diff -r 000000000000 -r 4f2f89ce4247 WebCore/mathml/RenderMathMLSquareRoot.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/mathml/RenderMathMLSquareRoot.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,203 @@
+/*
+ * Copyright (C) 2009 Alex Milowski (alex@milowski.com). All rights reserved.
+ * Copyright (C) 2010 François Sausset (sausset@gmail.com). All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+
+#if ENABLE(MATHML)
+
+#include "RenderMathMLSquareRoot.h"
+
+#include "GraphicsContext.h"
+#include "MathMLNames.h"
+#include "Path.h"
+
+namespace WebCore {
+    
+using namespace MathMLNames;
+
+// Bottom padding of the radical (px)
+const int gRadicalBasePad = 3;
+// Threshold above which the radical shape is modified to look nice with big bases (%)
+const float gThresholdBaseHeight = 1.5;
+// Radical width (%)
+const float gRadicalWidth = 0.75;
+// Horizontal position of the bottom point of the radical (%)
+const float gRadicalBottomPointXPos= 0.5;
+// Horizontal position of the top left point of the radical (%)
+const float gRadicalTopLeftPointXPos = 0.2;
+// Vertical position of the top left point of the radical (%)
+const float gRadicalTopLeftPointYPos = 0.5; 
+// Vertical shift of the left end point of the radical (%)
+const float gRadicalLeftEndYShift = 0.05;
+// Additional bottom root padding (%)
+const float gRootBottomPadding = 0.2;
+
+// Radical line thickness (%)
+const float gRadicalLineThickness = 0.02;
+// Radical thick line thickness (%)
+const float gRadicalThickLineThickness = 0.1;
+    
+RenderMathMLSquareRoot::RenderMathMLSquareRoot(Node *expression) 
+    : RenderMathMLBlock(expression) 
+{
+}
+
+void RenderMathMLSquareRoot::paint(PaintInfo& info, int tx, int ty)
+{
+    RenderMathMLBlock::paint(info, tx, ty);
+   
+    if (info.context->paintingDisabled())
+        return;
+    
+    tx += x();
+    ty += y();
+
+    int maxHeight = 0;
+    int width = 0;
+    RenderObject* current = firstChild();
+    while (current) {
+        if (current->isBoxModelObject()) {
+            
+            RenderBoxModelObject* box = toRenderBoxModelObject(current);
+            
+            // Check to see if this box has a larger height
+            if (box->offsetHeight() > maxHeight)
+                maxHeight = box->offsetHeight();
+            width += box->offsetWidth();
+        }
+        current = current->nextSibling();
+    }
+    // default to the font size in pixels if we're empty
+    if (!maxHeight)
+        maxHeight = style()->fontSize();
+    
+    int frontWidth = static_cast<int>(style()->fontSize() * gRadicalWidth);
+    int topStartShift = 0;
+    // Base height above which the shape of the root changes
+    int thresholdHeight = static_cast<int>(gThresholdBaseHeight * style()->fontSize());
+    
+    if (maxHeight > thresholdHeight && thresholdHeight) {
+        float shift = (maxHeight - thresholdHeight) / static_cast<float>(thresholdHeight);
+        if (shift > 1.)
+            shift = 1.;
+        topStartShift = static_cast<int>(gRadicalBottomPointXPos * frontWidth * shift);
+    }
+    
+    width += topStartShift;
+    
+    FloatPoint topStart(tx + frontWidth - topStartShift, ty);
+    FloatPoint bottomLeft(tx + frontWidth * gRadicalBottomPointXPos , ty + maxHeight + gRadicalBasePad);
+    FloatPoint topLeft(tx + frontWidth * gRadicalTopLeftPointXPos , ty + gRadicalTopLeftPointYPos * maxHeight);
+    FloatPoint leftEnd(tx , topLeft.y() + gRadicalLeftEndYShift * style()->fontSize());
+    
+    info.context->save();
+    
+    info.context->setStrokeThickness(gRadicalLineThickness * style()->fontSize());
+    info.context->setStrokeStyle(SolidStroke);
+    info.context->setStrokeColor(style()->visitedDependentColor(CSSPropertyColor), DeviceColorSpace);
+    info.context->setLineJoin(MiterJoin);
+    info.context->setMiterLimit(style()->fontSize());
+    
+    Path root;
+    
+    root.moveTo(FloatPoint(topStart.x() + width , ty));
+    // draw top
+    root.addLineTo(topStart);
+    // draw from top left corner to bottom point of radical
+    root.addLineTo(bottomLeft);
+    // draw from bottom point to top of left part of radical base "pocket"
+    root.addLineTo(topLeft);
+    // draw to end
+    root.addLineTo(leftEnd);
+    
+    info.context->beginPath();
+    info.context->addPath(root);
+    info.context->strokePath();
+    
+    info.context->save();
+    
+    // Build a mask to draw the thick part of the root.
+    Path mask;
+    
+    mask.moveTo(topStart);
+    mask.addLineTo(bottomLeft);
+    mask.addLineTo(topLeft);
+    mask.addLineTo(FloatPoint(2 * topLeft.x() - leftEnd.x(), 2 * topLeft.y() - leftEnd.y()));
+    
+    info.context->beginPath();
+    info.context->addPath(mask);
+    info.context->clip(mask);
+    
+    // Draw the thick part of the root.
+    info.context->setStrokeThickness(gRadicalThickLineThickness * style()->fontSize());
+    info.context->setLineCap(SquareCap);
+    
+    Path line;
+    
+    line = line.createLine(bottomLeft, topLeft);
+    
+    info.context->beginPath();
+    info.context->addPath(line);
+    info.context->strokePath();
+    
+    info.context->restore();
+    
+    info.context->restore();
+}
+
+void RenderMathMLSquareRoot::layout()
+{
+    int maxHeight = 0;
+    
+    RenderObject* current = firstChild();
+    while (current) {
+        if (current->isBoxModelObject()) {
+            RenderBoxModelObject* box = toRenderBoxModelObject(current);
+            
+            if (box->offsetHeight() > maxHeight)
+                maxHeight = box->offsetHeight();
+            
+            box->style()->setVerticalAlign(BASELINE);
+        }
+        current = current->nextSibling();
+    }
+    
+    if (!maxHeight)
+        maxHeight = style()->fontSize();
+
+    
+    if (maxHeight > static_cast<int>(gThresholdBaseHeight * style()->fontSize()))
+        style()->setPaddingBottom(Length(static_cast<int>(gRootBottomPadding * style()->fontSize()), Fixed));
+
+    
+    RenderBlock::layout();
+}
+    
+}
+
+#endif // ENABLE(MATHML)
+
+