From 06701a4d30f9c8ee9ddda9823f02b684f0239bd0 Mon Sep 17 00:00:00 2001
From: Dan Lipsa <dan.lipsa@kitware.com>
Date: Fri, 2 Sep 2016 14:37:51 -0400
Subject: [PATCH] BUG: Use of double LineSpacing results in one pixel off
errors.
Compute interLineSpacing as an integer and use that instead.
---
Rendering/FreeType/vtkFreeTypeTools.cxx | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)
diff --git a/Rendering/FreeType/vtkFreeTypeTools.cxx b/Rendering/FreeType/vtkFreeTypeTools.cxx
index 0577154ff65..4d2bc7d16e9 100644
--- a/Rendering/FreeType/vtkFreeTypeTools.cxx
+++ b/Rendering/FreeType/vtkFreeTypeTools.cxx
@@ -1443,15 +1443,19 @@ bool vtkFreeTypeTools::CalculateBoundingBox(const T& str,
metaData.maxLineWidth = std::max(metaData.maxLineWidth,
metaData.lineMetrics.back().width);
- // Calculate line height from a reference set of characters, since the global
- // face values are usually way too big.
+ int numLines = metaData.lineMetrics.size();
T heightString;
- if (metaData.textProperty->GetUseTightBoundingBox())
+ if (metaData.textProperty->GetUseTightBoundingBox() && numLines == 1)
{
+ // Calculate line hight from actual characters. This works only for single line text
+ // and may result in a hight that does not include descent. It is used to get
+ // a centered label.
heightString = str;
}
else
{
+ // Calculate line height from a reference set of characters, since the global
+ // face values are usually way too big.
heightString = defaultHeightString;
}
metaData.ascent = std::numeric_limits<int>::min();
@@ -1477,11 +1481,9 @@ bool vtkFreeTypeTools::CalculateBoundingBox(const T& str,
metaData.height = metaData.ascent - metaData.descent + 1;
// The unrotated height of the text
- int numLines = metaData.lineMetrics.size();
- double lineSpacing = numLines > 1 ? metaData.textProperty->GetLineSpacing()
- : 1.;
+ int interLineSpacing = (metaData.textProperty->GetLineSpacing() - 1) * metaData.height;
int fullHeight = numLines * metaData.height +
- (numLines - 1) * metaData.height * (lineSpacing - 1.) +
+ (numLines - 1) * interLineSpacing +
metaData.textProperty->GetLineOffset();
// Will we be rendering a background?
@@ -1555,7 +1557,6 @@ bool vtkFreeTypeTools::CalculateBoundingBox(const T& str,
// First baseline offset from top-left corner.
vtkVector2i penOffset(pad, -pad);
// Account for line spacing to center the text vertically in the bbox:
- penOffset[1] -= vtkMath::Ceil((lineSpacing - 1.) * metaData.height * 0.5);
penOffset[1] -= metaData.ascent;
penOffset[1] -= metaData.textProperty->GetLineOffset();
rotateVector2i(penOffset, s, c);
@@ -1568,7 +1569,7 @@ bool vtkFreeTypeTools::CalculateBoundingBox(const T& str,
textBbox[2] = textBbox[3] = pen[1];
// Calculate line offset:
- vtkVector2i lineFeed(0, -(metaData.height * lineSpacing));
+ vtkVector2i lineFeed(0, -(metaData.height + interLineSpacing));
rotateVector2i(lineFeed, s, c);
// Compile the metrics data to determine the final bounding box. Set line
--
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