penpot/render-wasm/src/shapes/text_paths.rs

use crate::render::text::decoration_segments;
use crate::shapes::text::{vertical_align_offset, Paragraph, TextContent};
use crate::shapes::text_paragraph::LayoutParagraph as SkiaParagraph;
use crate::shapes::VerticalAlign;
use skia_safe::{self as skia, textlayout::paragraph::VisitorInfo, Point};
use std::ops::Deref;

pub struct TextPaths(TextContent);

impl TextPaths {
    pub fn new(text_content: TextContent) -> Self {
        Self(text_content)
    }

    pub fn get_paths(&self, vertical_align: VerticalAlign) -> Vec<skia::Path> {
        if self.0.is_vertical() {
            return crate::shapes::text_vertical::vertical_text_paths(
                &self.0,
                vertical_align,
                true,
            )
            .into_iter()
            .map(|(path, _)| path)
            .collect();
        }

        let layout_width = self.0.get_width(self.bounds.width());
        let plans = self.0.horizontal_plans();
        let mut paragraph_builders = self.0.paragraph_builder_group_from_text(None);
        let mut paragraphs: Vec<SkiaParagraph> = paragraph_builders
            .iter_mut()
            .filter_map(|group| group.first_mut())
            .enumerate()
            .map(|(index, paragraph_builder)| {
                let mut paragraph = SkiaParagraph::build(paragraph_builder);
                paragraph.layout(plans[index].layout_width(layout_width));
                paragraph
            })
            .collect();

        let total_height: f32 = paragraphs.iter().map(|p| p.height()).sum();
        let mut offset_y = self.bounds.y()
            + vertical_align_offset(self.bounds.height(), total_height, vertical_align);

        let mut paths = Vec::new();
        for (index, (paragraph, text_paragraph)) in
            paragraphs.iter_mut().zip(self.0.paragraphs()).enumerate()
        {
            let plan = &plans[index];
            let origin = Point::new(
                self.bounds.x() + plan.x_offset(text_paragraph, layout_width),
                offset_y,
            );
            Self::collect_paragraph_paths(
                paragraph,
                text_paragraph,
                &plan.offsets,
                origin,
                &mut paths,
            );
            offset_y += paragraph.height();
        }

        paths
    }

    fn collect_paragraph_paths(
        paragraph: &mut SkiaParagraph,
        text_paragraph: &Paragraph,
        offsets: &crate::shapes::HorizontalOffsets,
        origin: Point,
        paths: &mut Vec<skia::Path>,
    ) {
        for deco in decoration_segments(paragraph, text_paragraph, offsets, origin.x, origin.y) {
            let mut builder = skia::PathBuilder::new();
            builder.add_rect(deco.rect(), None, None);
            paths.push(builder.detach());
        }

        let shifts: Vec<_> = (0..paragraph.get_line_metrics().len())
            .map(|line| Point::new(paragraph.line_x_shift(line), paragraph.line_shift(line)))
            .collect();
        paragraph.visit(|line: usize, info: Option<&VisitorInfo>| {
            let Some(info) = info else {
                return;
            };

            let font = info.font();
            let run_origin = origin + info.origin() + shifts[line];
            let mut builder = skia::PathBuilder::new();
            let mut has_glyphs = false;

            for (glyph, position) in info.glyphs().iter().zip(info.positions().iter()) {
                let Some(glyph_path) = font.get_path(*glyph) else {
                    continue;
                };
                builder.add_path(&glyph_path.with_offset(run_origin + *position), None);
                has_glyphs = true;
            }

            if has_glyphs {
                paths.push(builder.detach());
            }
        });
    }
}

impl Deref for TextPaths {
    type Target = TextContent;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}