void Translate(Matrix& m, float translateX, float translateY)
{
    m[2][0] = translateX; m[2][1] = translateY;
}
void Rotate(Matrix& m, float angle)
{
    m[0][0] = cos(angle), m[1][0] = -sin(angle);
    m[0][1] = sin(angle), m[1][1] = cos(angle);
}


void Scale(Matrix& m, float scaleX, float scaleY)
{
    m[0][0] = scaleX, m[1][1] = scaleY;
}

bool CohenSutherland(Point clippingWindow[4], Point line[2]) 
{
	int ymax = clippingWindow[0].y, xmin = clippingWindow[0].x, ymin =clippingWindow[2].y, xmax = clippingWindow[2].x;
	int outcode[2][4];
	memset(outcode, 0, sizeof(outcode));
	//为线段的两个端点编码
	outcode[0][0] = line[0].y > ymax; outcode[0][1] = line[0].y < ymin;
	outcode[0][2] = line[0].x > xmax; outcode[0][3] = line[0].x < xmin;
	outcode[1][0] = line[1].y > ymax; outcode[1][1] = line[1].y < ymin;
	outcode[1][2] = line[1].x > xmax; outcode[1][3] = line[1].x < xmin;
	int flag = (outcode[0][0] & outcode[1][0]) + (outcode[0][1] & outcode[1][1]) +(outcode[0][2] & outcode[1][2]) + (outcode[0][3] & outcode[1][3]);
	if (flag)return false;//code1&code2!=0,说明该线段在视窗外，所以将其舍弃
	if (outcode[0][0] | outcode[0][1] | outcode[0][2] | outcode[0][3]) {
	//若端点在视窗外，则将线段与视窗的交点作为新端点
    	if (outcode[0][0])line[0].y = ymax;
	    if (outcode[0][1])line[0].y = ymin;
	    if (outcode[0][2])line[0].x = xmax;
	    if (outcode[0][3])line[0].x = xmin; 	
    }
	if (outcode[1][0] | outcode[1][1] | outcode[1][2] | outcode[1][3]) {
	    if (outcode[1][0])line[1].y = ymax;
	    if (outcode[1][1])line[1].y = ymin;
	    if (outcode[1][2])line[1].x = xmax;
	    if (outcode[1][3])line[1].x = xmin; 
    }
	return true; 
}