A brief introduction to the python analysis inkscape path data scheme

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Sometimes you need to use path data during the development process, although python has its own svg Or other vector libraries, but this is just for experimental purposes, there is no need to study in depth, so some simple solutions are adopted: use inkscape to generate svg, and then python analyzes and outputs it to achieve the corresponding purpose

inkscape generates the path

Set document properties:

Set grid:

Import png images as reference:

Note that the imported image and document properties have the lower left corner as the origin. :

In the layer and object property bars, modify the image visibility and lock the image:

Create a new layer above the current layer to draw road strength
Draw a rectangle at will and make the corresponding shape. For example, cutting between two rectangles can be done through the menu: Path->Difference set

Convert shape to path

Theoretically, after saving, there is an svg file that can be converted to a path. However, due to the complex format of svg files, there will be various shape data, so here we need to uniformly convert various shapes into paths for simple analysis by python

Then the above example needs to be repeated Further processing:

• If the object is a rect or other shape, execute the menu: Path->Object to Path
• For combination For the shape of the path, execute the menu: Road Jin->Split Road Jin

The final layer obtained is as follows:

##After saving the svg file, open it with Notepad, and you will see the following key content:

     <g
     inkscape:groupmode="layer"
     id="layer2"
     inkscape:label="图层 2"><path
       style="fill:none;stroke:#000000;stroke-width:0.1;stroke-dasharray:none"
       d="m 510.66797,509.15234 3.82812,8.50586 h 3.92383 v -8.50586 z"
       id="path11706" /><path
       style="fill:none;stroke:#000000;stroke-width:0.1;stroke-dasharray:none"
       d="m 504.25195,509.15234 v 8.50586 h 8.14258 l -3.82812,-8.50586 z"
       id="rect3684" /></g>

Two of the path data start with m and end with At the end of z, it means that the data is ready.

python analysis svg

Regular expression analysis is used here, and the results are output as a lua table:

import re
import sys
f=open("绘图.svg","r",encoding='utf-8')
print("result={")
s=f.read()
for mg in re.finditer("<g.*?</g>",s,re.S):
    for mp in re.finditer("<path.*?/>",mg.group(),re.S):
        path=[]
        pathid=""
        md=re.search("\sd=\"(.+?)\"",mp.group(),re.S)
        if md:
            last_pos=(0,0)
            ###################### 1                 2                 3                 4                 5                 6                 7                 8                 9
            for ml in re.finditer("(M[^MmLlHhVvZz]+)|(m[^MmLlHhVvZz]+)|(L[^MmLlHhVvZz]+)|(l[^MmLlHhVvZz]+)|(H[^MmLlHhVvZz]+)|(h[^MmLlHhVvZz]+)|(V[^MmLlHhVvZz]+)|(v[^MmLlHhVvZz]+)|(Z|z)",md.group(1)):
                if ml.group(1):
                    ###################### 1               3
                    for mv in re.finditer("(-?\d+(\.\d+)?),(-?\d+(\.\d+)?)",ml.group(1)):
                        last_pos=(float(mv.group(1)),float(mv.group(3)))
                        path.append(last_pos)
                elif ml.group(2):
                    for mv in re.finditer("(-?\d+(\.\d+)?),(-?\d+(\.\d+)?)",ml.group(2)):
                        last_pos=(last_pos[0]+float(mv.group(1)),last_pos[1]+float(mv.group(3)))
                        path.append(last_pos)
                elif ml.group(3):
                    for mv in re.finditer("(-?\d+(\.\d+)?),(-?\d+(\.\d+)?)",ml.group(3)):
                        last_pos=(float(mv.group(1)),float(mv.group(3)))
                        path.append(last_pos)
                    pass
                elif ml.group(4):
                    for mv in re.finditer("(-?\d+(\.\d+)?),(-?\d+(\.\d+)?)",ml.group(4)):
                        last_pos=(last_pos[0]+float(mv.group(1)),last_pos[1]+float(mv.group(3)))
                        path.append(last_pos)
                    pass
                elif ml.group(5):
                    for mv in re.finditer("(-?\d+(\.\d+)?)",ml.group(5)):
                        last_pos=(float(mv.group(1)),last_pos[1])
                        path.append(last_pos)
                elif ml.group(6):
                    for mv in re.finditer("(-?\d+(\.\d+)?)",ml.group(6)):
                        last_pos=(last_pos[0]+float(mv.group(1)),last_pos[1])
                        path.append(last_pos)
                elif ml.group(7):
                    for mv in re.finditer("(-?\d+(\.\d+)?)",ml.group(7)):
                        last_pos=(last_pos[0],float(mv.group(1)))
                        path.append(last_pos)
                elif ml.group(8):
                    for mv in re.finditer("(-?\d+(\.\d+)?)",ml.group(8)):
                        last_pos=(last_pos[0],last_pos[1]+float(mv.group(1)))
                        path.append(last_pos)
                elif ml.group(9):
                    path.append(path[0])
        mid=re.search("\sinkscape:label=\"(.+?)\"",mp.group(),re.S) or re.search("\sid=\"(.+?)(-\d+)*?\"",mp.group(),re.S)
        if mid:
            pathid=mid.group(1)
        print("{\nid=\""+pathid+"\",")
        for pos in path:
            print("Vector2(%f,%f),"%(pos[0],pos[1]))
        print("},")
print("}\n")

Get the data after running ：

result={
{
id="path11706",
Vector2(510.667970,509.152340),
Vector2(514.496090,517.658200),
Vector2(518.419920,517.658200),
Vector2(518.419920,509.152340),
Vector2(510.667970,509.152340),
},
{
id="rect3684",
Vector2(504.251950,509.152340),
Vector2(504.251950,517.658200),
Vector2(512.394530,517.658200),
Vector2(508.566410,509.152340),
Vector2(504.251950,509.152340),
},
}

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