d04aaa3a84
Update https://skia.org/user/sample/pdf to use example. https://fiddle.skia.org/c/0777df0419252e28d93c26fb5b789059 Change-Id: Ia828cd5d2ffd30d24a237ffaa3b007984d98a3ba Reviewed-on: https://skia-review.googlesource.com/c/skia/+/216345 Auto-Submit: Hal Canary <halcanary@google.com> Commit-Queue: Ben Wagner <bungeman@google.com> Reviewed-by: Ben Wagner <bungeman@google.com>
65 lines
2.2 KiB
Markdown
65 lines
2.2 KiB
Markdown
Using Skia's PDF Backend
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========================
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Here is an example of using Skia's PDF backend (SkPDF) via the
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SkDocument and SkCanvas APIs.
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<fiddle-embed name='@PDF'></fiddle-embed>
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<!-- https://fiddle.skia.org/c/@PDF docs/examples/PDF.cpp -->
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* * *
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<span id="limits">SkPDF Limitations</span>
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------------------------------------------
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There are several corners of Skia's public API that SkPDF currently
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does not handle because either no known client uses the feature or
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there is no simple PDF-ish way to handle it.
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In this document:
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+ **drop** means to draw nothing.
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+ **ignore** means to draw without the effect
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+ **expand** means to implement something in a non-PDF-ish way.
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This may mean to rasterize vector graphics, to expand paths with
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path effects into many individual paths, or to convert text to
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paths.
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<style scoped><!--
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#pdftable {border-collapse:collapse;}
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#pdftable tr th, #pdftable tr td {border:#888888 2px solid;padding: 5px;}
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--></style>
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<table id="pdftable">
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<tr><th>Effect</th> <th>text</th> <th>images</th> <th>everything
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else</th></tr>
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<tr><th>SkMaskFilter</th> <td>drop</td> <td>ignore</td> <td>ignore</td></tr>
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<tr><th>SkPathEffect</th> <td>ignore</td> <td>n/a</td> <td>expand</td></tr>
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<tr><th>SkColorFilter</th> <td>ignore</td> <td>expand</td> <td>ignore</td></tr>
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<tr><th>SkImageFilter</th> <td>expand</td> <td>expand</td> <td>expand</td></tr>
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<tr><th>unsupported SkXferModes</th> <td>ignore</td> <td>ignore</td> <td>ignore</td></tr>
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<tr><th>non-gradient SkShader</th> <td>expand</td> <td>n/a</td> <td>expand</td></tr>
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</table>
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Notes:
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- *SkImageFilter*: When SkImageFilter is expanded, text-as-text is lost.
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- *SkXferMode*: The following transfer modes are not natively
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supported by PDF: DstOver, SrcIn, DstIn, SrcOut, DstOut, SrcATop,
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DstATop, and Modulate.
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Other limitations:
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- *drawText with VerticalText* — drop. No known clients seem to make use
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of the VerticalText flag.
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- *drawTextOnPath* — expand. (Text-as-text is lost.)
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- *drawVertices* — drop.
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- *drawPatch* — drop.
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* * *
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