Move the shadows out of paintTextWithShadows.

Source/core/rendering/InlineTextBox.cpp

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 311 matching lines @@
     return -1;
 }
 
 static Color textColorForWhiteBackground(Color textColor)
 {
     int distanceFromWhite = differenceSquared(textColor, Color::white);
     // semi-arbitrarily chose 65025 (255^2) value here after a few tests;
     return distanceFromWhite > 65025 ? textColor : textColor.dark();
 }
 
-static void updateGraphicsContext(GraphicsContext* context, const Color& fillColor, const Color& strokeColor, float strokeThickness)
-{
-    TextDrawingModeFlags mode = context->textDrawingMode();
-    if (strokeThickness > 0) {
-        TextDrawingModeFlags newMode = mode | TextModeStroke;
-        if (mode != newMode) {
-            context->setTextDrawingMode(newMode);
-            mode = newMode;
-        }
-    }
-
-    if (mode & TextModeFill && fillColor != context->fillColor())
-        context->setFillColor(fillColor);
-
-    if (mode & TextModeStroke) {
-        if (strokeColor != context->strokeColor())
-            context->setStrokeColor(strokeColor);
-        if (strokeThickness != context->strokeThickness())
-            context->setStrokeThickness(strokeThickness);
-    }
-}
-
 bool InlineTextBox::isLineBreak() const
 {
     return renderer().isBR() || (renderer().style()->preserveNewline() && len() == 1 && (*renderer().text().impl())[start()] == '\n');
 }
 
 bool InlineTextBox::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, LayoutUnit /* lineTop */, LayoutUnit /*lineBottom*/)
 {
     if (isLineBreak())
         return false;
 
     FloatPoint boxOrigin = locationIncludingFlipping();
     boxOrigin.moveBy(accumulatedOffset);
     FloatRect rect(boxOrigin, size());
     if (m_truncation != cFullTruncation && visibleToHitTestRequest(request) && locationInContainer.intersects(rect)) {
         renderer().updateHitTestResult(result, flipForWritingMode(locationInContainer.point() - toLayoutSize(accumulatedOffset)));
         if (!result.addNodeToRectBasedTestResult(renderer().node(), request, locationInContainer, rect))
             return true;
     }
     return false;
 }
 
-static void paintTextWithShadows(GraphicsContext* context,
+static void paintText(GraphicsContext* context,
     const Font& font, const TextRun& textRun,
     const AtomicString& emphasisMark, int emphasisMarkOffset,
     int startOffset, int endOffset, int truncationPoint,
-    const FloatPoint& textOrigin, const FloatRect& boxRect,
-    const ShadowList* shadowList, bool horizontal)
+    const FloatPoint& textOrigin, const FloatRect& boxRect)
 {
-    // Text shadows are disabled when printing. http://crbug.com/258321
-    bool hasShadow = shadowList && !context->printing();
-    if (hasShadow)
-        context->setDrawLooper(shadowList->createDrawLooper(DrawLooperBuilder::ShadowIgnoresAlpha, horizontal));
-
     TextRunPaintInfo textRunPaintInfo(textRun);
     textRunPaintInfo.bounds = boxRect;
     if (startOffset <= endOffset) {
         textRunPaintInfo.from = startOffset;
         textRunPaintInfo.to = endOffset;
         if (emphasisMark.isEmpty())
             context->drawText(font, textRunPaintInfo, textOrigin);
         else
             context->drawEmphasisMarks(font, textRunPaintInfo, emphasisMark, textOrigin + IntSize(0, emphasisMarkOffset));
     } else {
         if (endOffset > 0) {
             textRunPaintInfo.from = 0;
             textRunPaintInfo.to = endOffset;
             if (emphasisMark.isEmpty())
                 context->drawText(font, textRunPaintInfo, textOrigin);
             else
                 context->drawEmphasisMarks(font, textRunPaintInfo, emphasisMark, textOrigin + IntSize(0, emphasisMarkOffset));
         }
         if (startOffset < truncationPoint) {
             textRunPaintInfo.from = startOffset;
             textRunPaintInfo.to = truncationPoint;
             if (emphasisMark.isEmpty())
                 context->drawText(font, textRunPaintInfo, textOrigin);
             else
                 context->drawEmphasisMarks(font, textRunPaintInfo, emphasisMark, textOrigin + IntSize(0, emphasisMarkOffset));
         }
     }
-
-    if (hasShadow)
-        context->clearDrawLooper();
 }
 
 static void paintEmphasisMark(GraphicsContext* context,
     const AtomicString& emphasisMark, int emphasisMarkOffset,
     int startOffset, int endOffset, int paintRunLength,
-    const Font& font, Color emphasisMarkColor, Color textStrokeColor, float textStrokeWidth, const ShadowList* textShadow,
-    RenderCombineText* combinedText, const TextRun& textRun,
-    const FloatPoint& textOrigin, const FloatRect& boxRect, bool horizontal)
+    const Font& font, RenderCombineText* combinedText, const TextRun& textRun,
+    const FloatPoint& textOrigin, const FloatRect& boxRect)
 {
     ASSERT(!emphasisMark.isEmpty());
-    updateGraphicsContext(context, emphasisMarkColor, textStrokeColor, textStrokeWidth);
 
     if (combinedText) {
         DEFINE_STATIC_LOCAL(TextRun, objectReplacementCharacterTextRun, (&objectReplacementCharacter, 1));
         FloatPoint emphasisMarkTextOrigin(boxRect.x() + boxRect.width() / 2, boxRect.y() + font.fontMetrics().ascent());
         context->concatCTM(InlineTextBox::rotation(boxRect, InlineTextBox::Clockwise));
-        paintTextWithShadows(context, combinedText->originalFont(), objectReplacementCharacterTextRun, emphasisMark, emphasisMarkOffset, 0, 1, 1, emphasisMarkTextOrigin, boxRect, textShadow, horizontal);
+        paintText(context, combinedText->originalFont(), objectReplacementCharacterTextRun, emphasisMark, emphasisMarkOffset, 0, 1, 1, emphasisMarkTextOrigin, boxRect);
         context->concatCTM(InlineTextBox::rotation(boxRect, InlineTextBox::Counterclockwise));
     } else {
-        paintTextWithShadows(context, font, textRun, emphasisMark, emphasisMarkOffset, startOffset, endOffset, paintRunLength, textOrigin, boxRect, textShadow, horizontal);
+        paintText(context, font, textRun, emphasisMark, emphasisMarkOffset, startOffset, endOffset, paintRunLength, textOrigin, boxRect);
     }
 }
 
 bool InlineTextBox::getEmphasisMarkPosition(RenderStyle* style, TextEmphasisPosition& emphasisPosition) const
 {
     // This function returns true if there are text emphasis marks and they are suppressed by ruby text.
     if (style->textEmphasisMark() == TextEmphasisMarkNone)
         return false;
 
     emphasisPosition = style->textEmphasisPosition();
@@ skipping 91 matching lines @@
         // Text shadows are disabled when printing. http://crbug.com/258321
         if (isPrinting)
             selectionStyle.shadow = 0;
     }
 
     return selectionStyle;
 }
 
 } // namespace
 
+static void updateGraphicsContext(GraphicsContext* context, const TextPaintingStyle& textStyle, bool horizontal, GraphicsContextStateSaver* stateSaver = 0)

[f(malita), 2014/08/20 18:55:45]

Nit: this could live in the anonymous namespace above.

[jbroman, 2014/08/20 19:32:25]

Okay. At this point, I might as well push paintText and paintEmphasisMark in as
well.

+{
+    TextDrawingModeFlags mode = context->textDrawingMode();
+    if (textStyle.strokeWidth > 0) {
+        if (stateSaver) {

[f(malita), 2014/08/20 18:55:46]

Can we skip this when mode == newMode (move it inside the conditional below)?

[jbroman, 2014/08/20 19:32:25]

Done.

+            stateSaver->save();
+            stateSaver = 0;
+        }
+
+        TextDrawingModeFlags newMode = mode | TextModeStroke;
+        if (mode != newMode) {
+            context->setTextDrawingMode(newMode);
+            mode = newMode;
+        }
+    }
+
+    if (mode & TextModeFill && textStyle.fillColor != context->fillColor())
+        context->setFillColor(textStyle.fillColor);
+
+    if (mode & TextModeStroke) {
+        if (textStyle.strokeColor != context->strokeColor())
+            context->setStrokeColor(textStyle.strokeColor);
+        if (textStyle.strokeWidth != context->strokeThickness())
+            context->setStrokeThickness(textStyle.strokeWidth);
+    }
+
+    // Text shadows are disabled when printing. http://crbug.com/258321
+    if (textStyle.shadow && !context->printing()) {
+        context->setDrawLooper(textStyle.shadow->createDrawLooper(DrawLooperBuilder::ShadowIgnoresAlpha, horizontal));
+        if (stateSaver) {
+            stateSaver->save();

[f(malita), 2014/08/20 18:55:46]

We should save before touching the looper.

[jbroman, 2014/08/20 19:32:25]

Err, yes, of course. Hazard of "p" and "P" being so similar in vim.

Good catch. :)

+            stateSaver = 0;
+        }
+    }
+}
+
+static void paintTextWithEmphasisMark(
+    GraphicsContext* context, const Font& font, const TextPaintingStyle& textStyle, const TextRun& textRun,
+    const AtomicString& emphasisMark, int emphasisMarkOffset, int startOffset, int endOffset, int length,
+    RenderCombineText* combinedText, const FloatPoint& textOrigin, const FloatRect& boxRect, bool horizontal)
+{
+    GraphicsContextStateSaver stateSaver(*context, false);
+    updateGraphicsContext(context, textStyle, horizontal, &stateSaver);
+    paintText(context, font, textRun, nullAtom, 0, startOffset, endOffset, length, textOrigin, boxRect);
+
+    if (!emphasisMark.isEmpty()) {
+        if (textStyle.emphasisMarkColor != textStyle.fillColor)
+            context->setFillColor(textStyle.emphasisMarkColor);
+        paintEmphasisMark(context, emphasisMark, emphasisMarkOffset, startOffset, endOffset, length, font, combinedText, textRun, textOrigin, boxRect);
+    }
+}
+
 void InlineTextBox::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset, LayoutUnit /*lineTop*/, LayoutUnit /*lineBottom*/)
 {
     if (isLineBreak() || !paintInfo.shouldPaintWithinRoot(&renderer()) || renderer().style()->visibility() != VISIBLE
         || m_truncation == cFullTruncation || paintInfo.phase == PaintPhaseOutline || !m_len)
         return;
 
     ASSERT(paintInfo.phase != PaintPhaseSelfOutline && paintInfo.phase != PaintPhaseChildOutlines);
 
     LayoutRect logicalVisualOverflow = logicalOverflowRect();
     LayoutUnit logicalStart = logicalVisualOverflow.x() + (isHorizontal() ? paintOffset.x() : paintOffset.y());
@@ skipping 122 matching lines @@
         emphasisMarkOffset = emphasisMarkPosition == TextEmphasisPositionOver ? -font.fontMetrics().ascent() - font.emphasisMarkDescent(emphasisMark) : font.fontMetrics().descent() + font.emphasisMarkAscent(emphasisMark);
 
     if (!paintSelectedTextOnly) {
         // FIXME: Truncate right-to-left text correctly.
         int startOffset = 0;
         int endOffset = length;
         if (paintSelectedTextSeparately && ePos > sPos) {
             startOffset = ePos;
             endOffset = sPos;
         }
-
-        // For stroked painting, we have to change the text drawing mode.  It's probably dangerous to leave that mutated as a side
-        // effect, so only when we know we're stroking, do a save/restore.
-        GraphicsContextStateSaver stateSaver(*context, textStyle.strokeWidth > 0);
-
-        updateGraphicsContext(context, textStyle.fillColor, textStyle.strokeColor, textStyle.strokeWidth);
-        paintTextWithShadows(context, font, textRun, nullAtom, 0, startOffset, endOffset, length, textOrigin, boxRect, textStyle.shadow, isHorizontal());
-
-        if (!emphasisMark.isEmpty())
-            paintEmphasisMark(context, emphasisMark, emphasisMarkOffset, startOffset, endOffset, length, font, textStyle.emphasisMarkColor, textStyle.strokeColor, textStyle.strokeWidth, textStyle.shadow, combinedText, textRun, textOrigin, boxRect, isHorizontal());
+        paintTextWithEmphasisMark(context, font, textStyle, textRun, emphasisMark, emphasisMarkOffset, startOffset, endOffset, length, combinedText, textOrigin, boxRect, isHorizontal());
     }
 
     if ((paintSelectedTextOnly || paintSelectedTextSeparately) && sPos < ePos) {
         // paint only the text that is selected
-        GraphicsContextStateSaver stateSaver(*context, selectionStyle.strokeWidth > 0);
-
-        updateGraphicsContext(context, selectionStyle.fillColor, selectionStyle.strokeColor, selectionStyle.strokeWidth);
-        paintTextWithShadows(context, font, textRun, nullAtom, 0, sPos, ePos, length, textOrigin, boxRect, selectionStyle.shadow, isHorizontal());
-
-        if (!emphasisMark.isEmpty())
-            paintEmphasisMark(context, emphasisMark, emphasisMarkOffset, sPos, ePos, length, font, selectionStyle.emphasisMarkColor, selectionStyle.strokeColor, textStyle.strokeWidth, selectionStyle.shadow, combinedText, textRun, textOrigin, boxRect, isHorizontal());
+        paintTextWithEmphasisMark(context, font, selectionStyle, textRun, emphasisMark, emphasisMarkOffset, sPos, ePos, length, combinedText, textOrigin, boxRect, isHorizontal());
     }
 
     // Paint decorations
     TextDecoration textDecorations = styleToUse->textDecorationsInEffect();
-    if (textDecorations != TextDecorationNone && paintInfo.phase != PaintPhaseSelection) {
-        updateGraphicsContext(context, textStyle.fillColor, textStyle.strokeColor, textStyle.strokeWidth);
+    if (textDecorations != TextDecorationNone && !paintSelectedTextOnly) {
+        GraphicsContextStateSaver stateSaver(*context);

[f(malita), 2014/08/20 18:55:45]

Can't this save be deferred also? Why weren't we saving before?

[jbroman, 2014/08/20 19:32:24]

In the combinedText case, there's also the CTM rotations. But in the interest of
consistency and non-surprise, I've done as you asked (and restored the CCW
rotation).

+        updateGraphicsContext(context, textStyle, isHorizontal());
         if (combinedText)
             context->concatCTM(rotation(boxRect, Clockwise));
-        paintDecoration(context, boxOrigin, textDecorations, textStyle.shadow);
-        if (combinedText)
-            context->concatCTM(rotation(boxRect, Counterclockwise));
+        paintDecoration(context, boxOrigin, textDecorations);
     }
 
     if (paintInfo.phase == PaintPhaseForeground) {
         paintDocumentMarkers(context, boxOrigin, styleToUse, font, false);
 
         // Paint custom underlines for compositions.
         if (useCustomUnderlines) {
             const Vector<CompositionUnderline>& underlines = renderer().frame()->inputMethodController().customCompositionUnderlines();
             CompositionUnderlineRangeFilter filter(underlines, start(), end());
             for (CompositionUnderlineRangeFilter::ConstIterator it = filter.begin(); it != filter.end(); ++it) {
@@ skipping 36 matching lines @@
 
     Color c = renderer().selectionBackgroundColor();
     if (!c.alpha())
         return;
 
     // If the text color ends up being the same as the selection background, invert the selection
     // background.
     if (textColor == c)
         c = Color(0xff - c.red(), 0xff - c.green(), 0xff - c.blue());
 
-
     // If the text is truncated, let the thing being painted in the truncation
     // draw its own highlight.
     int length = m_truncation != cNoTruncation ? m_truncation : m_len;
     StringView string = renderer().text().createView();
 
     if (string.length() != static_cast<unsigned>(length) || m_start)
         string.narrow(m_start, length);
 
     StringBuilder charactersWithHyphen;
     bool respectHyphen = ePos == length && hasHyphen();
@@ skipping 246 matching lines @@
         context->setShouldAntialias(antialiasDecoration);
         // Fall through
     default:
         context->drawLineForText(start, width, isPrinting);
 
         if (decoration.style == TextDecorationStyleDouble)
             context->drawLineForText(start + FloatPoint(0, doubleOffset), width, isPrinting);
     }
 }
 
-void InlineTextBox::paintDecoration(GraphicsContext* context, const FloatPoint& boxOrigin, TextDecoration deco, const ShadowList* shadowList)
+void InlineTextBox::paintDecoration(GraphicsContext* context, const FloatPoint& boxOrigin, TextDecoration deco)
 {
     GraphicsContextStateSaver stateSaver(*context);
 
     if (m_truncation == cFullTruncation)
         return;
 
     FloatPoint localOrigin = boxOrigin;
 
     float width = m_logicalWidth;
     if (m_truncation != cNoTruncation) {
         width = renderer().width(m_start, m_truncation, textPos(), isLeftToRightDirection() ? LTR : RTL, isFirstLineStyle());
         if (!isLeftToRightDirection())
             localOrigin.move(m_logicalWidth - width, 0);
     }
 
     // Get the text decoration colors.
     RenderObject::AppliedTextDecoration underline, overline, linethrough;
-
     renderer().getTextDecorations(deco, underline, overline, linethrough, true);
     if (isFirstLineStyle())
         renderer().getTextDecorations(deco, underline, overline, linethrough, true, true);
 
     // Use a special function for underlines to get the positioning exactly right.
     bool isPrinting = renderer().document().printing();
 
-    bool linesAreOpaque = !isPrinting && (!(deco & TextDecorationUnderline) || underline.color.alpha() == 255) && (!(deco & TextDecorationOverline) || overline.color.alpha() == 255) && (!(deco & TextDecorationLineThrough) || linethrough.color.alpha() == 255);
-
     RenderStyle* styleToUse = renderer().style(isFirstLineStyle());
     int baseline = styleToUse->fontMetrics().ascent();
 
-    size_t shadowCount = shadowList ? shadowList->shadows().size() : 0;
     // Set the thick of the line to be 10% (or something else ?)of the computed font size and not less than 1px.
     // Using computedFontSize should take care of zoom as well.
 
     // Update Underline thickness, in case we have Faulty Font Metrics calculating underline thickness by old method.
     float textDecorationThickness = styleToUse->fontMetrics().underlineThickness();
     int fontHeightInt  = (int)(styleToUse->fontMetrics().floatHeight() + 0.5);
     if ((textDecorationThickness == 0.f) || (textDecorationThickness >= (fontHeightInt >> 1)))
         textDecorationThickness = std::max(1.f, styleToUse->computedFontSize() / 10.f);
 
     context->setStrokeThickness(textDecorationThickness);
 
     bool antialiasDecoration = shouldSetDecorationAntialias(overline.style, underline.style, linethrough.style)
         && RenderBoxModelObject::shouldAntialiasLines(context);
 
-    float extraOffset = 0;
-    if (!linesAreOpaque && shadowCount > 1) {
-        FloatRect clipRect(localOrigin, FloatSize(width, baseline + 2));
-        for (size_t i = shadowCount; i--; ) {
-            const ShadowData& s = shadowList->shadows()[i];
-            FloatRect shadowRect(localOrigin, FloatSize(width, baseline + 2));
-            shadowRect.inflate(s.blur());
-            float shadowX = isHorizontal() ? s.x() : s.y();
-            float shadowY = isHorizontal() ? s.y() : -s.x();
-            shadowRect.move(shadowX, shadowY);
-            clipRect.unite(shadowRect);
-            extraOffset = std::max(extraOffset, std::max(0.0f, shadowY) + s.blur());
-        }
-        context->clip(clipRect);
-        extraOffset += baseline + 2;
-        localOrigin.move(0, extraOffset);
+    // Offset between lines - always non-zero, so lines never cross each other.
+    float doubleOffset = textDecorationThickness + 1.f;
+
+    if (deco & TextDecorationUnderline) {
+        const int underlineOffset = computeUnderlineOffset(styleToUse->textUnderlinePosition(), styleToUse->fontMetrics(), this, textDecorationThickness);
+        paintAppliedDecoration(context, localOrigin + FloatPoint(0, underlineOffset), width, doubleOffset, 1, underline, textDecorationThickness, antialiasDecoration, isPrinting);
     }
-
-    for (size_t i = std::max(static_cast<size_t>(1), shadowCount); i--; ) {
-        // Even if we have no shadows, we still want to run the code below this once.
-        if (i < shadowCount) {
-            if (!i) {
-                // The last set of lines paints normally inside the clip.
-                localOrigin.move(0, -extraOffset);
-                extraOffset = 0;
-            }
-            const ShadowData& shadow = shadowList->shadows()[i];
-            float shadowX = isHorizontal() ? shadow.x() : shadow.y();
-            float shadowY = isHorizontal() ? shadow.y() : -shadow.x();
-            context->setShadow(FloatSize(shadowX, shadowY - extraOffset), shadow.blur(), shadow.color());
-        }
-
-        // Offset between lines - always non-zero, so lines never cross each other.
-        float doubleOffset = textDecorationThickness + 1.f;
-
-        if (deco & TextDecorationUnderline) {
-            const int underlineOffset = computeUnderlineOffset(styleToUse->textUnderlinePosition(), styleToUse->fontMetrics(), this, textDecorationThickness);
-            paintAppliedDecoration(context, localOrigin + FloatPoint(0, underlineOffset), width, doubleOffset, 1, underline, textDecorationThickness, antialiasDecoration, isPrinting);
-        }
-        if (deco & TextDecorationOverline) {
-            paintAppliedDecoration(context, localOrigin, width, -doubleOffset, 1, overline, textDecorationThickness, antialiasDecoration, isPrinting);
-        }
-        if (deco & TextDecorationLineThrough) {
-            const float lineThroughOffset = 2 * baseline / 3;
-            paintAppliedDecoration(context, localOrigin + FloatPoint(0, lineThroughOffset), width, doubleOffset, 0, linethrough, textDecorationThickness, antialiasDecoration, isPrinting);
-        }
+    if (deco & TextDecorationOverline) {
+        paintAppliedDecoration(context, localOrigin, width, -doubleOffset, 1, overline, textDecorationThickness, antialiasDecoration, isPrinting);
+    }
+    if (deco & TextDecorationLineThrough) {
+        const float lineThroughOffset = 2 * baseline / 3;
+        paintAppliedDecoration(context, localOrigin + FloatPoint(0, lineThroughOffset), width, doubleOffset, 0, linethrough, textDecorationThickness, antialiasDecoration, isPrinting);
     }
 }
 
 static GraphicsContext::DocumentMarkerLineStyle lineStyleForMarkerType(DocumentMarker::MarkerType markerType)
 {
     switch (markerType) {
     case DocumentMarker::Spelling:
         return GraphicsContext::DocumentMarkerSpellingLineStyle;
     case DocumentMarker::Grammar:
         return GraphicsContext::DocumentMarkerGrammarLineStyle;
@@ skipping 373 matching lines @@
     printedCharacters = fprintf(stderr, "\t%s %p", obj.renderName(), &obj);
     const int rendererCharacterOffset = 24;
     for (; printedCharacters < rendererCharacterOffset; printedCharacters++)
         fputc(' ', stderr);
     fprintf(stderr, "(%d,%d) \"%s\"\n", start(), start() + len(), value.utf8().data());
 }
 
 #endif
 
 } // namespace blink