(cairo-backend) Handle mask in a separate context.

7 files changed, 30 insertions, 33 deletions

diff --git a/src/backend_cairo/ext.rs b/src/backend_cairo/ext.rs
index 3debf51..fcf5335 100644
--- a/src/backend_cairo/ext.rs
+++ b/src/backend_cairo/ext.rs
@@ -8,12 +8,12 @@ use usvg;
 
 
 pub trait ReCairoContextExt {
-    fn set_source_color(&self, color: &usvg::Color, opacity: usvg::Opacity);
+    fn set_source_color(&self, color: usvg::Color, opacity: usvg::Opacity);
     fn reset_source_rgba(&self);
 }
 
 impl ReCairoContextExt for cairo::Context {
-    fn set_source_color(&self, color: &usvg::Color, opacity: usvg::Opacity) {
+    fn set_source_color(&self, color: usvg::Color, opacity: usvg::Opacity) {
         self.set_source_rgba(
             color.red as f64 / 255.0,
             color.green as f64 / 255.0,
diff --git a/src/backend_cairo/fill.rs b/src/backend_cairo/fill.rs
index 4f621ec..dc3d675 100644
--- a/src/backend_cairo/fill.rs
+++ b/src/backend_cairo/fill.rs
@@ -25,7 +25,7 @@ pub fn apply(
         Some(ref fill) => {
             match fill.paint {
                 usvg::Paint::Color(c) => {
-                    cr.set_source_color(&c, fill.opacity);
+                    cr.set_source_color(c, fill.opacity);
                 }
                 usvg::Paint::Link(ref id) => {
                     if let Some(node) = tree.defs_by_id(id) {
diff --git a/src/backend_cairo/mask.rs b/src/backend_cairo/mask.rs
index 4750c52..9ff485d 100644
--- a/src/backend_cairo/mask.rs
+++ b/src/backend_cairo/mask.rs
@@ -19,8 +19,8 @@ pub fn apply(
     mask: &usvg::Mask,
     opt: &Options,
     bbox: Rect,
-    opacity: Option<usvg::Opacity>,
     layers: &mut CairoLayers,
+    sub_cr: &cairo::Context,
     cr: &cairo::Context,
 ) {
     let mask_surface = try_opt!(layers.get(), ());
@@ -49,11 +49,17 @@ pub fn apply(
     {
         let mut data = try_opt_warn!(mask_surface.get_data().ok(), (),
                                      "Failed to borrow a surface for mask: {:?}.", mask.id);
-        mask::image_to_mask(&mut data, layers.image_size(), opacity);
+        mask::image_to_mask(&mut data, layers.image_size());
     }
 
-    let patt = cairo::SurfacePattern::create(&*mask_surface);
-    cr.set_matrix(cairo::Matrix::identity());
-    cr.mask(&cairo::Pattern::SurfacePattern(patt));
-    cr.reset_source_rgba();
+    sub_cr.set_matrix(cairo::Matrix::identity());
+    sub_cr.set_source_surface(&*mask_surface, 0.0, 0.0);
+    sub_cr.set_operator(cairo::Operator::DestIn);
+    sub_cr.paint();
+
+    // Reset operator.
+    sub_cr.set_operator(cairo::Operator::Over);
+
+    // Reset source to unborrow the `mask_surface` from the `Context`.
+    sub_cr.reset_source_rgba();
 }
diff --git a/src/backend_cairo/mod.rs b/src/backend_cairo/mod.rs
index 9238509..429e4b9 100644
--- a/src/backend_cairo/mod.rs
+++ b/src/backend_cairo/mod.rs
@@ -139,7 +139,7 @@ pub fn render_to_image(
 
     // Fill background.
     if let Some(color) = opt.background {
-        cr.set_source_color(&color, 1.0.into());
+        cr.set_source_color(color, 1.0.into());
         cr.paint();
     }
 
@@ -171,7 +171,7 @@ pub fn render_node_to_image(
 
     // Fill background.
     if let Some(color) = opt.background {
-        cr.set_source_color(&color, 1.0.into());
+        cr.set_source_color(color, 1.0.into());
         cr.paint();
     }
 
@@ -309,23 +309,21 @@ fn render_group_impl(
         }
     }
 
-    let curr_matrix = cr.get_matrix();
-    cr.set_matrix(cairo::Matrix::identity());
-    cr.set_source_surface(&*sub_surface, 0.0, 0.0);
-
     if let Some(ref id) = g.mask {
         if let Some(mask_node) = node.tree().defs_by_id(id) {
             if let usvg::NodeKind::Mask(ref mask) = *mask_node.borrow() {
-                cr.set_matrix(curr_matrix);
-                mask::apply(&mask_node, mask, opt, bbox, g.opacity, layers, cr);
+                mask::apply(&mask_node, mask, opt, bbox, layers, &sub_cr, cr);
             }
         }
+    }
+
+    let curr_matrix = cr.get_matrix();
+    cr.set_matrix(cairo::Matrix::identity());
+    cr.set_source_surface(&*sub_surface, 0.0, 0.0);
+    if let Some(opacity) = g.opacity {
+        cr.paint_with_alpha(*opacity);
     } else {
-        if let Some(opacity) = g.opacity {
-            cr.paint_with_alpha(*opacity);
-        } else {
-            cr.paint();
-        }
+        cr.paint();
     }
 
     cr.set_matrix(curr_matrix);
diff --git a/src/backend_cairo/stroke.rs b/src/backend_cairo/stroke.rs
index 8e6db8f..9a16d8b 100644
--- a/src/backend_cairo/stroke.rs
+++ b/src/backend_cairo/stroke.rs
@@ -25,7 +25,7 @@ pub fn apply(
         Some(ref stroke) => {
             match stroke.paint {
                 usvg::Paint::Color(c) => {
-                    cr.set_source_color(&c, stroke.opacity);
+                    cr.set_source_color(c, stroke.opacity);
                 }
                 usvg::Paint::Link(ref id) => {
                     if let Some(node) = tree.defs_by_id(id) {
diff --git a/src/backend_qt/mask.rs b/src/backend_qt/mask.rs
index a5a4c42..676a8f7 100644
--- a/src/backend_qt/mask.rs
+++ b/src/backend_qt/mask.rs
@@ -18,7 +18,7 @@ pub fn apply(
     bbox: Rect,
     layers: &mut QtLayers,
     sub_p: &mut qt::Painter,
-    p: &mut qt::Painter,
+    p: &qt::Painter,
 ) {
     let mask_img = try_opt!(layers.get(), ());
     let mut mask_img = mask_img.borrow_mut();
@@ -42,7 +42,7 @@ pub fn apply(
         super::render_group(node, opt, layers, &mut mask_p);
     }
 
-    mask::image_to_mask(&mut mask_img.data_mut(), layers.image_size(), None);
+    mask::image_to_mask(&mut mask_img.data_mut(), layers.image_size());
 
     sub_p.set_transform(&qt::Transform::default());
     sub_p.set_composition_mode(qt::CompositionMode::DestinationIn);
diff --git a/src/backend_utils/mask.rs b/src/backend_utils/mask.rs
index 4527054..48b79a3 100644
--- a/src/backend_utils/mask.rs
+++ b/src/backend_utils/mask.rs
@@ -2,9 +2,6 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-// external
-use usvg;
-
 // self
 use geom::*;
 
@@ -13,7 +10,6 @@ use geom::*;
 pub fn image_to_mask(
     data: &mut [u8],
     img_size: ScreenSize,
-    opacity: Option<usvg::Opacity>,
 ) {
     let width = img_size.width;
     let height = img_size.height;
@@ -31,10 +27,7 @@ pub fn image_to_mask(
             let g = data[idx + 1] as f64;
             let b = data[idx + 0] as f64;
 
-            let mut luma = r * coeff_r + g * coeff_g + b * coeff_b;
-            if let Some(opacity) = opacity {
-                luma *= opacity.value();
-            }
+            let luma = r * coeff_r + g * coeff_g + b * coeff_b;
 
             data[idx + 0] = 0;
             data[idx + 1] = 0;