The PNG Pipeline

The first utility I wanted to build was a set of tools to convert any appropriately scaled-down PNG to be viewable directly in PC-60 BASIC.

I’ve used Python for the scripts that convert and generate the necessary data plus the 3rd party tool txt2bas.exe available online.

I was able to draw directly using the PC-60 palette using this palette profile I made for Paint.Net, then convert the PNG to a BASIC program for display.

The Benchmark

Didn’t have much time last week to finish working on a PNG-to-PC-6001 compressed bitmaps pipeline (next blog post) but I saw this video on youtube and thought this would make a great quick test of performance level for 80s computers! (mostly z80-based) to understand how they compare to each other.

I used the exact same program in the video:

10 FOR I=2 to 1000
20 K=INT(SQR(I))+1
30 FOR J=2 TO K
40 K1=I/J
50 K2=INT(K1)
60 IF K1=K2 THEN GOTO 90
70 NEXT J
80 PRINT I
90 NEXT I

This is mostly a test of the embedded BASIC interpreter rather than the processing power in these computers. I’m sure running compiled assembly code should deliver similar performance since all Z80 PCs are running at the same frequency.

Toolbox

The most important tool you need is a good emulator! Here are two excellent emulators with all necessary settings and files as well as a collection of PC-6001 games and demos for testing here:

• PC6001VW3: Full featured accurate emulator with a built-in debugger and many useful tools.
• iP6+: Light-weight emulator, great for quick testing.

Of course both emulators use Japanese ROMs, maybe in the future if I had access to a Warka ROM chip I could dump it and use that instead. The main difference is language, the Warka had an Arabic font built-in while the PC-6001 had Japanese fonts.

A long time ago when I was 11 and lived in Basra south of Iraq my parents thought it was a good idea to get me into computers and programming. I’ve always been a gamer since birth pretty much so it fit nicely.

The year was around 1996 and Iraq was way behind the world in computing due to unfortunate circumstances.

During the 80s however, Iraq was a regional pioneer in digital technology despite the devastating 8 years war with Iran, this growth was led by a national group of companies collectively named: Electronics Industry Company or EIC (شركة الصناعات الوطنية).

This is mostly going to be an information dump. I’ve been researching this for a month or two and the amount of stuff happening out there these last few months is just mind-blowing. Progress achieved from mid 2016 till time of writing this post (end of 2017) wasn’t only impressive but paradigm shifting.

First off, this is not about robots or androids or skynet. This is about artificial intelligence that runs on software and hardware designed to resemble biological intelligence. Everytime you swipe through Snapchat’s filters, you’re running a variation of that intelligence that attempts to find where your face is, match its orientation and scale to superimpose dog-ears or makeup.

I’m always working on something but don’t usually write about it. Since this week I updated my Jekyll blog so it works again as well as a few other weby things.. here is a compilation of what I was focusing on last week.

Static Blog/Web Generators

So this blog is powered by Jekyll which is a static blog/web generator that is pretty straight forward and supported by github directly as it was actually developed by github developers. The code for this website is in a normal public github repository. Using some special flags github rebuilds the website using jekyll every time I perform a new push with some changes.

A word of warning: this is a very long post about nothing in particular, I just felt like writing something :)

Past Considerations

I’ve been mainly using Windows for most of my programming career starting with Windows XP. I also work on linux whenever possible but most game projects treat linux as a secondary platform to port to (if at all targeted) rather than a main platform of development so I always felt like my experience on POSIX-compliant operating systems was relatively lacking as a user and a developer due to less exposure despite a modest history of linux and open source community involvement.

Just a quick screenshot showing some progress:


I implemented a common shader library and 3 basic effects using shader model 3 and fx effects:

• Basic per-vertex lighting: ambient, diffuse, specular, and emissive lighting. Shader supports 1 point light and/or 1 directional light per-pass.
• Basic per-pixel: same lighting equation but calculated per-pixel.
• Wireframe shader for gizmo rendering.

I also added basic camera and lights scene node objects.

Today I worked on the mesh parsing section of Zenithia and got a basic scene-graph up and running that supports multiple nodes, meshes, subsets, and basic materials. The screenshot below is from a collada model exported from blender that includes multiple nodes, meshes, subsets, and textures.

The model is rendered using a simple fx effect and all resources are loaded in the resource thread and swapped to the scene at runtime by the resource system.

Dealing with resources is one of the most complex aspects of a graphics/game framework, this is due to the fact that:

• there are a lot of resource types each could be using a different format.
• some resources involve complex relatively expensive parsing.
• some resource types need to be associated directly with a device object, and that introduces several caveats.

I wanted Zenithia to be a streaming-based framework, so basically what I do is load all data from disk without blocking the main thread.