def get_move_cursor_name_for_edge(self,
cursor_pos,
edge_p1,
edge_p2,
tolerance=5,
finite=True):
"""Get move cursor & detect hits on a line between two points
:param tuple cursor_pos: cursor position, as display (x, y)
:param tuple edge_p1: point on the edge, as model (x, y)
:param tuple edge_p2: point on the edge, as model (x, y)
:param int tolerance: slack for cursor pos., in display pixels
:patam bool finite: if false, the edge extends beyond p1, p2
:returns: move direction cursor & distance from line (cursor, d)
:rtype: tuple
This can be used by special input modes when resizing objects on
screen, for example frame edges and the symmetry axis.
If the returned cursor isn't None, its value is the name of the
most appropriate move cursor to use during the move. This method
does not return a normal vector in model space; you'll have to
calculate that for yourself.
See also:
* gui.cursor.Name (naming consts for cursors)
"""
# Work in screen pixels only
x0, y0 = cursor_pos
x1, y1 = self.model_to_display(*edge_p1)
x2, y2 = self.model_to_display(*edge_p2)
Dx = x2 - x1
Dy = y2 - y1
edge_len = math.sqrt(Dx**2 + Dy**2)
if edge_len <= 0:
dist1 = math.hypot(x0 - x1, y0 - y1)
dist2 = math.hypot(x0 - x2, y0 - y2)
return (None, min(dist1, dist2))
# Perpendicular distance from a line.
two_triarea = abs(Dy * x0 - Dx * y0 - x1 * y2 + x2 * y1)
perp_dist = two_triarea / edge_len
if perp_dist > tolerance:
return (None, perp_dist)
# Rough approximation here, but good enough for hit calculation.
# Omit points too far away from the edge's centre point.
if finite:
xmid = (x1 + x2) / 2.0
ymid = (y1 + y2) / 2.0
dist_from_midpt = math.sqrt((xmid - x0)**2 + (ymid - y0)**2)
if dist_from_midpt > (edge_len / 2.0) + tolerance:
return (None, perp_dist)
# Cursor name by sector.
# Aiming for a cursor that looks perpendicular to the line.
# Ish.
theta = math.atan2(Dy, Dx)
c = cursor.get_move_cursor_name_for_angle(theta + math.pi / 2)
return (c, perp_dist)
def get_move_cursor_name_for_edge(self, cursor_pos, edge_p1, edge_p2,
tolerance=5, finite=True):
"""Get move cursor & detect hits on a line between two points
:param tuple cursor_pos: cursor position, as display (x, y)
:param tuple edge_p1: point on the edge, as model (x, y)
:param tuple edge_p2: point on the edge, as model (x, y)
:param int tolerance: slack for cursor pos., in display pixels
:patam bool finite: if false, the edge extends beyond p1, p2
:returns: move direction cursor & distance from line (cursor, d)
:rtype: tuple
This can be used by special input modes when resizing objects on
screen, for example frame edges and the symmetry axis.
If the returned cursor isn't None, its value is the name of the
most appropriate move cursor to use during the move. This method
does not return a normal vector in model space; you'll have to
calculate that for yourself.
See also:
* gui.cursor.Name (naming consts for cursors)
"""
# Work in screen pixels only
x0, y0 = cursor_pos
x1, y1 = self.model_to_display(*edge_p1)
x2, y2 = self.model_to_display(*edge_p2)
Dx = x2 - x1
Dy = y2 - y1
edge_len = math.sqrt(Dx**2 + Dy**2)
if edge_len <= 0:
dist1 = math.hypot(x0-x1, y0-y1)
dist2 = math.hypot(x0-x2, y0-y2)
return (None, min(dist1, dist2))
# Perpendicular distance from a line.
two_triarea = abs(Dy*x0 - Dx*y0 - x1*y2 + x2*y1)
perp_dist = two_triarea / edge_len
if perp_dist > tolerance:
return (None, perp_dist)
# Rough approximation here, but good enough for hit calculation.
# Omit points too far away from the edge's centre point.
if finite:
xmid = (x1 + x2)/2.0
ymid = (y1 + y2)/2.0
dist_from_midpt = math.sqrt((xmid-x0)**2 + (ymid-y0)**2)
if dist_from_midpt > (edge_len/2.0)+tolerance:
return (None, perp_dist)
# Cursor name by sector.
# Aiming for a cursor that looks perpendicular to the line.
# Ish.
theta = math.atan2(Dy, Dx)
c = cursor.get_move_cursor_name_for_angle(theta + math.pi/2)
return (c, perp_dist)