1 files changed, 67 insertions, 0 deletions
diff --git a/src/pdf.zig b/src/pdf.zig
index 712750dc..de5e6d86 100644
--- a/src/pdf.zig
+++ b/src/pdf.zig
@@ -1017,6 +1017,73 @@ pub const Document = struct {
         ) != c.PARDES_PDF_OK) return error.RenderFailed;
     }
 
+    /// Only the highlight pass of `renderIntoAtWithPaper`, over `rgba`, which
+    /// holds `band` of this page as that render left it before highlighting
+    /// (opaque paper). Rendering with highlights equals rendering without and
+    /// then this, row for row: the render draws highlights over the finished
+    /// page, and so does this.
+    pub fn paintHighlightsAt(
+        document: *Document,
+        page: usize,
+        request: RenderRequest,
+        raster: Raster,
+        band: Raster.Band,
+        highlights: []const Highlight,
+        rgba: []u8,
+    ) !void {
+        if (rgba.len != band.len) return error.BadPixmap;
+        if (band.height == 0 or band.y + band.height > raster.height)
+            return error.BadPixmap;
+        const bounded = try boundedRequest(document, page, request);
+        if (highlights.len > c.PARDES_PDF_MAX_RESULT_QUADS) return error.RenderFailed;
+        if (c.pardes_pdf_paint_highlights(
+            document.handle,
+            @intCast(page),
+            bounded.dpi,
+            bounded.minimum_width,
+            bounded.minimum_height,
+            bounded.max_dimension,
+            if (highlights.len == 0) null else @ptrCast(highlights.ptr),
+            highlights.len,
+            rgba.ptr,
+            rgba.len,
+            @intCast(raster.width),
+            @intCast(raster.height),
+            @intCast(raster.stride),
+            @intCast(band.y),
+            @intCast(band.height),
+        ) != c.PARDES_PDF_OK) return error.RenderFailed;
+    }
+
+    pub const Rows = struct { start: usize, end: usize };
+
+    /// The rows of `request`'s raster that painting `highlights` can touch,
+    /// by the transform the render itself uses (rotation included). Empty
+    /// when nothing would paint.
+    pub fn highlightRows(
+        document: *Document,
+        page: usize,
+        request: RenderRequest,
+        highlights: []const Highlight,
+    ) !Rows {
+        const bounded = try boundedRequest(document, page, request);
+        var row_start: c_int = 0;
+        var row_end: c_int = 0;
+        if (c.pardes_pdf_highlight_rows(
+            document.handle,
+            @intCast(page),
+            bounded.dpi,
+            bounded.minimum_width,
+            bounded.minimum_height,
+            bounded.max_dimension,
+            if (highlights.len == 0) null else @ptrCast(highlights.ptr),
+            highlights.len,
+            &row_start,
+            &row_end,
+        ) != c.PARDES_PDF_OK) return error.RenderFailed;
+        return .{ .start = @intCast(row_start), .end = @intCast(row_end) };
+    }
+
     const BoundedRequest = struct {
         dpi: c_int,
         minimum_width: c_int,