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FA-51691 / Raster clipping / Open access

Scanline polygon span clip: span start rounding · case 01

Span starts include the pixel containing the left crossing even when its center lies left of the edge.

Verified by executionVariant 1 · 13 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Span starts include the pixel containing the left crossing even when its center lies left of the edge.

VERIFIED REPAIR

Restore the specified clipping decision at span start rounding. Each command is [polygon,scissor]. Rows y in the scissor rows [top,bottom) intersected with [0,size) are sampled at y+1/2. Each polygon edge is oriented bottom to top and contributes a crossing when top<=yc<bottom (half-open in y), interpolated exactly. Crossings are sorted and paired even-odd. A pair covers pixels whose centers x+1/2 satisfy xa<=x+1/2<xb, i.e. [ceil(xa-1/2),ceil(xb-1/2)), then clipped to the scissor columns [left,right) intersected with [0,size). Non-empty spans are returned as [row,start,end].

Unsuccessful approach: Rounding the crossing uses half-even ties and misplaces starts whose pixel center is exactly on the edge.

Case contract

Each command is [polygon,scissor]. Rows y in the scissor rows [top,bottom) intersected with [0,size) are sampled at y+1/2. Each polygon edge is oriented bottom to top and contributes a crossing when top<=yc<bottom (half-open in y), interpolated exactly. Crossings are sorted and paired even-odd. A pair covers pixels whose centers x+1/2 satisfy xa<=x+1/2<xb, i.e. [ceil(xa-1/2),ceil(xb-1/2)), then clipped to the scissor columns [left,right) intersected with [0,size). Non-empty spans are returned as [row,start,end].

Why this case matters

Raster clipping decides which pixels a primitive may touch; a single wrong clip decision writes outside the target or scissor, or silently drops visible coverage.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import math
from fractions import Fraction
N = 1
observations = []
def solve(commands, size):
    out=[]
    for poly,clip in commands:
        l,t,r,b=max(clip[0],0),max(clip[1],0),min(clip[2],size),min(clip[3],size)
        pts=[(Fraction(x),Fraction(y)) for x,y in poly]
        spans=[]
        for y in range(t,b):
            yc=y+Fraction(1,2)
            xs=[]
            for i in range(len(pts)):
                (ax,ay),(bx,by)=pts[i-1],pts[i]
                if ay>by: ax,ay,bx,by=bx,by,ax,ay
                if ay<=yc<by:
                    xs.append(ax+(bx-ax)*(yc-ay)/(by-ay))
            xs.sort()
            for j in range(0,len(xs)-1,2):
                start=math.floor(xs[j])
                end=math.ceil(xs[j+1]-Fraction(1,2))
                start,end=max(start,l),min(end,r)
                if start<end: spans.append([y,start,end])
        out.append(spans)
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit case 0', solve([[[[1, 1], [5, 1], [5, 5], [1, 5]], [0, 0, 6, 6]]], 6), [[[1, 1, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 1', solve([[[[1, 0], [3, '5/2'], [5, 0], [5, 5], [1, 5]], [0, 0, 6, 6]]], 6), [[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 2', solve([[[[0, '1/2'], [4, '5/2'], [0, '9/2']], [0, 0, 6, 6]]], 6), [[[1, 0, 2], [2, 0, 4], [3, 0, 2]]])
    check('explicit case 3', solve([[[['1/2', 0], ['7/2', 0], ['7/2', 3], ['1/2', 3]], [0, 0, 6, 6]]], 6), [[[0, 0, 3], [1, 0, 3], [2, 0, 3]]])
    check('explicit case 4', solve([[[['3/2', 0], ['9/2', 0], ['9/2', 2], ['3/2', 2]], [0, 0, 6, 6]]], 6), [[[0, 1, 4], [1, 1, 4]]])
    check('explicit case 5', solve([[[[0, 0], [6, 0], [6, 6], [0, 6]], [2, 1, 4, 3]]], 6), [[[1, 2, 4], [2, 2, 4]]])
    check('explicit case 6', solve([[[[0, 0], [1, 4], [2, 0], [3, 4], [4, 0], [4, 5], [0, 5]], [0, 0, 6, 6]]], 6), [[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]])
    check('explicit case 7', solve([[[[-2, 0], [8, 0], [8, 2], [-2, 2]], [0, 0, 6, 6]]], 6), [[[0, 0, 6], [1, 0, 6]]])
    check('explicit case 8', solve([[[[0, 0], [2, 0], [2, 2], [0, 2]], [3, 0, 6, 6]]], 6), [[]])
    check('explicit case 9', solve([[[[1, 0], [5, 4], [1, 4]], [0, 0, 6, 6]]], 6), [[[1, 1, 2], [2, 1, 3], [3, 1, 4]]])
    check('explicit case 10', solve([[[['1/4', 0], ['5/2', 0], ['5/2', 2], ['1/4', 2]], [1, 0, 6, 6]]], 6), [[[0, 1, 2], [1, 1, 2]]])
    check('explicit case 11', solve([[[[4, 1], [4, 4], [1, 4], [1, 1]], [0, 0, 6, 6]]], 6), [[[1, 1, 4], [2, 1, 4], [3, 1, 4]]])
    check('explicit case 12', solve([[[[0, 0], [5, 0], [5, 4], [3, '3/2'], [1, 4], [0, 4]], [0, 0, 6, 6]]], 6), [[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]])
if N == 2:
    check('explicit case 0', solve([[[[1, 1], [6, 1], [6, 6], [1, 6]], [0, 0, 7, 7]]], 7), [[[1, 1, 6], [2, 1, 6], [3, 1, 6], [4, 1, 6], [5, 1, 6]]])
    check('explicit case 1', solve([[[[1, 0], [3, '5/2'], [5, 0], [5, 5], [1, 5]], [0, 0, 7, 7]]], 7), [[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 2', solve([[[[0, '1/2'], [4, '5/2'], [0, '9/2']], [0, 0, 7, 7]]], 7), [[[1, 0, 2], [2, 0, 4], [3, 0, 2]]])
    check('explicit case 3', solve([[[['1/2', 0], ['7/2', 0], ['7/2', 3], ['1/2', 3]], [0, 0, 7, 7]]], 7), [[[0, 0, 3], [1, 0, 3], [2, 0, 3]]])
    check('explicit case 4', solve([[[['3/2', 0], ['9/2', 0], ['9/2', 2], ['3/2', 2]], [0, 0, 7, 7]]], 7), [[[0, 1, 4], [1, 1, 4]]])
    check('explicit case 5', solve([[[[0, 0], [7, 0], [7, 7], [0, 7]], [2, 1, 4, 3]]], 7), [[[1, 2, 4], [2, 2, 4]]])
    check('explicit case 6', solve([[[[0, 0], [1, 4], [2, 0], [3, 4], [4, 0], [4, 5], [0, 5]], [0, 0, 7, 7]]], 7), [[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]])
    check('explicit case 7', solve([[[[-2, 0], [9, 0], [9, 2], [-2, 2]], [0, 0, 7, 7]]], 7), [[[0, 0, 7], [1, 0, 7]]])
    check('explicit case 8', solve([[[[0, 0], [2, 0], [2, 2], [0, 2]], [3, 0, 7, 7]]], 7), [[]])
    check('explicit case 9', solve([[[[1, 0], [5, 4], [1, 4]], [0, 0, 7, 7]]], 7), [[[1, 1, 2], [2, 1, 3], [3, 1, 4]]])
    check('explicit case 10', solve([[[['1/4', 0], ['5/2', 0], ['5/2', 2], ['1/4', 2]], [1, 0, 7, 7]]], 7), [[[0, 1, 2], [1, 1, 2]]])
    check('explicit case 11', solve([[[[4, 1], [4, 4], [1, 4], [1, 1]], [0, 0, 7, 7]]], 7), [[[1, 1, 4], [2, 1, 4], [3, 1, 4]]])
    check('explicit case 12', solve([[[[0, 0], [5, 0], [5, 4], [3, '3/2'], [1, 4], [0, 4]], [0, 0, 7, 7]]], 7), [[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]])
if N == 3:
    check('explicit case 0', solve([[[[1, 1], [7, 1], [7, 7], [1, 7]], [0, 0, 8, 8]]], 8), [[[1, 1, 7], [2, 1, 7], [3, 1, 7], [4, 1, 7], [5, 1, 7], [6, 1, 7]]])
    check('explicit case 1', solve([[[[1, 0], [3, '5/2'], [5, 0], [5, 5], [1, 5]], [0, 0, 8, 8]]], 8), [[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 2', solve([[[[0, '1/2'], [4, '5/2'], [0, '9/2']], [0, 0, 8, 8]]], 8), [[[1, 0, 2], [2, 0, 4], [3, 0, 2]]])
    check('explicit case 3', solve([[[['1/2', 0], ['7/2', 0], ['7/2', 3], ['1/2', 3]], [0, 0, 8, 8]]], 8), [[[0, 0, 3], [1, 0, 3], [2, 0, 3]]])
    check('explicit case 4', solve([[[['3/2', 0], ['9/2', 0], ['9/2', 2], ['3/2', 2]], [0, 0, 8, 8]]], 8), [[[0, 1, 4], [1, 1, 4]]])
    check('explicit case 5', solve([[[[0, 0], [8, 0], [8, 8], [0, 8]], [2, 1, 4, 3]]], 8), [[[1, 2, 4], [2, 2, 4]]])
    check('explicit case 6', solve([[[[0, 0], [1, 4], [2, 0], [3, 4], [4, 0], [4, 5], [0, 5]], [0, 0, 8, 8]]], 8), [[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]])
    check('explicit case 7', solve([[[[-2, 0], [10, 0], [10, 2], [-2, 2]], [0, 0, 8, 8]]], 8), [[[0, 0, 8], [1, 0, 8]]])
    check('explicit case 8', solve([[[[0, 0], [2, 0], [2, 2], [0, 2]], [3, 0, 8, 8]]], 8), [[]])
    check('explicit case 9', solve([[[[1, 0], [5, 4], [1, 4]], [0, 0, 8, 8]]], 8), [[[1, 1, 2], [2, 1, 3], [3, 1, 4]]])
    check('explicit case 10', solve([[[['1/4', 0], ['5/2', 0], ['5/2', 2], ['1/4', 2]], [1, 0, 8, 8]]], 8), [[[0, 1, 2], [1, 1, 2]]])
    check('explicit case 11', solve([[[[4, 1], [4, 4], [1, 4], [1, 1]], [0, 0, 8, 8]]], 8), [[[1, 1, 4], [2, 1, 4], [3, 1, 4]]])
    check('explicit case 12', solve([[[[0, 0], [5, 0], [5, 4], [3, '3/2'], [1, 4], [0, 4]], [0, 0, 8, 8]]], 8), [[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]])
if N == 4:
    check('explicit case 0', solve([[[[1, 1], [8, 1], [8, 8], [1, 8]], [0, 0, 9, 9]]], 9), [[[1, 1, 8], [2, 1, 8], [3, 1, 8], [4, 1, 8], [5, 1, 8], [6, 1, 8], [7, 1, 8]]])
    check('explicit case 1', solve([[[[1, 0], [3, '5/2'], [5, 0], [5, 5], [1, 5]], [0, 0, 9, 9]]], 9), [[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 2', solve([[[[0, '1/2'], [4, '5/2'], [0, '9/2']], [0, 0, 9, 9]]], 9), [[[1, 0, 2], [2, 0, 4], [3, 0, 2]]])
    check('explicit case 3', solve([[[['1/2', 0], ['7/2', 0], ['7/2', 3], ['1/2', 3]], [0, 0, 9, 9]]], 9), [[[0, 0, 3], [1, 0, 3], [2, 0, 3]]])
    check('explicit case 4', solve([[[['3/2', 0], ['9/2', 0], ['9/2', 2], ['3/2', 2]], [0, 0, 9, 9]]], 9), [[[0, 1, 4], [1, 1, 4]]])
    check('explicit case 5', solve([[[[0, 0], [9, 0], [9, 9], [0, 9]], [2, 1, 4, 3]]], 9), [[[1, 2, 4], [2, 2, 4]]])
    check('explicit case 6', solve([[[[0, 0], [1, 4], [2, 0], [3, 4], [4, 0], [4, 5], [0, 5]], [0, 0, 9, 9]]], 9), [[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]])
    check('explicit case 7', solve([[[[-2, 0], [11, 0], [11, 2], [-2, 2]], [0, 0, 9, 9]]], 9), [[[0, 0, 9], [1, 0, 9]]])
    check('explicit case 8', solve([[[[0, 0], [2, 0], [2, 2], [0, 2]], [3, 0, 9, 9]]], 9), [[]])
    check('explicit case 9', solve([[[[1, 0], [5, 4], [1, 4]], [0, 0, 9, 9]]], 9), [[[1, 1, 2], [2, 1, 3], [3, 1, 4]]])
    check('explicit case 10', solve([[[['1/4', 0], ['5/2', 0], ['5/2', 2], ['1/4', 2]], [1, 0, 9, 9]]], 9), [[[0, 1, 2], [1, 1, 2]]])
    check('explicit case 11', solve([[[[4, 1], [4, 4], [1, 4], [1, 1]], [0, 0, 9, 9]]], 9), [[[1, 1, 4], [2, 1, 4], [3, 1, 4]]])
    check('explicit case 12', solve([[[[0, 0], [5, 0], [5, 4], [3, '3/2'], [1, 4], [0, 4]], [0, 0, 9, 9]]], 9), [[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]])
if N == 5:
    check('explicit case 0', solve([[[[1, 1], [9, 1], [9, 9], [1, 9]], [0, 0, 10, 10]]], 10), [[[1, 1, 9], [2, 1, 9], [3, 1, 9], [4, 1, 9], [5, 1, 9], [6, 1, 9], [7, 1, 9], [8, 1, 9]]])
    check('explicit case 1', solve([[[[1, 0], [3, '5/2'], [5, 0], [5, 5], [1, 5]], [0, 0, 10, 10]]], 10), [[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 2', solve([[[[0, '1/2'], [4, '5/2'], [0, '9/2']], [0, 0, 10, 10]]], 10), [[[1, 0, 2], [2, 0, 4], [3, 0, 2]]])
    check('explicit case 3', solve([[[['1/2', 0], ['7/2', 0], ['7/2', 3], ['1/2', 3]], [0, 0, 10, 10]]], 10), [[[0, 0, 3], [1, 0, 3], [2, 0, 3]]])
    check('explicit case 4', solve([[[['3/2', 0], ['9/2', 0], ['9/2', 2], ['3/2', 2]], [0, 0, 10, 10]]], 10), [[[0, 1, 4], [1, 1, 4]]])
    check('explicit case 5', solve([[[[0, 0], [10, 0], [10, 10], [0, 10]], [2, 1, 4, 3]]], 10), [[[1, 2, 4], [2, 2, 4]]])
    check('explicit case 6', solve([[[[0, 0], [1, 4], [2, 0], [3, 4], [4, 0], [4, 5], [0, 5]], [0, 0, 10, 10]]], 10), [[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]])
    check('explicit case 7', solve([[[[-2, 0], [12, 0], [12, 2], [-2, 2]], [0, 0, 10, 10]]], 10), [[[0, 0, 10], [1, 0, 10]]])
    check('explicit case 8', solve([[[[0, 0], [2, 0], [2, 2], [0, 2]], [3, 0, 10, 10]]], 10), [[]])
    check('explicit case 9', solve([[[[1, 0], [5, 4], [1, 4]], [0, 0, 10, 10]]], 10), [[[1, 1, 2], [2, 1, 3], [3, 1, 4]]])
    check('explicit case 10', solve([[[['1/4', 0], ['5/2', 0], ['5/2', 2], ['1/4', 2]], [1, 0, 10, 10]]], 10), [[[0, 1, 2], [1, 1, 2]]])
    check('explicit case 11', solve([[[[4, 1], [4, 4], [1, 4], [1, 1]], [0, 0, 10, 10]]], 10), [[[1, 1, 4], [2, 1, 4], [3, 1, 4]]])
    check('explicit case 12', solve([[[[0, 0], [5, 0], [5, 4], [3, '3/2'], [1, 4], [0, 4]], [0, 0, 10, 10]]], 10), [[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
explicit case 0[[[1, 1, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]][[[1, 1, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]]Passed
explicit case 1[[[0, 4, 5], [1, 1, 2], [1, 3, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]][[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]]Failed
explicit case 2[[[1, 0, 2], [2, 0, 4], [3, 0, 2]]][[[1, 0, 2], [2, 0, 4], [3, 0, 2]]]Passed
explicit case 3[[[0, 0, 3], [1, 0, 3], [2, 0, 3]]][[[0, 0, 3], [1, 0, 3], [2, 0, 3]]]Passed
explicit case 4[[[0, 1, 4], [1, 1, 4]]][[[0, 1, 4], [1, 1, 4]]]Passed
explicit case 5[[[1, 2, 4], [2, 2, 4]]][[[1, 2, 4], [2, 2, 4]]]Passed
explicit case 6[[[0, 1, 2], [0, 3, 4], [1, 1, 2], [1, 3, 4], [2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]][[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]]Failed
explicit case 7[[[0, 0, 6], [1, 0, 6]]][[[0, 0, 6], [1, 0, 6]]]Passed
explicit case 8[[]][[]]Passed
explicit case 9[[[1, 1, 2], [2, 1, 3], [3, 1, 4]]][[[1, 1, 2], [2, 1, 3], [3, 1, 4]]]Passed
explicit case 10[[[0, 1, 2], [1, 1, 2]]][[[0, 1, 2], [1, 1, 2]]]Passed
explicit case 11[[[1, 1, 4], [2, 1, 4], [3, 1, 4]]][[[1, 1, 4], [2, 1, 4], [3, 1, 4]]]Passed
explicit case 12[[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 3, 5], [3, 0, 1], [3, 4, 5]]][[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]]Failed

SHA-256 / e4e0b7b2c894fe71869c7c56ac8345f12b119d3bf18cead1c437134b3379b4d0

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import math
from fractions import Fraction
N = 1
observations = []
def solve(commands, size):
    out=[]
    for poly,clip in commands:
        l,t,r,b=max(clip[0],0),max(clip[1],0),min(clip[2],size),min(clip[3],size)
        pts=[(Fraction(x),Fraction(y)) for x,y in poly]
        spans=[]
        for y in range(t,b):
            yc=y+Fraction(1,2)
            xs=[]
            for i in range(len(pts)):
                (ax,ay),(bx,by)=pts[i-1],pts[i]
                if ay>by: ax,ay,bx,by=bx,by,ax,ay
                if ay<=yc<by:
                    xs.append(ax+(bx-ax)*(yc-ay)/(by-ay))
            xs.sort()
            for j in range(0,len(xs)-1,2):
                start=round(xs[j])
                end=math.ceil(xs[j+1]-Fraction(1,2))
                start,end=max(start,l),min(end,r)
                if start<end: spans.append([y,start,end])
        out.append(spans)
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit case 0', solve([[[[1, 1], [5, 1], [5, 5], [1, 5]], [0, 0, 6, 6]]], 6), [[[1, 1, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 1', solve([[[[1, 0], [3, '5/2'], [5, 0], [5, 5], [1, 5]], [0, 0, 6, 6]]], 6), [[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 2', solve([[[[0, '1/2'], [4, '5/2'], [0, '9/2']], [0, 0, 6, 6]]], 6), [[[1, 0, 2], [2, 0, 4], [3, 0, 2]]])
    check('explicit case 3', solve([[[['1/2', 0], ['7/2', 0], ['7/2', 3], ['1/2', 3]], [0, 0, 6, 6]]], 6), [[[0, 0, 3], [1, 0, 3], [2, 0, 3]]])
    check('explicit case 4', solve([[[['3/2', 0], ['9/2', 0], ['9/2', 2], ['3/2', 2]], [0, 0, 6, 6]]], 6), [[[0, 1, 4], [1, 1, 4]]])
    check('explicit case 5', solve([[[[0, 0], [6, 0], [6, 6], [0, 6]], [2, 1, 4, 3]]], 6), [[[1, 2, 4], [2, 2, 4]]])
    check('explicit case 6', solve([[[[0, 0], [1, 4], [2, 0], [3, 4], [4, 0], [4, 5], [0, 5]], [0, 0, 6, 6]]], 6), [[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]])
    check('explicit case 7', solve([[[[-2, 0], [8, 0], [8, 2], [-2, 2]], [0, 0, 6, 6]]], 6), [[[0, 0, 6], [1, 0, 6]]])
    check('explicit case 8', solve([[[[0, 0], [2, 0], [2, 2], [0, 2]], [3, 0, 6, 6]]], 6), [[]])
    check('explicit case 9', solve([[[[1, 0], [5, 4], [1, 4]], [0, 0, 6, 6]]], 6), [[[1, 1, 2], [2, 1, 3], [3, 1, 4]]])
    check('explicit case 10', solve([[[['1/4', 0], ['5/2', 0], ['5/2', 2], ['1/4', 2]], [1, 0, 6, 6]]], 6), [[[0, 1, 2], [1, 1, 2]]])
    check('explicit case 11', solve([[[[4, 1], [4, 4], [1, 4], [1, 1]], [0, 0, 6, 6]]], 6), [[[1, 1, 4], [2, 1, 4], [3, 1, 4]]])
    check('explicit case 12', solve([[[[0, 0], [5, 0], [5, 4], [3, '3/2'], [1, 4], [0, 4]], [0, 0, 6, 6]]], 6), [[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]])
if N == 2:
    check('explicit case 0', solve([[[[1, 1], [6, 1], [6, 6], [1, 6]], [0, 0, 7, 7]]], 7), [[[1, 1, 6], [2, 1, 6], [3, 1, 6], [4, 1, 6], [5, 1, 6]]])
    check('explicit case 1', solve([[[[1, 0], [3, '5/2'], [5, 0], [5, 5], [1, 5]], [0, 0, 7, 7]]], 7), [[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 2', solve([[[[0, '1/2'], [4, '5/2'], [0, '9/2']], [0, 0, 7, 7]]], 7), [[[1, 0, 2], [2, 0, 4], [3, 0, 2]]])
    check('explicit case 3', solve([[[['1/2', 0], ['7/2', 0], ['7/2', 3], ['1/2', 3]], [0, 0, 7, 7]]], 7), [[[0, 0, 3], [1, 0, 3], [2, 0, 3]]])
    check('explicit case 4', solve([[[['3/2', 0], ['9/2', 0], ['9/2', 2], ['3/2', 2]], [0, 0, 7, 7]]], 7), [[[0, 1, 4], [1, 1, 4]]])
    check('explicit case 5', solve([[[[0, 0], [7, 0], [7, 7], [0, 7]], [2, 1, 4, 3]]], 7), [[[1, 2, 4], [2, 2, 4]]])
    check('explicit case 6', solve([[[[0, 0], [1, 4], [2, 0], [3, 4], [4, 0], [4, 5], [0, 5]], [0, 0, 7, 7]]], 7), [[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]])
    check('explicit case 7', solve([[[[-2, 0], [9, 0], [9, 2], [-2, 2]], [0, 0, 7, 7]]], 7), [[[0, 0, 7], [1, 0, 7]]])
    check('explicit case 8', solve([[[[0, 0], [2, 0], [2, 2], [0, 2]], [3, 0, 7, 7]]], 7), [[]])
    check('explicit case 9', solve([[[[1, 0], [5, 4], [1, 4]], [0, 0, 7, 7]]], 7), [[[1, 1, 2], [2, 1, 3], [3, 1, 4]]])
    check('explicit case 10', solve([[[['1/4', 0], ['5/2', 0], ['5/2', 2], ['1/4', 2]], [1, 0, 7, 7]]], 7), [[[0, 1, 2], [1, 1, 2]]])
    check('explicit case 11', solve([[[[4, 1], [4, 4], [1, 4], [1, 1]], [0, 0, 7, 7]]], 7), [[[1, 1, 4], [2, 1, 4], [3, 1, 4]]])
    check('explicit case 12', solve([[[[0, 0], [5, 0], [5, 4], [3, '3/2'], [1, 4], [0, 4]], [0, 0, 7, 7]]], 7), [[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]])
if N == 3:
    check('explicit case 0', solve([[[[1, 1], [7, 1], [7, 7], [1, 7]], [0, 0, 8, 8]]], 8), [[[1, 1, 7], [2, 1, 7], [3, 1, 7], [4, 1, 7], [5, 1, 7], [6, 1, 7]]])
    check('explicit case 1', solve([[[[1, 0], [3, '5/2'], [5, 0], [5, 5], [1, 5]], [0, 0, 8, 8]]], 8), [[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 2', solve([[[[0, '1/2'], [4, '5/2'], [0, '9/2']], [0, 0, 8, 8]]], 8), [[[1, 0, 2], [2, 0, 4], [3, 0, 2]]])
    check('explicit case 3', solve([[[['1/2', 0], ['7/2', 0], ['7/2', 3], ['1/2', 3]], [0, 0, 8, 8]]], 8), [[[0, 0, 3], [1, 0, 3], [2, 0, 3]]])
    check('explicit case 4', solve([[[['3/2', 0], ['9/2', 0], ['9/2', 2], ['3/2', 2]], [0, 0, 8, 8]]], 8), [[[0, 1, 4], [1, 1, 4]]])
    check('explicit case 5', solve([[[[0, 0], [8, 0], [8, 8], [0, 8]], [2, 1, 4, 3]]], 8), [[[1, 2, 4], [2, 2, 4]]])
    check('explicit case 6', solve([[[[0, 0], [1, 4], [2, 0], [3, 4], [4, 0], [4, 5], [0, 5]], [0, 0, 8, 8]]], 8), [[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]])
    check('explicit case 7', solve([[[[-2, 0], [10, 0], [10, 2], [-2, 2]], [0, 0, 8, 8]]], 8), [[[0, 0, 8], [1, 0, 8]]])
    check('explicit case 8', solve([[[[0, 0], [2, 0], [2, 2], [0, 2]], [3, 0, 8, 8]]], 8), [[]])
    check('explicit case 9', solve([[[[1, 0], [5, 4], [1, 4]], [0, 0, 8, 8]]], 8), [[[1, 1, 2], [2, 1, 3], [3, 1, 4]]])
    check('explicit case 10', solve([[[['1/4', 0], ['5/2', 0], ['5/2', 2], ['1/4', 2]], [1, 0, 8, 8]]], 8), [[[0, 1, 2], [1, 1, 2]]])
    check('explicit case 11', solve([[[[4, 1], [4, 4], [1, 4], [1, 1]], [0, 0, 8, 8]]], 8), [[[1, 1, 4], [2, 1, 4], [3, 1, 4]]])
    check('explicit case 12', solve([[[[0, 0], [5, 0], [5, 4], [3, '3/2'], [1, 4], [0, 4]], [0, 0, 8, 8]]], 8), [[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]])
if N == 4:
    check('explicit case 0', solve([[[[1, 1], [8, 1], [8, 8], [1, 8]], [0, 0, 9, 9]]], 9), [[[1, 1, 8], [2, 1, 8], [3, 1, 8], [4, 1, 8], [5, 1, 8], [6, 1, 8], [7, 1, 8]]])
    check('explicit case 1', solve([[[[1, 0], [3, '5/2'], [5, 0], [5, 5], [1, 5]], [0, 0, 9, 9]]], 9), [[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 2', solve([[[[0, '1/2'], [4, '5/2'], [0, '9/2']], [0, 0, 9, 9]]], 9), [[[1, 0, 2], [2, 0, 4], [3, 0, 2]]])
    check('explicit case 3', solve([[[['1/2', 0], ['7/2', 0], ['7/2', 3], ['1/2', 3]], [0, 0, 9, 9]]], 9), [[[0, 0, 3], [1, 0, 3], [2, 0, 3]]])
    check('explicit case 4', solve([[[['3/2', 0], ['9/2', 0], ['9/2', 2], ['3/2', 2]], [0, 0, 9, 9]]], 9), [[[0, 1, 4], [1, 1, 4]]])
    check('explicit case 5', solve([[[[0, 0], [9, 0], [9, 9], [0, 9]], [2, 1, 4, 3]]], 9), [[[1, 2, 4], [2, 2, 4]]])
    check('explicit case 6', solve([[[[0, 0], [1, 4], [2, 0], [3, 4], [4, 0], [4, 5], [0, 5]], [0, 0, 9, 9]]], 9), [[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]])
    check('explicit case 7', solve([[[[-2, 0], [11, 0], [11, 2], [-2, 2]], [0, 0, 9, 9]]], 9), [[[0, 0, 9], [1, 0, 9]]])
    check('explicit case 8', solve([[[[0, 0], [2, 0], [2, 2], [0, 2]], [3, 0, 9, 9]]], 9), [[]])
    check('explicit case 9', solve([[[[1, 0], [5, 4], [1, 4]], [0, 0, 9, 9]]], 9), [[[1, 1, 2], [2, 1, 3], [3, 1, 4]]])
    check('explicit case 10', solve([[[['1/4', 0], ['5/2', 0], ['5/2', 2], ['1/4', 2]], [1, 0, 9, 9]]], 9), [[[0, 1, 2], [1, 1, 2]]])
    check('explicit case 11', solve([[[[4, 1], [4, 4], [1, 4], [1, 1]], [0, 0, 9, 9]]], 9), [[[1, 1, 4], [2, 1, 4], [3, 1, 4]]])
    check('explicit case 12', solve([[[[0, 0], [5, 0], [5, 4], [3, '3/2'], [1, 4], [0, 4]], [0, 0, 9, 9]]], 9), [[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]])
if N == 5:
    check('explicit case 0', solve([[[[1, 1], [9, 1], [9, 9], [1, 9]], [0, 0, 10, 10]]], 10), [[[1, 1, 9], [2, 1, 9], [3, 1, 9], [4, 1, 9], [5, 1, 9], [6, 1, 9], [7, 1, 9], [8, 1, 9]]])
    check('explicit case 1', solve([[[[1, 0], [3, '5/2'], [5, 0], [5, 5], [1, 5]], [0, 0, 10, 10]]], 10), [[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 2', solve([[[[0, '1/2'], [4, '5/2'], [0, '9/2']], [0, 0, 10, 10]]], 10), [[[1, 0, 2], [2, 0, 4], [3, 0, 2]]])
    check('explicit case 3', solve([[[['1/2', 0], ['7/2', 0], ['7/2', 3], ['1/2', 3]], [0, 0, 10, 10]]], 10), [[[0, 0, 3], [1, 0, 3], [2, 0, 3]]])
    check('explicit case 4', solve([[[['3/2', 0], ['9/2', 0], ['9/2', 2], ['3/2', 2]], [0, 0, 10, 10]]], 10), [[[0, 1, 4], [1, 1, 4]]])
    check('explicit case 5', solve([[[[0, 0], [10, 0], [10, 10], [0, 10]], [2, 1, 4, 3]]], 10), [[[1, 2, 4], [2, 2, 4]]])
    check('explicit case 6', solve([[[[0, 0], [1, 4], [2, 0], [3, 4], [4, 0], [4, 5], [0, 5]], [0, 0, 10, 10]]], 10), [[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]])
    check('explicit case 7', solve([[[[-2, 0], [12, 0], [12, 2], [-2, 2]], [0, 0, 10, 10]]], 10), [[[0, 0, 10], [1, 0, 10]]])
    check('explicit case 8', solve([[[[0, 0], [2, 0], [2, 2], [0, 2]], [3, 0, 10, 10]]], 10), [[]])
    check('explicit case 9', solve([[[[1, 0], [5, 4], [1, 4]], [0, 0, 10, 10]]], 10), [[[1, 1, 2], [2, 1, 3], [3, 1, 4]]])
    check('explicit case 10', solve([[[['1/4', 0], ['5/2', 0], ['5/2', 2], ['1/4', 2]], [1, 0, 10, 10]]], 10), [[[0, 1, 2], [1, 1, 2]]])
    check('explicit case 11', solve([[[[4, 1], [4, 4], [1, 4], [1, 1]], [0, 0, 10, 10]]], 10), [[[1, 1, 4], [2, 1, 4], [3, 1, 4]]])
    check('explicit case 12', solve([[[[0, 0], [5, 0], [5, 4], [3, '3/2'], [1, 4], [0, 4]], [0, 0, 10, 10]]], 10), [[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
explicit case 0[[[1, 1, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]][[[1, 1, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]]Passed
explicit case 1[[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]][[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]]Passed
explicit case 2[[[1, 0, 2], [2, 0, 4], [3, 0, 2]]][[[1, 0, 2], [2, 0, 4], [3, 0, 2]]]Passed
explicit case 3[[[0, 0, 3], [1, 0, 3], [2, 0, 3]]][[[0, 0, 3], [1, 0, 3], [2, 0, 3]]]Passed
explicit case 4[[[0, 2, 4], [1, 2, 4]]][[[0, 1, 4], [1, 1, 4]]]Failed
explicit case 5[[[1, 2, 4], [2, 2, 4]]][[[1, 2, 4], [2, 2, 4]]]Passed
explicit case 6[[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]][[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]]Passed
explicit case 7[[[0, 0, 6], [1, 0, 6]]][[[0, 0, 6], [1, 0, 6]]]Passed
explicit case 8[[]][[]]Passed
explicit case 9[[[1, 1, 2], [2, 1, 3], [3, 1, 4]]][[[1, 1, 2], [2, 1, 3], [3, 1, 4]]]Passed
explicit case 10[[[0, 1, 2], [1, 1, 2]]][[[0, 1, 2], [1, 1, 2]]]Passed
explicit case 11[[[1, 1, 4], [2, 1, 4], [3, 1, 4]]][[[1, 1, 4], [2, 1, 4], [3, 1, 4]]]Passed
explicit case 12[[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]][[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]]Passed

SHA-256 / 13e87a1d4bc02167c48cef2407c5da234b4a3d57e4cd7ae6f2be2781a9df7c7e

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json
import math
from fractions import Fraction
N = 1
observations = []
def solve(commands, size):
    out=[]
    for poly,clip in commands:
        l,t,r,b=max(clip[0],0),max(clip[1],0),min(clip[2],size),min(clip[3],size)
        pts=[(Fraction(x),Fraction(y)) for x,y in poly]
        spans=[]
        for y in range(t,b):
            yc=y+Fraction(1,2)
            xs=[]
            for i in range(len(pts)):
                (ax,ay),(bx,by)=pts[i-1],pts[i]
                if ay>by: ax,ay,bx,by=bx,by,ax,ay
                if ay<=yc<by:
                    xs.append(ax+(bx-ax)*(yc-ay)/(by-ay))
            xs.sort()
            for j in range(0,len(xs)-1,2):
                start=math.ceil(xs[j]-Fraction(1,2))
                end=math.ceil(xs[j+1]-Fraction(1,2))
                start,end=max(start,l),min(end,r)
                if start<end: spans.append([y,start,end])
        out.append(spans)
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit case 0', solve([[[[1, 1], [5, 1], [5, 5], [1, 5]], [0, 0, 6, 6]]], 6), [[[1, 1, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 1', solve([[[[1, 0], [3, '5/2'], [5, 0], [5, 5], [1, 5]], [0, 0, 6, 6]]], 6), [[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 2', solve([[[[0, '1/2'], [4, '5/2'], [0, '9/2']], [0, 0, 6, 6]]], 6), [[[1, 0, 2], [2, 0, 4], [3, 0, 2]]])
    check('explicit case 3', solve([[[['1/2', 0], ['7/2', 0], ['7/2', 3], ['1/2', 3]], [0, 0, 6, 6]]], 6), [[[0, 0, 3], [1, 0, 3], [2, 0, 3]]])
    check('explicit case 4', solve([[[['3/2', 0], ['9/2', 0], ['9/2', 2], ['3/2', 2]], [0, 0, 6, 6]]], 6), [[[0, 1, 4], [1, 1, 4]]])
    check('explicit case 5', solve([[[[0, 0], [6, 0], [6, 6], [0, 6]], [2, 1, 4, 3]]], 6), [[[1, 2, 4], [2, 2, 4]]])
    check('explicit case 6', solve([[[[0, 0], [1, 4], [2, 0], [3, 4], [4, 0], [4, 5], [0, 5]], [0, 0, 6, 6]]], 6), [[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]])
    check('explicit case 7', solve([[[[-2, 0], [8, 0], [8, 2], [-2, 2]], [0, 0, 6, 6]]], 6), [[[0, 0, 6], [1, 0, 6]]])
    check('explicit case 8', solve([[[[0, 0], [2, 0], [2, 2], [0, 2]], [3, 0, 6, 6]]], 6), [[]])
    check('explicit case 9', solve([[[[1, 0], [5, 4], [1, 4]], [0, 0, 6, 6]]], 6), [[[1, 1, 2], [2, 1, 3], [3, 1, 4]]])
    check('explicit case 10', solve([[[['1/4', 0], ['5/2', 0], ['5/2', 2], ['1/4', 2]], [1, 0, 6, 6]]], 6), [[[0, 1, 2], [1, 1, 2]]])
    check('explicit case 11', solve([[[[4, 1], [4, 4], [1, 4], [1, 1]], [0, 0, 6, 6]]], 6), [[[1, 1, 4], [2, 1, 4], [3, 1, 4]]])
    check('explicit case 12', solve([[[[0, 0], [5, 0], [5, 4], [3, '3/2'], [1, 4], [0, 4]], [0, 0, 6, 6]]], 6), [[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]])
if N == 2:
    check('explicit case 0', solve([[[[1, 1], [6, 1], [6, 6], [1, 6]], [0, 0, 7, 7]]], 7), [[[1, 1, 6], [2, 1, 6], [3, 1, 6], [4, 1, 6], [5, 1, 6]]])
    check('explicit case 1', solve([[[[1, 0], [3, '5/2'], [5, 0], [5, 5], [1, 5]], [0, 0, 7, 7]]], 7), [[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 2', solve([[[[0, '1/2'], [4, '5/2'], [0, '9/2']], [0, 0, 7, 7]]], 7), [[[1, 0, 2], [2, 0, 4], [3, 0, 2]]])
    check('explicit case 3', solve([[[['1/2', 0], ['7/2', 0], ['7/2', 3], ['1/2', 3]], [0, 0, 7, 7]]], 7), [[[0, 0, 3], [1, 0, 3], [2, 0, 3]]])
    check('explicit case 4', solve([[[['3/2', 0], ['9/2', 0], ['9/2', 2], ['3/2', 2]], [0, 0, 7, 7]]], 7), [[[0, 1, 4], [1, 1, 4]]])
    check('explicit case 5', solve([[[[0, 0], [7, 0], [7, 7], [0, 7]], [2, 1, 4, 3]]], 7), [[[1, 2, 4], [2, 2, 4]]])
    check('explicit case 6', solve([[[[0, 0], [1, 4], [2, 0], [3, 4], [4, 0], [4, 5], [0, 5]], [0, 0, 7, 7]]], 7), [[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]])
    check('explicit case 7', solve([[[[-2, 0], [9, 0], [9, 2], [-2, 2]], [0, 0, 7, 7]]], 7), [[[0, 0, 7], [1, 0, 7]]])
    check('explicit case 8', solve([[[[0, 0], [2, 0], [2, 2], [0, 2]], [3, 0, 7, 7]]], 7), [[]])
    check('explicit case 9', solve([[[[1, 0], [5, 4], [1, 4]], [0, 0, 7, 7]]], 7), [[[1, 1, 2], [2, 1, 3], [3, 1, 4]]])
    check('explicit case 10', solve([[[['1/4', 0], ['5/2', 0], ['5/2', 2], ['1/4', 2]], [1, 0, 7, 7]]], 7), [[[0, 1, 2], [1, 1, 2]]])
    check('explicit case 11', solve([[[[4, 1], [4, 4], [1, 4], [1, 1]], [0, 0, 7, 7]]], 7), [[[1, 1, 4], [2, 1, 4], [3, 1, 4]]])
    check('explicit case 12', solve([[[[0, 0], [5, 0], [5, 4], [3, '3/2'], [1, 4], [0, 4]], [0, 0, 7, 7]]], 7), [[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]])
if N == 3:
    check('explicit case 0', solve([[[[1, 1], [7, 1], [7, 7], [1, 7]], [0, 0, 8, 8]]], 8), [[[1, 1, 7], [2, 1, 7], [3, 1, 7], [4, 1, 7], [5, 1, 7], [6, 1, 7]]])
    check('explicit case 1', solve([[[[1, 0], [3, '5/2'], [5, 0], [5, 5], [1, 5]], [0, 0, 8, 8]]], 8), [[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 2', solve([[[[0, '1/2'], [4, '5/2'], [0, '9/2']], [0, 0, 8, 8]]], 8), [[[1, 0, 2], [2, 0, 4], [3, 0, 2]]])
    check('explicit case 3', solve([[[['1/2', 0], ['7/2', 0], ['7/2', 3], ['1/2', 3]], [0, 0, 8, 8]]], 8), [[[0, 0, 3], [1, 0, 3], [2, 0, 3]]])
    check('explicit case 4', solve([[[['3/2', 0], ['9/2', 0], ['9/2', 2], ['3/2', 2]], [0, 0, 8, 8]]], 8), [[[0, 1, 4], [1, 1, 4]]])
    check('explicit case 5', solve([[[[0, 0], [8, 0], [8, 8], [0, 8]], [2, 1, 4, 3]]], 8), [[[1, 2, 4], [2, 2, 4]]])
    check('explicit case 6', solve([[[[0, 0], [1, 4], [2, 0], [3, 4], [4, 0], [4, 5], [0, 5]], [0, 0, 8, 8]]], 8), [[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]])
    check('explicit case 7', solve([[[[-2, 0], [10, 0], [10, 2], [-2, 2]], [0, 0, 8, 8]]], 8), [[[0, 0, 8], [1, 0, 8]]])
    check('explicit case 8', solve([[[[0, 0], [2, 0], [2, 2], [0, 2]], [3, 0, 8, 8]]], 8), [[]])
    check('explicit case 9', solve([[[[1, 0], [5, 4], [1, 4]], [0, 0, 8, 8]]], 8), [[[1, 1, 2], [2, 1, 3], [3, 1, 4]]])
    check('explicit case 10', solve([[[['1/4', 0], ['5/2', 0], ['5/2', 2], ['1/4', 2]], [1, 0, 8, 8]]], 8), [[[0, 1, 2], [1, 1, 2]]])
    check('explicit case 11', solve([[[[4, 1], [4, 4], [1, 4], [1, 1]], [0, 0, 8, 8]]], 8), [[[1, 1, 4], [2, 1, 4], [3, 1, 4]]])
    check('explicit case 12', solve([[[[0, 0], [5, 0], [5, 4], [3, '3/2'], [1, 4], [0, 4]], [0, 0, 8, 8]]], 8), [[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]])
if N == 4:
    check('explicit case 0', solve([[[[1, 1], [8, 1], [8, 8], [1, 8]], [0, 0, 9, 9]]], 9), [[[1, 1, 8], [2, 1, 8], [3, 1, 8], [4, 1, 8], [5, 1, 8], [6, 1, 8], [7, 1, 8]]])
    check('explicit case 1', solve([[[[1, 0], [3, '5/2'], [5, 0], [5, 5], [1, 5]], [0, 0, 9, 9]]], 9), [[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 2', solve([[[[0, '1/2'], [4, '5/2'], [0, '9/2']], [0, 0, 9, 9]]], 9), [[[1, 0, 2], [2, 0, 4], [3, 0, 2]]])
    check('explicit case 3', solve([[[['1/2', 0], ['7/2', 0], ['7/2', 3], ['1/2', 3]], [0, 0, 9, 9]]], 9), [[[0, 0, 3], [1, 0, 3], [2, 0, 3]]])
    check('explicit case 4', solve([[[['3/2', 0], ['9/2', 0], ['9/2', 2], ['3/2', 2]], [0, 0, 9, 9]]], 9), [[[0, 1, 4], [1, 1, 4]]])
    check('explicit case 5', solve([[[[0, 0], [9, 0], [9, 9], [0, 9]], [2, 1, 4, 3]]], 9), [[[1, 2, 4], [2, 2, 4]]])
    check('explicit case 6', solve([[[[0, 0], [1, 4], [2, 0], [3, 4], [4, 0], [4, 5], [0, 5]], [0, 0, 9, 9]]], 9), [[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]])
    check('explicit case 7', solve([[[[-2, 0], [11, 0], [11, 2], [-2, 2]], [0, 0, 9, 9]]], 9), [[[0, 0, 9], [1, 0, 9]]])
    check('explicit case 8', solve([[[[0, 0], [2, 0], [2, 2], [0, 2]], [3, 0, 9, 9]]], 9), [[]])
    check('explicit case 9', solve([[[[1, 0], [5, 4], [1, 4]], [0, 0, 9, 9]]], 9), [[[1, 1, 2], [2, 1, 3], [3, 1, 4]]])
    check('explicit case 10', solve([[[['1/4', 0], ['5/2', 0], ['5/2', 2], ['1/4', 2]], [1, 0, 9, 9]]], 9), [[[0, 1, 2], [1, 1, 2]]])
    check('explicit case 11', solve([[[[4, 1], [4, 4], [1, 4], [1, 1]], [0, 0, 9, 9]]], 9), [[[1, 1, 4], [2, 1, 4], [3, 1, 4]]])
    check('explicit case 12', solve([[[[0, 0], [5, 0], [5, 4], [3, '3/2'], [1, 4], [0, 4]], [0, 0, 9, 9]]], 9), [[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]])
if N == 5:
    check('explicit case 0', solve([[[[1, 1], [9, 1], [9, 9], [1, 9]], [0, 0, 10, 10]]], 10), [[[1, 1, 9], [2, 1, 9], [3, 1, 9], [4, 1, 9], [5, 1, 9], [6, 1, 9], [7, 1, 9], [8, 1, 9]]])
    check('explicit case 1', solve([[[[1, 0], [3, '5/2'], [5, 0], [5, 5], [1, 5]], [0, 0, 10, 10]]], 10), [[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]])
    check('explicit case 2', solve([[[[0, '1/2'], [4, '5/2'], [0, '9/2']], [0, 0, 10, 10]]], 10), [[[1, 0, 2], [2, 0, 4], [3, 0, 2]]])
    check('explicit case 3', solve([[[['1/2', 0], ['7/2', 0], ['7/2', 3], ['1/2', 3]], [0, 0, 10, 10]]], 10), [[[0, 0, 3], [1, 0, 3], [2, 0, 3]]])
    check('explicit case 4', solve([[[['3/2', 0], ['9/2', 0], ['9/2', 2], ['3/2', 2]], [0, 0, 10, 10]]], 10), [[[0, 1, 4], [1, 1, 4]]])
    check('explicit case 5', solve([[[[0, 0], [10, 0], [10, 10], [0, 10]], [2, 1, 4, 3]]], 10), [[[1, 2, 4], [2, 2, 4]]])
    check('explicit case 6', solve([[[[0, 0], [1, 4], [2, 0], [3, 4], [4, 0], [4, 5], [0, 5]], [0, 0, 10, 10]]], 10), [[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]])
    check('explicit case 7', solve([[[[-2, 0], [12, 0], [12, 2], [-2, 2]], [0, 0, 10, 10]]], 10), [[[0, 0, 10], [1, 0, 10]]])
    check('explicit case 8', solve([[[[0, 0], [2, 0], [2, 2], [0, 2]], [3, 0, 10, 10]]], 10), [[]])
    check('explicit case 9', solve([[[[1, 0], [5, 4], [1, 4]], [0, 0, 10, 10]]], 10), [[[1, 1, 2], [2, 1, 3], [3, 1, 4]]])
    check('explicit case 10', solve([[[['1/4', 0], ['5/2', 0], ['5/2', 2], ['1/4', 2]], [1, 0, 10, 10]]], 10), [[[0, 1, 2], [1, 1, 2]]])
    check('explicit case 11', solve([[[[4, 1], [4, 4], [1, 4], [1, 1]], [0, 0, 10, 10]]], 10), [[[1, 1, 4], [2, 1, 4], [3, 1, 4]]])
    check('explicit case 12', solve([[[[0, 0], [5, 0], [5, 4], [3, '3/2'], [1, 4], [0, 4]], [0, 0, 10, 10]]], 10), [[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
explicit case 0[[[1, 1, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]][[[1, 1, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]]Passed
explicit case 1[[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]][[[1, 1, 2], [1, 4, 5], [2, 1, 5], [3, 1, 5], [4, 1, 5]]]Passed
explicit case 2[[[1, 0, 2], [2, 0, 4], [3, 0, 2]]][[[1, 0, 2], [2, 0, 4], [3, 0, 2]]]Passed
explicit case 3[[[0, 0, 3], [1, 0, 3], [2, 0, 3]]][[[0, 0, 3], [1, 0, 3], [2, 0, 3]]]Passed
explicit case 4[[[0, 1, 4], [1, 1, 4]]][[[0, 1, 4], [1, 1, 4]]]Passed
explicit case 5[[[1, 2, 4], [2, 2, 4]]][[[1, 2, 4], [2, 2, 4]]]Passed
explicit case 6[[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]][[[2, 0, 1], [2, 1, 3], [2, 3, 4], [3, 0, 1], [3, 1, 3], [3, 3, 4], [4, 0, 4]]]Passed
explicit case 7[[[0, 0, 6], [1, 0, 6]]][[[0, 0, 6], [1, 0, 6]]]Passed
explicit case 8[[]][[]]Passed
explicit case 9[[[1, 1, 2], [2, 1, 3], [3, 1, 4]]][[[1, 1, 2], [2, 1, 3], [3, 1, 4]]]Passed
explicit case 10[[[0, 1, 2], [1, 1, 2]]][[[0, 1, 2], [1, 1, 2]]]Passed
explicit case 11[[[1, 1, 4], [2, 1, 4], [3, 1, 4]]][[[1, 1, 4], [2, 1, 4], [3, 1, 4]]]Passed
explicit case 12[[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]][[[0, 0, 5], [1, 0, 3], [1, 3, 5], [2, 0, 2], [2, 4, 5], [3, 0, 1]]]Passed

SHA-256 / 711b1a6a7773b7911b36539d16025d30d3aa9f00b98844921c0cd2ce19658a0a

Verification & scope

Exact integer/rational arithmetic on small stipulated fixtures models the clipping decision only; no memory layout, GPU pipeline, graphics API or standards conformance is claimed. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:45:21.449762+00:00.

Case digest / 4325b240798aa309091320f82306abf49910e9057bfe15752b413b78fd1e4b08