package x

import "image"
import "git.tebibyte.media/tomo/tomo"

type texture struct {
	pix         []uint8
	stride      int
	rect        image.Rectangle
	transparent bool
}

func (backend *Backend) NewTexture (source image.Image) tomo.Texture {
	bounds := source.Bounds()
	texture := &texture {
		pix:    make([]uint8, bounds.Dx() * bounds.Dy() * 4),
		stride: bounds.Dx(),
		rect:   bounds.Sub(bounds.Min),
	}

	index := 0
	var point image.Point
	for point.Y = bounds.Min.Y; point.Y < bounds.Max.Y; point.Y ++ {
	for point.X = bounds.Min.X; point.X < bounds.Max.X; point.X ++ {
		r, g, b, a := source.At(point.X, point.Y).RGBA()
		texture.pix[index + 0] = uint8(b >> 8)
		texture.pix[index + 1] = uint8(g >> 8)
		texture.pix[index + 2] = uint8(r >> 8)
		texture.pix[index + 3] = uint8(a >> 8)
		index += 4

		if a != 0xFFFF {
			texture.transparent = true
		}
	}}
	
	return texture
}

func (this *texture) Clip (bounds image.Rectangle) tomo.Texture {
	clipped := *this
	clipped.rect = bounds
	return &clipped
}

func (this *texture) Close () error {
	return nil
}

func assertTexture (unknown tomo.Texture) *texture {
	if tx, ok := unknown.(*texture); ok {
		return tx
	} else {
		panic("foregin texture implementation, i did not make this!")
	}
}