Slanting AA Dimension

Slanting Dimensions
Sloping at 30°	Sloping at 120°	Sloping at 210°	sloping at 300°

Slanting AA Dimension Properties

Show/Hide slant_dim_aa Attributes

• im

  PIL image handle, link to the calling program

• dr

  PIL drawing handle, link to the calling program

• ptA

  Start coordinates

• ptB

  Finishing coordinates, optional

• extA

  Two integer tuple, giving the extension line size and gap next to start

• angle

  Slope of dimension, optional

• length

  Dimension length, optional

• text

  Dimension text

• font

  Font of the text

• fill

  Line colour, RGB tuple

• back

  Background colour, RGB tuple

• tail

  Show tails or arrows, default True

• arrowhead

  Three integer tuple describing the shape and size of the arrow, default (10,8,3)

• arrow

  position of the arrow on the line, which influences the direction it points, default both

This dimension is set parallel to the slanting surface, with extensions perpendicular to the dimension. The text is set outside of the dimension with attention paid to the text orientation. Use either 45° short stubs or arrows. When using these dimensions remember that the starting position refers to the item.

In essence apart from the complication of the angled geometry, it follows much the same pattern as the outer dimension. Specify the dimension position by giving two coordinates on the object, ptA and ptB, at a perpendicular distance of the extension, extA, alternatively give the start position and angle with dimension length. It is assumed that both extensions are of equal size.

If the text lies on the wrong side of the object simply change the angle by 180°.

Show/Hide Code test_slant_aa_dim.py

import sys
sys.path.append('../dims')

from PIL import Image, ImageDraw, ImageFont
from math import radians, degrees, sin, cos
from DimLinesPIL import polar2cart, int_up, angled_text
from DimLinesAA import WideLineAA, LineAA, dimension_aa

def slant_dim_aa(im, dr, ptA, ptB =None, extA=(8,2),  angle=None, length=None,
              fill=(0,0,0), back=(255,255,221), text=None, font=None, tail=True,
                arrowhead=(8,10,3), arrow='both'):
    # slanting dimension with 45° tails
    # extension tuple first number drawn, second space
    # ptA point on item surface

    if isinstance(extA, int) or len(extA) == 1:
        extO = extA if isinstance(extA, int) else extA[0]
    elif len(extA) == 2:
        extO = sum(extA)
    else:
        raise Exception('slant_dim_aa: The leader tuple extA {} should be one or ' \
                'two entries'.format(extA))

    if ptB is None and length and 0 <= angle <360:
        phir = radians(angle)
        ptC = polar2cart(ptA, angle-90, extO)
        ptD = polar2cart(ptC, angle, length)
    elif length is None and ptB:
        phir = atan2(ptB[1]-ptA[1], ptB[0]-ptA[0])
        angle = int_up(degrees(phir))
        ptC = polar2cart(ptA, angle-90, extO)
        ptD = ptC[0] + (ptB[0] - ptA[0]), ptC[1] + (ptB[1] - ptA[1])
    else:
        raise Exception('slant_dim_aa: Either supply ptB {}, or length {} and ' \
                'angle {}'.format(ptB, length, angle))

    dirn = radians(45 + angle)

    # dimension line
    if tail:
        LineAA(dr, ptC, ptD, fill=fill, back=back)
        # create 45° end stubs
        p3=int_up(ptC[0]+4*cos(dirn)),int_up(ptC[1]+4*sin(dirn))
        p4=int_up(ptC[0]-4*cos(dirn)),int_up(ptC[1]-4*sin(dirn))
        p5=int_up(ptD[0]+4*cos(dirn)),int_up(ptD[1]+4*sin(dirn))
        p6=int_up(ptD[0]-4*cos(dirn)),int_up(ptD[1]-4*sin(dirn))

        LineAA(dr, p3,p4, back=back, fill=fill)
        LineAA(dr, p5,p6, back=back, fill=fill)
    else:
        dimension_aa(im, dr, ptC, ptB=ptD, fill=fill,
                     arrowhead=arrowhead, arrow=arrow)

    # extensions, leave a gap if extA 2 entries
    extO = extO if isinstance(extA, int) or len(extA) == 1 else extA[0]
    ptC3 = polar2cart(ptC, angle-90, 3)
    ptCe = polar2cart(ptC, angle+90, extO-1)
    LineAA(dr, ptC3, ptCe, back=back, fill=fill)
    ptD3 = polar2cart(ptD, angle-90, 3)
    ptDe = polar2cart(ptD, angle+90, extO-1)
    LineAA(dr, ptD3, ptDe, back=back, fill=fill)

    font = ImageFont.load_default() if font is None else font
    # ft = font.getsize(text)
    # unused1, unused2, wide, height
    ft = font.getbbox(text)

    h = ft[3] // 2

    angle = 360 + angle if angle < 0 else angle
    angle = angle if angle <= 360 else angle - 360

    mid = (ptC[0] + ptD[0])/2, (ptC[1] + ptD[1])/2
    at =  mid[0] + (h + 7) * sin(phir), mid[1] - (h + 7) * cos(phir)
    at = int_up(at[0]), int_up(at[1])

    angled_text(im, at, text, angle, font, aall=0)

if __name__ == "__main__":
    Text = 'Test'
    Angle = 330
    ct = (52, 45)
    Length = 40
    exta = (10, 5) #15 #
    Font = ImageFont.truetype('consola.ttf', 15)
    Back = (255,255,221)
    image2 = Image.new('RGB', (80, 80), Back)

    sdraw = ImageDraw.Draw(image2)
    bt = polar2cart(ct, Angle, Length//2)
    At = polar2cart(ct, 180+Angle, Length//2)
    Fill = (0,0,255)
    WideLineAA(sdraw, At, bt, width=2, fill=Fill, back=Back)

    slant_dim_aa(image2,sdraw, At, extA=exta, fill=(0,0,0), length=Length,
                    angle=Angle, back=Back, text=Text, font=Font, tail=True)

    image2.show()
    #image2.save('../../temp/slant_aa_dim_'+str(angle) +'.png')