zntg/allegro5/bitmap.go
Sander Schobers 2924980035 Basic wrapper around allegro5 libraries
- Depends on optional allegro libraries font, image, primitives and ttf as well.
2017-10-03 20:38:09 +02:00

97 lines
2.3 KiB
Go

package allegro5
// #include <allegro5/allegro.h>
// #include <stdlib.h>
import "C"
import (
"fmt"
"unsafe"
)
// Bitmap represents an in memory bitmap
type Bitmap struct {
bitmap *C.ALLEGRO_BITMAP
width int
height int
}
type DrawOptions struct {
Center bool
Scale *Scale
Tint *Color
}
type Scale struct {
Horizontal float32
Vertical float32
}
// NewBitmap creates a new bitmap of given width and height
func NewBitmap(width, height int) (*Bitmap, error) {
b := C.al_create_bitmap(C.int(width), C.int(height))
if nil == b {
return nil, fmt.Errorf("Error creating bitmap")
}
return &Bitmap{b, width, height}, nil
}
// LoadBitmap tries to load the image at the specified path as a bitmap
func LoadBitmap(path string) (*Bitmap, error) {
p := C.CString(path)
defer C.free(unsafe.Pointer(p))
b := C.al_load_bitmap(p)
if nil == b {
return nil, fmt.Errorf("Error loading bitmap")
}
width := int(C.al_get_bitmap_width(b))
height := int(C.al_get_bitmap_height(b))
return &Bitmap{b, width, height}, nil
}
// Draw draws the bitmap at the given location
func (b *Bitmap) Draw(left, top float32) {
C.al_draw_bitmap(b.bitmap, C.float(left), C.float(top), 0)
}
func (b *Bitmap) DrawOptions(left, top float32, options DrawOptions) {
width := float32(b.width)
height := float32(b.height)
scale := nil != options.Scale
if scale {
width *= options.Scale.Horizontal
height *= options.Scale.Vertical
}
if options.Center {
left -= width * 0.5
top -= height * 0.5
}
if scale {
if nil == options.Tint {
C.al_draw_scaled_bitmap(b.bitmap, 0, 0, C.float(b.width), C.float(b.height), C.float(left), C.float(top), C.float(width), C.float(height), 0)
} else {
C.al_draw_tinted_scaled_bitmap(b.bitmap, options.Tint.color, 0, 0, C.float(b.width), C.float(b.height), C.float(left), C.float(top), C.float(width), C.float(height), 0)
}
} else {
if nil == options.Tint {
C.al_draw_bitmap(b.bitmap, C.float(left), C.float(top), 0)
} else {
C.al_draw_tinted_bitmap(b.bitmap, options.Tint.color, C.float(left), C.float(top), 0)
}
}
}
func (b *Bitmap) Width() int {
return b.width
}
func (b *Bitmap) Height() int {
return b.height
}
// Destroy destroys the bitmap
func (b *Bitmap) Destroy() {
C.al_destroy_bitmap(b.bitmap)
}