Level AA Dimensions

Inner and Outer Levels

Outer Level dimension attributes

AA Level Properties

Show/Hide level_dim_aa Attributes

• im

  PIL image handle, link to the calling program

• dr

  PIL image handle, link to the calling program

• at

  Coordinates at left tank wall level

• diam

  Tank diameter, pixels

• ext

  Tuple of extender length and gap, default 0 (internal dimension), enlarge the gap with very thick tank walls

• ldrA

  Inclined leader length, default 20, if negative the dimension is switched around

• ldrA

  Horizontal leader length, default 20

• dash

  Tuple giving dash pattern, dash length then gap default (10, 4)

• text

  Dimension text

• fill

  Dimension colour, RGB tuple

• back

  background colour, RGB tuple

• tri

  Level indicator, equilateral triangle default 8

• font

  Font of the text, default None

Level dimension inside a tank

Level dimension negative leader

Outer level dimension

Negative outer level dimension

Contents of a tank are shown with dashed line and dashed leaders. Apart from the starting position, diameter of tank, the user can choose different dash patterns, the lengths of the inclined and horizontal leader, the length of the extender on outer dimensions and the indicating triangle size. Normally the leader lies to the right of the vessel, if a negative value (ldrA) is used the leader is on the lefthand side. As the dashed lines will be antialiased the method used in the plain dimensions was changed. If the extender ext is 0 then an inner dimension is shown.

Show/Hide Code test_level_aa_dim.py

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

from PIL import Image, ImageDraw, ImageFont
from math import sin, pi
from DimLinesAA import WideLineAA, DashedLineAA, polyAA
from DimLinesPIL import int_up, angled_text


def level_dim_aa(im, dr, at, diam, ext=(15, 3), ldrA=20, ldrB=50, dash=(10,4),
                text=None, fill=(0,0,0), back=(255,255,221), tri=8, font=None):
    # at on left tank wall, diam internal tank diameter,
    # triangle at level (8,8,8) p0 tip triangle, p1, p2 angles, p2 continues to p4
    # p3 opposite side to at, both drawn to inside tank wall
    # leader (ldr) at 60° up to p4 then horizontal to p5
    # if ext != 0, p7 position of end of extender before touching tank wall

    # check dash input
    if len(dash)%2 == 0 or len(dash) ==1:
        pass
    else:
        raise Exception('out_dim_level: the dash tuple {} should be one or an' \
                        ' equal number of entries'.format(dash))

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

    font = ImageFont.load_default() if font is None else font

    # (wide, ht) = font.getsize(text) if text is not None else (0,0)
    unused1, unused2, wide, ht = font.getbbox(text) if text is not None else (0,0)

    #hi = ht // 2

    angle = 0

    # check whether gap is required
    est = 0 if isinstance(ext, int) or len(ext) == 1 else ext[1] + 1
    print(exto)
    p3 = (at[0] + diam, at[1])
    # check whether left or right position
    if ldrA > 0:
        if ext == 0:
            p0 = (at[0] + int_up(diam * 0.4), at[1])
            p4 = (p0[0] + int_up(ldrA * 0.5), p0[1] - int_up(ldrA * sin(pi/3)))
            p5 = (at[0] + diam, p4[1]) if ldrB < diam else (at[0] + diam + ldrB, p4[1])
        else:
            p0 = (at[0] + int_up(diam + 0.6 * exto), at[1])
            p4 = (p0[0] + int_up(ldrA * 0.5), p0[1] - int_up(ldrA * sin(pi/3)))
            p5 = (p4[0] + ldrB, p4[1])  # end ldr
            p7 = (p3[0] + est, at[1])
    else:
        if ext == 0:
            p0 = (at[0] + int_up(diam * 0.6), at[1])
            p4 = (p0[0] + int_up(ldrA * 0.5), p0[1] + int_up(ldrA * sin(pi/3)))
            p5 = (at[0], p4[1])
        else:
            p0 = (at[0] - int_up(0.6 * exto), at[1])
            p4 = (p0[0] + int_up(ldrA * 0.5), p0[1] + int_up(ldrA * sin(pi/3)))
            p5 = (p4[0] - ldrB, p4[1])
            p7 = (at[0] - est, at[1])

    print(p4,p5)
    ldr_s = abs(p5[0] - p4[0])

    if ldr_s < wide:
        raise Exception('The leader size is too small: {} should be larger '\
                        'than the text width {}'.format(ldr_s, wide))

    p2 = (int_up(p0[0] + tri * 0.5), p0[1] - int_up(tri * sin(pi/3)))
    p1 = (p2[0] - tri, p2[1])

    DashedLineAA(dr, at, p3, dash=dash, fill=fill, back=back)
    polyAA(im, dr, [p0, p1, p2], outline=fill, back=back)

    if ldrA > 0:
        if ext == 0:
            DashedLineAA(dr, p2, p4, dash=dash, fill=fill, back=back)
        else:
            dr.line([p2, p4], width = 1, fill=fill)
            dr.line([p7, (p7[0] + exto, p7[1])], width = 1, fill=fill)
    else:
        if ext == 0:
            DashedLineAA(dr, p1, p4, dash=dash, fill=fill, back=back)
        else:
            dr.line([p1, p4], width = 1, fill=fill)
            dr.line([p7, (p7[0] - exto, p7[1])], width = 1, fill=fill)

    if ext == 0:
        DashedLineAA(dr, p4, p5, dash=dash, fill=fill, back=back)
    else:
        dr.line([p4, p5], width = 1, fill=fill)

    p6 = (int((p4[0] + p5[0])//2), p4[1] - ht - 5)

    angled_text(im, p6, text, angle, font, fill=fill)
    #print(p0,p1,p2,p3,p4,p5,p6) #,p7)

if __name__ == "__main__":

    Text='2500 hl'
    Font = ImageFont.truetype('consola.ttf', 12)
    # wi, height = Font.getsize(Text)
    unused1, unused2, wi, height = Font.getbbox(Text)

    Back = (255,255,221)

    w, h = 200, 200
    image = Image.new('RGB', (w,h), Back)

    draw = ImageDraw.Draw(image)

    a=(10,10) # (90,10)
    b=(10,190) # (90,190)
    c=(190,10) # (110,10)
    d=(190,190) # (110,190)
    Fill = (0,0,255)
    Fi = (0,0,0)

    WideLineAA(draw, a, b, width=2, fill=Fill, back=Back)
    WideLineAA(draw, c, d, width=2, fill=Fill, back=Back)

    At=(a[0],100)
    Diam = c[0] - a[0]

    #level_dim_aa(image, draw, At, Diam, ldrA=-20, ldrB=50, dash=(10,4), text=Text,
                #fill=Fi, back=Back, tri=8, font=Font)
    level_dim_aa(image, draw, At, Diam, ldrA=20, ldrB=50, dash=(10,4), text=Text,
                fill=Fi, back=Back, tri=8, font=Font, ext=0)

    image.show()
    #image.save('../../temp/out_level_aa_dim_neg.png')

If the normal level dimension cannot be used then an outside dimension can be used. This has an extension line outside of the vessel, the indicating triangle sits on the extension line. As the leaders are outside of the vessel they are drawn solidly.

The extender ext can be a single integer, in which case the line touches the vessel or as a tuple of two values, the first being the line length, the second the gap length.