Port font editor to SDL2

[jouae]

Replace X11 with SDL2 to improve the portability and cross-platform support

Migrated window creation from X11's XCreateWindow to SDL_CreateWindow.

Replaced X11 event handling with SDL2’s event loop (SDL_PollEvent) to capture input events such as keyboard and mouse interactions.

Updated rendering to use SDL_Renderer and SDL_Surface, replacing X11's rendering functions.

• Modified some key event logic:

1. SDLK_ESCAPE: ESC now exits the program.
2. SDL_QUIT: Clicking the "X" on the window exits the program.

• Unchanged key event logic:

1. SDLK_q: Switches to the next font.

• Features not fully implemented yet:

1. SDLK_s, SDLK_u, SDLK_f, SDLK_d, SDLK_DOWN: Handling logic for stripe drawing operations.
2. SDL_WINDOWEVENT, SDL_MOUSEBUTTONDOWN.

[jserv]

You don't have to write the message Resolved in <commit> literally. Instead, simply click the button "Resolve conversation" once you have confirmed.

[weihsinyeh]

How can I control the second control point, pt[1], when I press pt[2]? I can currently only control the first control point, pt[0].

[jouae]

How can I control the second control point, pt[1], when I press pt[2]? I can currently only control the first control point, pt[0].

@weihsinyeh

Sorry, this function is not supported now.

I'm trying to figure out how to let the second control point be moved by user.

[jserv]

Dump the usage before calling exit.

[jouae]

+    char_t *c;
+
+   /*
+    * Use the following command to start twin-fedit:

Don't do that. Dump the message.

What kind of usage should I dump here?

[jserv]

You can simply change the behavior of this font editor, allowing read a file from given filename (argv[1]). Thus, you can check argument count and the existence of file to proceed.

[jouae]

    if (argc < 2) {
        printf("Usage: %s <filename>\n", argv[0]);
        return 0;
    }

    FILE *file = fopen(argv[1], "r");
    if (!file) {
        printf("Failed to open file: %s\n", argv[1]);
        return 0;
    }
    if (!init(argc, argv))
        exit(1);
    while ((c = read_char(file)) && !exit_window) {
        play(c);
        print_char(c);
    }

    fclose(file);

Before initializing init(), use fopen to read the content of argv[1] and replace the previous method of reading strings from stdin in read_char().

I adopted this approach to make the file reading process clearer and improve the readability of the code. I'm not sure if there is a better way to improve it.

[jserv]

Don't use backtick characters in git commit messages for the sake of terminal compatibility. Also, avoid unnecessary bullets.

[weihsinyeh]

There are two ！.

[jserv]

The use of !! is a common trick to make sure the result will be either 0 or 1.

[jserv]

Append Close #7 at the end of git commit messages. Messages should use complete sentences and proper indentation.

[jouae]

Append Close #7 at the end of git commit messages. Messages should use complete sentences and proper indentation.

@jserv

I adopted the 50/72 rule and refined the commit message to improve readability.

[jserv]

Thank @jouae for contributing!