@@ -1926,8 +1924,7 @@ this kind of objects:</para>
<para>Instead of the <code>wmin,wmax</code> arguments of the normal constructor, i.e. the limits of the axis, the name of a <emphasisrole="bold"><code>TF1</code></emphasis> function can be specified. This function will be used to map the user coordinates to the axis values and ticks.</para>
<para>By default, an exponent of the form 10^N is used when the label values are either all very small or very large. One can disable the exponent by calling:</para>
<para>Note that this option is implicitly selected if the number of digits to draw a label is less than the <code>fgMaxDigits</code> global member. If the property <code>SetNoExponent</code> was set in <emphasisrole="bold"><code>TAxis</code></emphasis> (via <emphasisrole="bold"><code>TAxis</code></emphasis><code>::SetNoExponent)</code>, the <emphasisrole="bold"><code>TGaxis</code></emphasis> will inherit this property. <emphasisrole="bold"><code>TGaxis</code></emphasis> is the class responsible for drawing the axis. The method <code>SetNoExponent</code> is also available from the axis context menu.</para>
<para><emphasisrole="bold"><code>TGaxis</code></emphasis><code>::fgMaxDigits</code> is the maximum number of digits permitted for the axis labels above which the notation with 10^N is used. It must be greater than 0. By default <code>fgMaxDigits</code> is 5 and to change it use the <emphasisrole="bold"><code>TGaxis</code></emphasis><code>::SetMaxDigits</code> method. For example to set <code>fgMaxDigits</code> to accept 6 digits and accept numbers like 900000 on an axis call:</para>
<para>Use the <emphasisrole="bold"><code>TStyle</code></emphasis><code>::SetStripDecimals</code> to strip decimals when drawing axis labels. By default, the option is set to true, and <emphasisrole="bold"><code>TGaxis</code></emphasis><code>::PaintAxis</code> removes trailing zeros after the dot in the axis labels, e.g. {0, 0.5, 1, 1.5, 2, 2.5, etc.}</para>
<para>If this function is called with <code>strip=kFALSE</code>, <emphasisrole="bold"><code>TGaxis</code></emphasis><code>::PaintAxis()</code> will draw labels with the same number of digits after the dot, e.g. {0.0, 0.5, 1.0, 1.5, 2.0, 2.5, etc.}</para>
<para>Histograms' axis can be defined as "time axis". To do that it is enough to activate the <code>SetTimeDisplay</code> attribute on a given axis. If <code>h</code> is a histogram, it is done the following way:</para>
<programlistinglanguage="c++">
h->GetXaxis()->SetTimeDisplay(1); <emphasisrole="italic"><code>// X axis is a time axis</code></emphasis>
<programlistinglanguage="c++">h->GetXaxis()->SetTimeDisplay(1); <emphasisrole="italic"><code>// X axis is a time axis</code></emphasis>
</programlisting>
<para>Two parameters can be adjusted in order to define time axis: the time format and the time offset.</para>
...
...
@@ -2086,8 +2079,7 @@ h->GetXaxis()->SetTimeDisplay(1); <emphasis role="italic"><code>// X ax
</informaltable>
<para>The other characters are output as is. For example to have a format like <code>dd/mm/yyyy</code> one should do:</para>
<para>This is a time in seconds in the UNIX standard UTC format (the universal time, not the local one), defining the starting date of a histogram axis. This date should be greater than 01/01/95 and is given in seconds. There are three ways to define the time offset:</para>
<para>1. By setting the global default time offset:</para>
<para>3. Together with the time format using <code>SetTimeFormat</code>. The time offset can be specified using the control character %F after the normal time format. <code>%F</code> is followed by the date in the format: <code>yyyy-mm-dd hh:mm:ss</code>.</para>
<para>Notice that this date format is the same used by the <emphasisrole="bold"><code>TDatime</code></emphasis> function <code>AsSQLString</code>. If needed, this function can be used to translate a time in seconds into a character string which can be appended after <code>%F</code>. If the time format is not specified (before <code>%F</code>) the automatic one will be used. The following example illustrates the various possibilities.</para>
<emphasisrole="italic"><code> // Define the time offset as 2003, January 1st</code></emphasis>
TDatime T0(2003,01,01,00,00,00);
int X0 = T0.Convert();
...
...
@@ -2203,14 +2190,12 @@ h1->Draw();
<para>A <emphasisrole="bold"><code>TGaxis</code></emphasis> can be created the following way (a day has 86400 seconds):</para>
<programlistinglanguage="c++">
TGaxis *axis = new TGaxis(x1,y1,x2,y2,-100000,150000,2405,"t");
<programlistinglanguage="c++">TGaxis *axis = new TGaxis(x1,y1,x2,y2,-100000,150000,2405,"t");
</programlisting>
<para>the "<code>t</code>" option (in lower case) means it is a "time axis". The axis goes form 100000 seconds before <code>TimeOffset </code>and 150000 seconds after. So the complete macro is:</para>
<programlistinglanguage="c++">
{
<programlistinglanguage="c++">{
c1 = new TCanvas("c1","Examples of TGaxis",10,10,700,500);
c1->Range(-10,-1,10,1);
TGaxis *axis = new TGaxis(-8,-0.6,8,-0.6,-100000,150000,2405,"t");
<para>Thanks to the <emphasisrole="bold"><code>TLatex</code></emphasis> directive <code>#splitline</code> it is possible to write the time labels on two lines. In the previous example changing the <code>SetTimeFormat</code> line by:</para>
c1 = new TCanvas("c1","Examples of Gaxis",10,10,700,500);
c1->Range(-10,-1,10,1);
...
...
@@ -2310,8 +2292,7 @@ axis8->Draw();
<para>The second example shows the use of the second form of the constructor, with axis ticks position determined by a function <emphasisrole="bold"><code>TF1</code></emphasis>:</para>
<para>Text alignment may be set by a method call. What is said here applies to all objects deriving from <emphasisrole="bold"><code>TAttText</code></emphasis>, and there are many. We will take an example that may be transposed to other types. Suppose "<code>la</code>" is a <emphasisrole="bold"><code>TLatex</code></emphasis> object. The alignment is set with:</para>
<para>Use <emphasisrole="bold"><code>TAttText</code></emphasis><code>::SetTextAngle</code> to set the text angle. The <code>angle</code> is the degrees of the horizontal.</para>
<para>Use <emphasisrole="bold"><code>TAttText</code></emphasis><code>::SetTextColor</code> to set the text color. The <code>color</code> is the color index. The colors are described in "Color and Color Palettes".</para>
<para>Use <emphasisrole="bold"><code>TAttText</code></emphasis><code>::SetTextFont</code> to set the font. The parameter font is the font code, combining the font and precision: <code>font = 10 * fontID + precision</code></para>
<para>You can check that you indeed use the <code>TTF</code> in your Root session. When the <code>TTF</code> is active, you get the following message at the start of a session: "Free Type Engine v1.x used to render TrueType fonts." You can also check with the command:</para>
<programlistinglanguage="c++">
gEnv->Print()
<programlistinglanguage="c++">gEnv->Print()
</programlisting>
</sect3>
...
...
@@ -2794,8 +2762,7 @@ gEnv->Print()
<title>Setting Text Size</title>
<para>Use <emphasisrole="bold"><code>TAttText</code></emphasis><code>::SetTextSize</code> to set the text size.</para>
<para>All classes manipulating lines have to deal with line attributes: color, style and width. This is done by using secondary inheritance of the class <emphasisrole="bold"><code>TAttLine</code></emphasis>. The line color may be set by a method call. What is said here applies to all objects deriving from <emphasisrole="bold"><code>TAttLine</code></emphasis>, and there are many (histograms, plots). We will take an example that may be transposed to other types. Suppose "<code>li</code>" is a <emphasisrole="bold"><code>TLine</code></emphasis> object. The line color is set with:</para>
<para>The argument <code>color</code> is a color number. The colors are described in "Color and Color Palettes"</para>
<para>The line style may be set by a method call. What is said here applies to all objects deriving from <emphasisrole="bold"><code>TAttLine</code></emphasis>, and there are many (histograms, plots). We will take an example that may be transposed to other types. Suppose "<code>li</code>" is a <emphasisrole="bold"><code>TLine</code></emphasis> object. The line style is set with:</para>
<para>The argument style is one of: <code>1=solid</code>, 2=dash, 3=dash-dot, 4=dot-dot.</para>
<para>The line width may be set by a method call. What is said here applies to all objects deriving from <emphasisrole="bold"><code>TAttLine</code></emphasis>, and there are many (histograms, plots). We will take an example that may be transposed to other types. Suppose "<code>li</code>" is a <emphasisrole="bold"><code>TLine</code></emphasis> object. The line width is set with:</para>
<para>Almost all graphics classes have a fill area somewhere. These classes have to deal with fill attributes. This is done by using secondary inheritance of the class <emphasisrole="bold"><code>TAttFill</code></emphasis>. Fill color may be set by a method call. What is said here applies to all objects deriving from <emphasisrole="bold"><code>TAttFill</code></emphasis>, and there are many (histograms, plots). We will take an example that may be transposed to other types. Suppose "<code>h</code>" is a <emphasisrole="bold"><code>TH1F</code></emphasis> (1 dim histogram) object. The histogram fill color is set with:</para>
<para>The color is a color number. The colors are described in "Color and color palettes"</para>
<para>Fill style may be set by a method call. What is said here applies to all objects deriving from <code>TAttFill</code>, and there are many (histograms, plots). We will take an example that may be transposed to other types. Suppose "h" is a <emphasisrole="bold">TH1F</emphasis> (1 dim histogram) object. The histogram fill style is set with:</para>
<para>The list of currently supported basic colors (here dark and bright colors are not shown) are shown. The color numbers specified in the basic palette, and the picture above, can be viewed by selecting the menu entry Colors in the View canvas menu. The user may define other colors. To do this, one has to build a new <emphasisrole="bold"><code>TColor</code></emphasis>:</para>
<para>One has to give the color number and the three Red, Green, Blue values, each being defined from 0 (min) to 1(max). An optional name may be given. When built, this color is automatically added to the existing list of colors. If the color number already exists, one has to extract it from the list and redefine the RGB values. This may be done for example with:</para>
<para>Defining one color at a time may be tedious. The histogram classes (see Draw Options) use the color palette. For example, <emphasisrole="bold"><code>TH1</code></emphasis><code>::Draw("col")</code> draws a 2-D histogram with cells represented by a box filled with a color <code>CI</code> function of the cell content. If the cell content is <code>N</code>, the color <code>CI</code> used will be the color number in <code>colors[N]</code>. If the maximum cell content is <code>>ncolors</code>, all cell contents are scaled to <code>ncolors</code>. The current color palette does not have a class or global object of its own. It is defined in the current style as an array of color numbers. The current palette can be changed with:</para>
<para>By default, or if <code>ncolors <= 0</code>, a default palette (see above) of 50 colors is defined. The colors defined in this palette are good for coloring pads, labels, and other graphic objects. If <code>ncolors</code><code>> 0</code> and <code>colors = 0</code>, the default palette is used with a maximum of <code>ncolors</code>. If <code>ncolors == 1 && colors == 0</code>, then a pretty palette with a spectrum <code>Violet->Red</code> is created. It is recommended to use this pretty palette when drawing lego(s), surfaces or contours. For example, to set the current palette to the “<code>pretty</code>” one, do:</para>
<para>A more complete example is shown below. It illustrates the definition of a custom palette. You can adapt it to suit your needs. In case you use it for contour coloring, with the current color/contour algorithm, always define two more colors than the number of contours.</para>
<para/>
<para/>
<para/>
<para>A more complete example is shown below. It illustrates the definition of a
custom palette. You can adapt it to suit your needs. In case you use it for
contour coloring, with the current color/contour algorithm, always define two
more colors than the number of contours.</para>
<programlistinglanguage="c++">
void palette() { <emphasisrole="italic"><code>// Example of creating new colors (purples)</code></emphasis>
<programlistinglanguage="c++">void palette() { <emphasisrole="italic"><code>// Example of creating new colors (purples)</code></emphasis>
const Int_t colNum = 10; <emphasisrole="italic"><code>// and defining of a new palette</code></emphasis>
Int_t palette[colNum];
for (Int_t i=0; i<colNum; i++) {
...
...
@@ -2947,23 +2904,28 @@ f2->Draw("cont");
<sect1>
<title>The Graphics Editor</title>
<para>A new graphics editor took place in ROOT v4.0. The editor can be activated by selecting the Editor menu entry in the canvas View menu or one of the context menu entries for setting line, fill, marker or text attributes. The following object editors are available for the current ROOT version.</para>
<para>A new graphics editor took place in ROOT v4.0. The editor can be activated
by selecting the Editor menu entry in the canvas View menu or one of the context
menu entries for setting line, fill, marker or text attributes. The following
object editors are available for the current ROOT version.</para>
<para>Legends for a graph are obtained with a <emphasisrole="bold"><code>TLegend</code></emphasis> object. This object points to markers, lines, boxes, histograms, graphs and represent their marker, line, fill attributes. Any object that has a marker or line or fill attribute may have an associated legend. A <emphasisrole="bold"><code>TLegend</code></emphasis> is a panel with several entries (class <emphasisrole="bold"><code>TLegendEntry</code></emphasis>) and is created by the constructor</para>
<para>The title is a regular entry and supports <emphasisrole="bold"><code>TLatex</code></emphasis>. The default is no title (<code>header = 0</code>). The options are the same as for <emphasisrole="bold"><code>TPave</code></emphasis>; by default, they are "<code>brNDC</code>". Once the legend box is created, one has to add the text with the <code>AddEntry()</code> method:</para>
<para>Here <code>name</code> is the name of the object in the pad. Other parameters are as in the previous case. Next example shows how to create a legend:</para>
<programlistinglanguage="c++">
leg = new TLegend(0.4,0.6,0.89,0.89);
<programlistinglanguage="c++">leg = new TLegend(0.4,0.6,0.89,0.89);
leg->AddEntry(fun1,"One Theory","l");
leg->AddEntry(fun3,"Another Theory","f");
leg->AddEntry(gr,"The Data","p");
...
...
@@ -3122,15 +3078,13 @@ leg->Draw();
<listitem><para>Select to print the canvas in the PostScript file format from the File menu / Save or Save As menu entries. By default, a PostScript file is generated, if you do not specify the file format.</para></listitem>
<listitem><para>Click in the canvas area, near the edges, with the right mouse button and select the Print context menu entry. This will generate a file of canvas pointed to by c1. You can select the name of the PostScript file. If the file name is <code>xxx.ps</code>, you will generate a PostScript file named <code>xxx.ps</code>. If the file name is <code>xxx.eps</code>, you generate an encapsulated Postscript file instead. In your program (or script), you can type:</para></listitem>
<para> The <emphasisrole="bold"><code>TPad</code></emphasis><code>::Print </code>method has a second parameter called option. Its value can be:</para>
...
...
@@ -3155,8 +3109,7 @@ leg->Draw();
<para>You do not need to specify this second parameter; you can indicate by the filename extension what format you want to save a canvas in (i.e. <code>canvas.ps</code>, <code>canvas.gif</code>, <code>canvas.C</code>, etc).</para>
<para>The size of the PostScript picture, by default, is computed to keep the aspect ratio of the picture on the screen, where the size along <code>x</code> is always 20 cm. You can set the size of the PostScript picture before generating the picture with a command such as:</para>
<para>You can resume writing again in this file with <code>myps.Open()</code>. Note that you may have several Post Script files opened simultaneously. Use <emphasisrole="bold"><code>TPostScript</code></emphasis><code>::Text(x,y,"string")</code> to add text to a postscript file. This method writes the string in quotes into a PostScript file at position <code>x, y</code> in world coordinates.</para>
<title>Writing Several Canvases to the Same PostScript File</title>
<para>The following sequence writes the canvas to "<code>c1.ps</code>" and closes the postscript file:</para>
<programlistinglanguage="c++">
TCanvas c1("c1");
<programlistinglanguage="c++">TCanvas c1("c1");
h1.Draw();
c1.Print("c1.ps");
</programlisting>
<para>If the Postscript file name finishes with "<code>(</code>", the file remains opened (it is not closed). If the Postscript file name finishes with "<code>)</code>" and the file has been opened with "<code>(</code>", the file is closed.</para>
<programlistinglanguage="c++">
<code>{ </code>
<programlistinglanguage="c++"><code>{ </code>
<code> TCanvas c1("c1");</code>
<code> h1.Draw();</code>
<code> c1.Print("c1.ps("); </code><emphasisrole="italic"><code>// write canvas and keep the ps file open</code></emphasis>
...
...
@@ -3221,8 +3171,7 @@ c1.Print("c1.ps");
<para>The <emphasisrole="bold"><code>TCanvas</code></emphasis><code>::Print("file.ps(")</code> mechanism is very useful, but it can be a little inconvenient to have the action of opening/closing a file being atomic with printing a page. Particularly if pages are being generated in some loop, one needs to detect the special cases of first and last page. The "<code>[</code>" and "<code>]</code>" can be used instead of "<code>(</code>" and "<code>)</code>" as shown in the next example.</para>
<programlistinglanguage="c++">
<code>c1.Print("file.ps["); </code><emphasisrole="italic"><code>// no actual ptint; just open file.ps</code></emphasis>
<programlistinglanguage="c++"><code>c1.Print("file.ps["); </code><emphasisrole="italic"><code>// no actual ptint; just open file.ps</code></emphasis>
<para>This following example shows two pages. The canvas is divided. <emphasisrole="bold"><code>TPostScript</code></emphasis><code>::NewPage</code> must be called before starting a new picture. <code>object->Draw</code> does not clear the canvas in this case because we clear only the pads and not the main canvas. Note that <code>c1->Update</code> must be called at the end of the first picture.</para>
<para>The "<code>Default</code>" style is created by:</para>
<programlistinglanguage="c++">
TStyle *default = new TStyle("Default","Default Style");
<programlistinglanguage="c++">TStyle *default = new TStyle("Default","Default Style");
</programlisting>
<para>The "<code>Plain</code>" style can be used if you want to get a "conventional" PostScript output or if you are working on a monochrome display. The following example shows how to create it.</para>
<programlistinglanguage="c++">
TStyle *plain = new TStyle("Plain","Plain Style(no colors/fill areas)");
<programlistinglanguage="c++">TStyle *plain = new TStyle("Plain","Plain Style(no colors/fill areas)");
<para>Note that when an object is created, its attributes are taken from the current style. For example, you may have created a histogram in a previous session and saved it in a file. Meanwhile, if you have changed the style, the histogram will be drawn with the old attributes. You can force the current style attributes to be set when you read an object from a file by calling <code>ForceStyle</code> before reading the objects from the file.</para>
<para>When you call <code>gROOT->ForceStyle()</code> and read an object from a ROOT file, the object’s method <code>UseCurrentStyle</code> is called. The attributes saved with the object are replaced by the current style attributes. You call also call <code>myObject->UseCurrentStyle()</code> directly. For example if you have a canvas or pad with your histogram or any other object, you can force these objects to get the attributes of the current style by:</para>
<para>The description of the style functions should be clear from the name of the <emphasisrole="bold"><code>TStyle</code></emphasis> setters or getters. Some functions have an extended description, in particular:</para>
<para>A 3D viewer can be created in a script by passing the appropriate option to <code>Draw() </code>when attaching the drawn object(s) to a pad. For a fuller explanation of pads, attaching objects with <code>Draw()</code> etc. refer to “Graphical Containers: Canvas and Pad”.</para>
<para>Orthographic projections are generally constrained to look down one of the global axes of the world, with the other two axes lying horizontal/vertical on the viewer window. Therefore, XOY has the X-axis horizontal, the Y-axis vertical. You can always confirm the orientation and constraints of the camera in the world by enabling axis drawing in the “Guides” tab – see sections “Guides” and “Clipping” below. For orthographic camera a ruler-depicting current scene units is also available.</para>
<para>You can also pick the current camera by obtaining a handle to the GL Viewer object behind the interface:</para>
<programlistinglanguage="c++">
TGLViewer * v = (TGLViewer *)gPad->GetViewer3D();
<programlistinglanguage="c++">TGLViewer * v = (TGLViewer *)gPad->GetViewer3D();
</programlisting>
<para>calling the method <emphasisrole="bold"><code>TGLViewer</code></emphasis><code>::SetCurrentCamera</code> with one of the <emphasisrole="bold"><code>TGLViewer</code></emphasis><code>::ECameraType</code> types:</para>
<para>Configure the camera by calling the methods <code>SetPerspectiveCamera(</code>) or <code>SetOrthographicCamera()</code> of <emphasisrole="bold"><code>TGLViewer</code></emphasis>:</para>
<programlistinglanguage="c++">
TGLViewer * v = (TGLViewer *)gPad->GetViewer3D();
<programlistinglanguage="c++">TGLViewer * v = (TGLViewer *)gPad->GetViewer3D();
@@ -3562,8 +3496,7 @@ Black background. Black background. White background.
</para>
<para>Call method <emphasisrole="bold"><code>TGLViewer</code></emphasis><code>::SetStyle</code> with one of <emphasisrole="bold"><code>TGL</code></emphasis><emphasisrole="bold"><code>RnrCtx</code></emphasis><code>::EDrawStyle </code>flags <code>kFill</code>, <code>kOutline</code>, <code>kWireFrame</code>:</para>
<para>Light controls are located: Viewer Controls Pane ‘Style’.</para>
<para>Each light has a checkbox to enable/disable it. Set lights on/off with <emphasisrole="bold"><code>TGL</code></emphasis><emphasisrole="bold"><code>LightSet</code></emphasis><code>::SetLight</code> e.g.</para>
<para>Set the current clip object with <emphasisrole="bold"><code>TGL</code></emphasis><emphasisrole="bold"><code>ClipSet</code></emphasis><code>::SetClipType</code></para>
<para>Configure the clip object with <emphasisrole="bold"><code>TGL</code></emphasis><emphasisrole="bold"><code>ClipSet</code></emphasis><code>::SetClipState</code></para>
<para>A single orange sphere of fixed view port (window) size can be shown at any arbitrary position. Enable / disable the drawing with ‘<emphasisrole="italic">Show’</emphasis> checkbox. Enter X/Y/Z position in the edit boxes to set position. Initial position is at the center of the scene.</para>
<para>Set the guides using <emphasisrole="bold"><code>TGLViewer</code></emphasis><code>::SetGuideState</code> e.g. to enable edge axes, and enable a reference marker at world position 50, 60, 100:</para>
<para>External viewers are bound to a <emphasisrole="bold"><code>TPad</code></emphasis> object (this may be removed as a requirement in the future). You can create or obtain the current viewer handle via the method:</para>
<programlistinglanguage="c++">
TVirtualViewer3D * v = gPad->GetViewer3D("type");
<programlistinglanguage="c++">TVirtualViewer3D * v = gPad->GetViewer3D("type");
</programlisting>
<para>Here the “type” string defines the viewer type – currently one of:</para>
...
...
@@ -3779,26 +3707,29 @@ TVirtualViewer3D * v = gPad->GetViewer3D("type");
</itemizedlist>
<para>If no type is passed (null string), and there is no current viewer, then the type is defaulted to “<code>pad</code>”. If no type is passed and there is a current viewer, then this is returned – hence once a viewer is created it can be obtained elsewhere by:</para>
<programlistinglanguage="c++">
TVirtualViewer3D * v = gPad->GetViewer3D();
<programlistinglanguage="c++">TVirtualViewer3D * v = gPad->GetViewer3D();
</programlisting>
</sect3>
<sect3>
<title>Opening / Closing Scenes</title>
<para>Objects must be added to viewer between <code>BeginScene() </code>and <code>EndScene()</code> calls e.g.</para>
<para>Objects must be added to viewer between <code>BeginScene()</code> and
<para>These calls enable the viewer to suspend redraws, and perform internal caching/setup. If the object you attach to the pad derives from <emphasisrole="bold"><code>TAtt3D</code></emphasis>, then the pad will take responsibility for calling <code>BeginScene()</code> and <code>EndScene()</code> for you. You can always test if the scene is already open for object addition with:</para>
<para>These calls enable the viewer to suspend redraws, and perform internal
caching/setup. If the object you attach to the pad derives from
<emphasisrole="bold"><code>TAtt3D</code></emphasis>, then the pad will take
responsibility for calling <code>BeginScene()</code> and <code>EndScene()</code>
for you. You can always test if the scene is already open for object addition
<para><emphasisrole="bold"><code>TBuffer3D</code></emphasis> classes are conceptually divided into enumerated sections: <code>kCore</code>, <code>kBoundingBox</code>, <code>kRaw</code> – see the class diagram and the file <code>TBuffer3D.h</code> for more details. The <emphasisrole="bold"><code>TBuffer3D</code></emphasis> methods <code>SectionsValid()</code>, <code>SetSectionsValid()</code>, <code>ClearSectionsValid()</code> are used to test, set, clear these section validity flags e.g.</para>
<para>If the viewer requires more sections to be completed (<code>kRaw/kRawSizes</code>) <emphasisrole="bold"><code>TBuffer3D</code></emphasis><code>::AddObject()</code> will return flags indicating which ones, otherwise it returns <code>kNone</code>. If requested, you must fill the buffer, mark these sections valid, and call <emphasisrole="bold"><code>TBuffer3D</code></emphasis><code>::AddObject</code> again, to complete adding the object. For example, in out <emphasisrole="bold"><code>TGeo</code></emphasis> geometry package, in <emphasisrole="bold"><code>TGeoPainter</code></emphasis><code>::PaintShape</code>, we perform the negotiation with viewer:</para>
<para>The buffer is supplied/filled by the appropriate <emphasisrole="bold"><code>TShape</code></emphasis><code>::GetBuffer3D()</code> and <emphasisrole="bold"><code>TShape</code></emphasis><code>::FillBuffer3D</code> overloads e.g. for a sphere in <emphasisrole="bold"><code>TGeoSphere</code></emphasis>.</para>
<emphasisrole="italic"><code> // Fills a static 3D buffer and returns a reference.</code></emphasis>
static TBuffer3DSphere buffer;
...
...
@@ -3939,8 +3868,7 @@ return buffer;
<para>You are not obliged to complete the <code>kBoundingBox</code> section, as any viewer requiring one internally (GL Viewer) will build it if you do not provide. However to do this the viewer will force you to provide the (expensive) raw tessellation, and the resulting box will be axis aligned with the overall scene, which is non-ideal for rotated shapes. As we need to support orientated (rotated) bounding boxes, <emphasisrole="bold"><code>TBuffer3D</code></emphasis> requires the 6 vertices of the box. We also provide a convenience function, <emphasisrole="bold"><code>TBuffer</code></emphasis><code>::SetAABoundingBox()</code>, for simpler case of setting an axis aligned bounding box. The bounding box should be filled in same frame (local / master) as the rest of the <emphasisrole="bold"><code>TBuffer3D</code></emphasis>, and inaccordance with <code>fLocalFrame</code> flag.</para>
<para>A typical example from TGeoBBox::FillBuffer3D:</para>
<programlistinglanguage="c++">
if (reqSections & TBuffer3D::kBoundingBox) {
<programlistinglanguage="c++">if (reqSections & TBuffer3D::kBoundingBox) {
