package allegro5

// #include <allegro5/allegro.h>
// #include <allegro5/allegro_font.h>
// #include <allegro5/allegro_ttf.h>
import "C"

import (
  "fmt"
  "unsafe"
)

type Font struct {
  font *C.ALLEGRO_FONT
}

type HorizontalAlignment int

const (
  AlignLeft HorizontalAlignment = iota
  AlignCenter
  AlignRight
)

func LoadTTFFont(path string, size int) (*Font, error) {
  p := C.CString(path)
  defer C.free(unsafe.Pointer(p))
  
  f := C.al_load_ttf_font(p, C.int(size), 0)
  if nil == f {
    return nil, fmt.Errorf("Unable to load TTF font '%s'", path)
  }
  return &Font{f}, nil
}

func (f *Font) drawFlags(a HorizontalAlignment) C.int {
  switch a {
    case AlignLeft:
    return C.ALLEGRO_ALIGN_LEFT
    case AlignCenter:
    return C.ALLEGRO_ALIGN_CENTRE
    case AlignRight:
    return C.ALLEGRO_ALIGN_RIGHT
  }
  return C.ALLEGRO_ALIGN_LEFT
}

func (f *Font) Draw(left, top float32, color Color, align HorizontalAlignment, text string) {
  t := C.CString(text)
  defer C.free(unsafe.Pointer(t))
  
  flags := f.drawFlags(align)
  C.al_draw_text(f.font, color.color, C.float(left), C.float(top), flags, t)
}

func (f *Font) Destroy() {
  C.al_destroy_font(f.font)
}