void col_lerp(COLOR *_cT, COLOR *_c0, COLOR *_c1, var _factor, var _gamma) {
	_cT->red   = pow(pow(_c0->red, _gamma) * (1 - _factor)   + pow(_c1->red, _gamma) * _factor,   1.0 / _gamma);
	_cT->green = pow(pow(_c0->green, _gamma) * (1 - _factor) + pow(_c1->green, _gamma) * _factor, 1.0 / _gamma);
	_cT->blue  = pow(pow(_c0->blue, _gamma) * (1 - _factor)  + pow(_c1->blue, _gamma) * _factor,  1.0 / _gamma);
}

void bmap_paint_circle (
	BMAP *_bmp,      
	int _posX,         
	int _posY,         
	var _radiusInt,  
	var _radiusExt, 
	COLOR *_color, 
	var _alpha) 
	{
		var _g = _radiusExt - _radiusInt;
		if (_g == 0)
			_g = 0.001;
		int _x0 = maxv(-_radiusExt, -_posX);
		int _xL = minv(_radiusExt, bmap_width(_bmp) - _posX);
		int _y = maxv(-_radiusExt, -_posY);
		int _yL = minv(_radiusExt, bmap_height(_bmp) - _posY);
		var _frt = bmap_lock(_bmp, 0);
		for (; _y<_yL; _y+=1) {
			int _x = _x0;
			for (; _x<_xL; _x+=1) {
				var _r = sqrt(_y * _y + _x * _x);
				if (_r > _radiusExt)
					continue;
				var _f = (1 - maxv(_r - _radiusInt, 0) / _g) * _alpha / 100;
				var _p = pixel_for_bmap(_bmp, _posX + _x, _posY + _y);
				COLOR _c;
				pixel_to_vec(&_c, NULL, _frt, _p);
				col_lerp(&_c, &_c, _color, _f, 2.2);
//				vec_lerp(&_c, &_c, _color, _f);
				_p = pixel_for_vec(&_c, 100, _frt);
				pixel_to_bmap(_bmp, _posX + _x, _posY + _y, _p);
			}
		}
		bmap_unlock(_bmp);
	}