| <!doctype html> |
| <!-- |
| This test determines whether the feTurbulence algorithm allows zero length vectors on some particular seeds. These zero length |
| vectors result in large rectangular holes in the generated image. |
| Seed 514 is the first seed value that demonstrates the error. |
| Others are: 1977,2337,4777,8032,9615,14783,14862,14921,18607,19537,19852,19955,22456,23056,26678,27351,29383,29560,29929, ... |
| The feTurbulence algorithm in the specification uses rejection sampling to avoid generating zero length vectors and so in a |
| correct implementation we should not see any large holes in the image. |
| --> |
| <html> |
| <body> |
| <svg viewbox="0 0 512 256"> |
| <desc>Test passes if there are no red squares.</desc> |
| <defs> |
| <filter id="turb1" filterUnits="objectBoundingBox" x="0" y="0" width="100%" height="100%"> |
| <feTurbulence x="0" y="0" width="100%" height="100%" baseFrequency="0.02 0.1" numOctaves="5" seed="514" result="a" /> |
| <feComponentTransfer in="a"> |
| <!-- set colour to black everywhere and set opacity to full if alpha > 0 --> |
| <feFuncR type="linear" slope="-10000" intercept="0"/><feFuncG type="linear" slope="-10000" intercept="0"/><feFuncB type="linear" slope="-10000" intercept="0"/> |
| <feFuncA type="linear" slope="10000" intercept="0"/> |
| </feComponentTransfer> |
| </filter> |
| <filter id="turb2" filterUnits="objectBoundingBox" x="0" y="0" width="100%" height="100%"> |
| <feTurbulence x="0" y="0" width="100%" height="100%" baseFrequency="0.02 0.1" numOctaves="5" seed="14783" result="a" /> |
| <feComponentTransfer in="a"> |
| <feFuncR type="linear" slope="-10000" intercept="0"/><feFuncG type="linear" slope="-10000" intercept="0"/><feFuncB type="linear" slope="-10000" intercept="0"/> |
| <feFuncA type="linear" slope="10000" intercept="0"/> |
| </feComponentTransfer> |
| </filter> |
| <filter id="turb3" filterUnits="objectBoundingBox" x="0" y="0" width="100%" height="100%"> |
| <feTurbulence x="0" y="0" width="100%" height="100%" baseFrequency="0.02 0.1" numOctaves="5" seed="23056" result="a" /> |
| <feComponentTransfer in="a"> |
| <feFuncR type="linear" slope="-10000" intercept="0"/><feFuncG type="linear" slope="-10000" intercept="0"/><feFuncB type="linear" slope="-10000" intercept="0"/> |
| <feFuncA type="linear" slope="10000" intercept="0"/> |
| </feComponentTransfer> |
| </filter> |
| <filter id="turb4" filterUnits="objectBoundingBox" x="0" y="0" width="100%" height="100%"> |
| <feTurbulence x="0" y="0" width="100%" height="100%" baseFrequency="0.02 0.1" numOctaves="5" seed="9615" result="a" /> |
| <feComponentTransfer in="a"> |
| <feFuncR type="linear" slope="-10000" intercept="0"/><feFuncG type="linear" slope="-10000" intercept="0"/><feFuncB type="linear" slope="-10000" intercept="0"/> |
| <feFuncA type="linear" slope="10000" intercept="0"/> |
| </feComponentTransfer> |
| </filter> |
| </defs> |
| <rect x="0" y="0" width="256" height="128" fill="red" /> |
| <rect x="0" y="0" width="64" height="128" fill="black" filter="url(#turb1)"/> |
| <rect x="64" y="0" width="64" height="128" fill="blue" filter="url(#turb2)"/> |
| <rect x="128" y="0" width="64" height="128" fill="black" filter="url(#turb3)"/> |
| <rect x="192" y="0" width="64" height="128" fill="blue" filter="url(#turb4)"/> |
| </svg> |
| </body> |
| </html> |
