Understand the failure.
Verify the repair.
Small, reproducible software failures. The broken implementation, the fix that didn’t work, and the one that passed—preserved together.
Explore the cases ↓How results are verified ↗WHAT THE ARCHIVE CONTAINS
100840 executable cases. 20168 are open.
Every case records the implementation that fails, the fix that did not work, and the repair that passed its checks—with recorded outputs and source hashes. This release adds 100840 cases across 20168 failure mechanisms and 254 domains.
The open tier gives you the failure and the unsuccessful fix for one case in every mechanism. The remaining 80672 cases, 5 variants per mechanism, are member-only: the verified repair, its recorded checks, and the full fixture suite are held in the member archive. Read the methodology ↗
A RECORD OF WHAT WENT WRONG
Browse the archive / 100840
Scanline polygon span clip: crossings unsorted · case 01
Crossings are paired in edge order instead of x order, so concave rows pair the wrong edges.
Scanline polygon span clip: crossings unsorted · case 02
Crossings are paired in edge order instead of x order, so concave rows pair the wrong edges.
Scanline polygon span clip: crossings unsorted · case 03
Crossings are paired in edge order instead of x order, so concave rows pair the wrong edges.
Scanline polygon span clip: crossings unsorted · case 04
Crossings are paired in edge order instead of x order, so concave rows pair the wrong edges.
Scanline polygon span clip: crossings unsorted · case 05
Crossings are paired in edge order instead of x order, so concave rows pair the wrong edges.
Scanline polygon span clip: empty span emitted · case 01
Spans clipped to zero width are still emitted.
Scanline polygon span clip: empty span emitted · case 02
Spans clipped to zero width are still emitted.
Scanline polygon span clip: empty span emitted · case 03
Spans clipped to zero width are still emitted.
Scanline polygon span clip: empty span emitted · case 04
Spans clipped to zero width are still emitted.
Scanline polygon span clip: empty span emitted · case 05
Spans clipped to zero width are still emitted.
Scanline polygon span clip: edge orientation partial swap · case 01
Orienting a downward edge swaps only its y coordinates, reversing the x interpolation along the edge.
Scanline polygon span clip: edge orientation partial swap · case 02
Orienting a downward edge swaps only its y coordinates, reversing the x interpolation along the edge.
Scanline polygon span clip: edge orientation partial swap · case 03
Orienting a downward edge swaps only its y coordinates, reversing the x interpolation along the edge.
Scanline polygon span clip: edge orientation partial swap · case 04
Orienting a downward edge swaps only its y coordinates, reversing the x interpolation along the edge.
Scanline polygon span clip: edge orientation partial swap · case 05
Orienting a downward edge swaps only its y coordinates, reversing the x interpolation along the edge.
Scanline polygon span clip: even odd pair stride · case 01
Every adjacent crossing pair is filled, so holes between even-odd intervals are covered.
Scanline polygon span clip: even odd pair stride · case 02
Every adjacent crossing pair is filled, so holes between even-odd intervals are covered.
Scanline polygon span clip: even odd pair stride · case 03
Every adjacent crossing pair is filled, so holes between even-odd intervals are covered.
Scanline polygon span clip: even odd pair stride · case 04
Every adjacent crossing pair is filled, so holes between even-odd intervals are covered.
Scanline polygon span clip: even odd pair stride · case 05
Every adjacent crossing pair is filled, so holes between even-odd intervals are covered.
Scanline polygon span clip: scissor rows ignored · case 01
All raster rows are scanned regardless of the scissor top and bottom.
Scanline polygon span clip: scissor rows ignored · case 02
All raster rows are scanned regardless of the scissor top and bottom.
Scanline polygon span clip: scissor rows ignored · case 03
All raster rows are scanned regardless of the scissor top and bottom.
Scanline polygon span clip: scissor rows ignored · case 04
All raster rows are scanned regardless of the scissor top and bottom.
Scanline polygon span clip: scissor rows ignored · case 05
All raster rows are scanned regardless of the scissor top and bottom.
Clipped bresenham prestep: prestep ignored · case 01
Left-clipped lines start with the unclipped origin row, shifting every visible pixel vertically.
Clipped bresenham prestep: prestep ignored · case 02
Left-clipped lines start with the unclipped origin row, shifting every visible pixel vertically.
Clipped bresenham prestep: prestep ignored · case 03
Left-clipped lines start with the unclipped origin row, shifting every visible pixel vertically.
Clipped bresenham prestep: prestep ignored · case 04
Left-clipped lines start with the unclipped origin row, shifting every visible pixel vertically.
Clipped bresenham prestep: prestep ignored · case 05
Left-clipped lines start with the unclipped origin row, shifting every visible pixel vertically.
Clipped bresenham prestep: midpoint bias missing · case 01
The error term omits the half-pixel bias, so reference rows are floored instead of rounded.
Clipped bresenham prestep: midpoint bias missing · case 02
The error term omits the half-pixel bias, so reference rows are floored instead of rounded.
Clipped bresenham prestep: midpoint bias missing · case 03
The error term omits the half-pixel bias, so reference rows are floored instead of rounded.
Clipped bresenham prestep: midpoint bias missing · case 04
The error term omits the half-pixel bias, so reference rows are floored instead of rounded.
Clipped bresenham prestep: midpoint bias missing · case 05
The error term omits the half-pixel bias, so reference rows are floored instead of rounded.
Clipped bresenham prestep: negative prestep truncation · case 01
Pre-stepping a descending line truncates toward zero while the error keeps a floored remainder, desynchronising row and error.
Clipped bresenham prestep: negative prestep truncation · case 02
Pre-stepping a descending line truncates toward zero while the error keeps a floored remainder, desynchronising row and error.
Clipped bresenham prestep: negative prestep truncation · case 03
Pre-stepping a descending line truncates toward zero while the error keeps a floored remainder, desynchronising row and error.
Clipped bresenham prestep: negative prestep truncation · case 04
Pre-stepping a descending line truncates toward zero while the error keeps a floored remainder, desynchronising row and error.
Clipped bresenham prestep: negative prestep truncation · case 05
Pre-stepping a descending line truncates toward zero while the error keeps a floored remainder, desynchronising row and error.
Clipped bresenham prestep: right bound inclusive · case 01
The walk includes the column equal to the half-open scissor right edge.
Clipped bresenham prestep: right bound inclusive · case 02
The walk includes the column equal to the half-open scissor right edge.
Clipped bresenham prestep: right bound inclusive · case 03
The walk includes the column equal to the half-open scissor right edge.
Clipped bresenham prestep: right bound inclusive · case 04
The walk includes the column equal to the half-open scissor right edge.
Clipped bresenham prestep: right bound inclusive · case 05
The walk includes the column equal to the half-open scissor right edge.
Clipped bresenham prestep: start before origin · case 01
The walk always starts at the scissor left edge, emitting pixels before the line begins.
Clipped bresenham prestep: start before origin · case 02
The walk always starts at the scissor left edge, emitting pixels before the line begins.
Clipped bresenham prestep: start before origin · case 03
The walk always starts at the scissor left edge, emitting pixels before the line begins.
Clipped bresenham prestep: start before origin · case 04
The walk always starts at the scissor left edge, emitting pixels before the line begins.
Clipped bresenham prestep: start before origin · case 05
The walk always starts at the scissor left edge, emitting pixels before the line begins.
Clipped bresenham prestep: point unclipped · case 01
Zero-length lines bypass scissor testing.
Clipped bresenham prestep: point unclipped · case 02
Zero-length lines bypass scissor testing.
Clipped bresenham prestep: point unclipped · case 03
Zero-length lines bypass scissor testing.
Clipped bresenham prestep: point unclipped · case 04
Zero-length lines bypass scissor testing.
Clipped bresenham prestep: point unclipped · case 05
Zero-length lines bypass scissor testing.
Clipped bresenham prestep: early exit direction · case 01
The walk stops whenever y is outside the scissor, even before a line travelling toward the scissor has entered it.
Clipped bresenham prestep: early exit direction · case 02
The walk stops whenever y is outside the scissor, even before a line travelling toward the scissor has entered it.
Clipped bresenham prestep: early exit direction · case 03
The walk stops whenever y is outside the scissor, even before a line travelling toward the scissor has entered it.
Clipped bresenham prestep: early exit direction · case 04
The walk stops whenever y is outside the scissor, even before a line travelling toward the scissor has entered it.
Clipped bresenham prestep: early exit direction · case 05
The walk stops whenever y is outside the scissor, even before a line travelling toward the scissor has entered it.
Guard band triangle clip: reject any edge · case 01
Triangles are rejected when every vertex is outside some edge, discarding large triangles that cover the viewport.
Guard band triangle clip: reject any edge · case 02
Triangles are rejected when every vertex is outside some edge, discarding large triangles that cover the viewport.
Guard band triangle clip: reject any edge · case 03
Triangles are rejected when every vertex is outside some edge, discarding large triangles that cover the viewport.
Guard band triangle clip: reject any edge · case 04
Triangles are rejected when every vertex is outside some edge, discarding large triangles that cover the viewport.
Guard band triangle clip: reject any edge · case 05
Triangles are rejected when every vertex is outside some edge, discarding large triangles that cover the viewport.
Guard band triangle clip: reject right boundary · case 01
Triangles touching the right viewport edge are rejected even though boundary points are inside.
Guard band triangle clip: reject right boundary · case 02
Triangles touching the right viewport edge are rejected even though boundary points are inside.
Guard band triangle clip: reject right boundary · case 03
Triangles touching the right viewport edge are rejected even though boundary points are inside.
Guard band triangle clip: reject right boundary · case 04
Triangles touching the right viewport edge are rejected even though boundary points are inside.
Guard band triangle clip: reject right boundary · case 05
Triangles touching the right viewport edge are rejected even though boundary points are inside.
Guard band triangle clip: guard band y ignored · case 01
Guard-band classification checks only x, so triangles far beyond the guard band vertically skip geometric clipping.
Guard band triangle clip: guard band y ignored · case 02
Guard-band classification checks only x, so triangles far beyond the guard band vertically skip geometric clipping.
Guard band triangle clip: guard band y ignored · case 03
Guard-band classification checks only x, so triangles far beyond the guard band vertically skip geometric clipping.
Guard band triangle clip: guard band y ignored · case 04
Guard-band classification checks only x, so triangles far beyond the guard band vertically skip geometric clipping.
Guard band triangle clip: guard band y ignored · case 05
Guard-band classification checks only x, so triangles far beyond the guard band vertically skip geometric clipping.
Guard band triangle clip: bbox right floor · case 01
The exclusive right bound floors the maximum x, dropping the final partially covered column.
Guard band triangle clip: bbox right floor · case 02
The exclusive right bound floors the maximum x, dropping the final partially covered column.
Guard band triangle clip: bbox right floor · case 03
The exclusive right bound floors the maximum x, dropping the final partially covered column.
Guard band triangle clip: bbox right floor · case 04
The exclusive right bound floors the maximum x, dropping the final partially covered column.
Guard band triangle clip: bbox right floor · case 05
The exclusive right bound floors the maximum x, dropping the final partially covered column.
Guard band triangle clip: bbox left unclamped · case 01
Guard-band triangles report bounding boxes starting left of the viewport.
Guard band triangle clip: bbox left unclamped · case 02
Guard-band triangles report bounding boxes starting left of the viewport.
Guard band triangle clip: bbox left unclamped · case 03
Guard-band triangles report bounding boxes starting left of the viewport.
Guard band triangle clip: bbox left unclamped · case 04
Guard-band triangles report bounding boxes starting left of the viewport.
Guard band triangle clip: bbox left unclamped · case 05
Guard-band triangles report bounding boxes starting left of the viewport.
Guard band triangle clip: guard band width · case 01
A zero-width guard band sends every triangle that extends past the viewport to geometric clipping.
Guard band triangle clip: guard band width · case 02
A zero-width guard band sends every triangle that extends past the viewport to geometric clipping.
Guard band triangle clip: guard band width · case 03
A zero-width guard band sends every triangle that extends past the viewport to geometric clipping.
Guard band triangle clip: guard band width · case 04
A zero-width guard band sends every triangle that extends past the viewport to geometric clipping.
Guard band triangle clip: guard band width · case 05
A zero-width guard band sends every triangle that extends past the viewport to geometric clipping.
Polyline strip window clip: reentry merged · case 01
A part that re-enters the window at a different point is appended to the previous piece, drawing a false connector along the boundary.
Polyline strip window clip: reentry merged · case 02
A part that re-enters the window at a different point is appended to the previous piece, drawing a false connector along the boundary.
Polyline strip window clip: reentry merged · case 03
A part that re-enters the window at a different point is appended to the previous piece, drawing a false connector along the boundary.
Polyline strip window clip: reentry merged · case 04
A part that re-enters the window at a different point is appended to the previous piece, drawing a false connector along the boundary.
Polyline strip window clip: reentry merged · case 05
A part that re-enters the window at a different point is appended to the previous piece, drawing a false connector along the boundary.
Polyline strip window clip: joint duplicated · case 01
Continuing a piece appends the shared joint again, duplicating every interior vertex.
Polyline strip window clip: joint duplicated · case 02
Continuing a piece appends the shared joint again, duplicating every interior vertex.
Polyline strip window clip: joint duplicated · case 03
Continuing a piece appends the shared joint again, duplicating every interior vertex.
Polyline strip window clip: joint duplicated · case 04
Continuing a piece appends the shared joint again, duplicating every interior vertex.
Polyline strip window clip: joint duplicated · case 05
Continuing a piece appends the shared joint again, duplicating every interior vertex.
INSPECTABLE BY DESIGN
Every result has a runnable source.
Runnable implementations with recorded outputs, source hashes, and explicit contracts. Related variants share a failure mechanism and belong together in evaluation splits.
Read the methodology ↗