librsvg source for verification 2026-05-22

rsvg/tests/text.rs

@@ -0,0 +1,131 @@
+use float_cmp::approx_eq;
+use rsvg::{CairoRenderer, Loader};
+
+use rsvg::test_utils::setup_font_map;
+use rsvg::{test_compare_render_output, test_svg_reference};
+
+// From https://www.w3.org/Style/CSS/Test/Fonts/Ahem/
+//
+//   > The Ahem font was developed by Todd Fahrner and Myles C. Maxfield to
+//   > help test writers develop predictable tests. The units per em is 1000,
+//   > the ascent is 800, and the descent is 200, thereby making the em
+//   > square exactly square. The glyphs for most characters is simply a box
+//   > which fills this square. The codepoints mapped to this full square
+//   > with a full advance are the following ranges:
+//
+// So, ascent is 4/5 of the font-size, descent is 1/5.  Mind the positions below.
+test_compare_render_output!(
+    ahem_font,
+    500,
+    500,
+    br##"<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg" width="500" height="500">
+  <text style="font: 50px Ahem;" x="50" y="50" fill="black">abcde</text>
+</svg>"##,
+    br##"<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg" width="500" height="500">
+  <rect x="50" y="10" width="250" height="50" fill="black"/>
+</svg>"##,
+);
+
+test_svg_reference!(
+    text_anchor_chunk_806,
+    "tests/fixtures/text/bug806-text-anchor-chunk.svg",
+    "tests/fixtures/text/bug806-text-anchor-chunk-ref.svg"
+);
+
+test_svg_reference!(
+    span_bounds_when_offset_by_dx,
+    "tests/fixtures/text/span-bounds-when-offset-by-dx.svg",
+    "tests/fixtures/text/span-bounds-when-offset-by-dx-ref.svg"
+);
+
+// FIXME: Ignored because with the change to render all text as paths, the rendering
+// of these is different.
+//
+// test_svg_reference!(
+//     tspan_direction_change_804,
+//     "tests/fixtures/text/bug804-tspan-direction-change.svg",
+//     "tests/fixtures/text/bug804-tspan-direction-change-ref.svg"
+// );
+
+test_svg_reference!(
+    unicode_bidi_override,
+    "tests/fixtures/text/unicode-bidi-override.svg",
+    "tests/fixtures/text/unicode-bidi-override-ref.svg"
+);
+
+test_svg_reference!(
+    display_none,
+    "tests/fixtures/text/display-none.svg",
+    "tests/fixtures/text/display-none-ref.svg"
+);
+
+test_svg_reference!(
+    visibility_hidden,
+    "tests/fixtures/text/visibility-hidden.svg",
+    "tests/fixtures/text/visibility-hidden-ref.svg"
+);
+
+test_svg_reference!(
+    visibility_hidden_x_attr,
+    "tests/fixtures/text/visibility-hidden-x-attr.svg",
+    "tests/fixtures/text/visibility-hidden-ref.svg"
+);
+
+test_svg_reference!(
+    bounds,
+    "tests/fixtures/text/bounds.svg",
+    "tests/fixtures/text/bounds-ref.svg"
+);
+
+test_svg_reference!(
+    bug1109_scaled_text_anchor_middle,
+    "tests/fixtures/text/bug1109-scaled-text-anchor-middle.svg",
+    "tests/fixtures/text/bug1109-scaled-text-anchor-middle-ref.svg"
+);
+
+fn rect(x: f64, y: f64, width: f64, height: f64) -> cairo::Rectangle {
+    cairo::Rectangle::new(x, y, width, height)
+}
+
+fn rectangle_approx_eq(a: &cairo::Rectangle, b: &cairo::Rectangle) -> bool {
+    // FIXME: this is super fishy; shouldn't we be using 2x the epsilon against the width/height
+    // instead of the raw coordinates?
+    approx_eq!(f64, a.x(), b.x())
+        && approx_eq!(f64, a.y(), b.y())
+        && approx_eq!(f64, a.width(), b.width())
+        && approx_eq!(f64, a.height(), b.height())
+}
+
+// Test that the computed geometry of text layers is as expected.
+#[test]
+fn test_text_layer_geometry() {
+    setup_font_map();
+
+    let handle = Loader::new()
+        .read_path("tests/fixtures/text/bounds.svg")
+        .unwrap_or_else(|e| panic!("could not load: {}", e));
+
+    let renderer = CairoRenderer::new(&handle).test_mode(true);
+
+    let viewport = rect(0.0, 0.0, 600.0, 600.0);
+
+    // tuples of (element_id, ink_rect)
+    let cases = vec![
+        ("#a", rect(50.0, 60.0, 100.0, 50.0)),
+        ("#b", rect(200.0, 60.0, 50.0, 100.0)),
+        ("#c", rect(300.0, 60.0, 50.0, 100.0)),
+        ("#d", rect(400.0, 60.0, 100.0, 50.0)),
+    ];
+
+    for (id, expected_ink_rect) in cases {
+        let (ink_rect, _) = renderer.geometry_for_layer(Some(id), &viewport).unwrap();
+        assert!(
+            rectangle_approx_eq(&ink_rect, &expected_ink_rect),
+            "ink_rect: {:?}, expected: {:?}",
+            ink_rect,
+            expected_ink_rect
+        );
+    }
+}