jimmi [Lexaloffle Blog Feed]

Particle Fluid Demo

Sat, 17 Jul 2021 11:14:25 UTC

Demo of particle fluids.
Click, drag and release mouse to push particles around.

pic0-el8 trader

Mon, 03 Aug 2020 09:15:20 UTC

pic0_el8_trader

by jimmi

[Click to Play]

This is a pico-8 implementation of the trading system from Elite. This allows you to travel the galaxy and buy/sell goods.

Navigation between screens is done using the pause menu. If you can jump to a new planet a prompt will be displayed. Currently this is restricted to a single galaxy.

Intro screen - the option to load a previous game only shows if you have a previous save. Games are saved automatically when docking in a new station.

Commander status - shows all information about the current game, including cash, fuel, inventory and equipment.

Local system - use the arrow keys and o button to select a planet as a hyperspace destination. The yellow ring shows the current planet. The red ring shows the current destination.

Galaxy - shows the current galaxy, hyperspace destinations can be selected like in the local system.

Planet information - shows information about a hyperspace destination. This information is shown when you select a new destination from the system or galaxy screens.

Market - up/down arrows select goods, left/right sell and buy goods.

Equipment - up/down arrows select equipment, o button purchases equipment. If replacing a laser, the cost of the replaced laser is refunded. Most equipment is unused in this game, only fuel has a function.

3d Environment/Material Mapping

Tue, 21 Apr 2020 11:13:28 UTC

bunny_envmap

by jimmi

[Click to Play]

This is a demo using tline to perform 3d environment/material mapping in pico8.

Both the object and the texture are stored in sprite memory.

Pico Physics Demos

Mon, 09 Dec 2019 19:29:30 UTC

pico_physics

by jimmi

[Click to Play]

Z/X - previous/next demo
up - turn on/off aabb tree
down - reset simulation

Several physics demos I've written in pico-8. These follow from the work of Erin Catto (see http://twvideo01.ubm-us.net/o1/vault/gdc09/slides/04-GDC09_Catto_Erin_Solver.pdf)

The solver solves both inequality constraints (e.g. collisions) and equality constraints (e.g. joints).

I've reduced the framerate for web down to 30fps, but it works well at 60fps (in face the higher framerate is better for the solver).

Still issues to solve, e.g. jitter on resting contact, so I probably need to do a rewrite at some point.

update
I've added a couple more demos including mass-spring-damper systems

3D Lighting + Texture Mapping Demo

Sat, 26 Oct 2019 15:17:04 UTC

Demo of 3D lighting and texture mapping.

feisar

by jimmi

[Click to Play]

updated version without flicker:

feisar

by jimmi

[Click to Play]

up/down/left/right - orient the model
z - toggle lighting/texture-mapping

3D Rendering Demo

Sat, 07 Sep 2019 09:55:25 UTC

threed 1.2

by jimmi

[Click to Play]

This cart demos some work I've been doing on 3d rendering - including both flat shading and per-vertex shading.

up/down/left/right - orient
z - change colour palette
x - change render mode

The per-vertex shading is experimental code using sspr for render scanlines from the spritesheet. There are some issues with this - lighting discontinuities possibly fixed-point related.

I wouldn't be surprised if there are some bugs, and I need to update the transform code and add in viewport culling.

Comments/suggestions welcome.

update:

increased rendering performance (radix sort + pipeline changes)
fixed per-vertex shading

waves

Mon, 02 Sep 2019 10:20:09 UTC

A simple demo of 2.5D waves.

waves

by jimmi

[Click to Play]