[librsvg/wip/dimensions-api] draw_in_viewport(): Take the viewport as a Rectangle, not as separate values

[Federico Mena Quintero <federico src gnome org>]

commit 0b7d5fc9c78daac25565e5cef9d93e61c3ef8e60
Author: Federico Mena Quintero <federico gnome org>
Date:   Fri Feb 8 20:34:34 2019 -0600

    draw_in_viewport(): Take the viewport as a Rectangle, not as separate values

 rsvg_internals/src/structure.rs | 27 ++++++++++++++-------------
 rsvg_internals/src/viewport.rs  | 17 ++++++-----------
 2 files changed, 20 insertions(+), 24 deletions(-)
---
diff --git a/rsvg_internals/src/structure.rs b/rsvg_internals/src/structure.rs
index 3040285d..e2a89d92 100644
--- a/rsvg_internals/src/structure.rs
+++ b/rsvg_internals/src/structure.rs
@@ -1,6 +1,8 @@
 use std::cell::Cell;
 use std::cell::RefCell;
 
+use cairo::Rectangle;
+
 use allowed_url::Fragment;
 use aspect_ratio::*;
 use attributes::Attribute;
@@ -14,6 +16,7 @@ use node::*;
 use parsers::{Parse, ParseValue};
 use properties::Overflow;
 use property_bag::{OwnedPropertyBag, PropertyBag};
+use rect::RectangleExt;
 use viewbox::*;
 use viewport::{draw_in_viewport, ClipMode};
 
@@ -220,18 +223,17 @@ impl NodeTrait for NodeSvg {
 
         let params = draw_ctx.get_view_params();
 
-        let nx = self.x.get().normalize(values, &params);
-        let ny = self.y.get().normalize(values, &params);
-        let nw = self.w.get().normalize(values, &params);
-        let nh = self.h.get().normalize(values, &params);
+        let viewport = Rectangle::new(
+            self.x.get().normalize(values, &params),
+            self.y.get().normalize(values, &params),
+            self.w.get().normalize(values, &params),
+            self.h.get().normalize(values, &params),
+        );
 
         let do_clip = !values.is_overflow() && node.get_parent().is_some();
 
         draw_in_viewport(
-            nx,
-            ny,
-            nw,
-            nh,
+            &viewport,
             ClipMode::ClipToViewport,
             do_clip,
             self.vbox.get(),
@@ -362,9 +364,11 @@ impl NodeTrait for NodeUse {
             return Ok(());
         }
 
+        let viewport = Rectangle::new(nx, ny, nw, nh);
+
         if child.get_type() != NodeType::Symbol {
             let cr = draw_ctx.get_cairo_context();
-            cr.translate(nx, ny);
+            cr.translate(viewport.x, viewport.y);
 
             draw_ctx.with_discrete_layer(node, values, clipping, &mut |dc| {
                 dc.draw_node_from_stack(
@@ -379,10 +383,7 @@ impl NodeTrait for NodeUse {
                     || (values.overflow == Overflow::Visible && child.is_overflow());
 
                 draw_in_viewport(
-                    nx,
-                    ny,
-                    nw,
-                    nh,
+                    &viewport,
                     ClipMode::ClipToVbox,
                     do_clip,
                     symbol.vbox.get(),
diff --git a/rsvg_internals/src/viewport.rs b/rsvg_internals/src/viewport.rs
index f2641cf5..25203fec 100644
--- a/rsvg_internals/src/viewport.rs
+++ b/rsvg_internals/src/viewport.rs
@@ -7,7 +7,6 @@ use error::RenderingError;
 use float_eq_cairo::ApproxEqCairo;
 use node::RsvgNode;
 use properties::ComputedValues;
-use rect::RectangleExt;
 use viewbox::*;
 
 #[derive(Debug, Copy, Clone, PartialEq)]
@@ -17,10 +16,7 @@ pub enum ClipMode {
 }
 
 pub fn draw_in_viewport(
-    vx: f64,
-    vy: f64,
-    vw: f64,
-    vh: f64,
+    viewport: &Rectangle,
     clip_mode: ClipMode,
     do_clip: bool,
     vbox: Option<ViewBox>,
@@ -38,14 +34,14 @@ pub fn draw_in_viewport(
     // https://www.w3.org/TR/SVG/struct.html#ImageElementWidthAttribute
     // https://www.w3.org/TR/SVG/painting.html#MarkerWidthAttribute
 
-    if vw.approx_eq_cairo(&0.0) || vh.approx_eq_cairo(&0.0) {
+    if viewport.width.approx_eq_cairo(&0.0) || viewport.height.approx_eq_cairo(&0.0) {
         return Ok(());
     }
 
     draw_ctx.with_discrete_layer(node, values, clipping, &mut |dc| {
         if do_clip && clip_mode == ClipMode::ClipToViewport {
             dc.get_cairo_context().set_matrix(affine);
-            dc.clip(vx, vy, vw, vh);
+            dc.clip(viewport.x, viewport.y, viewport.width, viewport.height);
         }
 
         let _params = if let Some(vbox) = vbox {
@@ -60,8 +56,7 @@ pub fn draw_in_viewport(
 
             let params = dc.push_view_box(vbox.width, vbox.height);
 
-            let (x, y, w, h) =
-                preserve_aspect_ratio.compute(&vbox, &Rectangle::new(vx, vy, vw, vh));
+            let (x, y, w, h) = preserve_aspect_ratio.compute(&vbox, viewport);
 
             affine.translate(x, y);
             affine.scale(w / vbox.width, h / vbox.height);
@@ -75,8 +70,8 @@ pub fn draw_in_viewport(
 
             params
         } else {
-            let params = dc.push_view_box(vw, vh);
-            affine.translate(vx, vy);
+            let params = dc.push_view_box(viewport.width, viewport.height);
+            affine.translate(viewport.x, viewport.y);
             dc.get_cairo_context().set_matrix(affine);
             params
         };