sdltext

Small, WIP, single-header, no dependency, text points compiler library

Details

Currently only implements a 5x5 font (size multiplier and/or specifier are WIP) which supports ASCII (UTF-8 support is WIP), but the API is made to support UTF-8 whilst also having an ergonomic API for ASCII strings.
Work for basic font formats support is expected, too, but there's no ETA.

Cool stuff

This primitively implements one of my very basic ideas (transforms) which is a function (currently takes cursor, whole input length and progression (character index), returns point) which allows for easy text manipulation. This may (very likely will) be extended to implement stuff such as rotations, too.

Theoretical scenario

Say I wanted to expose only vowels in a word. Instead of hacking the implementation with multiple calls to a text rendering API, I can simply pass a transformer that automatically does my intended function.

Demonstration

Sine-wave transform + width-wrapping on alphabet + numbers + special characters:

// gdt is an example local pointer to delta time, not offerred by the API
static SDLText_Point sine_transform(const unsigned char *cursor,
                                    unsigned in_len, unsigned i) {
  (void)cursor;
  (void)in_len;

  return (SDLText_Point){.x = (int)((*gdt) * 20) % (WIDTH - 10),
                         .y = (int)(sinf((*gdt) * 10 + (float)i) * 2.f)};
}


    p = sdltext_compile_text_ex(
        (SDLText_Point){.x = 3, .y = 10},
        "1234567890\n"
        "!@#$%^&*-=+_()[]{}/\\<>\"'`~;:\n"
        "???dac???,,, hello, world,!@@... DAB			bac cab bada "
        "dabadabada "
        "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqr"
        "stuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz",
        &n, sine_transform);
     if (p) SDL_RenderDrawPoints(mder.renderer, (const SDL_Point *)p, n);
    free(p);

Rotating circle transform:

// gdt is an example local pointer to delta time, not offerred by the API
#define DEGS(x) 360 / (x)
#define RADIUS 40
static SDLText_Point rotating_circle_transform(const unsigned char *cursor,
                                               unsigned text_len, unsigned i) {
  (void)cursor;

  unsigned offset;
  float rot;
  float rad;
  float o;

  o = fmodf((*gdt) * 50.f, 40.f);
  if (o > 20.f)
    o = 40.f - o;

  rad = RADIUS + o;

  offset = (SDLTEXT_FONT_SIZE + SDLTEXT_FONT_SPACING) * i;

  SDLText_Point p;

  p.x = p.y = 0;
  p.x -= offset;

  rot = fmodf(((DEGS(text_len) * (float)i) + (*gdt) * 100), 360.f);

  p.x += (int)(sinf(rot / 57.2958f) * rad);
  p.y -= (int)(cosf(rot / 57.2958f) * rad);

  return p;
}


    p = sdltext_compile_text_ex(
        (SDLText_Point){.x = (WIDTH / 2), .y = (HEIGHT / 2)}, "not too fond of israel",
        &n, rotating_circle_transform);
    if (p) SDL_RenderDrawPoints(mder.renderer, (const SDL_Point *)p, n);
    free(p);

Implementation

First, you must #define a type named number, example: #define number int, then, you must include sdltext.h, and afterwards it's recommended that you #undef number.

Then, you must call sdltext_initialize with width as your argument for text wrapping to work, then you may call sdltext_compile_text_* as shown above (or in the API), and then you can do anything with the points. For one, you may draw them in only one call using SDL_RenderDrawPoints.

Should I use this?

Do it at your own risk, I'll probably make many changes to the API eventually, it's meant to just be dropped into a SDL application, and to just work, providing you with benefits through its simplicity, and it'll stay this way. You never really have to update this, but you might want to once you see new functionality, but I can't promise backwards compatibility.

cristeigabriel / sdltext