The Tor Browser: layout/svg/nsSVGMaskFrame.cpp@b8a032363ba2 (annotated)

layout/svg/nsSVGMaskFrame.cpp@b8a032363ba2 (annotated)

layout/svg/nsSVGMaskFrame.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 // Main header first:
 #include "nsSVGMaskFrame.h"
 // Keep others in (case-insensitive) order:
 #include "gfxContext.h"
 #include "gfxImageSurface.h"
 #include "nsRenderingContext.h"
 #include "nsSVGEffects.h"
 #include "mozilla/dom/SVGMaskElement.h"
 using namespace mozilla::dom;
 /**
  * Byte offsets of channels in a native packed gfxColor or cairo image surface.
  */
 #ifdef IS_BIG_ENDIAN
 #define GFX_ARGB32_OFFSET_A 0
 #define GFX_ARGB32_OFFSET_R 1
 #define GFX_ARGB32_OFFSET_G 2
 #define GFX_ARGB32_OFFSET_B 3
 #else
 #define GFX_ARGB32_OFFSET_A 3
 #define GFX_ARGB32_OFFSET_R 2
 #define GFX_ARGB32_OFFSET_G 1
 #define GFX_ARGB32_OFFSET_B 0
 #endif
 // c = n / 255
 // c <= 0.04045 ? c / 12.92 : pow((c + 0.055) / 1.055, 2.4)) * 255 + 0.5
 static const uint8_t gsRGBToLinearRGBMap[256] = {
 ,   0,   0,   0,   0,   0,   0,   1,
 ,   1,   1,   1,   1,   1,   1,   1,
 ,   1,   2,   2,   2,   2,   2,   2,
 ,   2,   3,   3,   3,   3,   3,   3,
 ,   4,   4,   4,   4,   5,   5,   5,
 ,   6,   6,   6,   6,   7,   7,   7,
 ,   8,   8,   8,   9,   9,   9,  10,
 ,  10,  11,  11,  12,  12,  12,  13,
 ,  13,  14,  14,  15,  15,  16,  16,
 ,  17,  17,  18,  18,  19,  19,  20,
 ,  21,  22,  22,  23,  23,  24,  24,
 ,  25,  26,  27,  27,  28,  29,  29,
 ,  30,  31,  32,  32,  33,  34,  35,
 ,  36,  37,  37,  38,  39,  40,  41,
 ,  42,  43,  44,  45,  45,  46,  47,
 ,  49,  50,  51,  51,  52,  53,  54,
 ,  56,  57,  58,  59,  60,  61,  62,
 ,  64,  65,  66,  67,  68,  69,  70,
 ,  72,  73,  74,  76,  77,  78,  79,
 ,  81,  82,  84,  85,  86,  87,  88,
 ,  91,  92,  93,  95,  96,  97,  99,
 , 101, 103, 104, 105, 107, 108, 109,
 , 112, 114, 115, 116, 118, 119, 121,
 , 124, 125, 127, 128, 130, 131, 133,
 , 136, 138, 139, 141, 142, 144, 146,
 , 149, 151, 152, 154, 156, 157, 159,
 , 163, 164, 166, 168, 170, 171, 173,
 , 177, 179, 181, 183, 184, 186, 188,
 , 192, 194, 196, 198, 200, 202, 204,
 , 208, 210, 212, 214, 216, 218, 220,
 , 224, 226, 229, 231, 233, 235, 237,
 , 242, 244, 246, 248, 250, 253, 255
 };
 static void
 ComputesRGBLuminanceMask(uint8_t *aData,
                          int32_t aStride,
                          const nsIntRect &aRect,
                          float aOpacity)
 {
   for (int32_t y = aRect.y; y < aRect.YMost(); y++) {
     for (int32_t x = aRect.x; x < aRect.XMost(); x++) {
       uint8_t *pixel = aData + aStride * y + 4 * x;
       uint8_t a = pixel[GFX_ARGB32_OFFSET_A];
       uint8_t luminance;
       if (a) {
         /* sRGB -> intensity (unpremultiply cancels out the
          * (a/255.0) multiplication with aOpacity */
         luminance =
           static_cast<uint8_t>
                      ((pixel[GFX_ARGB32_OFFSET_R] * 0.2125 +
                        pixel[GFX_ARGB32_OFFSET_G] * 0.7154 +
                        pixel[GFX_ARGB32_OFFSET_B] * 0.0721) *
                       aOpacity);
       } else {
         luminance = 0;
       }
       memset(pixel, luminance, 4);
     }
   }
 }
 static void
 ComputeLinearRGBLuminanceMask(uint8_t *aData,
                               int32_t aStride,
                               const nsIntRect &aRect,
                               float aOpacity)
 {
   for (int32_t y = aRect.y; y < aRect.YMost(); y++) {
     for (int32_t x = aRect.x; x < aRect.XMost(); x++) {
       uint8_t *pixel = aData + aStride * y + 4 * x;
       uint8_t a = pixel[GFX_ARGB32_OFFSET_A];
       uint8_t luminance;
       // unpremultiply
       if (a) {
         if (a != 255) {
           pixel[GFX_ARGB32_OFFSET_B] =
             (255 * pixel[GFX_ARGB32_OFFSET_B]) / a;
           pixel[GFX_ARGB32_OFFSET_G] =
             (255 * pixel[GFX_ARGB32_OFFSET_G]) / a;
           pixel[GFX_ARGB32_OFFSET_R] =
             (255 * pixel[GFX_ARGB32_OFFSET_R]) / a;
         }
         /* sRGB -> linearRGB -> intensity */
         luminance =
           static_cast<uint8_t>
                      ((gsRGBToLinearRGBMap[pixel[GFX_ARGB32_OFFSET_R]] *
 .2125 +
                        gsRGBToLinearRGBMap[pixel[GFX_ARGB32_OFFSET_G]] *
 .7154 +
                        gsRGBToLinearRGBMap[pixel[GFX_ARGB32_OFFSET_B]] *
 .0721) * (a / 255.0) * aOpacity);
       } else {
         luminance = 0;
       }
       memset(pixel, luminance, 4);
     }
   }
 }
 static void
 ComputeAlphaMask(uint8_t *aData,
                  int32_t aStride,
                  const nsIntRect &aRect,
                  float aOpacity)
 {
   for (int32_t y = aRect.y; y < aRect.YMost(); y++) {
     for (int32_t x = aRect.x; x < aRect.XMost(); x++) {
       uint8_t *pixel = aData + aStride * y + 4 * x;
       uint8_t luminance = pixel[GFX_ARGB32_OFFSET_A] * aOpacity;
       memset(pixel, luminance, 4);
     }
   }
 }
 //----------------------------------------------------------------------
 // Implementation
 nsIFrame*
 NS_NewSVGMaskFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
 {
   return new (aPresShell) nsSVGMaskFrame(aContext);
 }
 NS_IMPL_FRAMEARENA_HELPERS(nsSVGMaskFrame)
 already_AddRefed<gfxPattern>
 nsSVGMaskFrame::ComputeMaskAlpha(nsRenderingContext *aContext,
                                  nsIFrame* aParent,
                                  const gfxMatrix &aMatrix,
                                  float aOpacity)
 {
   // If the flag is set when we get here, it means this mask frame
   // has already been used painting the current mask, and the document
   // has a mask reference loop.
   if (mInUse) {
     NS_WARNING("Mask loop detected!");
     return nullptr;
   }
   AutoMaskReferencer maskRef(this);
   SVGMaskElement *mask = static_cast<SVGMaskElement*>(mContent);
   uint16_t units =
     mask->mEnumAttributes[SVGMaskElement::MASKUNITS].GetAnimValue();
   gfxRect bbox;
   if (units == SVG_UNIT_TYPE_OBJECTBOUNDINGBOX) {
     bbox = nsSVGUtils::GetBBox(aParent);
   }
   gfxRect maskArea = nsSVGUtils::GetRelativeRect(units,
     &mask->mLengthAttributes[SVGMaskElement::ATTR_X], bbox, aParent);
   gfxContext *gfx = aContext->ThebesContext();
   // Get the clip extents in device space:
   gfx->Save();
   nsSVGUtils::SetClipRect(gfx, aMatrix, maskArea);
   gfx->IdentityMatrix();
   gfxRect clipExtents = gfx->GetClipExtents();
   clipExtents.RoundOut();
   gfx->Restore();
   bool resultOverflows;
   gfxIntSize surfaceSize =
     nsSVGUtils::ConvertToSurfaceSize(gfxSize(clipExtents.Width(),
                                              clipExtents.Height()),
                                      &resultOverflows);
   // 0 disables mask, < 0 is an error
   if (surfaceSize.width <= 0 || surfaceSize.height <= 0)
     return nullptr;
   if (resultOverflows)
     return nullptr;
   nsRefPtr<gfxImageSurface> image =
     new gfxImageSurface(surfaceSize, gfxImageFormat::ARGB32);
   if (!image || image->CairoStatus())
     return nullptr;
   // We would like to use gfxImageSurface::SetDeviceOffset() to position
   // 'image'. However, we need to set the same matrix on the temporary context
   // and pattern that we create below as is currently set on 'gfx'.
   // Unfortunately, any device offset set by SetDeviceOffset() is affected by
   // the transform passed to the SetMatrix() calls, so to avoid that we account
   // for the device offset in the transform rather than use SetDeviceOffset().
   gfxMatrix matrix =
     gfx->CurrentMatrix() * gfxMatrix().Translate(-clipExtents.TopLeft());
   nsRefPtr<nsRenderingContext> tmpCtx(new nsRenderingContext);
   tmpCtx->Init(this->PresContext()->DeviceContext(), image);
   tmpCtx->ThebesContext()->SetMatrix(matrix);
   mMaskParent = aParent;
   if (mMaskParentMatrix) {
     *mMaskParentMatrix = aMatrix;
   } else {
     mMaskParentMatrix = new gfxMatrix(aMatrix);
   }
   for (nsIFrame* kid = mFrames.FirstChild(); kid;
        kid = kid->GetNextSibling()) {
     // The CTM of each frame referencing us can be different
     nsISVGChildFrame* SVGFrame = do_QueryFrame(kid);
     if (SVGFrame) {
       SVGFrame->NotifySVGChanged(nsISVGChildFrame::TRANSFORM_CHANGED);
     }
     nsSVGUtils::PaintFrameWithEffects(tmpCtx, nullptr, kid);
   }
   uint8_t *data   = image->Data();
   int32_t  stride = image->Stride();
   nsIntRect rect(0, 0, surfaceSize.width, surfaceSize.height);
   if (StyleSVGReset()->mMaskType == NS_STYLE_MASK_TYPE_LUMINANCE) {
     if (StyleSVG()->mColorInterpolation ==
         NS_STYLE_COLOR_INTERPOLATION_LINEARRGB) {
       ComputeLinearRGBLuminanceMask(data, stride, rect, aOpacity);
     } else {
       ComputesRGBLuminanceMask(data, stride, rect, aOpacity);
     }
   } else {
     ComputeAlphaMask(data, stride, rect, aOpacity);
   }
   nsRefPtr<gfxPattern> retval = new gfxPattern(image);
   retval->SetMatrix(matrix);
   return retval.forget();
 }
 nsresult
 nsSVGMaskFrame::AttributeChanged(int32_t  aNameSpaceID,
                                  nsIAtom* aAttribute,
                                  int32_t  aModType)
 {
   if (aNameSpaceID == kNameSpaceID_None &&
       (aAttribute == nsGkAtoms::x ||
        aAttribute == nsGkAtoms::y ||
        aAttribute == nsGkAtoms::width ||
        aAttribute == nsGkAtoms::height||
        aAttribute == nsGkAtoms::maskUnits ||
        aAttribute == nsGkAtoms::maskContentUnits)) {
     nsSVGEffects::InvalidateDirectRenderingObservers(this);
   }
   return nsSVGMaskFrameBase::AttributeChanged(aNameSpaceID,
                                               aAttribute, aModType);
 }
 #ifdef DEBUG
 void
 nsSVGMaskFrame::Init(nsIContent* aContent,
                      nsIFrame* aParent,
                      nsIFrame* aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::mask),
                "Content is not an SVG mask");
   nsSVGMaskFrameBase::Init(aContent, aParent, aPrevInFlow);
 }
 #endif /* DEBUG */
 nsIAtom *
 nsSVGMaskFrame::GetType() const
 {
   return nsGkAtoms::svgMaskFrame;
 }
 gfxMatrix
 nsSVGMaskFrame::GetCanvasTM(uint32_t aFor, nsIFrame* aTransformRoot)
 {
   NS_ASSERTION(mMaskParentMatrix, "null parent matrix");
   SVGMaskElement *mask = static_cast<SVGMaskElement*>(mContent);
   return nsSVGUtils::AdjustMatrixForUnits(
     mMaskParentMatrix ? *mMaskParentMatrix : gfxMatrix(),
     &mask->mEnumAttributes[SVGMaskElement::MASKCONTENTUNITS],
     mMaskParent);
 }

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layout/svg/nsSVGMaskFrame.cpp@b8a032363ba2 (annotated)

layout/svg/nsSVGMaskFrame.cpp