car-scene-assembly

cat /home/user/task/scenes/car.tscn 2>/dev/null; echo "---ASSETS---"; ls /home/user/task/assets/ 2>/dev/null; echo "---PROJECT---"; cat /home/user/task/project.godot 2>/dev/null | head -50

{
  "description": "Inspect car.tscn, assets, project"
}

cat /home/user/task/assets/spritesheet_vehicles.png.import; echo "---"; ls -la /home/user/task/assets/; echo "---XML?---"; find /home/user/task -name "*.xml" 2>/dev/null; echo "---IMG INFO---"; file /home/user/task/assets/spritesheet_vehicles.png; python3 -c "from PIL import Image; print(Image.open('/home/user/task/assets/spritesheet_vehicles.png').size)" 2>/dev/null || echo "no PIL"

{
  "description": "Inspect spritesheet import and dimensions"
}

cd /home/user/task; python3 -c "
import struct
with open('assets/spritesheet_vehicles.png','rb') as f:
    data=f.read()
# PNG IHDR
w,h=struct.unpack('>II', data[16:24])
print('size',w,h)
"

{
  "description": "Read PNG dimensions"
}

cd /home/user/task; python3 -c "import zlib; print('zlib ok')"; python3 - <<'EOF'
import struct, zlib
with open('assets/spritesheet_vehicles.png','rb') as f:
    d=f.read()
pos=8
width=height=bitd=colort=None
idat=b''
while pos<len(d):
    ln=struct.unpack('>I',d[pos:pos+4])[0]
    typ=d[pos+4:pos+8]
    chunk=d[pos+8:pos+8+ln]
    if typ==b'IHDR':
        width,height,bitd,colort=struct.unpack('>IIBB',chunk[:10])
    elif typ==b'IDAT':
        idat+=chunk
    pos+=12+ln
print('w',width,'h',height,'bitd',bitd,'color',colort)
raw=zlib.decompress(idat)
# color type 6 = RGBA
ch={0:1,2:3,3:1,4:2,6:4}[colort]
bpp=ch*bitd//8
stride=width*bpp
def paeth(a,b,c):
    p=a+b-c; pa=abs(p-a);pb=abs(p-b);pc=abs(p-c)
    return a if pa<=pb and pa<=pc else (b if pb<=pc else c)
out=bytearray()
prev=bytearray(stride)
i=0
for y in range(height):
    f=raw[i]; i+=1
    line=bytearray(raw[i:i+stride]); i+=stride
    if f==1:
        for x in range(bpp,stride): line[x]=(line[x]+line[x-bpp])&255
    elif f==2:
        for x in range(stride): line[x]=(line[x]+prev[x])&255
    elif f==3:
        for x in range(stride):
            a=line[x-bpp] if x>=bpp else 0
            line[x]=(line[x]+((a+prev[x])>>1))&255
    elif f==4:
        for x in range(stride):
            a=line[x-bpp] if x>=bpp else 0
            c=prev[x-bpp] if x>=bpp else 0
            line[x]=(line[x]+paeth(a,prev[x],c))&255
    out+=line
    prev=line
# save alpha map analysis
import sys
# Find connected components of alpha>0 to detect sprites. Simpler: scan rows/cols of alpha.
alpha=[[out[(y*width+x)*4+3] for x in range(width)] for y in range(height)]
# column and row occupancy to find grid gaps
colocc=[any(alpha[y][x]>0 for y in range(height)) for x in range(width)]
rowocc=[any(alpha[y][x]>0 for x in range(width)) for y in range(height)]
def spans(occ):
    s=[];start=None
    for i,v in enumerate(occ):
        if v and start is None: start=i
        elif not v and start is not None: s.append((start,i-1)); start=None
    if start is not None: s.append((start,len(occ)-1))
    return s
print('col spans',spans(colocc))
print('row spans',spans(rowocc))
EOF

{
  "description": "Decode PNG and find sprite spans"
}

cd /home/user/task; python3 - <<'EOF'
import struct, zlib, sys
sys.setrecursionlimit(10000)
with open('assets/spritesheet_vehicles.png','rb') as f:
    d=f.read()
pos=8; idat=b''
while pos<len(d):
    ln=struct.unpack('>I',d[pos:pos+4])[0]; typ=d[pos+4:pos+8]; chunk=d[pos+8:pos+8+ln]
    if typ==b'IHDR': width,height=struct.unpack('>II',chunk[:8])
    elif typ==b'IDAT': idat+=chunk
    pos+=12+ln
raw=zlib.decompress(idat); bpp=4; stride=width*bpp
def paeth(a,b,c):
    p=a+b-c; pa=abs(p-a);pb=abs(p-b);pc=abs(p-c)
    return a if pa<=pb and pa<=pc else (b if pb<=pc else c)
out=bytearray(); prev=bytearray(stride); i=0
for y in range(height):
    f=raw[i]; i+=1; line=bytearray(raw[i:i+stride]); i+=stride
    if f==1:
        for x in range(bpp,stride): line[x]=(line[x]+line[x-bpp])&255
    elif f==2:
        for x in range(stride): line[x]=(line[x]+prev[x])&255
    elif f==3:
        for x in range(stride):
            a=line[x-bpp] if x>=bpp else 0; line[x]=(line[x]+((a+prev[x])>>1))&255
    elif f==4:
        for x in range(stride):
            a=line[x-bpp] if x>=bpp else 0; c=prev[x-bpp] if x>=bpp else 0
            line[x]=(line[x]+paeth(a,prev[x],c))&255
    out+=line; prev=line
W,H=width,height
def A(x,y): return out[(y*W+x)*4+3]
# iterative flood fill connected components (8-conn)
lab=[[0]*W for _ in range(H)]
boxes=[]
cur=0
from collections import deque
for y in range(H):
    for x in range(W):
        if A(x,y)>10 and lab[y][x]==0:
            cur+=1; q=deque([(x,y)]); lab[y][x]=cur
            minx=maxx=x; miny=maxy=y; cnt=0
            while q:
                cx,cy=q.popleft(); cnt+=1
                if cx<minx:minx=cx
                if cx>maxx:maxx=cx
                if cy<miny:miny=cy
                if cy>maxy:maxy=cy
                for dx in(-1,0,1):
                    for dy in(-1,0,1):
                        nx,ny=cx+dx,cy+dy
                        if 0<=nx<W and 0<=ny<H and lab[ny][nx]==0 and A(nx,ny)>10:
                            lab[ny][nx]=cur; q.append((nx,ny))
            boxes.append((minx,miny,maxx-minx+1,maxy-miny+1,cnt))
boxes=[b for b in boxes if b[4]>200]
boxes.sort(key=lambda b:(b[1],b[0]))
print('num',len(boxes))
for b in boxes: print(b)
EOF

{
  "description": "Connected components to find sprites"
}

cd /home/user/task; python3 - <<'EOF'
import struct, zlib
with open('assets/spritesheet_vehicles.png','rb') as f:
    d=f.read()
pos=8; idat=b''
while pos<len(d):
    ln=struct.unpack('>I',d[pos:pos+4])[0]; typ=d[pos+4:pos+8]; chunk=d[pos+8:pos+8+ln]
    if typ==b'IHDR': width,height=struct.unpack('>II',chunk[:8])
    elif typ==b'IDAT': idat+=chunk
    pos+=12+ln
raw=zlib.decompress(idat); bpp=4; stride=width*bpp
def paeth(a,b,c):
    p=a+b-c; pa=abs(p-a);pb=abs(p-b);pc=abs(p-c)
    return a if pa<=pb and pa<=pc else (b if pb<=pc else c)
out=bytearray(); prev=bytearray(stride); i=0
for y in range(height):
    f=raw[i]; i+=1; line=bytearray(raw[i:i+stride]); i+=stride
    if f==1:
        for x in range(bpp,stride): line[x]=(line[x]+line[x-bpp])&255
    elif f==2:
        for x in range(stride): line[x]=(line[x]+prev[x])&255
    elif f==3:
        for x in range(stride):
            a=line[x-bpp] if x>=bpp else 0; line[x]=(line[x]+((a+prev[x])>>1))&255
    elif f==4:
        for x in range(stride):
            a=line[x-bpp] if x>=bpp else 0; c=prev[x-bpp] if x>=bpp else 0
            line[x]=(line[x]+paeth(a,prev[x],c))&255
    out+=line; prev=line
W,H=width,height
def A(x,y): return out[(y*W+x)*4+3]
# coarse grid 8px cells over region x0..700
cw=8
cols=700//cw
rows=H//cw
chars=' .:-=+*#%@'
for cy in range(rows):
    line=''
    for cx in range(cols):
        s=0;n=0
        for yy in range(cy*cw,(cy+1)*cw):
            for xx in range(cx*cw,(cx+1)*cw):
                s+=A(xx,yy);n+=1
        v=s//n
        line+=chars[min(9,v*10//256)]
    print('%3d '%(cy*cw)+line)
# print column ruler
print('    '+''.join(str((c*cw//100)%10) for c in range(cols)))
EOF

{
  "description": "ASCII visualization of spritesheet"
}

cd /home/user/task; python3 - <<'EOF'
import struct, zlib
from collections import deque
with open('assets/spritesheet_vehicles.png','rb') as f:
    d=f.read()
pos=8; idat=b''
while pos<len(d):
    ln=struct.unpack('>I',d[pos:pos+4])[0]; typ=d[pos+4:pos+8]; chunk=d[pos+8:pos+8+ln]
    if typ==b'IHDR': width,height=struct.unpack('>II',chunk[:8])
    elif typ==b'IDAT': idat+=chunk
    pos+=12+ln
raw=zlib.decompress(idat); bpp=4; stride=width*bpp
def paeth(a,b,c):
    p=a+b-c; pa=abs(p-a);pb=abs(p-b);pc=abs(p-c)
    return a if pa<=pb and pa<=pc else (b if pb<=pc else c)
out=bytearray(); prev=bytearray(stride); i=0
for y in range(height):
    f=raw[i]; i+=1; line=bytearray(raw[i:i+stride]); i+=stride
    if f==1:
        for x in range(bpp,stride): line[x]=(line[x]+line[x-bpp])&255
    elif f==2:
        for x in range(stride): line[x]=(line[x]+prev[x])&255
    elif f==3:
        for x in range(stride):
            a=line[x-bpp] if x>=bpp else 0; line[x]=(line[x]+((a+prev[x])>>1))&255
    elif f==4:
        for x in range(stride):
            a=line[x-bpp] if x>=bpp else 0; c=prev[x-bpp] if x>=bpp else 0
            line[x]=(line[x]+paeth(a,prev[x],c))&255
    out+=line; prev=line
W,H=width,height
def A(x,y): return out[(y*W+x)*4+3]
TH=128
lab=[[0]*W for _ in range(H)]; cur=0; boxes=[]
for y in range(H):
    for x in range(W):
        if A(x,y)>=TH and lab[y][x]==0:
            cur+=1; q=deque([(x,y)]); lab[y][x]=cur
            minx=maxx=x;miny=maxy=y;cnt=0
            while q:
                cx,cy=q.popleft();cnt+=1
                minx=min(minx,cx);maxx=max(maxx,cx);miny=min(miny,cy);maxy=max(maxy,cy)
                for dx,dy in((1,0),(-1,0),(0,1),(0,-1)):
                    nx,ny=cx+dx,cy+dy
                    if 0<=nx<W and 0<=ny<H and lab[ny][nx]==0 and A(nx,ny)>=TH:
                        lab[ny][nx]=cur;q.append((nx,ny))
            boxes.append([minx,miny,maxx-minx+1,maxy-miny+1,cnt])
boxes=[b for b in boxes if b[4]>300]
boxes.sort(key=lambda b:(round(b[1]/30),b[0]))
print('num',len(boxes))
for b in boxes: print('x=%d y=%d w=%d h=%d area=%d'%tuple(b))
EOF

{
  "description": "Strict 4-conn components"
}

{
  "file_path": "/home/user/task/scenes/car.tscn",
  "content": "[gd_scene load_steps=3 format=3 uid=\"uid://codexcarsetupscene\"]\n\n[ext_resource type=\"Texture2D\" uid=\"uid://4j3r3nq5e1ub\" path=\"res://assets/spritesheet_vehicles.png\" id=\"1_car\"]\n\n[sub_resource type=\"CapsuleShape2D\" id=\"CapsuleShape2D_car\"]\nradius = 33.0\nheight = 121.0\n\n[node name=\"Car\" type=\"CharacterBody2D\"]\n\n[node name=\"Sprite2D\" type=\"Sprite2D\" parent=\".\"]\nrotation = 1.5707964\ntexture = ExtResource(\"1_car\")\nregion_enabled = true\nregion_rect = Rect2(363, 265, 68, 121)\n\n[node name=\"CollisionShape2D\" type=\"CollisionShape2D\" parent=\".\"]\nrotation = 1.5707964\nshape = SubResource(\"CapsuleShape2D_car\")\n\n[node name=\"Camera2D\" type=\"Camera2D\" parent=\".\"]\n"
}

{
  "file_path": "/home/user/task/scenes/car.tscn"
}

{
  "file_path": "/home/user/task/scenes/car.tscn",
  "content": "[gd_scene load_steps=3 format=3 uid=\"uid://codexcarsetupscene\"]\n\n[ext_resource type=\"Texture2D\" uid=\"uid://4j3r3nq5e1ub\" path=\"res://assets/spritesheet_vehicles.png\" id=\"1_car\"]\n\n[sub_resource type=\"CapsuleShape2D\" id=\"CapsuleShape2D_car\"]\nradius = 33.0\nheight = 121.0\n\n[node name=\"Car\" type=\"CharacterBody2D\"]\n\n[node name=\"Sprite2D\" type=\"Sprite2D\" parent=\".\"]\nrotation = 1.5707964\ntexture = ExtResource(\"1_car\")\nregion_enabled = true\nregion_rect = Rect2(363, 265, 68, 121)\n\n[node name=\"CollisionShape2D\" type=\"CollisionShape2D\" parent=\".\"]\nrotation = 1.5707964\nshape = SubResource(\"CapsuleShape2D_car\")\n\n[node name=\"Camera2D\" type=\"Camera2D\" parent=\".\"]\n"
}