class LinearInterpolator {
	struct Dda2 {
		int count, lift, rem, mod, p;
		
		void  Set(int a, int b, int len);
//		int   Get();
		int Get()
		{
			int pp = p;
			mod += rem;
			p += lift;
			if(mod > 0) {
				mod -= count;
				p++;
			}
			return pp;
		}

	};

	Xform2D xform;
	Dda2    ddax, dday;

	static int Q8(double x) { return int(256 * x + 0.5); }
	
public:
	void   Set(const Xform2D& m)                    { xform = m; }

	void   Begin(int x, int y, int len);
//	Point  Get();
	Point Get()
	{
		return Point(ddax.Get(), dday.Get());
	}

};

	virtual void Get(RGBA *span, int x, int y, unsigned len)
	{
		interpolator.Begin(x, y, len);
		fixed = hstyle && vstyle;
		
		if((hstyle|vstyle)==0 && fast){
			while(len--){
				Point l = interpolator.Get() >> 8;
				if(l.x > 0 && l.x < maxx && l.y > 0 && l.y < maxy) *span = Pixel(l.x, l.y);
				else if(style == 0 && (l.x < -1 || l.x > cx || l.y < -1 || l.y > cy)) *span = RGBAZero();
				else *span = GetPixel(l.x, l.y);
				++span;
			}
			return;
		}
		
		while(len--) {
			Point h = interpolator.Get();
	//		h -= 128;
			Point l = h >> 8;
	...

void SpanFiller::Render(int val, int len)
{
	if(val == 0) {
		t += len;
		s += len;
		return;
	}
	const RGBA *e = t + len;
	if(alpha != 256)
		val = alpha * val >> 8;
	if(val == 256)
		for(int i=0;i<len;i++) if(s[i].a==255) t[i]=s[i]; else AlphaBlend(t[i], s[i]);
/*		while(t < e) {
			if(s->a == 255)
				*t++ = *s++;
			else
				AlphaBlend(*t++, *s++);
		}
*/	else
		while(t < e)
			AlphaBlendCover8(*t++, *s++, val);
}