/* ============================================================================================= */
void WindowClipper::cohen_sutherland_clipping(Line &line)
/* ============================================================================================= */
{
DCoordVector newVertices;
double x1 = line.p1()->xnc();
double x2 = line.p2()->xnc();
double y1 = line.p1()->ync();
double y2 = line.p2()->ync();
int outcode1 = computeOutcode(x1, y1);
int outcode2 = computeOutcode(x2, y2);
bool accept = false;
while(true) {
if (!(outcode1 | outcode2)) {
accept = true;
break;
} else if (outcode1 & outcode2) {
break;
} else {
double x, y;
int outcodeOut = outcode1 ? outcode1 : outcode2;
if ( outcodeOut & TOP) {
x = x1 + (x2 - x1) * (Y_MAX - y1) / (y2 - y1);
y = Y_MAX;
} else if (outcodeOut & BOTTOM) {
x = x1 + (x2 - x1) * (Y_MIN - y2) / (y2 - y1);
y = Y_MIN;
} else if (outcodeOut & RIGHT) {
y = y1 + (y2 - y1) * (X_MAX - x1) / (x2 - x1);
x = X_MAX;
} else if(outcodeOut & LEFT) {
y = y1 + (y2 - y1) * (X_MIN - x1) / (x2 - x1);
x = X_MIN;
}
if (outcodeOut == outcode1) {
x1 = x;
y1 = y;
outcode1 = computeOutcode(x1, y1);
} else {
x2 = x;
y2 = y;
outcode2 = computeOutcode(x2, y2);
}
}
}
if (accept) {
DEBUG_MSG("X1: " << x1);
DEBUG_MSG("Y1: " << y1);
DEBUG_MSG("X2: " << x2);
DEBUG_MSG("Y2: " << y2);
newVertices.push_back(new Coord<double>(x1, y1));
newVertices.push_back(new Coord<double>(x2, y2));
}
line.update_normalized_coords(newVertices);
}
Line CohenShutterlandAlgorithm::getLineInView(Line line,Point viewPortStart,Point viewPortEnd) {
Point linePosition = line.getPosition();
int x0 = line.getBeginPoint().x + linePosition.x;
int y0 = line.getBeginPoint().y + linePosition.y;
int x1 = line.getEndPoint().x + linePosition.x;
int y1 = line.getEndPoint().y + linePosition.y;
Point point1(x0,y0);
Point point2(x1,y1);
int outcode1 = computeOutcode(point1,viewPortStart,viewPortEnd);
int outcode2 = computeOutcode(point2,viewPortStart,viewPortEnd);
while(true) {
int outcodeOut = outcode1 ? outcode1 : outcode2;
if (!(outcode1|outcode2)){
return Line(Point(x0,y0),Point(x1,y1),line.getColor());
}
else if (outcode1 & outcode2){
return Line(Point(0,0),Point(0,0),Color(0,0,0,0));
}
else {
int x,y;
if ( outcodeOut & TOP ) {
x = x0 + (x1-x0) * (viewPortStart.y - y0) / (y1-y0) ;
y = viewPortStart.y;
} else if (outcodeOut & BOTTOM) {
x = x0 + (x1-x0) * (viewPortEnd.y - y0) / (y1-y0);
y = viewPortEnd.y;
} else if (outcodeOut & LEFT ) {
y = y0 + (y1-y0) * (viewPortStart.x - x0) / (x1-x0);
x = viewPortStart.x;
} else if (outcodeOut & RIGHT) {
y = y0 + (y1-y0) * (viewPortEnd.x - x0 ) / (x1-x0);
x = viewPortEnd.x;
}
if (outcodeOut == outcode1) {
x0 = x;
y0 = y;
outcode1 = computeOutcode(Point(x0,y0),viewPortStart,viewPortEnd);
}
else {
x1 = x;
y1 = y;
outcode2 = computeOutcode(Point(x1,y1),viewPortStart,viewPortEnd);
}
}
}
}
