class tkMath( object ):
PIXELS_PER_INCH = 0
PIXELS_PER_CM = 0
PIXELS_PER_MM = 0
PIXELS_PER_POINT = 0
@staticmethod
def setup( root ):
'''Must be called before any of the methods are used to initialize
the conversion constants.'''
tkMath.PIXELS_PER_INCH = root.winfo_fpixels( '1i' )
tkMath.PIXELS_PER_CM = root.winfo_fpixels( '1c' )
tkMath.PIXELS_PER_MM = root.winfo_fpixels( '1m' )
tkMath.PIXELS_PER_POINT = root.winfo_fpixels( '1p' )
@staticmethod
def pixelsToInches( pixels ):
'''Convert pixels (python float or int) to inches.'''
return pixels / tkMath.PIXELS_PER_INCH
@staticmethod
def pixelsToCM( pixels ):
'''Convert pixels (python float or int) to centimeters.'''
return pixels / tkMath.PIXELS_PER_CM
@staticmethod
def pixelsToMM( pixels ):
'''Convert pixels (python float or int) to millimeters.'''
return pixels / tkMath.PIXELS_PER_MM
@staticmethod
def pixelsToPoints( pixels ):
'''Convert pixels (python float or int) to points.'''
return pixels / tkMath.PIXELS_PER_POINT
@staticmethod
def inchesToPixels( inches ):
'''Convert inches (python float or int) to pixels.'''
return inches * tkMath.PIXELS_PER_INCH
@staticmethod
def cmToPixels( cm ):
'''Convert centimeters (python float or int) to pixels.'''
return cm * tkMath.PIXELS_PER_CM
def mmToPixels( mm ):
'''Convert millimeters (python float or int) to pixels.'''
return mm * tkMath.PIXELS_PER_MM
def pointsToPixels( points ):
'''Convert points (python float or int) to pixels.'''
return points * tkMath.PIXELS_PER_POINTS
@staticmethod
def toPixels( tkCoord ):
'''Convenience function for inches, cm, mm and pointsToPixels().
Convert a tkCoord (string appended by 'i', 'c', 'm' or 'p') to pixels.'''
if isinstance( tkCoord, str ):
if tkCoord[-1] == 'i':
return tkMath.inchesToPixels( float(tkCoord[:-1]) )
elif tkCoord[-1] == 'c':
return tkMath.cmToPixels( float(tkCoord[:-1]) )
elif tkCoord[-1] == 'm':
return tkMath.mmToPixels( float(tkCoord[:-1]) )
elif tkCoord[-1] == 'p':
return tkMath.pointsToPixels( float(tkCoord[:-1]) )
else:
return float(tkCoord)
else:
return tkCoord
@staticmethod
def compare( coord1, coord2 ):
'''Compare two tk measures -- they need not be in the same units.'''
return tkMath.coordToPixels(coord1) - tkMath.coordToPixels(coord2)
@staticmethod
def add( coord1, coord2 ):
'''Add two tk measures -- they need not be in the same units.'''
return tkMath.coordToPixels(coord1) + tkMath.coordToPixels(coord2)
@staticmethod
def sub( coord1, coord2 ):
'''Subtract two tk measures -- they need not be in the same units.'''
return tkMath.coordToPixels(coord1) - tkMath.coordToPixels(coord2)
@staticmethod
def tkPolar( x1, y1, x2, y2 ):
'''Calculate the direction (in radians, 3 o'clock is 0,
down is 1/2 PI, etc.) and distance (in pixels) between to points.
All arguments should be in the same units (python float or int).
The result is in the same units as the arguments.'''
import math
deltaX = math.fabs( x1 - x2 )
deltaY = math.fabs( y1 - y2 )
direction = math.atan2( deltaY, deltaX )
distance = math.sqrt( math.pow(deltaX, 2) + math.pow(deltaY, 2) )
return direction, distance
@staticmethod
def tkCartesian( x, y, direction, distance ):
'''Complementary to tkPolar(). Given a x,y point, direction in
radians (0 is at 3 o'clock, 1/2 PI is straight down, etc.) and a
distance (all as python float or int). This function returns
the x and y of the end-point.'''
import math
deltaX = distance * math.cos( direction )
deltaY = distance * math.sin( direction )
return x + deltaX, y + deltaY
