Implement sideways text.

src/components/gfx/display_list/mod.rs

@@ -21,7 +21,7 @@ use text::TextRun;
 
 use collections::dlist::DList;
 use collections::dlist;
-use geom::{Point2D, Rect, SideOffsets2D, Size2D};
+use geom::{Point2D, Rect, SideOffsets2D, Size2D, Matrix2D};
 use libc::uintptr_t;
 use servo_net::image::base::Image;
 use servo_util::geometry::Au;
@@ -337,10 +337,11 @@ impl DisplayList {
 
     /// Draws the display list into the given render context. The display list must be flattened
     /// first for correct painting.
-    pub fn draw_into_context(&self, render_context: &mut RenderContext) {
+    pub fn draw_into_context(&self, render_context: &mut RenderContext,
+                             current_transform: &Matrix2D<AzFloat>) {
         debug!("Beginning display list.");
         for item in self.list.iter() {
-            item.draw_into_context(render_context)
+            item.draw_into_context(render_context, current_transform)
         }
         debug!("Ending display list.");
     }
@@ -483,6 +484,16 @@ pub struct TextDisplayItem {
 
     /// The color of the text.
     pub text_color: Color,
+
+    pub baseline_origin: Point2D<Au>,
+    pub orientation: TextOrientation,
+}
+
+#[deriving(Clone, Eq, PartialEq)]
+pub enum TextOrientation {
+    Upright,
+    SidewaysLeft,
+    SidewaysRight,
 }
 
 /// Renders an image.
@@ -560,7 +571,8 @@ impl<'a> Iterator<&'a DisplayItem> for DisplayItemIterator<'a> {
 
 impl DisplayItem {
     /// Renders this display item into the given render context.
-    fn draw_into_context(&self, render_context: &mut RenderContext) {
+    fn draw_into_context(&self, render_context: &mut RenderContext,
+                         current_transform: &Matrix2D<AzFloat>) {
         // This should have been flattened to the content stacking level first.
         assert!(self.base().level == ContentStackingLevel);
 
@@ -572,31 +584,61 @@ impl DisplayItem {
             ClipDisplayItemClass(ref clip) => {
                 render_context.draw_push_clip(&clip.base.bounds);
                 for item in clip.children.iter() {
-                    (*item).draw_into_context(render_context);
+                    (*item).draw_into_context(render_context, current_transform);
                 }
                 render_context.draw_pop_clip();
             }
 
             TextDisplayItemClass(ref text) => {
-                debug!("Drawing text at {:?}.", text.base.bounds);
+                debug!("Drawing text at {}.", text.base.bounds);
 
-                // FIXME(pcwalton): Allocating? Why?
+                // Optimization: Don’t set a transform matrix for upright text,
-                let text_run = text.text_run.clone();
+                // and pass a strart point to `draw_text_into_context`.
+                // For sideways text, it’s easier to do the rotation such that its center
+                // (the baseline’s start point) is at (0, 0) coordinates.
+                let baseline_origin = match text.orientation {
+                    Upright => text.baseline_origin,
+                    SidewaysLeft => {
+                        let x = text.baseline_origin.x.to_nearest_px() as AzFloat;
+                        let y = text.baseline_origin.y.to_nearest_px() as AzFloat;
+                        render_context.draw_target.set_transform(&current_transform.mul(
+                            &Matrix2D::new(
+                                0., -1.,
+                                1., 0.,
+                                x, y
+                            )
+                        ));
+                        Zero::zero()
+                    },
+                    SidewaysRight => {
+                        let x = text.baseline_origin.x.to_nearest_px() as AzFloat;
+                        let y = text.baseline_origin.y.to_nearest_px() as AzFloat;
+                        render_context.draw_target.set_transform(&current_transform.mul(
+                            &Matrix2D::new(
+                                0., 1.,
+                                -1., 0.,
+                                x, y
+                            )
+                        ));
+                        Zero::zero()
+                    }
+                };
 
-                let font = render_context.font_ctx.get_render_font_from_template(
+                render_context.font_ctx.get_render_font_from_template(
-                                            &text_run.font_template,
+                    &text.text_run.font_template,
-                                            text_run.pt_size,
+                    text.text_run.pt_size,
-                                            render_context.opts.render_backend);
+                    render_context.opts.render_backend
-                let font = font.borrow();
+                ).borrow().draw_text_into_context(
+                    render_context,
+                    &*text.text_run,
+                    &text.range,
+                    baseline_origin,
+                    text.text_color
+                );
 
-                let origin = text.base.bounds.origin;
+                // Undo the transform, only when we did one.
-                let baseline_origin = Point2D(origin.x, origin.y + text_run.font_metrics.ascent);
+                if text.orientation != Upright {
-                {
+                    render_context.draw_target.set_transform(current_transform)
-                    font.draw_text_into_context(render_context,
-                                                &*text.text_run,
-                                                &text.range,
-                                                baseline_origin,
-                                                text.text_color);
                 }
             }
 

src/components/gfx/render_task.rs

@@ -352,7 +352,7 @@ impl<C:RenderListener + Send> RenderTask<C> {
 
                     // Draw the display list.
                     profile(time::RenderingDrawingCategory, self.time_profiler_chan.clone(), || {
-                        display_list.draw_into_context(&mut ctx);
+                        display_list.draw_into_context(&mut ctx, &matrix);
                         ctx.draw_target.flush();
                     });
                 }

src/components/layout/fragment.rs

@@ -29,6 +29,7 @@ use gfx::display_list::{ImageDisplayItemClass, LineDisplayItem};
 use gfx::display_list::{LineDisplayItemClass, OpaqueNode, PseudoDisplayItemClass};
 use gfx::display_list::{SolidColorDisplayItem, SolidColorDisplayItemClass, StackingLevel};
 use gfx::display_list::{TextDisplayItem, TextDisplayItemClass};
+use gfx::display_list::{Upright, SidewaysLeft, SidewaysRight};
 use gfx::font::FontStyle;
 use gfx::text::glyph::CharIndex;
 use gfx::text::text_run::TextRun;
@@ -935,12 +936,31 @@ impl Fragment {
             TableColumnFragment(_) => fail!("Shouldn't see table column fragments here."),
             ScannedTextFragment(ref text_fragment) => {
                 // Create the text display item.
+                let orientation = if self.style.writing_mode.is_vertical() {
+                    if self.style.writing_mode.is_sideways_left() {
+                        SidewaysLeft
+                    } else {
+                        SidewaysRight
+                    }
+                } else {
+                    Upright
+                };
+
+                let metrics = &text_fragment.run.font_metrics;
+                let baseline_origin ={
+                    let mut tmp = content_box.start;
+                    tmp.b = tmp.b + metrics.ascent;
+                    tmp.to_physical(self.style.writing_mode, container_size) + flow_origin
+                };
+
                 let text_display_item = box TextDisplayItem {
                     base: BaseDisplayItem::new(
                         absolute_content_box, self.node, ContentStackingLevel),
                     text_run: text_fragment.run.clone(),
                     range: text_fragment.range,
                     text_color: self.style().get_color().color.to_gfx_color(),
+                    orientation: orientation,
+                    baseline_origin: baseline_origin,
                 };
                 accumulator.push(display_list, TextDisplayItemClass(text_display_item));
 
@@ -965,7 +985,6 @@ impl Fragment {
 
                     let text_decorations =
                         self.style().get_inheritedtext()._servo_text_decorations_in_effect;
-                    let metrics = &text_fragment.run.font_metrics;
                     line(text_decorations.underline, || {
                         let mut rect = content_box.clone();
                         rect.start.b = rect.start.b + metrics.ascent - metrics.underline_offset;

src/components/layout/inline.rs

@@ -1100,13 +1100,10 @@ impl Flow for InlineFlow {
             line_distance_from_flow_block_start = line_distance_from_flow_block_start + line.bounds.size.block;
         } // End of `lines.each` loop.
 
-        self.base.position.size.block =
+        self.base.position.size.block = match self.lines.as_slice().last() {
-            if self.lines.len() > 0 {
+            Some(ref last_line) => last_line.bounds.start.b + last_line.bounds.size.block,
-                self.lines.as_slice().last().get_ref().bounds.start.b +
+            None => Au::new(0)
-                    self.lines.as_slice().last().get_ref().bounds.size.block
+        };
-            } else {
-                Au::new(0)
-            };
 
         self.base.floats = scanner.floats();
         self.base.floats.translate(LogicalSize::new(

src/components/layout/text.rs

@@ -9,16 +9,16 @@
 use flow::Flow;
 use fragment::{Fragment, ScannedTextFragment, ScannedTextFragmentInfo, UnscannedTextFragment};
 
-use gfx::font::{FontMetrics, FontStyle};
+use gfx::font::{FontMetrics, FontStyle, RunMetrics};
 use gfx::font_context::FontContext;
 use gfx::text::glyph::CharIndex;
 use gfx::text::text_run::TextRun;
 use gfx::text::util::{CompressWhitespaceNewline, transform_text, CompressNone};
 use servo_util::geometry::Au;
-use servo_util::logical_geometry::LogicalSize;
+use servo_util::logical_geometry::{LogicalSize, WritingMode};
 use servo_util::range::Range;
 use style::ComputedValues;
-use style::computed_values::{font_family, line_height, white_space};
+use style::computed_values::{font_family, line_height, text_orientation, white_space};
 use sync::Arc;
 
 struct NewLinePositions {
@@ -150,8 +150,8 @@ impl TextRunScanner {
                            *text);
                     let range = Range::new(CharIndex(0), run.char_len());
                     let new_metrics = run.metrics_for_range(&range);
-                    let bounding_box_size = LogicalSize::from_physical(
+                    let bounding_box_size = bounding_box_for_run_metrics(
-                        old_fragment.style.writing_mode, new_metrics.bounding_box.size);
+                        &new_metrics, old_fragment.style.writing_mode);
                     let new_text_fragment_info = ScannedTextFragmentInfo::new(Arc::new(run), range);
                     let mut new_fragment = old_fragment.transform(
                         bounding_box_size, ScannedTextFragment(new_text_fragment_info));
@@ -234,8 +234,8 @@ impl TextRunScanner {
                     let new_text_fragment_info = ScannedTextFragmentInfo::new(run.get_ref().clone(), range);
                     let old_fragment = &in_fragments[i.to_uint()];
                     let new_metrics = new_text_fragment_info.run.metrics_for_range(&range);
-                    let bounding_box_size = LogicalSize::from_physical(
+                    let bounding_box_size = bounding_box_for_run_metrics(
-                        old_fragment.style.writing_mode, new_metrics.bounding_box.size);
+                        &new_metrics, old_fragment.style.writing_mode);
                     let mut new_fragment = old_fragment.transform(
                         bounding_box_size, ScannedTextFragment(new_text_fragment_info));
                     new_fragment.new_line_pos = new_line_positions[logical_offset.to_uint()].new_line_pos.clone();
@@ -251,6 +251,32 @@ impl TextRunScanner {
     } // End of `flush_clump_to_list`.
 }
 
+
+#[inline]
+fn bounding_box_for_run_metrics(metrics: &RunMetrics, writing_mode: WritingMode)
+                                -> LogicalSize<Au> {
+
+    // This does nothing, but it will fail to build
+    // when more values are added to the `text-orientation` CSS property.
+    // This will be a reminder to update the code below.
+    let dummy: Option<text_orientation::T> = None;
+    match dummy {
+        Some(text_orientation::sideways_right) |
+        Some(text_orientation::sideways_left) |
+        Some(text_orientation::sideways) |
+        None => {}
+    }
+
+    // In vertical sideways or horizontal upgright text,
+    // the "width" of text metrics is always inline
+    // This will need to be updated when other text orientations are supported.
+    LogicalSize::new(
+        writing_mode,
+        metrics.bounding_box.size.width,
+        metrics.bounding_box.size.height)
+
+}
+
 /// Returns the metrics of the font represented by the given `FontStyle`, respectively.
 ///
 /// `#[inline]` because often the caller only needs a few fields from the font metrics.

src/components/util/logical_geometry.rs

@@ -41,6 +41,11 @@ impl WritingMode {
     pub fn is_bidi_ltr(&self) -> bool {
         !self.intersects(FlagRTL)
     }
+
+    #[inline]
+    pub fn is_sideways_left(&self) -> bool {
+        self.intersects(FlagSidewaysLeft)
+    }
 }
 
 impl Show for WritingMode {