#include <u.h>
#include <libn.h>
#include <libfont.h>

#define STB_IMAGE_WRITE_IMPLEMENTATION
#include "stb_image_write.h"

#define W 512
#define H 128
#define L 64

static char *phrase = "the quick brown";

int
main()
{
    int i, err;
    float x, dx, scale;
    uchar *bitmap;
    font·Info *info;
    mmap·Reader fontfile;
    int off, y, ascent, descent, baseln;
    int adv, lsb, r0[2], r1[2];

    err = 0;
    fontfile = mmap·open("/home/nolln/root/data/DejaVuSans.ttf");
    if (!fontfile.len) {
        err = 1;
        goto end;
    }
    info   = font·make(fontfile.ubuf, 0);
    if (!info) 
        panicf("failed to load info");

    bitmap = calloc(W*H, sizeof(*bitmap)); 
    scale  = font·scaleheightto(info, L);

    font·vmetrics(info, &ascent, &descent, &baseln);
    ascent *= scale;

    x = 0.;
    for (i = 0; i < strlen(phrase); i++) {
        dx = x - (float)floor(x);
        font·code_hmetrics(info, phrase[i], &adv, &lsb);
        font·code_bitmapbox_subpixel(info, phrase[i], scale, scale, dx, 0, r0, r0+1, r1, r1+1);

        y   = ascent + r0[1];
        off = (int)floor(x) + (lsb * scale) + y * W; 

        font·code_fillbitmap_subpixel(info, bitmap+off, r1[0]-r0[0], r1[1]-r0[1], W, scale, scale, dx, 0, phrase[i]);

        x += scale * adv;
        if (phrase[i+1])
            x += scale * font·code_kernadvance(info, phrase[i], phrase[i+1]);
    }

    stbi_write_png("out.png", W, H, 1, bitmap, W);

    font·free(info);
    free(bitmap);
end:
    mmap·close(fontfile);
    return err;
}