void
ddisplay_add_update(DDisplay *ddisp, const Rectangle *rect)
{
Rectangle *r;
int top,bottom,left,right;
Rectangle *visible;
int width, height;
if (!ddisp->renderer)
return; /* can happen at creation time of the diagram */
width = dia_renderer_get_width_pixels (ddisp->renderer);
height = dia_renderer_get_height_pixels (ddisp->renderer);
if (!rectangle_intersects(rect, &ddisp->visible))
return;
/* Temporarily just do a union of all rectangles: */
if (ddisp->update_areas==NULL) {
r = g_new(Rectangle,1);
*r = *rect;
rectangle_intersection(r, &ddisp->visible);
ddisp->update_areas = g_slist_prepend(ddisp->update_areas, r);
} else {
r = (Rectangle *) ddisp->update_areas->data;
rectangle_union(r, rect);
rectangle_intersection(r, &ddisp->visible);
}
visible = &ddisp->visible;
left = floor( (r->left - visible->left) * (real)width /
(visible->right - visible->left) ) - 1;
top = floor( (r->top - visible->top) * (real)height /
(visible->bottom - visible->top) ) - 1;
right = ceil( (r->right - visible->left) * (real)width /
(visible->right - visible->left) ) + 1;
bottom = ceil( (r->bottom - visible->top) * (real)height /
(visible->bottom - visible->top) ) + 1;
ddisplay_add_display_area(ddisp,
left, top,
right, bottom);
}
int main() {
assert(EQ(20, rectangle_area(point(1, 1), point(5, 6))));
assert(point_in_rectangle(point(0, -1), point(0, -3), 3, 2));
assert(point_in_rectangle(point(2, -2), point(3, -3), -3, 2));
assert(!point_in_rectangle(point(0, 0), point(3, -1), -3, -2));
assert(point_in_rectangle(point(2, -2), point(3, -3), point(0, -1)));
assert(!point_in_rectangle(point(-1, -2), point(3, -3), point(0, -1)));
point p, q;
assert(-1 == rectangle_intersection(point(0, 0), point(1, 1),
point(2, 2), point(3, 3)));
assert(0 == rectangle_intersection(point(1, 1), point(7, 7),
point(5, 5), point(0, 0), &p, &q));
assert(EQP(p, point(1, 1)) && EQP(q, point(5, 5)));
assert(1 == rectangle_intersection(point(1, 1), point(0, 0),
point(0, 0), point(1, 10), &p, &q));
assert(EQP(p, point(0, 0)) && EQP(q, point(1, 1)));
assert(2 == rectangle_intersection(point(0, 5), point(5, 7),
point(1, 6), point(2, 5), &p, &q));
assert(EQP(p, point(1, 6)) && EQP(q, point(2, 5)));
return 0;
}
bool rectangle_superposition (rectangle r1, rectangle r2)
{
rectangle inter = rectangle_intersection (r1,r2);
return inter.w && inter.h;
}
