git_graph/print/
svg.rs

1//! Create graphs in SVG format (Scalable Vector Graphics).
2
3use crate::graph::GitGraph;
4use crate::settings::Settings;
5use svg::node::element::path::Data;
6use svg::node::element::{Circle, Line, Path};
7use svg::Document;
8
9/// Creates a SVG visual representation of a graph.
10pub fn print_svg(graph: &GitGraph, settings: &Settings) -> Result<String, String> {
11    let mut document = Document::new();
12
13    let max_idx = graph.commits.len();
14    let mut max_column = 0;
15
16    if settings.debug {
17        for branch in &graph.all_branches {
18            if let (Some(start), Some(end)) = branch.range {
19                document = document.add(bold_line(
20                    start,
21                    branch.visual.column.unwrap(),
22                    end,
23                    branch.visual.column.unwrap(),
24                    "cyan",
25                ));
26            }
27        }
28    }
29
30    for (idx, info) in graph.commits.iter().enumerate() {
31        if let Some(trace) = info.branch_trace {
32            let branch = &graph.all_branches[trace];
33            let branch_color = &branch.visual.svg_color;
34
35            if branch.visual.column.unwrap() > max_column {
36                max_column = branch.visual.column.unwrap();
37            }
38
39            for p in 0..2 {
40                let parent = info.parents[p];
41                let Some(par_oid) = parent else {
42                    continue;
43                };
44                let Some(par_idx) = graph.indices.get(&par_oid) else {
45                    // Parent is outside scope of graph.indices
46                    // so draw a vertical line to the bottom
47                    let idx_bottom = max_idx;
48                    document = document.add(line(
49                        idx,
50                        branch.visual.column.unwrap(),
51                        idx_bottom,
52                        branch.visual.column.unwrap(),
53                        branch_color,
54                    ));
55                    continue;
56                };
57                let par_info = &graph.commits[*par_idx];
58                let par_branch = &graph.all_branches[par_info.branch_trace.unwrap()];
59
60                let color = if info.is_merge {
61                    &par_branch.visual.svg_color
62                } else {
63                    branch_color
64                };
65
66                if branch.visual.column == par_branch.visual.column {
67                    document = document.add(line(
68                        idx,
69                        branch.visual.column.unwrap(),
70                        *par_idx,
71                        par_branch.visual.column.unwrap(),
72                        color,
73                    ));
74                } else {
75                    let split_index = super::get_deviate_index(graph, idx, *par_idx);
76                    document = document.add(path(
77                        idx,
78                        branch.visual.column.unwrap(),
79                        *par_idx,
80                        par_branch.visual.column.unwrap(),
81                        split_index,
82                        color,
83                    ));
84                }
85            }
86
87            document = document.add(commit_dot(
88                idx,
89                branch.visual.column.unwrap(),
90                branch_color,
91                !info.is_merge,
92            ));
93        }
94    }
95    let (x_max, y_max) = commit_coord(max_idx + 1, max_column + 1);
96    document = document
97        .set("viewBox", (0, 0, x_max, y_max))
98        .set("width", x_max)
99        .set("height", y_max);
100
101    let mut out: Vec<u8> = vec![];
102    svg::write(&mut out, &document).map_err(|err| err.to_string())?;
103    Ok(String::from_utf8(out).unwrap_or_else(|_| "Invalid UTF8 character.".to_string()))
104}
105
106fn commit_dot(index: usize, column: usize, color: &str, filled: bool) -> Circle {
107    let (x, y) = commit_coord(index, column);
108    Circle::new()
109        .set("cx", x)
110        .set("cy", y)
111        .set("r", 4)
112        .set("fill", if filled { color } else { "white" })
113        .set("stroke", color)
114        .set("stroke-width", 1)
115}
116
117fn line(index1: usize, column1: usize, index2: usize, column2: usize, color: &str) -> Line {
118    let (x1, y1) = commit_coord(index1, column1);
119    let (x2, y2) = commit_coord(index2, column2);
120    Line::new()
121        .set("x1", x1)
122        .set("y1", y1)
123        .set("x2", x2)
124        .set("y2", y2)
125        .set("stroke", color)
126        .set("stroke-width", 1)
127}
128
129fn bold_line(index1: usize, column1: usize, index2: usize, column2: usize, color: &str) -> Line {
130    let (x1, y1) = commit_coord(index1, column1);
131    let (x2, y2) = commit_coord(index2, column2);
132    Line::new()
133        .set("x1", x1)
134        .set("y1", y1)
135        .set("x2", x2)
136        .set("y2", y2)
137        .set("stroke", color)
138        .set("stroke-width", 5)
139}
140
141fn path(
142    index1: usize,
143    column1: usize,
144    index2: usize,
145    column2: usize,
146    split_idx: usize,
147    color: &str,
148) -> Path {
149    let c0 = commit_coord(index1, column1);
150
151    let c1 = commit_coord(split_idx, column1);
152    let c2 = commit_coord(split_idx + 1, column2);
153
154    let c3 = commit_coord(index2, column2);
155
156    let m = (0.5 * (c1.0 + c2.0), 0.5 * (c1.1 + c2.1));
157
158    let data = Data::new()
159        .move_to(c0)
160        .line_to(c1)
161        .quadratic_curve_to((c1.0, m.1, m.0, m.1))
162        .quadratic_curve_to((c2.0, m.1, c2.0, c2.1))
163        .line_to(c3);
164
165    Path::new()
166        .set("d", data)
167        .set("fill", "none")
168        .set("stroke", color)
169        .set("stroke-width", 1)
170}
171
172fn commit_coord(index: usize, column: usize) -> (f32, f32) {
173    (15.0 * (column as f32 + 1.0), 15.0 * (index as f32 + 1.0))
174}
git_graph/print/svg.rs

git_graph/print/
svg.rs
