Changeset 191658 in webkit

Timestamp:

Oct 27, 2015 10:20:08 PM (8 years ago)

Author:

Hunseop Jeong

Message:

[Cairo] Incorrect dashed and dotted border painting after r177686.
​https://bugs.webkit.org/show_bug.cgi?id=141967

Reviewed by Gyuyoung Kim.

Fix the incorrect dashed/dotted border painting in cairo.

Source/WebCore:

• platform/graphics/cairo/GraphicsContextCairo.cpp:

(WebCore::GraphicsContext::drawLine):
(WebCore::calculateStrokePatternOffset): Deleted.
(WebCore::drawLineOnCairoContext): Deleted.

LayoutTests:

• platform/gtk/TestExpectations: Removed the passed test.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/platform/gtk/TestExpectations (modified) (1 diff)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/platform/graphics/cairo/GraphicsContextCairo.cpp (modified) (2 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2015-10-27  Hunseop Jeong  <hs85.jeong@samsung.com>
+
+        [Cairo] Incorrect dashed and dotted border painting after r177686.
+        https://bugs.webkit.org/show_bug.cgi?id=141967
+
+        Reviewed by Gyuyoung Kim.
+
+        Fix the incorrect dashed/dotted border painting in cairo.
+
+        * platform/gtk/TestExpectations: Removed the passed test.
+
 2015-10-27  Chris Dumez  <cdumez@apple.com>
 

trunk/LayoutTests/platform/gtk/TestExpectations

@@ -530 +530 @@
 webkit.org/b/141837 fast/borders/border-painting-correctness-dashed.html [ ImageOnlyFailure ]
 webkit.org/b/141837 fast/borders/border-painting-correctness-dotted.html [ ImageOnlyFailure ]
-webkit.org/b/141838 fast/borders/0px-borders.html [ ImageOnlyFailure ]
 
 webkit.org/b/141458 imported/mozilla/svg/blend-color-burn.svg [ ImageOnlyFailure ]

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2015-10-27  Hunseop Jeong  <hs85.jeong@samsung.com>
+
+        [Cairo] Incorrect dashed and dotted border painting after r177686.
+        https://bugs.webkit.org/show_bug.cgi?id=141967
+
+        Reviewed by Gyuyoung Kim.
+
+        Fix the incorrect dashed/dotted border painting in cairo.
+
+        * platform/graphics/cairo/GraphicsContextCairo.cpp:
+        (WebCore::GraphicsContext::drawLine):
+        (WebCore::calculateStrokePatternOffset): Deleted.
+        (WebCore::drawLineOnCairoContext): Deleted.
+
 2015-10-27  Chris Dumez  <cdumez@apple.com>
 

trunk/Source/WebCore/platform/graphics/cairo/GraphicsContextCairo.cpp

@@ -254 +254 @@
 }
 
-static double calculateStrokePatternOffset(int distance, int patternWidth)
-{
-    // Example: 80 pixels with a width of 30 pixels. Remainder is 20.
-    // The maximum pixels of line we could paint will be 50 pixels.
-    int remainder = distance % patternWidth;
-    int numSegments = (distance - remainder) / patternWidth;
-
-    // Special case 1px dotted borders for speed.
-    if (patternWidth == 1)
-        return 1;
-
-    bool evenNumberOfSegments = !(numSegments % 2);
-    if (remainder)
-        evenNumberOfSegments = !evenNumberOfSegments;
-
-    if (evenNumberOfSegments) {
-        if (remainder)
-            return (patternWidth - remainder) + (remainder / 2);
-        return patternWidth / 2;
-    }
-
-    // Odd number of segments.
-    if (remainder)
-        return (patternWidth - remainder) / 2.f;
-    return 0;
-}
-
-static void drawLineOnCairoContext(GraphicsContext* graphicsContext, cairo_t* context, const FloatPoint& point1, const FloatPoint& point2)
-{
-    StrokeStyle style = graphicsContext->strokeStyle();
-    if (style == NoStroke)
-        return;
-
-    const Color& strokeColor = graphicsContext->strokeColor();
-    int strokeThickness = floorf(graphicsContext->strokeThickness());
-    if (graphicsContext->strokeThickness() < 1)
-        strokeThickness = 1;
-
-    int patternWidth = 0;
-    if (style == DottedStroke)
-        patternWidth = strokeThickness;
-    else if (style == DashedStroke)
-        patternWidth = 3 * strokeThickness;
-
-    bool isVerticalLine = point1.x() == point2.x();
-    FloatPoint point1OnPixelBoundaries = point1;
-    FloatPoint point2OnPixelBoundaries = point2;
-    GraphicsContext::adjustLineToPixelBoundaries(point1OnPixelBoundaries, point2OnPixelBoundaries, strokeThickness, style);
-
-    if (patternWidth) {
-        // Do a rect fill of our endpoints.  This ensures we always have the
-        // appearance of being a border.  We then draw the actual dotted/dashed line.
-        FloatRect firstRect(point1OnPixelBoundaries, FloatSize(strokeThickness, strokeThickness));
-        FloatRect secondRect(point2OnPixelBoundaries, FloatSize(strokeThickness, strokeThickness));
-        if (isVerticalLine) {
-            firstRect.move(-strokeThickness / 2, -strokeThickness);
-            secondRect.move(-strokeThickness / 2, 0);
-        } else {
-            firstRect.move(-strokeThickness, -strokeThickness / 2);
-            secondRect.move(0, -strokeThickness / 2);
-        }
-        fillRectWithColor(context, firstRect, strokeColor);
-        fillRectWithColor(context, secondRect, strokeColor);
-
-        int distance = (isVerticalLine ? (point2.y() - point1.y()) : (point2.x() - point1.x())) - 2 * strokeThickness;
-        double patternOffset = calculateStrokePatternOffset(distance, patternWidth);
-        double patternWidthAsDouble = patternWidth;
-        cairo_set_dash(context, &patternWidthAsDouble, 1, patternOffset);
-    }
-
-    setSourceRGBAFromColor(context, strokeColor);
-    cairo_set_line_width(context, strokeThickness);
-    cairo_move_to(context, point1OnPixelBoundaries.x(), point1OnPixelBoundaries.y());
-    cairo_line_to(context, point2OnPixelBoundaries.x(), point2OnPixelBoundaries.y());
-    cairo_stroke(context);
-}
-
 // This is only used to draw borders, so we should not draw shadows.
 void GraphicsContext::drawLine(const FloatPoint& point1, const FloatPoint& point2)
@@ -337 +260 @@
         return;
 
+    if (strokeStyle() == NoStroke)
+        return;
+
+    const Color& strokeColor = this->strokeColor();
+    float thickness = strokeThickness();
+    bool isVerticalLine = (point1.x() + thickness == point2.x());
+    float strokeWidth = isVerticalLine ? point2.y() - point1.y() : point2.x() - point1.x();
+    if (!thickness || !strokeWidth)
+        return;
+
     cairo_t* cairoContext = platformContext()->cr();
-    cairo_save(cairoContext);
-    drawLineOnCairoContext(this, cairoContext, point1, point2);
-    cairo_restore(cairoContext);
+    StrokeStyle strokeStyle = this->strokeStyle();
+    float cornerWidth = 0;
+    bool drawsDashedLine = strokeStyle == DottedStroke || strokeStyle == DashedStroke;
+
+    if (drawsDashedLine) {
+        cairo_save(cairoContext);
+        // Figure out end points to ensure we always paint corners.
+        cornerWidth = strokeStyle == DottedStroke ? thickness : std::min(2 * thickness, std::max(thickness, strokeWidth / 3));
+        if (isVerticalLine) {
+            fillRectWithColor(cairoContext, FloatRect(point1.x(), point1.y(), thickness, cornerWidth), strokeColor);
+            fillRectWithColor(cairoContext, FloatRect(point1.x(), point2.y() - cornerWidth, thickness, cornerWidth), strokeColor);
+        } else {
+            fillRectWithColor(cairoContext, FloatRect(point1.x(), point1.y(), cornerWidth, thickness), strokeColor);
+            fillRectWithColor(cairoContext, FloatRect(point2.x() - cornerWidth, point1.y(), cornerWidth, thickness), strokeColor);
+        }
+        strokeWidth -= 2 * cornerWidth;
+        float patternWidth = strokeStyle == DottedStroke ? thickness : std::min(3 * thickness, std::max(thickness, strokeWidth / 3));
+        // Check if corner drawing sufficiently covers the line.
+        if (strokeWidth <= patternWidth + 1) {
+            cairo_restore(cairoContext);
+            return;
+        }
+
+        // Pattern starts with full fill and ends with the empty fill.
+        // 1. Let's start with the empty phase after the corner.
+        // 2. Check if we've got odd or even number of patterns and whether they fully cover the line.
+        // 3. In case of even number of patterns and/or remainder, move the pattern start position
+        // so that the pattern is balanced between the corners.
+        float patternOffset = patternWidth;
+        int numberOfSegments = std::floor(strokeWidth / patternWidth);
+        bool oddNumberOfSegments = numberOfSegments % 2;
+        float remainder = strokeWidth - (numberOfSegments * patternWidth);
+        if (oddNumberOfSegments && remainder)
+            patternOffset -= remainder / 2.f;
+        else if (!oddNumberOfSegments) {
+            if (remainder)
+                patternOffset += patternOffset - (patternWidth + remainder) / 2.f;
+            else
+                patternOffset += patternWidth / 2.f;
+        }
+        const double dashedLine[2] = { static_cast<double>(patternWidth), static_cast<double>(patternWidth) };
+        cairo_set_dash(cairoContext, dashedLine, 2, patternOffset);
+    }
+
+    FloatPoint p1 = point1;
+    FloatPoint p2 = point2;
+    // Center line and cut off corners for pattern patining.
+    if (isVerticalLine) {
+        float centerOffset = (p2.x() - p1.x()) / 2;
+        p1.move(centerOffset, cornerWidth);
+        p2.move(-centerOffset, -cornerWidth);
+    } else {
+        float centerOffset = (p2.y() - p1.y()) / 2;
+        p1.move(cornerWidth, centerOffset);
+        p2.move(-cornerWidth, -centerOffset);
+    }
+
+    if (shouldAntialias())
+        cairo_set_antialias(cairoContext, CAIRO_ANTIALIAS_NONE);
+
+    cairo_new_path(cairoContext);
+    cairo_move_to(cairoContext, p1.x(), p1.y());
+    cairo_line_to(cairoContext, p2.x(), p2.y());
+    cairo_stroke(cairoContext);
+    if (drawsDashedLine)
+        cairo_restore(cairoContext);
+    if (shouldAntialias())
+        cairo_set_antialias(cairoContext, CAIRO_ANTIALIAS_DEFAULT);
 }