Use gears.matrix instead of cairo.Matrix everywhere

This has some positive results on the "benchmark test". Each single number is
the best one out of three runs.

Before:
        create wibox: 0.0826502  sec/iter ( 13 iters, 1.157 sec for benchmark)
    update textclock: 0.0186952  sec/iter ( 57 iters, 2.473 sec for benchmark)
  relayout textclock: 0.0158112  sec/iter ( 64 iters, 1.028 sec for benchmark)
    redraw textclock: 0.0015197  sec/iter (662 iters, 1.861 sec for benchmark)

After:
        create wibox: 0.0825672  sec/iter ( 13 iters, 1.154 sec for benchmark)
    update textclock: 0.00378412 sec/iter (277 iters, 4.216 sec for benchmark)
  relayout textclock: 0.00259056 sec/iter (420 iters, 1.09 sec for benchmark)
    redraw textclock: 0.00105128 sec/iter (958 iters, 1.79 sec for benchmark)

We see no significant change in the creation of wiboxes (99.9% compared to
before). Update (20% of the previous run time), relayout (16%) and redraw (69%)
are all sped up by this change.

Signed-off-by: Uli Schlachter <psychon@znc.in>

lib/gears/matrix.lua

@@ -11,16 +11,6 @@ local cairo = require("lgi").cairo
 local debug = require("gears.debug")
 local matrix = {}
 
---- Copy a cairo matrix
--- @param matrix The matrix to copy.
--- @return A copy of the given cairo matrix.
-function matrix.copy(matrix)
-    debug.assert(cairo.Matrix:is_type_of(matrix), "Argument should be a cairo matrix")
-    local ret = cairo.Matrix()
-    ret:init(matrix.xx, matrix.yx, matrix.xy, matrix.yy, matrix.x0, matrix.y0)
-    return ret
-end
-
 -- Metatable for matrix instances. This is set up near the end of the file.
 local matrix_mt = {}
 

lib/wibox/hierarchy.lua

@@ -37,11 +37,8 @@ local function hierarchy_new(context, widget, width, height, redraw_callback, la
     widget:weak_connect_signal("widget::layout_changed", result._layout)
 
     for _, w in ipairs(children or {}) do
-        local to_dev = cairo.Matrix.create_identity()
-        to_dev:multiply(matrix_to_device, w._matrix)
-
         local r = hierarchy_new(context, w._widget, w._width, w._height, redraw_callback, layout_callback,
-                callback_arg, matrix.copy(w._matrix), to_dev)
+                callback_arg, w._matrix, matrix_to_device * w._matrix)
         table.insert(result._children, r)
 
         -- Update our drawing extents
@@ -82,7 +79,7 @@ end
 -- @return A new widget hierarchy
 function hierarchy.new(context, widget, width, height, redraw_callback, layout_callback, callback_arg)
     return hierarchy_new(context, widget, width, height, redraw_callback, layout_callback, callback_arg,
-            cairo.Matrix.create_identity(), cairo.Matrix.create_identity())
+            matrix.identity, matrix.identity)
 end
 
 --- Get the widget that this hierarchy manages.
@@ -90,38 +87,36 @@ function hierarchy:get_widget()
     return self._widget
 end
 
---- Get a cairo matrix that transforms to the parent's coordinate space from
+--- Get a matrix that transforms to the parent's coordinate space from this
--- this hierarchy's coordinate system.
+-- hierarchy's coordinate system.
--- @return A cairo matrix describing the transformation.
+-- @return A matrix describing the transformation.
 function hierarchy:get_matrix_to_parent()
-    return matrix.copy(self._matrix)
+    return self._matrix
 end
 
---- Get a cairo matrix that transforms to the base of this hierarchy's
+--- Get a matrix that transforms to the base of this hierarchy's coordinate
--- coordinate system (aka the coordinate system of the device that this
+-- system (aka the coordinate system of the device that this
 -- hierarchy is applied upon) from this hierarchy's coordinate system.
--- @return A cairo matrix describing the transformation.
+-- @return A matrix describing the transformation.
 function hierarchy:get_matrix_to_device()
-    return matrix.copy(self._matrix_to_device)
+    return self._matrix_to_device
 end
 
---- Get a cairo matrix that transforms from the parent's coordinate space into
+--- Get a matrix that transforms from the parent's coordinate space into this
--- this hierarchy's coordinate system.
+-- hierarchy's coordinate system.
--- @return A cairo matrix describing the transformation.
+-- @return A matrix describing the transformation.
 function hierarchy:get_matrix_from_parent()
     local m = self:get_matrix_to_parent()
-    m:invert()
+    return m:invert()
-    return m
 end
 
---- Get a cairo matrix that transforms from the base of this hierarchy's
+--- Get a matrix that transforms from the base of this hierarchy's coordinate
--- coordinate system (aka the coordinate system of the device that this
+-- system (aka the coordinate system of the device that this
 -- hierarchy is applied upon) into this hierarchy's coordinate system.
--- @return A cairo matrix describing the transformation.
+-- @return A matrix describing the transformation.
 function hierarchy:get_matrix_from_device()
     local m = self:get_matrix_to_device()
-    m:invert()
+    return m:invert()
-    return m
 end
 
 --- Get the extents that this hierarchy possibly draws to (in the current coordinate space).
@@ -198,7 +193,7 @@ function hierarchy:draw(context, cr)
     end
 
     cr:save()
-    cr:transform(self:get_matrix_to_parent())
+    cr:transform(self:get_matrix_to_parent():to_cairo_matrix())
 
     -- Clip to the draw extents
     cr:rectangle(self:get_draw_extents())

lib/wibox/layout/mirror.lua

@@ -11,7 +11,7 @@ local pairs = pairs
 local ipairs = ipairs
 local setmetatable = setmetatable
 local base = require("wibox.widget.base")
-local Matrix = require("lgi").cairo.Matrix
+local matrix = require("gears.matrix")
 
 local mirror = { mt = {} }
 
@@ -23,7 +23,7 @@ function mirror:layout(context, cr, width, height)
         return
     end
 
-    local m = Matrix.create_identity()
+    local m = matrix.identity
     local t = { x = 0, y = 0 } -- translation
     local s = { x = 1, y = 1 } -- scale
     if self.horizontal then
@@ -34,8 +34,8 @@ function mirror:layout(context, cr, width, height)
         t.x = width
         s.x = -1
     end
-    m:translate(t.x, t.y)
+    m = m:translate(t.x, t.y)
-    m:scale(s.x, s.y)
+    m = m:scale(s.x, s.y)
 
     return base.place_widget_via_matrix(widget, m, width, height)
 end

lib/wibox/layout/rotate.lua

@@ -12,7 +12,7 @@ local type = type
 local setmetatable = setmetatable
 local tostring = tostring
 local base = require("wibox.widget.base")
-local Matrix = require("lgi").cairo.Matrix
+local matrix = require("gears.matrix")
 
 local rotate = { mt = {} }
 
@@ -32,16 +32,16 @@ function rotate:layout(context, width, height)
 
     local dir = self:get_direction()
 
-    local m = Matrix.create_identity()
+    local m = matrix.identity
     if dir == "west" then
-        m:rotate(pi / 2)
+        m = m:rotate(pi / 2)
-        m:translate(0, -width)
+        m = m:translate(0, -width)
     elseif dir == "south" then
-        m:rotate(pi)
+        m = m:rotate(pi)
-        m:translate(-width, -height)
+        m = m:translate(-width, -height)
     elseif dir == "east" then
-        m:rotate(3 * pi / 2)
+        m = m:rotate(3 * pi / 2)
-        m:translate(-height, 0)
+        m = m:translate(-height, 0)
     end
 
     -- Since we rotated, we might have to swap width and height.

lib/wibox/widget/base.lua

@@ -9,7 +9,6 @@ local debug = require("gears.debug")
 local object = require("gears.object")
 local cache = require("gears.cache")
 local matrix = require("gears.matrix")
-local Matrix = require("lgi").cairo.Matrix
 local setmetatable = setmetatable
 local pairs = pairs
 local type = type
@@ -204,8 +203,8 @@ end
 --- Create widget placement information. This should be used for a widget's
 -- `:layout()` callback.
 -- @param widget The widget that should be placed.
--- @param mat A cairo matrix transforming from the parent widget's coordinate
+-- @param mat A matrix transforming from the parent widget's coordinate
---        system. For example, use cairo.Matrix.create_translate(1, 2) to draw a
+--        system. For example, use matrix.create_translate(1, 2) to draw a
 --        widget at position (1, 2) relative to the parent widget.
 -- @param width The width of the widget in its own coordinate system. That is,
 --        after applying the transformation matrix.
@@ -217,7 +216,7 @@ function base.place_widget_via_matrix(widget, mat, width, height)
         _widget = widget,
         _width = width,
         _height = height,
-        _matrix = matrix.copy(mat)
+        _matrix = mat
     }
 end
 
@@ -232,7 +231,7 @@ end
 --        after applying the transformation matrix.
 -- @return An opaque object that can be returned from :layout()
 function base.place_widget_at(widget, x, y, width, height)
-    return base.place_widget_via_matrix(widget, Matrix.create_translate(x, y), width, height)
+    return base.place_widget_via_matrix(widget, matrix.create_translate(x, y), width, height)
 end
 
 --[[--

spec/wibox/hierarchy_spec.lua

@@ -5,7 +5,7 @@
 
 local hierarchy = require("wibox.hierarchy")
 
-local cairo = require("lgi").cairo
+local Region = require("lgi").cairo.Region
 local matrix = require("gears.matrix")
 local object = require("gears.object")
 local utils = require("wibox.test_utils")
@@ -37,23 +37,19 @@ describe("wibox.hierarchy", function()
         end)
 
         it("get_matrix_to_parent", function()
-            assert.is_true(matrix.equals(cairo.Matrix.create_identity(),
+            assert.is.equal(matrix.identity, instance:get_matrix_to_parent())
-                    instance:get_matrix_to_parent()))
         end)
 
         it("get_matrix_to_device", function()
-            assert.is_true(matrix.equals(cairo.Matrix.create_identity(),
+            assert.is.equal(matrix.identity, instance:get_matrix_to_device())
-                    instance:get_matrix_to_device()))
         end)
 
         it("get_matrix_from_parent", function()
-            assert.is_true(matrix.equals(cairo.Matrix.create_identity(),
+            assert.is.equal(matrix.identity, instance:get_matrix_from_parent())
-                    instance:get_matrix_from_parent()))
         end)
 
         it("get_matrix_from_device", function()
-            assert.is_true(matrix.equals(cairo.Matrix.create_identity(),
+            assert.is.equal(matrix.identity, instance:get_matrix_from_device())
-                    instance:get_matrix_from_device()))
         end)
 
         it("get_draw_extents", function()
@@ -72,7 +68,7 @@ describe("wibox.hierarchy", function()
     it("disconnect works", function()
         local child = make_widget(nil)
         local parent = make_widget({
-            make_child(child, 2, 5, cairo.Matrix.create_translate(10, 0))
+            make_child(child, 2, 5, matrix.create_translate(10, 0))
         })
 
         local extra_arg = {}
@@ -129,10 +125,10 @@ describe("wibox.hierarchy", function()
         before_each(function()
             child = make_widget(nil)
             intermediate = make_widget({
-                make_child(child, 10, 20, cairo.Matrix.create_translate(0, 5))
+                make_child(child, 10, 20, matrix.create_translate(0, 5))
             })
             parent = make_widget({
-                make_child(intermediate, 5, 2, cairo.Matrix.create_translate(4, 0))
+                make_child(intermediate, 5, 2, matrix.create_translate(4, 0))
             })
 
             local function nop() end
@@ -156,27 +152,27 @@ describe("wibox.hierarchy", function()
         end)
 
         it("get_matrix_to_parent", function()
-            assert.is_true(matrix.equals(hierarchy_child:get_matrix_to_parent(), cairo.Matrix.create_translate(0, 5)))
+            assert.is.equal(hierarchy_child:get_matrix_to_parent(), matrix.create_translate(0, 5))
-            assert.is_true(matrix.equals(hierarchy_intermediate:get_matrix_to_parent(), cairo.Matrix.create_translate(4, 0)))
+            assert.is.equal(hierarchy_intermediate:get_matrix_to_parent(), matrix.create_translate(4, 0))
-            assert.is_true(matrix.equals(hierarchy_parent:get_matrix_to_parent(), cairo.Matrix.create_identity()))
+            assert.is.equal(hierarchy_parent:get_matrix_to_parent(), matrix.identity)
         end)
 
         it("get_matrix_to_device", function()
-            assert.is_true(matrix.equals(hierarchy_child:get_matrix_to_device(), cairo.Matrix.create_translate(4, 5)))
+            assert.is.equal(hierarchy_child:get_matrix_to_device(), matrix.create_translate(4, 5))
-            assert.is_true(matrix.equals(hierarchy_intermediate:get_matrix_to_device(), cairo.Matrix.create_translate(4, 0)))
+            assert.is.equal(hierarchy_intermediate:get_matrix_to_device(), matrix.create_translate(4, 0))
-            assert.is_true(matrix.equals(hierarchy_parent:get_matrix_to_device(), cairo.Matrix.create_identity()))
+            assert.is.equal(hierarchy_parent:get_matrix_to_device(), matrix.identity)
         end)
 
         it("get_matrix_from_parent", function()
-            assert.is_true(matrix.equals(hierarchy_child:get_matrix_from_parent(), cairo.Matrix.create_translate(0, -5)))
+            assert.is.equal(hierarchy_child:get_matrix_from_parent(), matrix.create_translate(0, -5))
-            assert.is_true(matrix.equals(hierarchy_intermediate:get_matrix_from_parent(), cairo.Matrix.create_translate(-4, 0)))
+            assert.is.equal(hierarchy_intermediate:get_matrix_from_parent(), matrix.create_translate(-4, 0))
-            assert.is_true(matrix.equals(hierarchy_parent:get_matrix_from_parent(), cairo.Matrix.create_identity()))
+            assert.is.equal(hierarchy_parent:get_matrix_from_parent(), matrix.identity)
         end)
 
         it("get_matrix_from_device", function()
-            assert.is_true(matrix.equals(hierarchy_child:get_matrix_from_device(), cairo.Matrix.create_translate(-4, -5)))
+            assert.is.equal(hierarchy_child:get_matrix_from_device(), matrix.create_translate(-4, -5))
-            assert.is_true(matrix.equals(hierarchy_intermediate:get_matrix_from_device(), cairo.Matrix.create_translate(-4, 0)))
+            assert.is.equal(hierarchy_intermediate:get_matrix_from_device(), matrix.create_translate(-4, 0))
-            assert.is_true(matrix.equals(hierarchy_parent:get_matrix_from_device(), cairo.Matrix.create_identity()))
+            assert.is.equal(hierarchy_parent:get_matrix_from_device(), matrix.identity)
         end)
 
         it("get_draw_extents", function()
@@ -199,10 +195,10 @@ describe("wibox.hierarchy", function()
         before_each(function()
             child = make_widget(nil)
             intermediate = make_widget({
-                make_child(child, 10, 20, cairo.Matrix.create_translate(0, 5))
+                make_child(child, 10, 20, matrix.create_translate(0, 5))
             })
             parent = make_widget({
-                make_child(intermediate, 5, 2, cairo.Matrix.create_translate(4, 0))
+                make_child(intermediate, 5, 2, matrix.create_translate(4, 0))
             })
 
             local context = {}
@@ -218,7 +214,7 @@ describe("wibox.hierarchy", function()
 
         it("child moved", function()
             intermediate.layout = function()
-                return { make_child(child, 10, 20, cairo.Matrix.create_translate(0, 4)) }
+                return { make_child(child, 10, 20, matrix.create_translate(0, 4)) }
             end
             local context = {}
             local instance2 = hierarchy.new(context, parent, 15, 16, nop, nop)