feat: finish ghostty pane backend integration

1 files changed, 63 insertions, 0 deletions

diff --git a/vendor/libghostty-vt/src/renderer/row.zig b/vendor/libghostty-vt/src/renderer/row.zig
new file mode 100644
index 00000000..74a64101
--- /dev/null
+++ b/vendor/libghostty-vt/src/renderer/row.zig
@@ -0,0 +1,63 @@
+const terminal = @import("../terminal/main.zig");
+
+// TODO: Test neverExtendBg function
+
+/// Returns true if the row of this pin should never have its background
+/// color extended for filling padding space in the renderer. This is
+/// a set of heuristics that help making our padding look better.
+pub fn neverExtendBg(
+    row: terminal.page.Row,
+    cells: []const terminal.page.Cell,
+    styles: []const terminal.Style,
+    palette: *const terminal.color.Palette,
+    default_background: terminal.color.RGB,
+) bool {
+    // Any semantic prompts should not have their background extended
+    // because prompts often contain special formatting (such as
+    // powerline) that looks bad when extended.
+    switch (row.semantic_prompt) {
+        .prompt, .prompt_continuation => return true,
+        .none => {},
+    }
+
+    for (0.., cells) |x, *cell| {
+        // If any cell has a default background color then we don't
+        // extend because the default background color probably looks
+        // good enough as an extension.
+        switch (cell.content_tag) {
+            // If it is a background color cell, we check the color.
+            .bg_color_palette, .bg_color_rgb => {
+                const s: terminal.Style = if (cell.hasStyling()) styles[x] else .{};
+                const bg = s.bg(cell, palette) orelse return true;
+                if (bg.eql(default_background)) return true;
+            },
+
+            // If its a codepoint cell we can check the style.
+            .codepoint, .codepoint_grapheme => {
+                // For codepoint containing, we also never extend bg
+                // if any cell has a powerline glyph because these are
+                // perfect-fit.
+                switch (cell.codepoint()) {
+                    // Powerline
+                    0xE0B0...0xE0C8,
+                    0xE0CA,
+                    0xE0CC...0xE0D2,
+                    0xE0D4,
+                    => return true,
+
+                    else => {},
+                }
+
+                // Never extend a cell that has a default background.
+                // A default background is applied if there is no background
+                // on the style or the explicitly set background
+                // matches our default background.
+                const s: terminal.Style = if (cell.hasStyling()) styles[x] else .{};
+                const bg = s.bg(cell, palette) orelse return true;
+                if (bg.eql(default_background)) return true;
+            },
+        }
+    }
+
+    return false;
+}