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ivac2:firdef_map_pattern [2015/04/11 01:20] filip.jonckers |
ivac2:firdef_map_pattern [2017/04/08 14:27] |
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| - | [[ivac2:firdef_toc|Back]] | ||
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| - | ====== Pattern attribute ====== | ||
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| - | To draw a line pattern (dotted or dashed), use the pattern attribute to define the line pattern. | ||
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| - | The pattern attribute value consists of one or more comma separated double values, this array of numbers specifies the sequence of dash/space/dash/space etc. When finished the sequence repeats itself to the end of the line. | ||
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| - | * Ordered List ItemPattern="5" | ||
| - | A basic setting that will result in a dashed line where both the dashes and spaces are 5 pixels in size. | ||
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| - | context.setLineDash([1,2]) | ||
| - | A setting that will result in a dotted line where the dashes are 1 pixel in size and the spaces are 2 pixels. | ||
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| - | context.setLineDash([2,3]) | ||
| - | Another dashed line but with small dashes. | ||
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| - | context.setLineDash([5,5,2,2]) | ||
| - | A setting where the first dash is five pixels, then a space of five pixels, then a dash of two pixels, then a space of two pixels, then the sequence starts again. | ||
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| - | The pattern argument is a 16-bit series of 0s and 1s, and it's repeated as necessary to //stipple// a given line. A 1 indicates that drawing occurs, and 0 that it does not, on a pixel-by-pixel basis, beginning with the low-order bits of the pattern. | ||
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| - | <code XML> | ||
| - | <line stipple="16135"> | ||
| - | <point lon="E0042957" lat="N0511059"/> | ||
| - | <point lon="E0044324" lat="N0510755"/> | ||
| - | </line> | ||
| - | </code> | ||
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| - | where 16135 = 0011111100000111 in binary | ||
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| - | With the preceding example and the pattern 16135 (which translates to 0011111100000111 in binary), a line would be drawn with 3 pixels on, then 5 off, 6 on, and 2 off. (If this seems backward, remember that the low-order bits are used first.) If factor had been 2, the pattern would have been elongated: 6 pixels on, 10 off, 12 on, and 4 off. | ||