void pontilharReta(){
Color gray = Color(0.8, 0.8, 0.8, 1);
if (outcodeOut == outcode0) {
auxPoints->push_back(Point2D(x0, y0, 10, gray));
points->at(0).setX(x);
points->at(0).setY(y);
outcode0 = computeOutCode(x0, y0);
} else {
auxPoints->push_back(Point2D(x1, y1, 10, gray));
points->at(1).setX(x);
points->at(1).setY(y);
outcode1 = computeOutCode(x1, y1);
}
points->pop_back();
auxPoints->push_back(Point2D(x, y, 10, Color(0,0,0,0)));
step++;
finished = true;
}
int clip(double *x0, double *y0, double *x1, double *y1, double xmin, double ymin, double xmax, double ymax) {
int outcode0 = computeOutCode(*x0, *y0, xmin, ymin, xmax, ymax);
int outcode1 = computeOutCode(*x1, *y1, xmin, ymin, xmax, ymax);
int accept = 0;
int changed = 0;
while (1) {
if (!(outcode0 | outcode1)) { // Bitwise OR is 0. Trivially accept and get out of loop
accept = 1;
break;
} else if (outcode0 & outcode1) { // Bitwise AND is not 0. Trivially reject and get out of loop
break;
} else {
// failed both tests, so calculate the line segment to clip
// from an outside point to an intersection with clip edge
double x = *x0, y = *y0;
// At least one endpoint is outside the clip rectangle; pick it.
int outcodeOut = outcode0 ? outcode0 : outcode1;
// Now find the intersection point;
// use formulas y = y0 + slope * (x - x0), x = x0 + (1 / slope) * (y - y0)
if (outcodeOut & TOP) { // point is above the clip rectangle
x = *x0 + (*x1 - *x0) * (ymax - *y0) / (*y1 - *y0);
y = ymax;
} else if (outcodeOut & BOTTOM) { // point is below the clip rectangle
x = *x0 + (*x1 - *x0) * (ymin - *y0) / (*y1 - *y0);
y = ymin;
} else if (outcodeOut & RIGHT) { // point is to the right of clip rectangle
y = *y0 + (*y1 - *y0) * (xmax - *x0) / (*x1 - *x0);
x = xmax;
} else if (outcodeOut & LEFT) { // point is to the left of clip rectangle
y = *y0 + (*y1 - *y0) * (xmin - *x0) / (*x1 - *x0);
x = xmin;
}
// Now we move outside point to intersection point to clip
// and get ready for next pass.
if (outcodeOut == outcode0) {
*x0 = x;
*y0 = y;
outcode0 = computeOutCode(*x0, *y0, xmin, ymin, xmax, ymax);
changed = 1;
} else {
*x1 = x;
*y1 = y;
outcode1 = computeOutCode(*x1, *y1, xmin, ymin, xmax, ymax);
changed = 1;
}
}
}
if (accept == 0) {
return 0;
} else {
return changed + 1;
}
}
//http://en.wikipedia.org/wiki/Cohen%E2%80%93Sutherland_algorithm
bool Rectangle::intersect(blib::math::Line l) const
{
// compute outcodes for P0, P1, and whatever point lies outside the clip rectangle
int outcode0 = computeOutCode(l.p1);
int outcode1 = computeOutCode(l.p2);
bool accept = false;
while (true)
{
if (!(outcode0 | outcode1)) { // Bitwise OR is 0. Trivially accept and get out of loop
accept = true;
break;
}
else if (outcode0 & outcode1) { // Bitwise AND is not 0. Trivially reject and get out of loop
break;
}
else {
// failed both tests, so calculate the line segment to clip
// from an outside point to an intersection with clip edge
float x, y;
// At least one endpoint is outside the clip rectangle; pick it.
int outcodeOut = outcode0 ? outcode0 : outcode1;
// Now find the intersection point;
// use formulas y = y0 + slope * (x - x0), x = x0 + (1 / slope) * (y - y0)
if (outcodeOut & TOP) { // point is above the clip rectangle
x = l.p1.x + (l.p2.x - l.p1.x) * (bottomright.y - l.p1.y) / (l.p2.y - l.p1.y);
y = bottomright.y;
}
else if (outcodeOut & BOTTOM) { // point is below the clip rectangle
x = l.p1.x + (l.p2.x - l.p1.x) * (topleft.y - l.p1.y) / (l.p2.y - l.p1.y);
y = topleft.y;
}
else if (outcodeOut & RIGHT) { // point is to the right of clip rectangle
y = l.p1.y + (l.p2.y - l.p1.y) * (bottomright.x - l.p1.x) / (l.p2.x - l.p1.x);
x = bottomright.x;
}
else if (outcodeOut & LEFT) { // point is to the left of clip rectangle
y = l.p1.y + (l.p2.y - l.p1.y) * (topleft.x - l.p1.x) / (l.p2.x - l.p1.x);
x = topleft.x;
}
// Now we move outside point to intersection point to clip
// and get ready for next pass.
if (outcodeOut == outcode0) {
l.p1 = glm::vec2(x, y);
outcode0 = computeOutCode(l.p1);
}
else {
l.p2 = glm::vec2(x, y);
outcode1 = computeOutCode(l.p2);
}
}
}
return accept;
}
CohenSutherlandStep(Drawer *drawer, vector<Point2D> *points, vector<Point2D> *auxPoints, double xMin, double yMin, double xMax, double yMax){
this->drawer = drawer;
this->points = points;
this->auxPoints = auxPoints;
this->xMin = xMin;
this->yMin = yMin;
this->xMax = xMax;
this->yMax = yMax;
Point2D a = points->at(0);
Point2D b = points->at(1);
x0 = a.getX();
y0 = a.getY();
x1 = b.getX();
y1 = b.getY();
// compute outcodes for P0, P1, and whatever point lies outside the clip rectangle
outcode0 = computeOutCode(x0, y0);
outcode1 = computeOutCode(x1, y1);
}
