2024-07-24 Gridmapper Local

I was wondering whether I should get back to Gridmapper, but not using Javascript and the web but using Common Lisp. I spent some time on this two years ago. Of course by now I have forgotten everything – like how to build it!

two years ago

This is the Makefile that seems to work, given that I have both `gridmapper.asd` and `gridmapper.lisp` in the current directory.

SHELL = /bin/sh
LISP ?= sbcl --non-interactive
PWD   = $(shell pwd)

build:
	$(LISP) --eval '(asdf:load-asd "$(PWD)/gridmapper.asd")' \
	--eval '(asdf:load-system :gridmapper)' \
	--eval '(asdf:make :gridmapper)' \
	--eval '(quit)'

Surely there is a better way to do this?

If I replace `(asdf:load-system :gridmapper)` with `(ql:quickload :gridmapper)` it no longer gives me a warning about `cl-colors.asd` which I don't know anything about. I guess the warning is still preferable because it means no dependency on Quicklisp? I have no idea. The README comes with a long explanation of what to install and how to do it, in order to build Gridmapper – including the use of Quicklisp.

README

The hairiest part is that I need access to a function that isn't exported from the Cairo package. So now I'm accessing the private function (using two colons):

;; Sorry for the ugly hack… cairo_format_stride_for_width is not exported.
(cairo::cairo_format_stride_for_width :CAIRO_FORMAT_ARGB32 (surface-width surface)))))

Two years ago, there was a different solution to this that apparently no longer works. 🤷

​#Common Lisp

• *2024-07-25**. Another option would be to switch to a different binding of the SDL2 library, of course. `hu.dwim.sdl` sounds like the package I need? Sadly, there is no documentation. The SDL2 symbols are translated by the rules given into Common Lisp symbols. Given my lack of understanding, that makes it difficult. Furthermore, the binding I've been using until now came with hand-written convenience methods such as `with-rects` that don't exist in this other binding. There is some porting to do. And given all of that… I must confess that it makes me tired.

Using the browser as a universal user-interface is a pretty cool idea! Even if the application itself is a stand-alone program that can act as a web-server (like Oddmu), all the hard parts are abstracted away: line-breaks, hyphenation, spell-checking when writing. Perhaps using the canvas is hard? But using the DOM and SVG is something I've done countless times and by now I know my way around.

Oddmu

Sigh.

I suspect something like the following is required for every symbol that I want to use:

(defun render-fill-rect (&rest args) (apply 'HU.DWIM.SDL.FFI::|SDL_RenderFillRect| args))

And then take a look at the arguments. The other SDL2 binding already has this.

`rect.lisp` defines these:

(defun make-rect (x y w h)
  "Allocate and return a new SDL_Rect filled in with the arguments."
  (c-let ((rect sdl2-ffi:sdl-rect))
    (setf (rect :x) x
          (rect :y) y
          (rect :w) w
          (rect :h) h)
    rect))

(define-struct-accessors (rect sdl2-ffi:sdl-rect)
  :x :y (width :w) (height :h))

`render.lisp` defines this:

(defun render-fill-rect (renderer sdl-rect)
  "Use this function to fill a rectangle on the current rendering target with
the drawing color. "
  (check-rc (sdl2-ffi.functions:sdl-render-fill-rect renderer sdl-rect)))

So I am between a rock and a hard place. The SDL2 bindings I had were pretty good. They don't come with bindings for SDL2/gfx so I would I need to do the missing legwork myself. Which I could do.

Or I could stick with Javascript and the web.

Sadly, the situation for the Cairo library doesn't appear to be much better. The function `format-stride-for-width` is not exported and I suspect nobody is actively working on the library. My issue has no reaction since Jul 20, 2022.

My issue