From 5dcad9788f710a5a9727cb3c1da34c7db396feb0 Mon Sep 17 00:00:00 2001
From: Max Smolens <max.smolens@kitware.com>
Date: Tue, 12 Apr 2016 12:09:34 -0400
Subject: [PATCH] vtkTextMapper: fix rendering of empty string
vtkTextMapper improperly renders empty strings. Instead of rendering nothing, as
expected for an empty string, a rectangle is rendered. The rectangle is visible
only when the text property's background is not completely transparent.
This commit fixes the problem at two levels: in vtkFreeTypeTools and in
vtkTextMapper.
vtkFreeTypeTools now checks for an empty string when rendering to an image.
Without this check, rendering an empty string results in the small rectangle.
vtkTextMapper::RenderOverlay() is updated to handle the case of an empty image.
This also serves as a revised solution to #15787:
http://www.vtk.org/Bug/view.php?id=15787
Fixes #16071:
http://www.vtk.org/Bug/view.php?id=16071
---
Rendering/Core/vtkTextMapper.cxx | 16 ++++++++--------
.../Testing/Cxx/TestFreeTypeTextMapperNoMath.cxx | 14 ++++++++++++++
Rendering/FreeType/vtkFreeTypeTools.cxx | 8 ++++++++
3 files changed, 30 insertions(+), 8 deletions(-)
diff --git a/Rendering/Core/vtkTextMapper.cxx b/Rendering/Core/vtkTextMapper.cxx
index da885b6a0e..6d9ea59c4c 100644
--- a/Rendering/Core/vtkTextMapper.cxx
+++ b/Rendering/Core/vtkTextMapper.cxx
@@ -367,7 +367,7 @@ void vtkTextMapper::RenderOverlay(vtkViewport *viewport, vtkActor2D *actor)
vtkDebugMacro(<<"RenderOverlay called");
vtkRenderer *ren = NULL;
- if (this->Input)
+ if (this->Input && this->Input[0])
{
vtkWindow *win = viewport->GetVTKWindow();
if (!win)
@@ -394,15 +394,15 @@ void vtkTextMapper::RenderOverlay(vtkViewport *viewport, vtkActor2D *actor)
info->Set(vtkProp::GeneralTextureUnit(),
this->Texture->GetTextureUnit());
}
- }
- vtkDebugMacro(<<"PolyData::RenderOverlay called");
- this->Mapper->RenderOverlay(viewport, actor);
+ vtkDebugMacro(<<"PolyData::RenderOverlay called");
+ this->Mapper->RenderOverlay(viewport, actor);
- // clean up
- if (ren)
- {
- this->Texture->PostRender(ren);
+ // clean up
+ if (ren)
+ {
+ this->Texture->PostRender(ren);
+ }
}
vtkDebugMacro(<<"Superclass::RenderOverlay called");
diff --git a/Rendering/FreeType/Testing/Cxx/TestFreeTypeTextMapperNoMath.cxx b/Rendering/FreeType/Testing/Cxx/TestFreeTypeTextMapperNoMath.cxx
index ad66e49630..03f6d00c11 100644
--- a/Rendering/FreeType/Testing/Cxx/TestFreeTypeTextMapperNoMath.cxx
+++ b/Rendering/FreeType/Testing/Cxx/TestFreeTypeTextMapperNoMath.cxx
@@ -172,6 +172,19 @@ int TestFreeTypeTextMapperNoMath(int argc, char *argv[])
mapper11->SetInput("oTeVaVoVAW");
actor11->SetPosition(300, 200);
+ // Empty string, solid background: should not render
+ vtkNew<vtkTextMapper> mapper12;
+ vtkNew<vtkActor2D> actor12;
+ actor12->SetMapper(mapper12.GetPointer());
+ mapper12->GetTextProperty()->SetFontSize(16);
+ mapper12->GetTextProperty()->SetColor(1.0, 0.0, 0.0);
+ mapper12->GetTextProperty()->SetBackgroundColor(1.0, 0.5, 1.0);
+ mapper12->GetTextProperty()->SetBackgroundOpacity(1.0);
+ mapper12->GetTextProperty()->SetJustificationToRight();
+ mapper12->GetTextProperty()->SetVerticalJustificationToCentered();
+ mapper12->SetInput("");
+ actor12->SetPosition(0, 0);
+
// Boring rendering setup....
vtkNew<vtkRenderer> ren;
@@ -193,6 +206,7 @@ int TestFreeTypeTextMapperNoMath(int argc, char *argv[])
ren->AddActor(actor9.GetPointer());
ren->AddActor(actor10.GetPointer());
ren->AddActor(actor11.GetPointer());
+ ren->AddActor(actor12.GetPointer());
win->SetMultiSamples(0);
win->Render();
diff --git a/Rendering/FreeType/vtkFreeTypeTools.cxx b/Rendering/FreeType/vtkFreeTypeTools.cxx
index 114f5f85c3..e071bea9d1 100644
--- a/Rendering/FreeType/vtkFreeTypeTools.cxx
+++ b/Rendering/FreeType/vtkFreeTypeTools.cxx
@@ -1239,6 +1239,14 @@ bool vtkFreeTypeTools::RenderStringInternal(vtkTextProperty *tprop,
return false;
}
+ if (str.empty())
+ {
+ data->Initialize();
+ textDims[0] = 0;
+ textDims[1] = 0;
+ return true;
+ }
+
ImageMetaData metaData;
// Setup the metadata cache
--
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