Changeset 173941 in webkit


Ignore:
Timestamp:
Sep 24, 2014 7:32:06 PM (10 years ago)
Author:
mmaxfield@apple.com
Message:

REGRESSION: Text with a zero offset, zero blur shadow vanishes
​https://bugs.webkit.org/show_bug.cgi?id=136801

Reviewed by Darin Adler.

Source/WebCore:

This patch performs some cleanup regarding TextPainter's shadow logic and handles an
additional case of empty shadows. Previously, there was tight coupling between
applyShadowToGraphicalContext() and paintTextWithShadows(), as they both used a
collection of variables to determine how shadows are to be drawn. This complexity has
been moved into a helper class, ShadowApplier, which performs what
applyShadowToGraphicsContext() used to do, and cleans up correctly in its destructor.
This removes the tight coupling mentioned earlier.

Test: fast/text/empty-shadow.html

  • rendering/InlineTextBox.cpp:

(WebCore::InlineTextBox::applyShadowToGraphicsContext): Moved to ShadowApplier.

  • rendering/InlineTextBox.h: Deleted applyShadowToGraphicsContext signature.
  • rendering/TextPainter.cpp:

(WebCore::ShadowApplier::ShadowApplier): Perform the contents of applyShadowToGraphicsContext()
(WebCore::ShadowApplier::~ShadowApplier): Undo the work done previously
(WebCore::paintTextWithShadows): Create a ShadowApplier to do the relevant shadow work. In addition,
refactor some boolean flags to more meaningful ones with relation to the computation at hand.
(WebCore::isEmptyShadow): Moved to TextPainter.h, named shadowIsCompletelyCoveredByText()

  • rendering/TextPainter.h:

(WebCore::ShadowApplier::ShadowApplier): Moved from InlineTextBox::applyShadowToGraphicsContext().
(WebCore::ShadowApplier::extraOffset): Getter.
(WebCore::ShadowApplier::~ShadowApplier): Moved from TextPainter::paintTextWithShadows().
(WebCore::isLastShadowIteration): Helper function.
(WebCore::shadowIsCompletelyCoveredByText): Determines whether or not we should not draw the shadow.

  • rendering/svg/SVGInlineTextBox.cpp:

(WebCore::SVGInlineTextBox::paintTextWithShadows): Update to use ShadowApplier.

LayoutTests:

This test should be a comprehensive test of empty shadows. It tests every
combination of one and two shadows being empty, as well as transparent and
opaque text.

After updating fast/text/empty-shadow.html, fast/text/empty-shadow-with-color.html
is no longer necessary.

  • fast/text/empty-shadow-expected.html:
  • fast/text/empty-shadow-with-color-expected.html: Removed.
  • fast/text/empty-shadow-with-color.html: Removed.
  • fast/text/empty-shadow.html:
Location:
trunk
Files:
2 deleted
9 edited

Legend:

Unmodified
Added
Removed

  • trunk/LayoutTests/ChangeLog

    r173925 r173941  
     12014-09-22  Myles C. Maxfield  <mmaxfield@apple.com>
     2
     3        REGRESSION: Text with a zero offset, zero blur shadow vanishes
     4        https://bugs.webkit.org/show_bug.cgi?id=136801
     5
     6        Reviewed by Darin Adler.
     7
     8        This test should be a comprehensive test of empty shadows. It tests every
     9        combination of one and two shadows being empty, as well as transparent and
     10        opaque text.
     11
     12        After updating fast/text/empty-shadow.html, fast/text/empty-shadow-with-color.html
     13        is no longer necessary.
     14
     15        * fast/text/empty-shadow-expected.html:
     16        * fast/text/empty-shadow-with-color-expected.html: Removed.
     17        * fast/text/empty-shadow-with-color.html: Removed.
     18        * fast/text/empty-shadow.html:
     19
    1202014-09-24  Shivakumar JM  <shiva.jm@samsung.com>
    221

  • trunk/LayoutTests/fast/text/empty-shadow-expected.html

    r172153 r173941  
    1 This tests that text drawn with text-shadows of radius 0 and (0, 0) offset are not drawn.
    2 This is a better outcome than them being drawn in an ugly way.
    3 This test is successful if the text below is completely invisible.
     1<p>This tests that text drawn with text-shadows of radius 0 and (0, 0) offset are not drawn.</p>
     2<p>In the following tests, the actual text is green while the shadows are blue.</p>
     3
     4<div style="color: green;">
     5<div style="text-shadow: 5px 5px blue;">Text with a single shadow.</div>
     6<div>Text with one empty (undrawn) shadow.</div>
     7<div style="text-shadow: 5px 5px blue, 10px 10px blue;">Text with two shadows</div>
     8<div style="text-shadow: 5px 5px blue;">Text with two shadows: first drawn and second empty (undrawn).</div>
     9<div style="text-shadow: 10px 10px blue;">Text with two shadows: first empty (undrawn) and second drawn.</div>
     10<div>Text with two empty (undrawn) shadows.</div>
     11</div>
     12
     13<div style="color: transparent;">
     14<div style="text-shadow: 5px 5px blue;">Transparent text with a single shadow.</div>
     15<div style="color: blue;">Transparent text with one empty shadow.</div>
     16<div style="text-shadow: 5px 5px blue, 10px 10px blue;">Transparent text with two shadows</div>
     17<div style="color: blue; text-shadow: 7px 7px blue;">Transparent text with two shadows: first drawn and second empty.</div>
     18<div style="color: blue; text-shadow: 10px 10px blue;">Transparent text with two shadows: first drawn and second empty.</div>
     19<div style="color: blue; position: relative;"><div style="position: absolute; left: 0px; top: 0px;">Transparent text with two empty shadows.</div><div style="position: absolute; left: 0px; top: 0px;">Transparent text with two empty shadows.</div></div>
     20</div>

  • trunk/LayoutTests/fast/text/empty-shadow.html

    r172153 r173941  
    1 This tests that text drawn with text-shadows of radius 0 and (0, 0) offset are not drawn.
    2 This is a better outcome than them being drawn in an ugly way.
    3 This test is successful if the text below is completely invisible.
    4 <div style="color:#fff;text-shadow:0 0 #000">This is some text</div>
     1<p>This tests that text drawn with text-shadows of radius 0 and (0, 0) offset are not drawn.</p>
     2<p>In the following tests, the actual text is green while the shadows are blue.</p>
     3
     4<div style="color: green;">
     5<div style="text-shadow: 5px 5px blue;">Text with a single shadow.</div>
     6<div style="text-shadow: 0px 0px blue;">Text with one empty (undrawn) shadow.</div>
     7<div style="text-shadow: 5px 5px blue, 10px 10px blue;">Text with two shadows</div>
     8<div style="text-shadow: 5px 5px blue, 0px 0px blue;">Text with two shadows: first drawn and second empty (undrawn).</div>
     9<div style="text-shadow: 0px 0px blue, 10px 10px blue;">Text with two shadows: first empty (undrawn) and second drawn.</div>
     10<div style="text-shadow: 0px 0px blue, 0px 0px blue;">Text with two empty (undrawn) shadows.</div>
     11</div>
     12
     13<div style="color: transparent;">
     14<div style="text-shadow: 5px 5px blue;">Transparent text with a single shadow.</div>
     15<div style="text-shadow: 0px 0px blue;">Transparent text with one empty shadow.</div>
     16<div style="text-shadow: 5px 5px blue, 10px 10px blue;">Transparent text with two shadows</div>
     17<div style="text-shadow: 7px 7px blue, 0px 0px blue;">Transparent text with two shadows: first drawn and second empty.</div>
     18<div style="text-shadow: 0px 0px blue, 10px 10px blue;">Transparent text with two shadows: first drawn and second empty.</div>
     19<div style="text-shadow: 0px 0px blue, 0px 0px blue;">Transparent text with two empty shadows.</div>
     20</div>

  • trunk/Source/WebCore/ChangeLog

    r173939 r173941  
     12014-09-22  Myles C. Maxfield  <mmaxfield@apple.com>
     2
     3        REGRESSION: Text with a zero offset, zero blur shadow vanishes
     4        https://bugs.webkit.org/show_bug.cgi?id=136801
     5
     6        Reviewed by Darin Adler.
     7
     8        This patch performs some cleanup regarding TextPainter's shadow logic and handles an
     9        additional case of empty shadows. Previously, there was tight coupling between
     10        applyShadowToGraphicalContext() and paintTextWithShadows(), as they both used a
     11        collection of variables to determine how shadows are to be drawn. This complexity has
     12        been moved into a helper class, ShadowApplier, which performs what
     13        applyShadowToGraphicsContext() used to do, and cleans up correctly in its destructor.
     14        This removes the tight coupling mentioned earlier.
     15
     16        Test: fast/text/empty-shadow.html
     17
     18        * rendering/InlineTextBox.cpp:
     19        (WebCore::InlineTextBox::applyShadowToGraphicsContext): Moved to ShadowApplier.
     20        * rendering/InlineTextBox.h: Deleted applyShadowToGraphicsContext signature.
     21        * rendering/TextPainter.cpp:
     22        (WebCore::ShadowApplier::ShadowApplier): Perform the contents of applyShadowToGraphicsContext()
     23        (WebCore::ShadowApplier::~ShadowApplier): Undo the work done previously
     24        (WebCore::paintTextWithShadows): Create a ShadowApplier to do the relevant shadow work. In addition,
     25        refactor some boolean flags to more meaningful ones with relation to the computation at hand.
     26        (WebCore::isEmptyShadow): Moved to TextPainter.h, named shadowIsCompletelyCoveredByText()
     27        * rendering/TextPainter.h:
     28        (WebCore::ShadowApplier::ShadowApplier): Moved from InlineTextBox::applyShadowToGraphicsContext().
     29        (WebCore::ShadowApplier::extraOffset): Getter.
     30        (WebCore::ShadowApplier::~ShadowApplier): Moved from TextPainter::paintTextWithShadows().
     31        (WebCore::isLastShadowIteration): Helper function.
     32        (WebCore::shadowIsCompletelyCoveredByText): Determines whether or not we should not draw the shadow.
     33        * rendering/svg/SVGInlineTextBox.cpp:
     34        (WebCore::SVGInlineTextBox::paintTextWithShadows): Update to use ShadowApplier.
     35
    1362014-09-24  Brian J. Burg  <burg@cs.washington.edu>
    237

  • trunk/Source/WebCore/rendering/InlineTextBox.cpp

    r173502 r173941  
    423423    }
    424424    return false;
    425 }
    426 
    427 FloatSize InlineTextBox::applyShadowToGraphicsContext(GraphicsContext& context, const ShadowData* shadow, const FloatRect& textRect, bool stroked, bool opaque, bool horizontal, bool& didSaveContext)
    428 {
    429     if (!shadow)
    430         return FloatSize();
    431 
    432     FloatSize extraOffset;
    433     int shadowX = horizontal ? shadow->x() : shadow->y();
    434     int shadowY = horizontal ? shadow->y() : -shadow->x();
    435     FloatSize shadowOffset(shadowX, shadowY);
    436     int shadowRadius = shadow->radius();
    437     const Color& shadowColor = shadow->color();
    438 
    439     if (shadow->next() || stroked || !opaque) {
    440         FloatRect shadowRect(textRect);
    441         shadowRect.inflate(shadow->paintingExtent());
    442         shadowRect.move(shadowOffset);
    443         context.save();
    444         context.clip(shadowRect);
    445 
    446         extraOffset = FloatSize(0, 2 * textRect.height() + std::max(0.0f, shadowOffset.height()) + shadowRadius);
    447         shadowOffset -= extraOffset;
    448         didSaveContext = true;
    449     }
    450 
    451     context.setShadow(shadowOffset, shadowRadius, shadowColor, context.fillColorSpace());
    452     return extraOffset;
    453425}
    454426

  • trunk/Source/WebCore/rendering/InlineTextBox.h

    r173502 r173941  
    155155    virtual float positionForOffset(int offset) const;
    156156
    157     // Needs to be public, so the static paintTextWithShadows() function can use it.
    158     static FloatSize applyShadowToGraphicsContext(GraphicsContext&, const ShadowData*, const FloatRect& textRect, bool stroked, bool opaque, bool horizontal, bool& didSaveContext);
    159 
    160157protected:
    161158    void paintCompositionBackground(GraphicsContext*, const FloatPoint& boxOrigin, const RenderStyle&, const Font&, int startPos, int endPos);

  • trunk/Source/WebCore/rendering/TextPainter.cpp

    r173502 r173941  
    6666}
    6767
    68 static bool isEmptyShadow(const ShadowData* shadow)
    69 {
    70     if (!shadow)
    71         return false;
    72     return shadow->location() == IntPoint() && !shadow->radius();
     68ShadowApplier::ShadowApplier(GraphicsContext& context, const ShadowData* shadow, const FloatRect& textRect, bool lastShadowIterationShouldDrawText, bool opaque, FontOrientation orientation)
     69    : m_context(context)
     70    , m_shadow(shadow)
     71    , m_onlyDrawsShadow(!isLastShadowIteration() || !lastShadowIterationShouldDrawText)
     72    , m_avoidDrawingShadow(shadowIsCompletelyCoveredByText(opaque))
     73    , m_nothingToDraw(shadow && m_avoidDrawingShadow && m_onlyDrawsShadow)
     74    , m_didSaveContext(false)
     75{
     76    if (!shadow || m_nothingToDraw) {
     77        m_shadow = nullptr;
     78        return;
     79    }
     80
     81    int shadowX = orientation == Horizontal ? shadow->x() : shadow->y();
     82    int shadowY = orientation == Horizontal ? shadow->y() : -shadow->x();
     83    FloatSize shadowOffset(shadowX, shadowY);
     84    int shadowRadius = shadow->radius();
     85    const Color& shadowColor = shadow->color();
     86
     87    // When drawing shadows, we usually clip the context to the area the shadow will reside, and then
     88    // draw the text itself outside the clipped area (so only the shadow shows up). However, we can
     89    // often draw the *last* shadow and the text itself in a single call.
     90    if (m_onlyDrawsShadow) {
     91        FloatRect shadowRect(textRect);
     92        shadowRect.inflate(shadow->paintingExtent());
     93        shadowRect.move(shadowOffset);
     94        context.save();
     95        context.clip(shadowRect);
     96
     97        m_didSaveContext = true;
     98        m_extraOffset = FloatSize(0, 2 * textRect.height() + std::max(0.0f, shadowOffset.height()) + shadowRadius);
     99        shadowOffset -= m_extraOffset;
     100    }
     101
     102    if (!m_avoidDrawingShadow)
     103        context.setShadow(shadowOffset, shadowRadius, shadowColor, context.fillColorSpace());
     104}
     105
     106ShadowApplier::~ShadowApplier()
     107{
     108    if (!m_shadow)
     109        return;
     110    if (m_onlyDrawsShadow)
     111        m_context.restore();
     112    else if (!m_avoidDrawingShadow)
     113        m_context.clearShadow();
    73114}
    74115
    … …  
    80121    ColorSpace fillColorSpace = context.fillColorSpace();
    81122    bool opaque = !fillColor.hasAlpha();
     123    bool lastShadowIterationShouldDrawText = !stroked && opaque;
    82124    if (!opaque)
    83125        context.setFillColor(Color::black, fillColorSpace);
    84126
    85127    do {
    86         if (isEmptyShadow(shadow)) {
     128        ShadowApplier shadowApplier(context, shadow, boxRect, lastShadowIterationShouldDrawText, opaque, horizontal ? Horizontal : Vertical);
     129        if (shadowApplier.nothingToDraw()) {
    87130            shadow = shadow->next();
    88131            continue;
    89132        }
    90133
    91         IntSize extraOffset;
    92         bool didSaveContext = false;
    93         if (shadow)
    94             extraOffset = roundedIntSize(InlineTextBox::applyShadowToGraphicsContext(context, shadow, boxRect, stroked, opaque, horizontal, didSaveContext));
    95         else if (!opaque)
     134        IntSize extraOffset = roundedIntSize(shadowApplier.extraOffset());
     135        if (!shadow && !opaque)
    96136            context.setFillColor(fillColor, fillColorSpace);
    97137
    … …  
    108148            break;
    109149
    110         if (didSaveContext)
    111             context.restore();
    112         else
    113             context.clearShadow();
    114 
    115150        shadow = shadow->next();
    116     } while (shadow || stroked || !opaque);
     151    } while (shadow || !lastShadowIterationShouldDrawText);
    117152}
    118153

  • trunk/Source/WebCore/rendering/TextPainter.h

    r173502 r173941  
    2626#include "AffineTransform.h"
    2727#include "DashArray.h"
     28#include "FontOrientation.h"
    2829#include "RenderText.h"
    2930
    … …  
    7475};
    7576
     77class ShadowApplier {
     78public:
     79    ShadowApplier(GraphicsContext&, const ShadowData*, const FloatRect& textRect, bool lastShadowIterationShouldDrawText = true, bool opaque = false, FontOrientation = Horizontal);
     80    FloatSize extraOffset() const { return m_extraOffset; }
     81    bool nothingToDraw() const { return m_nothingToDraw; }
     82    bool didSaveContext() const { return m_didSaveContext; }
     83    ~ShadowApplier();
     84
     85private:
     86    bool isLastShadowIteration()
     87    {
     88        return m_shadow && !m_shadow->next();
     89    }
     90
     91    bool shadowIsCompletelyCoveredByText(bool textIsOpaque)
     92    {
     93        return textIsOpaque && shadow && m_shadow->location() == IntPoint() && !m_shadow->radius();
     94    }
     95
     96    FloatSize m_extraOffset;
     97    GraphicsContext& m_context;
     98    const ShadowData* m_shadow;
     99    bool m_onlyDrawsShadow : 1;
     100    bool m_avoidDrawingShadow : 1;
     101    bool m_nothingToDraw : 1;
     102    bool m_didSaveContext : 1;
     103};
     104
    76105} // namespace WebCore
    77106

  • trunk/Source/WebCore/rendering/svg/SVGInlineTextBox.cpp

    r173502 r173941  
    3838#include "SVGRootInlineBox.h"
    3939#include "SVGTextRunRenderingContext.h"
     40#include "TextPainter.h"
    4041
    4142namespace WebCore {
    … …  
    595596            break;
    596597
    597         FloatSize extraOffset;
    598         bool didSaveContext = false;
    599         if (shadow)
    600             extraOffset = applyShadowToGraphicsContext(*context, shadow, shadowRect, false /* stroked */, true /* opaque */, true /* horizontal */, didSaveContext);
    601 
    602         context->save();
    603         context->scale(FloatSize(1 / scalingFactor, 1 / scalingFactor));
    604 
    605         scaledFont.drawText(context, textRun, textOrigin + extraOffset, startPosition, endPosition);
    606 
    607         context->restore();
    608 
    609         if (shadow) {
    610             if (didSaveContext)
     598        {
     599            ShadowApplier shadowApplier(*context, shadow, shadowRect);
     600
     601            if (!shadowApplier.didSaveContext())
     602                context->save();
     603            context->scale(FloatSize(1 / scalingFactor, 1 / scalingFactor));
     604
     605            scaledFont.drawText(context, textRun, textOrigin + shadowApplier.extraOffset(), startPosition, endPosition);
     606
     607            if (!shadowApplier.didSaveContext())
    611608                context->restore();
    612             else
    613                 context->clearShadow();
    614609        }
    615610
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