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| author |  commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> | 2013-08-23 13:13:12 +0000 |
|---|---|---|
| committer | commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> | 2013-08-23 13:13:12 +0000 |
| commit | eaa77979908d1b9fff00b73d02c4576901448933 (patch) | |
| tree | ebd7aacc3b4f02ac7935573deb8c20a260d00302 /include/effects | |
| parent | 44a77c8158016996f79eb0ac98bb85996174bb89 (diff) | |
Add luminance mask transfer modes.
This adds kSrcInLum_Mode and kDstInLum_Mode, to support CSS and SVG luminance masks (http://www.w3.org/TR/css-masking/#MaskValues , http://www.w3.org/TR/SVG/masking.html#Masking ).
The transfer coefficient is computed according to http://www.w3.org/TR/2011/REC-SVG11-20110816/filters.html#feColorMatrixElement "luminance-to-alpha":
luma = 0.2125 * r + 0.7154 * g + 0.0721 * b
R=bsalomon@google.com, reed@google.com, robertphillips@google.com, vandebo@chromium.org
Author: fmalita@chromium.org
Review URL: https://chromiumcodereview.appspot.com/22918012
git-svn-id: http://skia.googlecode.com/svn/trunk@10887 2bbb7eff-a529-9590-31e7-b0007b416f81
Diffstat (limited to 'include/effects')
| -rw-r--r-- | include/effects/SkLumaXfermode.h | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/include/effects/SkLumaXfermode.h b/include/effects/SkLumaXfermode.h new file mode 100644 index 0000000000..5bcd10eff1 --- /dev/null +++ b/include/effects/SkLumaXfermode.h @@ -0,0 +1,58 @@ +/* + * Copyright 2013 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#ifndef SkLumaXfermode_DEFINED +#define SkLumaXfermode_DEFINED + +#include "SkXfermode.h" + +/** + * Luminance mask transfer, as defined in + * http://www.w3.org/TR/SVG/masking.html#Masking + * http://www.w3.org/TR/css-masking/#MaskValues + * + * The luminance-to-alpha function is applied before performing a standard + * SrcIn/DstIn xfer: + * + * luma(C) = (0.2125 * C.r + 0.7154 * C.g + 0.0721 * C.b) * C.a + * + * (where C is un-premultiplied) + */ +class SK_API SkLumaMaskXfermode : public SkXfermode { +public: + /** Return an SkLumaMaskXfermode object for the specified submode. + * + * Only kSrcIn_Mode and kDstIn_Mode are supported - for everything else, + * the factory returns NULL. + */ + static SkXfermode* Create(SkXfermode::Mode); + + virtual SkPMColor xferColor(SkPMColor, SkPMColor) const SK_OVERRIDE; + virtual void xfer32(SkPMColor dst[], const SkPMColor src[], int count, + const SkAlpha aa[]) const SK_OVERRIDE; + + SK_DEVELOPER_TO_STRING() + SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkLumaMaskXfermode) + +#if SK_SUPPORT_GPU + virtual bool asNewEffectOrCoeff(GrContext*, GrEffectRef**, Coeff*, Coeff*, + GrTexture*) const SK_OVERRIDE; +#endif + +protected: + SkLumaMaskXfermode(SkFlattenableReadBuffer&); + virtual void flatten(SkFlattenableWriteBuffer&) const SK_OVERRIDE; + +private: + SkLumaMaskXfermode(SkXfermode::Mode); + + const SkXfermode::Mode fMode; + + typedef SkXfermode INHERITED; +}; + +#endif |