Replace DPI with universal scale and use separate DPI only for raster…

… images
staticintlucas · Aug 13, 2023 · c715f0d · c715f0d
1 parent 613e919
commit c715f0d
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Showing 4 changed files with 84 additions and 48 deletions.
diff --git a/src/drawing/mod.rs b/src/drawing/mod.rs
@@ -35,16 +35,16 @@ impl Drawing {
         Self {
             bounds,
             keys,
-            scale: options.dpi * 0.75, // 1u = 0.75in => dpu = 0.75*dpi
+            scale: options.scale,
         }
     }
 
     pub fn to_svg(&self) -> String {
         svg::draw(self)
     }
 
-    pub fn to_png(&self) -> Result<Vec<u8>> {
-        png::draw(self)
+    pub fn to_png(&self, dpi: f64) -> Result<Vec<u8>> {
+        png::draw(self, dpi)
     }
 
     pub fn to_pdf(&self) -> Vec<u8> {
@@ -66,7 +66,7 @@ impl Drawing {
 pub struct DrawingOptions {
     profile: Profile,
     font: Font,
-    dpi: f64,
+    scale: f64,
     outline_width: f64,
     show_keys: bool,
     show_margin: bool,
@@ -77,7 +77,7 @@ impl Default for DrawingOptions {
         Self {
             profile: Profile::default(),
             font: Font::default(),
-            dpi: 96.,
+            scale: 1.,
             outline_width: 10.,
             show_keys: true,
             show_margin: false,
@@ -101,8 +101,8 @@ impl DrawingOptions {
         self
     }
 
-    pub fn dpi(&mut self, dpi: f64) -> &mut Self {
-        self.dpi = dpi;
+    pub fn scale(&mut self, scale: f64) -> &mut Self {
+        self.scale = scale;
         self
     }
 
@@ -140,7 +140,7 @@ mod tests {
     fn test_drawing_options() {
         let options = DrawingOptions::default();
 
-        assert_approx_eq!(options.dpi, 96.);
+        assert_approx_eq!(options.scale, 1.);
         assert_eq!(options.font.glyphs.len(), 0);
 
         let profile = Profile::default();
@@ -149,7 +149,7 @@ mod tests {
         options
             .profile(profile)
             .font(font)
-            .dpi(192.)
+            .scale(2.)
             .show_keys(false)
             .show_margin(true);
 
@@ -158,6 +158,6 @@ mod tests {
             ProfileType::Cylindrical { .. }
         );
         assert_eq!(options.font.glyphs.len(), 2);
-        assert_eq!(options.dpi, 192.);
+        assert_eq!(options.scale, 2.);
     }
 }
diff --git a/src/drawing/pdf.rs b/src/drawing/pdf.rs
@@ -1,18 +1,34 @@
-use kurbo::{PathEl, Point};
+use kurbo::{Affine, PathEl, Point};
 use miniz_oxide::deflate::{compress_to_vec_zlib, CompressionLevel};
 use pdf_writer::{Content, Filter, Finish, PdfWriter, Rect, Ref, TextStr};
 
 use crate::drawing::Drawing;
 
 use super::{KeyDrawing, Path};
 
+const PDF_DPI: f64 = 72.0; // PDF uses 72 dpi
 const COMPRESSION_LEVEL: u8 = CompressionLevel::DefaultLevel as u8;
 
 macro_rules! transform {
-    (($($x:expr, $y:expr),+), $origin:expr, $scale:expr) => {
-        // Negate Y since PDF has rising Y axis
-        ($((($origin.x + $x / 1e3) * $scale) as f32, (($origin.y - $y / 1e3) * $scale) as f32),+)
-    };
+    ($p:expr, $affine:expr) => {{
+        let p = $affine * $p;
+        (p.x as f32, p.y as f32)
+    }};
+    ($p1:expr, $p:expr, $affine:expr) => {{
+        let (p1, p) = ($affine * $p1, $affine * $p);
+        (p1.x as f32, p1.y as f32, p.x as f32, p.y as f32)
+    }};
+    ($p1:expr, $p2:expr, $p:expr, $affine:expr) => {{
+        let (p1, p2, p) = ($affine * $p1, $affine * $p2, $affine * $p);
+        (
+            p1.x as f32,
+            p1.y as f32,
+            p2.x as f32,
+            p2.y as f32,
+            p.x as f32,
+            p.y as f32,
+        )
+    }};
 }
 
 struct RefGen(i32);
@@ -29,7 +45,7 @@ impl RefGen {
 }
 
 pub(crate) fn draw(drawing: &Drawing) -> Vec<u8> {
-    let scale = drawing.scale * (72.0 / 96.0);
+    let scale = drawing.scale * PDF_DPI * 0.75; // 0.75 in/key
     let size = drawing.bounds.size() * scale;
 
     let mut ref_gen = RefGen::new();
@@ -56,8 +72,10 @@ pub(crate) fn draw(drawing: &Drawing) -> Vec<u8> {
 
     let mut content = Content::new();
 
+    // Flip origin since PDF has rising Y axis
+    let affine = Affine::scale_non_uniform(scale, -scale).then_translate((0., size.height).into());
     for key in &drawing.keys {
-        draw_key(&mut content, key, drawing.bounds.height(), scale);
+        draw_key(&mut content, key, &affine);
     }
 
     let data = compress_to_vec_zlib(&content.finish(), COMPRESSION_LEVEL);
@@ -76,45 +94,45 @@ pub(crate) fn draw(drawing: &Drawing) -> Vec<u8> {
     writer.finish()
 }
 
-fn draw_key(content: &mut Content, key: &KeyDrawing, height: f64, scale: f64) {
+fn draw_key(content: &mut Content, key: &KeyDrawing, affine: &Affine) {
+    let affine = *affine * Affine::scale(1e-3).then_translate(key.origin.to_vec2());
     for path in &key.paths {
-        // Flip origin since PDF has rising Y axis
-        let origin = Point::new(key.origin.x, height - key.origin.y);
-        draw_path(content, path, origin, scale);
+        draw_path(content, path, &affine);
     }
 }
 
-fn draw_path(content: &mut Content, path: &Path, origin: Point, scale: f64) {
+fn draw_path(content: &mut Content, path: &Path, affine: &Affine) {
     // previous point, needed for quad => cubic Bézier conversion
+    let mut origin = Point::ORIGIN;
     let mut p0 = Point::ORIGIN;
 
     for el in &path.path {
         match el {
             PathEl::MoveTo(p) => {
+                origin = p;
                 p0 = p;
-                let (x, y) = transform!((p.x, p.y), origin, scale);
+                let (x, y) = transform!(p, *affine);
                 content.move_to(x, y);
             }
             PathEl::LineTo(p) => {
                 p0 = p;
-                let (x, y) = transform!((p.x, p.y), origin, scale);
+                let (x, y) = transform!(p, *affine);
                 content.line_to(x, y);
             }
             PathEl::CurveTo(p1, p2, p) => {
                 p0 = p;
-                let (x1, y1, x2, y2, x, y) =
-                    transform!((p1.x, p1.y, p2.x, p2.y, p.x, p.y), origin, scale);
+                let (x1, y1, x2, y2, x, y) = transform!(p1, p2, p, *affine);
                 content.cubic_to(x1, y1, x2, y2, x, y);
             }
             PathEl::QuadTo(p1, p) => {
                 // Convert quad to cubic since PostScript doesn't have quadratic Béziers
                 let (p1, p2) = (p0 + (2.0 / 3.0) * (p1 - p0), p + (2.0 / 3.0) * (p1 - p));
                 p0 = p;
-                let (x1, y1, x2, y2, x, y) =
-                    transform!((p1.x, p1.y, p2.x, p2.y, p.x, p.y), origin, scale);
+                let (x1, y1, x2, y2, x, y) = transform!(p1, p2, p, *affine);
                 content.cubic_to(x1, y1, x2, y2, x, y);
             }
             PathEl::ClosePath => {
+                p0 = origin;
                 content.close_path();
             }
         }
@@ -129,7 +147,7 @@ fn draw_path(content: &mut Content, path: &Path, origin: Point, scale: f64) {
         let (r, g, b) = outline.color.into();
         content.set_stroke_rgb(r, g, b);
         #[allow(clippy::cast_possible_truncation)]
-        content.set_line_width((outline.width * scale / 1e3) as f32);
+        content.set_line_width((outline.width * affine.as_coeffs()[0]) as f32);
     }
 
     match (path.fill, path.outline) {

diff --git a/src/drawing/png.rs b/src/drawing/png.rs
@@ -1,6 +1,6 @@
 use std::fmt;
 
-use kurbo::{PathEl, Point};
+use kurbo::{Affine, PathEl};
 use tiny_skia::{FillRule, Paint, PathBuilder, Pixmap, Shader, Stroke, Transform};
 
 use crate::drawing::Drawing;
@@ -20,15 +20,32 @@ impl fmt::Display for PngEncodingError {
 }
 
 macro_rules! transform {
-    (($($x:expr, $y:expr),+), $origin:expr, $scale:expr) => {
-        ($((($origin.x + $x / 1e3) * $scale) as f32, (($origin.y + $y / 1e3) * $scale) as f32),+)
-    };
+    ($p:expr, $affine:expr) => {{
+        let p = $affine * $p;
+        (p.x as f32, p.y as f32)
+    }};
+    ($p1:expr, $p:expr, $affine:expr) => {{
+        let (p1, p) = ($affine * $p1, $affine * $p);
+        (p1.x as f32, p1.y as f32, p.x as f32, p.y as f32)
+    }};
+    ($p1:expr, $p2:expr, $p:expr, $affine:expr) => {{
+        let (p1, p2, p) = ($affine * $p1, $affine * $p2, $affine * $p);
+        (
+            p1.x as f32,
+            p1.y as f32,
+            p2.x as f32,
+            p2.y as f32,
+            p.x as f32,
+            p.y as f32,
+        )
+    }};
 }
 
 impl std::error::Error for PngEncodingError {}
 
-pub(crate) fn draw(drawing: &Drawing) -> Result<Vec<u8>> {
-    let size = drawing.bounds.size() * drawing.scale;
+pub(crate) fn draw(drawing: &Drawing, dpi: f64) -> Result<Vec<u8>> {
+    let scale = drawing.scale * dpi * 0.75; // 0.75 in/key
+    let size = drawing.bounds.size() * scale;
 
     #[allow(clippy::cast_possible_truncation, clippy::cast_sign_loss)]
     let (width, height) = (size.width.ceil() as u32, size.height.ceil() as u32);
@@ -39,40 +56,41 @@ pub(crate) fn draw(drawing: &Drawing) -> Result<Vec<u8>> {
 
     pixmap.fill(tiny_skia::Color::TRANSPARENT);
 
+    let affine = Affine::scale(scale);
     for key in &drawing.keys {
-        draw_key(&mut pixmap, key, drawing.scale);
+        draw_key(&mut pixmap, key, &affine);
     }
 
     Ok(pixmap.encode_png().map_err(|e| PngEncodingError {
         message: e.to_string(),
     })?)
 }
 
-fn draw_key(pixmap: &mut Pixmap, key: &KeyDrawing, scale: f64) {
+fn draw_key(pixmap: &mut Pixmap, key: &KeyDrawing, affine: &Affine) {
+    let affine = *affine * Affine::scale(1e-3).then_translate(key.origin.to_vec2());
     for path in &key.paths {
-        draw_path(pixmap, path, key.origin, scale);
+        draw_path(pixmap, path, &affine);
     }
 }
 
-fn draw_path(pixmap: &mut Pixmap, path: &Path, origin: Point, scale: f64) {
+fn draw_path(pixmap: &mut Pixmap, path: &Path, affine: &Affine) {
     let mut path_builder = PathBuilder::new();
     for el in &path.path {
         match el {
             PathEl::MoveTo(p) => {
-                let (x, y) = transform!((p.x, p.y), origin, scale);
+                let (x, y) = transform!(p, *affine);
                 path_builder.move_to(x, y);
             }
             PathEl::LineTo(p) => {
-                let (x, y) = transform!((p.x, p.y), origin, scale);
+                let (x, y) = transform!(p, *affine);
                 path_builder.line_to(x, y);
             }
             PathEl::CurveTo(p1, p2, p) => {
-                let (x1, y1, x2, y2, x, y) =
-                    transform!((p1.x, p1.y, p2.x, p2.y, p.x, p.y), origin, scale);
+                let (x1, y1, x2, y2, x, y) = transform!(p1, p2, p, *affine);
                 path_builder.cubic_to(x1, y1, x2, y2, x, y);
             }
             PathEl::QuadTo(p1, p) => {
-                let (x1, y1, x, y) = transform!((p1.x, p1.y, p.x, p.y), origin, scale);
+                let (x1, y1, x, y) = transform!(p1, p, *affine);
                 path_builder.quad_to(x1, y1, x, y);
             }
             PathEl::ClosePath => path_builder.close(),
@@ -103,7 +121,7 @@ fn draw_path(pixmap: &mut Pixmap, path: &Path, origin: Point, scale: f64) {
         };
         #[allow(clippy::cast_possible_truncation)]
         let stroke = Stroke {
-            width: (outline.width * scale / 1e3) as f32,
+            width: (outline.width * affine.as_coeffs()[0]) as f32,
             ..Default::default()
         };
         pixmap.stroke_path(&skia_path, &paint, &stroke, Transform::default(), None);

diff --git a/src/drawing/svg.rs b/src/drawing/svg.rs
@@ -15,11 +15,11 @@ macro_rules! fmt_num {
 
 pub(crate) fn draw(drawing: &Drawing) -> String {
     let size = drawing.bounds.size() * drawing.scale;
-    let view_box = drawing.bounds.scale_from_origin(1e3);
+    let view_box = drawing.bounds.scale_from_origin(1e3); // Use 1000 user units per key
 
     let document = Document::new()
-        .set("width", fmt_num!("{}", size.width))
-        .set("height", fmt_num!("{}", size.height))
+        .set("width", fmt_num!("{}mm", size.width * 19.05))
+        .set("height", fmt_num!("{}mm", size.height * 19.05))
         .set(
             "viewBox",
             fmt_num!(