import bpy, sys
import numpy as np
bpy.ops.wm.open_mainfile(filepath=sys.argv[sys.argv.index("--")+1])
ob = max([o for o in bpy.data.objects if o.type=='MESH'], key=lambda o: len(o.data.vertices))
me = ob.data
n_v = len(me.vertices)
co = np.empty(n_v*3); me.vertices.foreach_get("co", co); co = co.reshape(-1,3)
img = next(i for i in bpy.data.images if "basecolor" in i.name.lower())
w,h = img.size
px = np.empty(w*h*4, dtype=np.float32); img.pixels.foreach_get(px)
rgb = px.reshape(h,w,4)[:,:,:3]
lv = np.empty(len(me.loops), dtype=np.int32); me.loops.foreach_get("vertex_index", lv)
uv = np.empty(len(me.loops)*2); me.uv_layers.active.data.foreach_get("uv", uv); uv = uv.reshape(-1,2)
fl = np.full(n_v, len(lv), dtype=np.int64); np.minimum.at(fl, lv, np.arange(len(lv)))
fl = np.minimum(fl, len(lv)-1)
c = rgb[(np.clip(uv[fl,1],0,1)*(h-1)).astype(int), (np.clip(uv[fl,0],0,1)*(w-1)).astype(int)]
mx = c.max(axis=1); mn = c.min(axis=1)
sat = np.where(mx>1e-5,(mx-mn)/np.maximum(mx,1e-5),0)
rb = c[:,0]/np.maximum(c[:,2],1e-5)
luma = 0.2126*c[:,0]+0.7152*c[:,1]+0.0722*c[:,2]
for nm, m in (
  ("strap front", (co[:,2]>0.75)&(co[:,2]<0.83)&(np.abs(co[:,0])>0.035)&(np.abs(co[:,0])<0.09)&(co[:,1]<0)),
  ("strap top",   (co[:,2]>0.775)&(co[:,2]<0.805)&(np.abs(co[:,0])>0.035)&(np.abs(co[:,0])<0.09)),
  ("shoulder skin",(co[:,2]>0.75)&(co[:,2]<0.80)&(np.abs(co[:,0])>0.10)&(np.abs(co[:,0])<0.16)),
  ("chest skin",  (co[:,2]>0.74)&(co[:,2]<0.77)&(np.abs(co[:,0])<0.03)&(co[:,1]<0)),
):
    if m.sum():
        print(f"{nm}: n={m.sum():6d} sat p25/50/75 = {np.percentile(sat[m],25):.3f}/{np.median(sat[m]):.3f}/{np.percentile(sat[m],75):.3f}  rb {np.median(rb[m]):.2f}  luma {np.median(luma[m]):.3f}")
print("STRAP_PROBE_DONE")