation from animdata string
    local stream=readstrstream(animdata)
    anims=loadanims(stream)

    -- extract animation to play    
    anim=anims["intro"]

Playing Ramps with a racing wheel

Sat, 06 Jun 2020 01:58:54 UTC

OK, this may be a bit bonkers, but I figured out how to play Ramps with a racing wheel, with proper analogue steering and acceleration/braking.

It's a little involved and only works on Windows.

Mouse input

First, you need a version of Ramps (or whatever game you plan to play) edited to accept mouse input. Like this version:

Ramps - with mouse input

by Mot

[Click to Play]

WARNING: Attempting to drive with an actual mouse may cause high blood pressure and throwing things.
Also I've only tried this in PICO-8 itself - not sure if it works when running in a browser.

Joystick -> mouse

Next, you need a utility to convert game controller input to mouse movement.

I couldn't find one that did exactly what I needed, so I ended up making my own here.
Tip: If you try it out remember F12 toggles it on/off - as you can't use the mouse when it's enabled.

Race

So basically run the utility, run the mouse-input version of Ramps in PICO-8, switch to full-screen, and go :-)

Suggestion: UDP/IP networking

Fri, 05 Jun 2020 09:36:53 UTC

I'm a bit new here, so I don't know if adding network capability has previously been discussed (?)

But it feels to me some simple UDP send/receive instructions would add some cool functionality, without adding too much complexity.

Perhaps something like:

[write message to RAM]
poke4([ip-locn],ip)
poke2([port-locn],port)
send(0x4300,length)

Where [ip-locn],[port-locn] would be some special reserved locations for IP address and port.
UDP packets are usually small. I've seen <=512 bytes recommended in places, which easily fits into the user RAM address range.
And an IPV4 address would fit in a number variable, and would be adequate for LAN play.

Receive could be:

length=recv(0x4300,maxlength)
[read message from RAM]

Returning 0 if nothing is waiting.
It could also populate [ip-locn] with the return IP address so that replying would be straightforward.

Perhaps [port-locn] could be pre-populated with a default port number (0x1C08 ?).

Any thoughts?
Am I trying to make it simpler than is actually possible? (I haven't done socket programming in a while, so I forget what's necessary to get UDP/IP working).

Ramps

Sun, 31 May 2020 05:23:50 UTC

Ramps

Ramps

by Mot

[Click to Play]

This is Ramps! A 3D racer inspired by Powerdrift, Stunt Car Racer, Hard Drivin'.

Choose from 8 varied race tracks, and overtake the other drivers in 5 laps to win.
As well as racing you'll need to navigate jumps, roller-coaster like ramps and occasionally even drive upside down.

Includes 3 difficulty levels, plus a practice mode for getting the feel of the tracks.

This all started as an experiment to see how well Pico-8 could render a Powerdrift-like scaled sprite racetrack (pretty well, as it turns out). Then it was about trying to implement a driving model that could handle the ramps, jumps and loops. And finally wrapping it up into a somewhat finished game.

Like with Loose Gravel, I would have liked to add a championship mode, but there just aren't enough tokens :-)

Big thanks to everybody who gave advice and feedback. Particularly @freds72 who even went as far as digging into the code and making some performance optimisations (~20% CPU improvement!).

Tips

Z = Accelerate
X = Brake
Left/Right to steer

You don't have to wait to be automatically respawned after you fall of the track, select "Respawn" in the pause menu to get back into the race faster.

The green and red lines on the speedometer are recommended minimum and maximum speeds.
The green line (minimum speed) is particularly important for clearing jumps (and occasionally getting up steep hills), so make sure to keep your speed above it.
The red line (maximum speed) is to prevent you from sliding out on sharp corners or overshooting the jumps. Typically this is just a suggested speed. Depending on your racing line, driving style etc you may be able to go faster.

Enjoy,
-Mot

Update: Other cars' speeds now vary randomly throughout the race
Update 2: Can knock other cars sideways a bit & they don't knock you sideways as much. Round road sprite corners a bit.
Update 3: Fix game crashes in AI code when road is blocked.

Instant 3D plus!

Sun, 17 May 2020 00:58:30 UTC

Instant 3D plus!

Instant 3D! was a random idea, quickly thrown together to see if it was possible. But after seeing the cool things people can do with it, I wanted to clean it up properly, and also present some of the internal functions more cleanly.

Making the 3D functions more accessible means:

You can often get your game working correctly in 3D even if the Instant 3D "magic" doesn't work correctly, by calling the 3D spr/map functions directly with the right parameters.
You can do things that the original Instant 3D can't do, like having objects that hover into the air.

I've added a little tutorial of converting a 2D game to 3D to illustrate how this works, at the bottom of this post.

Obviously this "snippet" is still very limited, compared to a general purpose 3D library say. You can't use it to create an FPS or a flight simulator. But I think it's a lot easier to use - start with a 2D game, drop it in, and fix up the bits that don't come out right. And you can still do some cool looking 3D stuff with it.

Here's the updated snippet:

-- instant 3d+!

do
 -- parameters
 p3d={
  vanish={x=64,y=0}, -- vanishing pt
  d=128,             -- screen dist in pixels
  near=1,            -- near plane z
  camyoff=32,        -- added to cam y pos
  camheight=32       -- camera height
 }

 -- save 2d versions
 map2d,spr2d,sspr2d,pset2d,camera2d=map,spr,sspr,pset,camera

 -- 3d camera position
 local cam={x=0,y=0,z=0}

 -- is 3d mode enabled?
 is3d=false

 -- helper functions

 -- screen to camera space
 local function s2c(x,y,z)
  return x-cam.x,y-cam.y,z-cam.z
 end

 -- perspective projection
 local function proj(x,y,z)
  if -y>=p3d.near then
   local scale=p3d.d/-y
   return x*scale+p3d.vanish.x,-z*scale+p3d.vanish.y,scale
  end
 end

 -- screen to projected
 local function s2p(x,y,z)
  local x,y,z=s2c(x,y,z)
  return proj(x,y,z)
 end

 -- 3d drawing fns
 function sspr3d(sx,sy,sw,sh,x,y,z,w,h,fx,fy)
  w=w or sw
  h=h or sh
  local px,py,scale=s2p(x,y,z)

  if(not scale)return
  local pw,ph=w*scale,h*scale

  -- sub pixel stuff
  local x0,x1=flr(px),flr(px+pw)
  local y0,y1=flr(py),flr(py+ph)
  sspr2d(sx,sy,sw,sh,x0,y0,x1-x0,y1-y0,fx,fy)
 end

 spr3d=function(n,x,y,z,w,h,fx,fy)
  if(not z)return
  -- convert to equivalent sspr() call
  w=(w or 1)*8
  h=(h or 1)*8
  local sx,sy=flr(n%16)*8,flr(n/16)*8
  sspr3d(sx,sy,w,h,x,y,z,w,h,fx,fy)
 end 

 function map3d(cx,cy,x,y,z,w,h,lyr)
  if(not h)return

  -- near/far corners
  local fx,fy,fz=s2c(x,y,z)
  local nx,ny,nz=s2c(x,y+h*8,z)

  -- clip
  ny=min(ny,-p3d.near)
  if(fy>=ny)return

  -- project
  local npx,npy,nscale=proj(nx,ny,nz)
  local fpx,fpy,fscale=proj(fx,fy,fz)

  if npy<fpy then
   local tx,ty,ts=npx,npy,nscale
   npx,npy,nscale=fpx,fpy,fscale
   fpx,fpy,fscale=tx,ty,ts
  end

  -- clamp
  npy=min(npy,128)
  fpy=max(fpy,0)

  -- rasterise
  local py=flr(npy)
  while py>=fpy do

   -- floor plane intercept
   local g=(py-p3d.vanish.y)/p3d.d
   local d=-nz/g  

   -- map coords
   local mx,my=cx,(-fy-d)/8+cy

   -- project to get left/right
   local lpx,lpy,lscale=proj(nx,-d,nz)
   local rpx,rpy,rscale=proj(nx+w*8,-d,nz)

   -- delta x
   local dx=w/(rpx-lpx)

   -- sub-pixel correction
   local l,r=flr(lpx+0.5)+1,flr(rpx+0.5)
   mx+=(l-lpx)*dx

   -- render
   tline(l,py,r,py,mx,my,dx,0,lyr)

   py-=1
  end 
 end 

 function map3dupright(cx,cy,x,y,z,w,h,lyr)
  if(not h)return
  local px,py,scale=s2p(x,y,z)
  if(not scale)return

  local pw,ph=w*8*scale,h*8*scale

  -- texture step
  local dx,dy=w/pw,h/ph
  local mx,my=cx+0.0625,cy+0.0625

  -- sub pixel stuff
  local x0,x1=flr(px),flr(px+pw)
  local y0,y1=flr(py),flr(py+ph)
  mx+=(x0-px)*dx
  my+=(y0-py)*dy  

  if(x0>=x1 or y0>=y1)return

  for y=y0,y1-1 do
   tline(x0,y,x1,y,mx,my,dx,0,lyr)
   my+=dy
  end
 end

 function camera3d(x,y,z)
  cam.x,cam.y,cam.z=x,y,z
 end

 -- "instant 3d" wrapper functions
 local function icamera(x,y)
  cam.x=(x or 0)+64
  cam.y=(y or 0)+128+p3d.camyoff
  cam.z=p3d.camheight
 end

 local function isspr(sx,sy,sw,sh,x,y,w,h,fx,fy)
  z=h or sh
  y+=z
  sspr3d(sx,sy,sw,sh,x,y,z,w,h,fx,fy)
 end

 local function ispr(n,x,y,w,h,fx,fy)
  z=(h or 1)*8
  y+=z
  spr3d(n,x,y,z,w,h,fx,fy)
 end

 local function imap(cx,cy,x,y,w,h,lyr)
  cx=cx or 0
  cy=cy or 0
  x=x or 0
  y=y or 0
  w=w or 128
  h=h or 64
  map3d(cx,cy,x,y,0,w,h,lyr)
 end

 function go3d()
  camera,sspr,spr,map=icamera,isspr,ispr,imap
  camera2d()
  is3d=true
 end

 function go2d()
  map,spr,sspr,pset,camera=map2d,spr2d,sspr2d,pset2d,camera2d
  is3d=false
 end

 -- defaults
 icamera()
end

-- enable 3d mode
go3d()
menuitem(3,"3d",go3d)
menuitem(2,"2d",go2d)

As before, to use it, just copy it into your 2D program. It should behave exactly the same.
There's one new feature, in that you can toggle between 2D and 3D in the Pico-8 menu.

You can also do it in code using

go2d()

and

go3d()

which might be useful for 2D title screens etc.

Taking it further

The basics are the same as before, but you can now - with a little bit of work - take your games a bit further by making use of explicit 2D and 3D commands, rather than leaving it up to the snippet to guess your intent.

To illustrate this, I made a little 2D cart to convert into 3D.

instant3dplus

by Mot

[Click to Play]

This is a simple little game where you're a bouncing ball that collects coins. It's not finished, but is enough to demonstrate the process. The game is already a little bit 3D in that the ball and coins also have a height, and objects can move in front and behind each other, so it has to sort their positions and draw them from back to front.

Dropping the snippet into this program has... mixed results.

As you can see, it's kind of 3D, but it has some issues:

The ball doesn't always bounce straight up. In fact if you look closely it's actually staying on the ground and just bounces away and back again.
The coins aren't raised up properly either.
The metallic struts are flat on the ground, rather than standing up.
Likewise the gratings on top are also flat on the ground.
The 3 lives are displayed in the wrong place.

Obviously the snippet doesn't know exactly what we're trying to achieve, but fortunately we can help it out.

With a little bit of work we can make it look like this:

3D functions

We can fix up the ball using an explicit 3D function. The snippet provides explicit 3D functions spr3d, sspr3d and map3d. They have the same parameters as the standard functions, except there's a Z parameter immediately after the X and Y screen parameters.

They use a 3D coordinate system where:

The X axis is to the right
The Y axis is out of the screen (towards you)
The Z axis is up

This keeps X and Y consistent with the "Instant 3D" logic, where instead of moving up the screen as Y decreases, objects move away from you. The new Z parameter allows us to also specify the height.

The ball drawing code looks like this:

  elseif thing.typ=="player" then
   shadowcols()
   sspr(0,32,
      8,8,
     thing.x-4,thing.y-1,
     8,4)
   pal()
   spr(64+thing.frame%9,
       thing.x-4,
       thing.y-thing.height-8)   
  end

The sspr() call draws the shadow, which looks correct already, so it doesn't need to change.
The spr() call draws the ball, based on the thing.x,-.y and -.height variables. The game stores the position of bottom center of the ball, so it has to subtract 4 and 8 to get the top left corner for spr().
We can change it to an explicit 3D call as follows:

   spr3d(64+thing.frame%9,
       thing.x-4,
       thing.y,
       thing.height+8)

We're still specifying the top left corner, but now it's in 3D.

The coin code is similar:

  if thing.typ=="coin" then
   shadowcols()
   sspr(0,40,
        8,8,
        thing.x-4,thing.y-1,
        8,4)
   pal()
   spr(80,
       thing.x-4,thing.y-thing.height-8)

Once again we change the spr call to an spr3d:

   spr3d(80,
       thing.x-4,
       thing.y,
       thing.height+8)

With 3D positions supplied, the ball and coins now bounce/float above the ground properly.

Upright maps

Next we can address the red metal structs. Currently they are lying flat on the ground instead of standing up straight.
The "instant 3D" snippet assumes everything drawn with "spr"/"sspr" is upright, and everything drawn with "map" is flat on the ground. However the struts are drawn using map(), so that they can be composed of multiple sprites.
So we need to tell the game to draw them upright.

map3d won't help in this case. We can use it to draw them higher up, but they will still be lying flat, not standing upright. So to help with this the snippet provides an alternative "map3dupright" function.

The strut drawing code is:

  elseif thing.typ=="strut" then
   map(127,0,
       thing.x,thing.y-40,
       1,5)

We can change the map call to a map3dupright like this:

   map3dupright(127,0,
       thing.x,
       thing.y,
       40,
       1,5)

Once again it has the same parameters as "map", except there's a Z parameter immediately after the X and Y.
The struts are 40 pixels high, so we set the Z (i.e. the height) to 40, to specify the top left corner position.

With this in place, the struts now stand upright.

instant3dplus

by Mot

[Click to Play]

3D parameters

Now that objects are above the ground they often disappear above the top of the screen.
This is due to the camera height, and the "vanishing point" of the 3D projection, which is currently set to the top of the screen.

We can easily fix this by changing the 3D parameters.
The default parameters are in the snippet:

 -- parameters
 p3d={
  vanish={x=64,y=0}, -- vanishing pt
  d=128,             -- screen dist in pixels
  near=1,            -- near plane z
  camyoff=32,        -- added to cam y pos
  camheight=32       -- camera height
 }

We can move the vanishing point into the center of the screen by adding a line to the _init function:

 p3d.vanish.y=64

Moving the vanishing point is like rotating the camera upwards slightly. Now we can easily see everything.
In fact we can even move the camera down a little and nearer to the ball:

 p3d.camheight=20
 p3d.camyoff=20

3D map coordinates

Now we'll fix the metal grates. These are supposed to sit on top of the struts.
The grates are rendered as a single map, much like the floor. We need to tell the game to draw that map above the ground.

This time map3d is the correct function to use.

The existing code looks like this.

 -- roof map
 map(32,0,0,-40,16,64)

The 3D code is quite similar:

 -- roof map
 map3d(32,0,0,0,40,16,64)

Once again we have a new Z parameter after the X and Y, which we set to 40 to move it up into the air.

In the 2D version the grates are drawn last, as because they are above everything. However in the 3D version they actually need to be drawn before the ball, coins and struts to get the correct ordering.
So the line should be moved up immediately after the "map" call that draws the floor.

2D drawing

The last thing to fix is the lives display. Lives are displayed as 3 balls, but they are drawn in the wrong place, because the "instant 3D" logic is trying to position them in 3D.

In this case we really just want to draw them in 2D.

Fortunately the snippet saves the original 2D functions as "spr2d", "sspr2d" and "map2d", so we can call them directly if we need to.

The life drawing code looks like this:

-- overlay
camera()
fancyprint("lives",4,4,12)
for i=1,player.lives do
 spr(64,25+(i-1)*9,2)
end

Simply change the "spr" to "spr2d" and we're done.

2D/3D code

Adding the various 3D calls makes the game look correct in 3D now. But if you switch it back to 2D (via the pause menu) it now looks broken.

One solution is to simply remove the "menuitem" calls from the snippet and disable mode switching. This is perfectly valid if the game is only supposed to be 3D.

But if you really do want the 2D option, it is still possible. The snippet includes a variable "is3d" which is set to true in 3D mode. Before calling any 3D function, check it to ensure you are actually in 3D mode. If not, perform the original 2D call instead. For example:

if is3d then
 spr3d(64+thing.frame%9,
  thing.x-4,
  thing.y,
  thing.height+8)
else
 spr(64+thing.frame%9,
  thing.x-4,
  thing.y-thing.height-8)    
end

Here's the final cart with 2D and 3D mode support.

instant3dplus

by Mot

[Click to Play]

Other bits

That's the gist of how to use it. There are a couple of functions I've missed, like camera3d (sets the 3D camera position explicitly, rather than inferring it from the 2D position and height/y-offset parameters), and a pset3d/pset2d which should do what you'd expect.

Feel free to throw me any questions you have.

-Mot

** Update 1: Fix spr() when drawing larger than 1x1 sprites

Object literals and token counting

Thu, 14 May 2020 02:15:29 UTC

I often find myself declaring a lot of arrays/object literals that are essentially just data. No computation involved.
For example:

-- background types
bg_tree={
 tex={
  {sx=0,sy=64,sw=32,sh=32}
 }, 
 w=2,h=2,
 spacing=2
}
bg_lamp={
 tex={
  {sx=0,sy=32,sw=16,sh=8}
 }, 
 w=.5,h=.25,
 spacing=2,
 trans=12
}

It's a useful way to create flexible, extendable systems.

Unfortunately it quickly chews through the token count.

So I was wondering what people's views were of changing the token counting rules around such object literals? - say 1 token per object literal.

They would have to be restricted in order to qualify for a reduced token count, i.e. data only, no computation, functions etc, similar to how JSON is a restricted subset of JavaScript.
The compiler could either detect this automatically, or possibly a new "data only literal" syntax could be introduced.

I feel like this probably aligns with the PICO-8 principals, as it's arguably data rather than code, and you still have the compressed size limit. It seems like a much cleaner solution than the string shredding/JSON parsing workarounds that are currently used.

Variable inspector

Sat, 09 May 2020 02:37:20 UTC

Variable inspector window

Debugging carts with "print" and "printh" can be cumbersome, so I made a little snippet to help.
It adds a little window where you can view variables and drill down into them.

To use it, add the snippet somewhere into your program:

dbg=(function()

    poke(0x5f2d, 1)

    -- watched variables
    local vars,emp={},true

    -- window state
    local exp=false

    -- text cursor
    local x,y

    -- scrollbar
    local sy=0 
    local sdrag

    -- mouse state
    local mx,my,mb,pb,click,mw

    function clicked(x,y,w,h)
        return click and mx>=x and mx<x+w and my>=y and my<y+h
    end

    function butn(txt,x,y,c)
        print(txt,x,y,c)
        return clicked(x,y,4,6)
    end

    -- convert value into something easier to traverse and inspect
    function inspect(v,d)
        d=d or 0
        local t=type(v)  
        if t=="table" then
            if(d>5)return "[table]"
            local props={}
            for key,val in pairs(v) do
                props[key]=inspect(val,d+1)
            end
            return {
                expand=false,
                props=props
            }
        elseif t=="string" then
            return chr(34)..v..chr(34)
        elseif t=="boolean" then
            return v and "true" or "false"
        elseif t=="nil" or t=="function" or t=="thread" then
            return "["..t.."]"
        else 
            return ""..v
        end
    end

    function drawvar(var,name)
        if type(var)=="string" then     
            print(name..":",x+4,y,6)
            print(var,x+#(""..name)*4+8,y,7)
            y+=6
        else

            -- expand button
            if(butn(var.expand and "-" or "+",x,y,7))var.expand=not var.expand

            -- name
            print(name,x+4,y,12) y+=6

            -- content
            if var.expand then
                x+=4
                for key,val in pairs(var.props) do
                    drawvar(val,key)       
                end
                x-=4
            end
        end
    end

    function copyuistate(src,dst)
        if type(src)=="table" and type(dst)=="table" then
            dst.expand=src.expand
            for key,val in pairs(src.props) do
                copyuistate(val,dst.props[key])
            end
        end
    end

    function watch(var,name)
        name=name or "[var]"
        local p,i=vars[name],inspect(var)
        if(p)copyuistate(p,i)
        vars[name]=i
        emp=false
    end 

    function clear()
        vars,emp={},true
    end 

    function draw(dx,dy,w,h)
        dx=dx or 0
        dy=dy or 48
        w=w or 128-dx
        h=h or 128-dy

        -- collapsed mode
        if not exp then
            dx+=w-10
            w,h=10,5
        end

        -- window
        clip(dx,dy,w,h)
        rectfill(0,0,128,128,1)
        x=dx+2 y=dy+2-sy

        -- read mouse
        mx,my,mw=stat(32),stat(33),stat(36)
        mb=band(stat(34),1)~=0
        click=mb and not pb and mx>=dx and mx<dx+w and my>=dy and my<dy+h
        pb=mb

        if exp then     

            -- variables                            
            for k,v in pairs(vars) do
                drawvar(v,k)
            end

            -- scrollbar
            local sh=y+sy-dy
            if sh>h then
                local sx=dx+w-4
                local by=sy/sh*h+dy
                local bh=h/sh*h
                rectfill(sx,dy,dx+w,dy+h-1,5)
                rectfill(sx,by,dx+w,by+bh-1,sdrag and 12 or 6)
                rect(sx,by,dx+w-1,by+bh-1,13)
                if click and mx>=sx then
                    if my<by then
                        sy-=h
                    elseif my>by+bh then
                        sy+=h
                    else
                        sdrag=by-my
                    end             
                end
                if sdrag then 
                    sy=(my+sdrag-dy)*sh/h
                else
                    sy-=mw*8
                end
                if(sy<0)sy=0
                if(sy+h>sh)sy=sh-h
                if(not mb)sdrag=nil
            else
                sy=0
            end

            -- clear btn
            if(butn("x",dx+w-15,dy,14))clear()
        end

        -- expand/collapse btn
        if(butn(exp and "-" or "+",dx+w-10,dy,14))exp=not exp

        -- draw mouse ptr
        clip()          
        line(mx,my,mx,my+2,8)
        color(7) 
    end

    function show()
        exp=true
        while exp do
            draw()
            flip()
        end
    end

    function prnt(v,name)
        watch(v,name)
        show()
    end

    return{
        watch=watch,
        clear=clear,
        empty=function()
            return emp
        end,
        expand=function(val)
            if(val~=nil)exp=val
            return exp
        end,
        draw=draw,
        show=show,
        print=prnt
    }
end)()

There are a few different ways to use it.

Global variables

You can view global variables when your program is paused by typing:

dbg.print(myvariable)

The window will popup and run until you click "-" at the top right to exit it.
Note: If you press "Esc" to exit the inspection window, and try to resume your game with "resume", it will resume the popup window instead! To avoid this, use the "-" button.

Local variables

To view a local variable inside a function you need to add code to that function to capture it.

dbg.watch(myvariable,"my variable")

This will capture it's value and add it to your variable list. The second parameter is the name. You can add multiple variables so long as they all have different names. Calling dbg.watch again with the same name causes it to replace the previous value.

To view your captured variables, pause your program by pressing Esc, and type:

dbg.show()

Be aware that the variable inspector window shows the variable's value at the time dbg.watch() was executed. If the variable has been changed since, the changes will not show in the inspector. (This is deliberate.)

Displaying variables while the program is running

If you want to run the inspector window directly in your program, add:

dbg.draw()

to your _draw() function.

You can optionally specify the window position (x,y,width,height), e.g.

dbg.draw(64,0,64,48)

By default the window displays collapsed, until you click the "+" button.

Remember you still need to capture variables with "dbg.watch()", otherwise the window will be empty.

Pausing while the inspector is open

The game will continue running while the inspector window is open.
If you'd prefer it to pause the game, you can add:

if(dbg.expand())return

to the top of your "_update" function.

dbg.expand()

returns true when the window is expanded or false when collapsed.
You can also force it open with:

dbg.expand(true)

or collapse it with:

dbg.expand(false)

For example, to invoke the editor from the Pico-8 built in menu:

menuitem(1,"debug",function()dbg.expand(true)end)

Performance considerations

This snippet works by traversing your variables and building a "snapshot" tree structure. If you capture large variables every frame you might get some slow down, due to the traversal and possibly the Lua garbage collector cleaning up snapshots from previous frames. So make sure to remove your dbg.watch() calls when you want your program to run fast again.

Mot [Lexaloffle Blog Feed]

Feature suggestion - Enhanced controller input

Variable inspector (debugging)

Feature request: Metronome in sfx editor

Trial of the Sorcerer

Input

Tips

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UI

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smap - sspr for maps

Mot's Animation System

Mot's Animation System

Disclaimer

Overview and basic navigation

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Menus

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Creating animations

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Information and settings

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Playing animations in your own carts

Loading and playback code

Loading from an external cart

Rendering an animation

Drawing text

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After frame rendering

Embedding animations as Lua strings

Playing Ramps with a racing wheel

Mouse input

Joystick -> mouse

Race

Suggestion: UDP/IP networking

Ramps

Ramps

Tips

Instant 3D plus!

Instant 3D plus!

Taking it further

3D functions

Upright maps

3D parameters

3D map coordinates

2D drawing

2D/3D code

Other bits

Object literals and token counting

Variable inspector

Variable inspector window

Global variables

Local variables

Displaying variables while the program is running

Pausing while the inspector is open

Performance considerations