Comment by tony | Hacker News Reader

Comment by tony | Hacker News Reader

If you are interested in the code behind bitmaps / pixel sprites that scale, pan, and zoom, I'd like to offer up OpenTTD.

https://www.openttd.org/

Specifically, Viewports, Blitter and Resize handling:

Viewport: https://github.com/OpenTTD/OpenTTD/blob/1.9.3/src/viewport.c...

Window resizing: https://github.com/OpenTTD/OpenTTD/blob/1.9.3/src/video/sdl_...

Zoom: https://github.com/OpenTTD/OpenTTD/blob/1.9.3/src/main_gui.c...

OpenTTD is interesting because it can have multiple "cameras" following objects on the screen. e.g. a viewport can be opened to follow a bus or train, zoomed in, while the main viewport is zoomed out.

Also I'd like to recommend aseprite (https://www.aseprite.org/), which has even cleaner code with zoom / panning / etc. The GUI itself is also pixel art: https://github.com/aseprite/aseprite/blob/v1.2.16.3/src/rend..., https://github.com/aseprite/aseprite/blob/v1.2.16.3/src/app/..., https://github.com/aseprite/aseprite/blob/v1.2.16.3/src/ui/v...

Or, if you want to loose a few months of your life, instead of looking at the code, just play the game. After 5 years, I am still improving the urban rail system of my metropolis.

> OpenTTD is interesting because it can have multiple "cameras" following objects on the screen. e.g. a viewport can be opened to follow a bus or train, zoomed in, while the main viewport is zoomed out.

I have used OpenTTD, so I don’t know the specifics, but from how you describe it, RollerCoaster Tycoon has/had this too. The main viewport would show what you’re zoomed in/out on, while you could have a screen open following a roller coaster train.

That's because Rollercoaster tycoon and Transport tycoon (of which Openttd is a remake) were made by the same programmer: Chris Sawyer.

> were made by the same programmer: Chris Sawyer.

... in x86 assembly language:

> https://en.wikipedia.org/w/index.php?title=RollerCoaster_Tyc...

> https://en.wikipedia.org/w/index.php?title=RollerCoaster_Tyc...

Wow! That game was developed by a single guy? In assembly?? That's incredible!

How does one even begin to manage a project this large and complex in assembly?

It’s an achievement, for sure. Maybe it’s just me, but there’s not really anything special about assembly. It does require a different way of thinking than higher level languages, but if you’re used to it, why not continue using what you’re good at?

Does anything similar exist for creating responsive ascii art?

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