sftd crappy atlas

#define ATLAS_W 512
#define ATLAS_H 512

typedef struct {
    int x, y, w, h, left, top, v;
    int advance_x, advance_y;
} atlas_position;

struct sftd_font {
    sftd_font_load_from from;
    union {
        char *filename;
        struct {
            const void *font_buffer;
            unsigned int buffer_size;
        };
    };
    FTC_CMapCache cmapcache;
    FTC_ImageCache imagecache;

    // Atlas
    sf2d_texture *atlas;
    atlas_position atlas_pos[65536];
    int atlas_x;
    int atlas_y;
};


sftd_font *sftd_load_font_mem(const void *buffer, unsigned int size)
{
    sftd_font *font = malloc(sizeof(*font));
    font->font_buffer = buffer;
    font->buffer_size = size;

    FTC_CMapCache_New(ftcmanager, &font->cmapcache);
    FTC_ImageCache_New(ftcmanager, &font->imagecache);

    // Atlas
    font->atlas = sf2d_create_texture(ATLAS_W, ATLAS_H, TEXFMT_RGBA8, SF2D_PLACE_RAM);
    memset(font->atlas_pos, 0, sizeof(*font->atlas_pos) * 65536);
    font->atlas->tiled = 1;
    font->atlas_x = 0;
    font->atlas_y = 0;

    font->from = SFTD_LOAD_FROM_MEM;

    return font;
}


void sftd_draw_text(sftd_font *font, int x, int y, unsigned int color, unsigned int size, const char *text)
{
    FTC_FaceID face_id = (FTC_FaceID)font;
    FT_Face face;
    FTC_Manager_LookupFace(ftcmanager, face_id, &face);

    FT_Int charmap_index;
    charmap_index = FT_Get_Charmap_Index(face->charmap);

    FT_Glyph glyph;
    FT_Bool use_kerning = FT_HAS_KERNING(face);
    FT_UInt glyph_index, previous = 0;
    int pen_x = x;
    int pen_y = y;

    FTC_ScalerRec scaler;
    scaler.face_id = face_id;
    scaler.width = size;
    scaler.height = size;
    scaler.pixel = 1;

    FT_ULong flags = FT_LOAD_RENDER | FT_LOAD_TARGET_NORMAL;

    while (*text) {
        glyph_index = FTC_CMapCache_Lookup(font->cmapcache, (FTC_FaceID)font, charmap_index, *text);

        if (use_kerning && previous && glyph_index) {
            FT_Vector delta;
            FT_Get_Kerning(face, previous, glyph_index, FT_KERNING_DEFAULT, &delta);
            pen_x += delta.x >> 6;
        }

        if (font->atlas_pos[glyph_index].v) {
            sf2d_draw_texture_part(font->atlas,
                pen_x + font->atlas_pos[glyph_index].left + x,
                pen_y - font->atlas_pos[glyph_index].top + y,
                font->atlas_pos[glyph_index].x,
                font->atlas_pos[glyph_index].y,
                font->atlas_pos[glyph_index].w,
                font->atlas_pos[glyph_index].h);

            pen_x += font->atlas_pos[glyph_index].advance_x >> 16;
            pen_y += font->atlas_pos[glyph_index].advance_y >> 16;

        } else {
            FTC_ImageCache_LookupScaler(font->imagecache, &scaler, flags, glyph_index, &glyph, NULL);
            if (glyph->format == FT_GLYPH_FORMAT_BITMAP) {
                FT_BitmapGlyph bitmap_glyph = (FT_BitmapGlyph)glyph;

                FT_Bitmap *bitmap = &bitmap_glyph->bitmap;

                // Get next atlas pos;
                if (font->atlas_x + size > ATLAS_W) {
                    font->atlas_x = 0;
                    font->atlas_y += size;
                }

                //printf("atlas_x: %i  atlas_y: %i\n", font->atlas_x, font->atlas_y);
                //printf("bwidth: %i  brows: %i\n", bitmap->width, bitmap->rows);

                //draw_bitmap(&bitmap_glyph->bitmap, pen_x + bitmap_glyph->left + x, pen_y - bitmap_glyph->top + y, color);
                int j, k;
                for (j = 0; j < bitmap->rows; j++) {
                    for (k = 0; k < bitmap->width; k++) {
                        sf2d_set_pixel(font->atlas,
                            (font->atlas_x + k),
                            (font->atlas_y + j),
                            __builtin_bswap32((color & ~0xFF) | bitmap->buffer[j*bitmap->width + k]));
                    }
                }

                font->atlas_pos[glyph_index].left = bitmap_glyph->left;
                font->atlas_pos[glyph_index].top = bitmap_glyph->top;
                font->atlas_pos[glyph_index].x = font->atlas_x;
                font->atlas_pos[glyph_index].y = font->atlas_y;
                font->atlas_pos[glyph_index].w = bitmap->width;
                font->atlas_pos[glyph_index].h = bitmap->rows;
                font->atlas_pos[glyph_index].advance_x = bitmap_glyph->root.advance.x;
                font->atlas_pos[glyph_index].advance_y = bitmap_glyph->root.advance.y;
                font->atlas_pos[glyph_index].v = 1;

                sf2d_draw_texture_part(font->atlas,
                    pen_x + font->atlas_pos[glyph_index].left + x,
                    pen_y - font->atlas_pos[glyph_index].top + y,
                    font->atlas_pos[glyph_index].x,
                    font->atlas_pos[glyph_index].y,
                    font->atlas_pos[glyph_index].w,
                    font->atlas_pos[glyph_index].h);

                font->atlas_x += size;

                pen_x += bitmap_glyph->root.advance.x >> 16;
                pen_y += bitmap_glyph->root.advance.y >> 16;
            }

        }

        previous = glyph_index;
        text++;
    }
}