[librsvg] NodeSvg: Don't inline the computation of the SVG's affine

[Federico Mena Quintero <federico src gnome org>]

commit 5ecce07b482d5b991a47d16ba03a51f80ad7cbb5
Author: Federico Mena Quintero <federico gnome org>
Date:   Thu Mar 23 07:31:54 2017 -0600

    NodeSvg: Don't inline the computation of the SVG's affine
    
    Make it more clear by actually performing each step separately.

 rust/src/structure.rs |   13 +++++--------
 1 files changed, 5 insertions(+), 8 deletions(-)
---
diff --git a/rust/src/structure.rs b/rust/src/structure.rs
index e9999b9..45076da 100644
--- a/rust/src/structure.rs
+++ b/rust/src/structure.rs
@@ -182,14 +182,11 @@ impl NodeTrait for NodeSvg {
             let (x, y, w, h) = self.preserve_aspect_ratio.get ().compute (vbox.rect.width, vbox.rect.height,
                                                                           nx, ny, nw, nh);
 
-            let affine = cairo::Matrix::new (w / vbox.rect.width,
-                                             0.0,
-                                             0.0,
-                                             h / vbox.rect.height,
-                                             x - vbox.rect.x * w / vbox.rect.width,
-                                             y - vbox.rect.y * h / vbox.rect.height);
-
-            drawing_ctx::set_current_state_affine (draw_ctx, cairo::Matrix::multiply (&affine, &affine_old));
+            let mut affine = affine_old;
+            affine.translate (x, y);
+            affine.scale (w / vbox.rect.width, h / vbox.rect.height);
+            affine.translate (-vbox.rect.x, -vbox.rect.y);
+            drawing_ctx::set_current_state_affine (draw_ctx, affine);
 
             drawing_ctx::push_view_box (draw_ctx, vbox.rect.width, vbox.rect.height);
         } else {