Screw conveyors join across the corner to diagonals (t62)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

test/t_smooth.py

@@ -97,6 +97,34 @@ with sync_playwright() as p:
     }''')
     check('sidewall stays behind the grain colour in pixels and smooth',
           wall and wall['colors'][0] == wall['colors'][1] and wall['grainClass'] == 2, wall)
+    # All 64 straight/diagonal mouths must have copper casing on both sides of the join.
+    pg.set_viewport_size({"width": 2100, "height": 1300})
+    ev("part.fill(0); blockP.fill(0); occ.fill(0); mach.fill(0); ents=[]; ghostBlocks.clear();")
+    ev("() => {" + (root / "tools/scenes/t62-joins.js").read_text() + "}")
+    mouths = ev('''() => {
+      SET.zoom=6; SET.lighting="off"; SET.glow="off"; resizeRender();
+      bot.x=CAM[0]-bot.w/2;bot.y=CAM[1]-bot.h/2;snapCamera();
+      const out={};
+      for(const look of ["pixel","smooth"]) {
+        SET.look=look;SM.scale=1;drawWorld();
+        const bad=[];
+        for(const j of T62_JOINTS) {
+          const slope=j.v===4 || j.v===6?-1:1;
+          const end=j.end*SCREW_DIRS[j.v][0];
+          const dx=j.vertical?0:end,dy=j.vertical?end*slope:0;
+          const ox=j.corner && j.vertical?end*4:0,oy=j.corner && !j.vertical?end*slope*4:0;
+          for(const side of [-1,1])for(const along of [-0.3,0.3]) {
+            const x=j.bx*4+2+ox+dx*(2+along)-dy*side*1.6;
+            const y=j.by*4+2+oy+dy*(2+along)+dx*side*1.6;
+            const p=worldToScreenPx(x,y),c=R.ctx.getImageData(Math.floor(p.x),Math.floor(p.y),1,1).data;
+            if(!(c[0]>c[1]*1.15 && c[1]>c[2]*1.1))bad.push([j,x,y,Array.from(c)]);
+          }
+        }
+        out[look]=bad;
+      }return out;
+    }''')
+    for look, bad in mouths.items():
+        check(f"{look}: all 64 screw joints have closed casing across both mouth edges", not bad, bad[:2])
     # a browser without hardware drawing gets the pixel look and a note
     pg2 = b.new_page(viewport={'width': 800, 'height': 500})
     pg2.add_init_script('localStorage.clear();')