I'm using graphviz to visualize the AST of a language I'm parsing. I want to include the source code (as a label) but graphviz aligns the text inside the label, which messes with my indentation (and code is indentation-sensitive). Here's an example of the problem, the second line of code should not be indented:
This is the relevant part of the generated .dot file:
graph [fontname=Courier,fontsize=10.0,labeljust=l,nojustify=true];
node [shape=box,width=0.2,height=0.2,fontname=Courier,fontsize=10.0,penwidth=0.5];
edge [weight=1.2,penwidth=0.5,fontname=Courier,fontsize=10.0,labeljust=c];
labelloc="t";
label="\ndef square(a, b) -> a * b\ndef dotProduct(a, b) -> \n a.x * b.x + a.y * b.y\n";
You may use \l instead of \n in order to divide the label into left-justified lines.
Related
I am trying to render text with Harfbuzz and a signed distance field atlas.
The code is basically this:
void drawText(const std::wstring &str, Vec2 pos)
{
// Init harfbuzz
hb_buffer_t *hbBuf = hb_buffer_create();
hb_buffer_set_direction(hbBuf, HB_DIRECTION_LTR);
hb_buffer_set_script(hbBuf, HB_SCRIPT_LATIN);
hb_buffer_set_language(hbBuf, hb_language_from_string("en", 2));
// Process string
hb_buffer_add_utf32(hbBuf, reinterpret_cast<const uint32_t*>(str.c_str()), -1, 0, -1);
hb_shape(font.hb, hbBuf, nullptr, 0);
// Display string
unsigned int nbGlyphs;
hb_glyph_info_t *glyphInfos = hb_buffer_get_glyph_infos(hbBuf, &nbGlyphs);
hb_glyph_position_t *glyphPos = hb_buffer_get_glyph_positions(hbBuf, &nbGlyphs);
for(unsigned int i = 0; i < nbGlyphs; i++)
{
Vec2 drawPos = pos + Vec2(glyphPos[i].x_offset, glyphPos[i].y_offset) / 64.f;
drawGlyph(glyphInfos[i].codepoint, drawPos);
pos.x += glyphPos[i].x_advance / 64.f;
pos.y += glyphPos[i].y_advance / 64.f;
}
}
The text looks correctly shaped for an English phrase, but when I test it with diacritics, they look misplaced.
I am testing it with aâa aâ̈a bb̂b bb̂̈b bb̧b bb͜b bb︠︡b. The Unicode string does not contain precombined characters. Harfbuzz uses the precombined character â, which makes this one look good. Most other diacritics are off.
Text with diacritics on the left of where they should be
When I multiply x_offset by 0.5, the combining characters are better placed. The accents and the cedilla are at the right x position. The accents do not stack and are too low on the b. The arc under BBB (U+035C) should join the two last letters instead of being centered on the 2nd b.
I also tried with U+FE20 and U+FE21 on the previous group of b. In my tests, U+FE21 is on the 2nd b, but it looks like it should be on the 3rd.
Test with glyphPos[i].x_offset * 0.5f, better but still wrong
I tried with several fonts, but of those fonts, only NotoSansDisplay-Regular.ttf had combining characters. I did not manage to make a program display that string as expected on my Debian system (testing, with HarfBuzz 2.6.4-1).
With Windows, I got better results. Here is what I expect: the accents are stacked, the combining double breve below it at the right place, the cedilla is off.
Text rendering closer to what I expect
Am I doing something wrong with HarfBuzz, or I am testing to niche cases that HarfBuzz does support yet?
EDIT:
The actual problem was not described above.
I loaded a font with FreeType FT_New_Face then created a hb_font_t with hb_ft_font_create.
For every string drawn, I called FT_Set_Pixel_Sizes but kept that hb_font_t.
You should try shaping the same text and font with hb-view / hb-shape. That would help you narrow down where the problem is. I'm making a wild guess that the problem is in how / whether you are accounting for glyph origin in your atlas.
Create a new hb_font_t with hb_ft_font_create every time the font size i changed with FT_Set_Pixel_Sizes.
Hi my arrow like following:
https://i.imgur.com/EJNtfc3.png
Arrow on the red marked is glutinous.
How do I divide it?
add code
https://www.codepile.net/pile/XKvOwL3A
In your situation fastest fix would be to add nodesep = 0.15 graph attribute (right after digraph { statement). This attribute adjusts the minimal distance between the nodes in one rank. This results in:
Also you may play with headport and tailport attributes, as I suggested in the comment. Shortcut for them is to add a colon after node when you are defining edge.
If you replace TR_Client_Data -> idle with TR_Client_Data -> idle:e you will get this result:
Edges are crossed, but they are apart.
Also I've noticed that you define node attributes in a wrong way: keyword node defines global attributes for all nodes in the graph (or subgraph). If you want to specify attributes for a single node, place them after node definition.
e.g.
WRONG:
node [
shape = point,
fontsize = 12
] start_point;
CORRECT:
start_point [
shape = point,
fontsize = 12
];
In my Graphviz graph (written in DOT), I want each node to have a label, but in addition to that, I want some nodes to have a small caption denoting some other unique value for that node. For example, if this were for a history diagram, a node's label might be something like "Birth of George Washington" and the caption might read "See also: American Revolution."
This is fairly flexible, so the caption doesn't necessarily need to be inside the node, but I do need some other way of putting text that clearly isn't part of the label (e.g. is a different size, possibly a different color) and is in a different location but is still clearly a part of the node.
Is there any way to do this?
To place captions outside the node, you may use xlabel:
digraph g {
forcelabels=true;
a [label="Birth of George Washington", xlabel="See also: American Revolution"];
b [label="Main label", xlabel="Additional caption"];
a-> b;
}
forcelabels=true makes sure no xlabel is omitted.
A second option is to use HTML-like labels:
digraph g {
a[label=<Birth of George Washington<BR />
<FONT POINT-SIZE="10">See also: American Revolution</FONT>>];
}
I need to print a large number of graphs using Graphviz DOT. To distinguish which input each graph corresponds to, I want to also have a caption for each graph. Is there anyway to embed this into the DOT representation of the graphs.
You can use label to add a caption to the graph.
Example:
digraph {
A -> B;
label="Graph";
labelloc=top;
labeljust=left;
}
labelloc and labeljust can be used to determine top/bottom and left/right position of the graph label.
All the details and other attributes that can be used to modify the label (font etc) in the graphviz attribute reference.
Tip: Define the graph label end of your dot file, otherwise subgraphs will inherit those properties.
Graph's can have attributes just like nodes and edges do:
digraph {
graph [label="The Tale of Two Cities", labelloc=t, fontsize=30];
node [color=blue];
rankdir = LR;
London -> Paris;
Paris -> London;
}
That dot file produces this graph.
If you are looking for a way to add a caption to a Graph object of graphviz in python. Then the following code can help:
from graphviz import Graph
dot = Graph()
dot.node('1','1')
dot.node('2','2')
dot.edge('1','2', label="link")
dot.attr(label="My caption")
dot.attr(fontsize='25')
dot.render(view=True)
Output:
When I changed the rankdir of my graph from LR to TD, my record nodes also changed their layout direction so they no longer look like a 'record'. I tried applying a separate rankdir to the nodes, but this had no effect.
How does one keep the record nodes with the correct layout?
digraph sample {
graph [rankdir=TD];
node [shape=record];
A [label="ShouldBeTop | ShouldBeBottom"];
B [label="Top | Bottom"];
A -> B;
}
Taking into account that rankdir effectively replaces the notion of "top" and "bottom" for the given graph, that's not surprising.
I am afraid that there is no easy remedy for this, save hacking the source (and that would not be easy at all). You can surround your labels in "{}" with some kind of mass search-replace solution to get the requested effect:
digraph sample { graph [rankdir=TD]; node [shape=record];
A [label="{ShouldBeTop | ShouldBeBottom}"];
B [label="{Top | Bottom}"]; A -> B;
}
You can use html table like labels instead of records. IIRC the table based labels do not rotate with the rank direction. See http://www.graphviz.org/doc/info/shapes.html#html