cfc/docs/品牌资产/gen_trace.py

import zlib, struct, os, re

PNG = r"E:/cfc/docs/品牌资产/assets/cf_logo_primary.png"
with open(PNG,"rb") as f: data=f.read()
pos=8; idat=b""
while pos<len(data):
    ln=struct.unpack(">I",data[pos:pos+4])[0]; ctype=data[pos+4:pos+8]; chunk=data[pos+8:pos+8+ln]
    if ctype==b"IHDR": width,height,bit_depth,color_type=struct.unpack(">IIBB",chunk[:10])
    elif ctype==b"IDAT": idat+=chunk
    elif ctype==b"IEND": break
    pos+=12+ln
channels=4; raw=zlib.decompress(idat); stride=width*channels
out=bytearray(); prev=bytearray(stride); i=0
def paeth(a,b,c):
    p=a+b-c; pa,pb,pc=abs(p-a),abs(p-b),abs(p-c)
    if pa<=pb and pa<=pc: return a
    if pb<=pc: return b
    return c
for y in range(height):
    ft=raw[i]; i+=1; line=bytearray(raw[i:i+stride]); i+=stride
    for x in range(stride):
        a=line[x-channels] if x>=channels else 0; b=prev[x]; c=prev[x-channels] if x>=channels else 0
        if ft==1: line[x]=(line[x]+a)&255
        elif ft==2: line[x]=(line[x]+b)&255
        elif ft==3: line[x]=(line[x]+((a+b)>>1))&255
        elif ft==4: line[x]=(line[x]+paeth(a,b,c))&255
    out+=line; prev=line
def px(x,y):
    o=y*stride+x*channels; return (out[o],out[o+1],out[o+2],out[o+3])

def is_logo(r,g,b,a):
    if a<128: return False
    if abs(r-220)<24 and abs(g-240)<24 and abs(b-249)<24: return False
    return True
mask=[[is_logo(*px(x,y)) for x in range(width)] for y in range(height)]

def run_rects(y0,y1,x0,x1,exclude=None):
    rects=[]
    for y in range(max(0,y0), min(height,y1)):
        if exclude and exclude[0]<=y<exclude[1]: continue
        x=max(0,x0)
        while x<min(width,x1):
            if mask[y][x]:
                x0r=x
                while x<min(width,x1) and mask[y][x]:
                    x+=1
                rects.append((x0r,y,x-x0r))
            else:
                x+=1
    return rects

def build_svg(name, y0,y1,x0,x1, with_bg=False, exclude=None, text=None):
    rects=run_rects(y0,y1,x0,x1,exclude)
    ys=[y for (_,y,_) in rects]
    if text: ys += [text["y"]-text["size"], text["y"]]
    loy,hiy=(min(ys),max(ys)) if ys else (0,height)
    grad=(f'<linearGradient id="cfBlue" x1="0" y1="{loy}" x2="0" y2="{hiy}" gradientUnits="userSpaceOnUse">\n'
           f'    <stop offset="0" stop-color="#6FB6E3"/>\n'
           f'    <stop offset="1" stop-color="#3A8FCC"/>\n  </linearGradient>')
    body="".join(f'<rect x="{x}" y="{y}" width="{w}" height="1" fill="url(#cfBlue)"/>' for (x,y,w) in rects)
    bgrect='' if not with_bg else f'<rect x="0" y="0" width="{width}" height="{height}" rx="28" fill="#DCF0F9"/>'
    txt=''
    if text:
        txt=(f'<text x="{text["x"]}" y="{text["y"]}" text-anchor="middle" '
             f'font-family="\'Segoe UI\',\'Helvetica Neue\',Arial,\'Noto Sans SC\',sans-serif" '
             f'font-size="{text["size"]}" font-weight="600" letter-spacing="0.5" fill="url(#cfBlue)">{text["content"]}</text>')
    svg=(f'<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 {width} {height}" width="{width}" height="{height}">\n'
         f'  <defs>{grad}</defs>\n  {bgrect}\n  {body}\n  {txt}\n</svg>\n')
    return svg

outdir=r"E:/cfc/docs/品牌资产/assets"

# wordmark bbox in 144 canvas: x[42,103] y[112,120]; baseline ~121, size ~13, center x=72
WM={"x":72,"y":121,"size":13,"content":"Care Family"}

# primary: monogram pixel-trace (exclude wordmark rows) + smooth vector wordmark text
prim=build_svg("primary",0,height,0,width,with_bg=False,exclude=(108,144),text=WM)
icon=build_svg("icon",36,107,25,119)
primbg=build_svg("primary_bg",0,height,0,width,with_bg=True,exclude=(108,144),text=WM)

# standalone wordmark: smooth vector text on its own clean canvas
wm_svg=(f'<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 220 44" width="220" height="44">\n'
        f'  <defs><linearGradient id="cfBlue" x1="0" y1="6" x2="0" y2="38" gradientUnits="userSpaceOnUse">\n'
        f'    <stop offset="0" stop-color="#6FB6E3"/>\n    <stop offset="1" stop-color="#3A8FCC"/>\n  </linearGradient></defs>\n'
        f'  <text x="110" y="32" text-anchor="middle" '
        f'font-family="\'Segoe UI\',\'Helvetica Neue\',Arial,\'Noto Sans SC\',sans-serif" '
        f'font-size="28" font-weight="600" letter-spacing="1" fill="url(#cfBlue)">Care Family</text>\n</svg>\n')

files={"cf_logo_primary.svg":prim,"cf_logo_icon.svg":icon,"cf_logo_wordmark.svg":wm_svg,"cf_logo_primary_bg.svg":primbg}
for nm,content in files.items():
    with open(os.path.join(outdir,nm),"w",encoding="utf-8") as f:
        f.write(content)
    print("wrote",nm,len(content),"bytes")

# verify primary monogram region still pixel-exact vs original
svg=open(os.path.join(outdir,"cf_logo_primary.svg"),encoding="utf-8").read()
rects=[(int(x),int(y),int(w)) for (x,y,w) in re.findall(r'<rect x="(\d+)" y="(\d+)" width="(\d+)"',svg)]
recon=[[False]*width for _ in range(height)]
for (x,y,w) in rects:
    for xx in range(x,min(width,x+w)): recon[y][xx]=True
diff=sum(1 for y in range(36,107) for x in range(25,119) if mask[y][x]!=recon[y][x])
print("primary monogram-region diff vs original:",diff,"(0 = pixel-exact)")
print("done")