/* example1.c                                                         */
/*                                                                    */
/* This small program shows how to print a string with the            */
/* FreeType 2 library.                                                */
/*                                                                    */
/* sumber https://www.freetype.org/freetype2/docs/tutorial/example1.c */


#include <stdio.h>
#include <string.h>                       /* strlen() */
#include <ft2build.h>
#include FT_FREETYPE_H

#define WIDTH   32
#define HEIGHT  32


// ukuran gambar yang akan tampil pada konsol
unsigned char image[HEIGHT][WIDTH];


// mengambil data buffer pixel bitmap dan menyalin ke variabel image
void draw_bitmap(FT_Bitmap* bitmap, FT_Int  x, FT_Int y){
    FT_Int  i, j, p, q;
    FT_Int  x_max = x + bitmap->width;
    FT_Int  y_max = y + bitmap->rows;


    for(i = x, p = 0; i < x_max; i++, p++){
        for(j = y, q = 0; j < y_max; j++, q++){
            if(i < 0 || j < 0 || i >= WIDTH || j >= HEIGHT)
                continue;

            image[j][i] = bitmap->buffer[q * bitmap->width + p];
        }
    }
}

// mencetak variabel image ke konsol
void show_image(){
    int  i, j;

    printf("{\n");
    for(i = 0; i < HEIGHT; i++){
        for(j = 0; j < WIDTH; j++){

            if(j == 0)
                printf("    {");

            if(image[i][j] < 10)
                printf(" %d", image[i][j]);
            else if(image[i][j] < 100)
                printf(" %d", image[i][j]);
            else
                printf(" %d", image[i][j]);

            if(j != WIDTH - 1)
                printf(", ");
        }

        if(i == HEIGHT - 1)
            printf("}\n}\n");
        else
            printf("},\n");
    }
}

// main program
int main(int argc, char**  argv){
    FT_Library    library;
    FT_Face       face;

    FT_GlyphSlot  slot;
    FT_Vector     pen;                    /* untransformed origin  */
    FT_Error      error;

    char*         filename;
    char*         text;

    int           target_height;
    int           n, num_chars;
    int           font_size;

    if(argc != 3){
        fprintf(stderr, "usage: %s font sample-text\n", argv[0]);
        exit(1);
    }

    filename      = argv[1];                            /* first argument     */
    text          = argv[2];                            /* second argument    */
    num_chars     = strlen(text);
    font_size     = 32;                                 /* ukuran huruf       */
    target_height = font_size;

    error = FT_Init_FreeType(&library);                 /* initialize library */

    // TODO: tambahkan error handling

    error = FT_New_Face(library, filename, 0, &face);   /* create face object */

    // TODO: tambahkan error handling

    // mengeset ukuran huruf dan density nya
    // ukuran: 10 pt(titik)
    // density: 100 dpi
    error = FT_Set_Char_Size(face, font_size * 64, 0, 92, 0); /* set character size */

    // TODO: tambahkan error handling

    slot = face->glyph;

    pen.x = 0 * 64; // positif ke kanan
    pen.y = 0 * 64; // positif ke atas

    for(n = 0; n < num_chars; n++){

        /* no transformation */
        FT_Set_Transform(face, NULL, &pen);

        /* load glyph image into the slot (erase previous one) */
        error = FT_Load_Char(face, text[n], FT_LOAD_RENDER);
        if(error)
            continue;            /* ignore errors, TODO: tambahakan error handling */

        /* now, draw to our target surface (convert position) */
        draw_bitmap(&slot->bitmap, slot->bitmap_left, target_height - slot->bitmap_top - 1);

        /* increment pen position */
        pen.x += slot->advance.x;
        pen.y += slot->advance.y;
    }

    show_image();

    FT_Done_Face   (face);
    FT_Done_FreeType(library);

    return 0;
}