Fix grammar and punctuation in viewports (#2111)

Misleading information: (I think) the function signature for [Viewport.set_size_override](https://godot.readthedocs.io/en/latest/classes/class_viewport.html#class-viewport-set-size-override) goes against the example provided.

tutorials/viewports/viewports.rst

@@ -6,8 +6,8 @@ Viewports
 Introduction
 ------------
 
-Think of :ref:`Viewports <class_Viewport>` as a screen that the game is projected onto. In order
-to see the game we need to have a surface to draw it on, this surface is
+Think of a :ref:`Viewport <class_Viewport>` as a screen onto which the game is projected. In order
+to see the game, we need to have a surface on which to draw it; that surface is
 the Root :ref:`Viewport <class_Viewport>`.
 
 .. image:: img/viewportnode.png
@@ -15,14 +15,14 @@ the Root :ref:`Viewport <class_Viewport>`.
 
 :ref:`Viewports <class_Viewport>` can also be added to the scene so that there
 are multiple surfaces to draw on. When we are drawing to a :ref:`Viewport <class_Viewport>`
-that is not the Root we call it a render target. We can access the contents
+that is not the Root, we call it a render target. We can access the contents
 of a render target by accessing its corresponding :ref:`texture <class_ViewportTexture>`.
-By using a :ref:`Viewport <class_Viewport>` as a render target
+By using a :ref:`Viewport <class_Viewport>` as a render target,
 we can either render multiple scenes simultaneously or we can render to
 a :ref:`texture <class_ViewportTexture>` which is applied to an object in the scene, for example a dynamic
 skybox.
 
-:ref:`Viewports <class_Viewport>` have a variety of use cases including:
+:ref:`Viewports <class_Viewport>` have a variety of use cases, including:
 
 - Rendering 3D objects within a 2D game
 - Rendering 2D elements in a 3D game
@@ -31,26 +31,26 @@ skybox.
 - Rendering multiple cameras in the same scene
 
 What all these use cases have in common is that you are given the ability to
-draw objects to a texture as if it were another screen and then you can choose
+draw objects to a texture as if it were another screen and can then choose
 what to do with the resulting texture.
 
 Input
 -----
 
 :ref:`Viewports <class_Viewport>` are also responsible for delivering properly adjusted and
-scaled input events to all their children nodes. Typically input is received by the
-nearest :ref:`Viewport <class_Viewport>` in the tree, but you can set :ref:`Viewports <class_Viewport>` to not receive input by checking
-'Disable Input' to 'on', this will allow the next nearest :ref:`Viewport <class_Viewport>` in the tree to capture
+scaled input events to all their children nodes. Typically, input is received by the
+nearest :ref:`Viewport <class_Viewport>` in the tree, but you can set :ref:`Viewports <class_Viewport>` not to receive input by checking
+'Disable Input' to 'on'; this will allow the next nearest :ref:`Viewport <class_Viewport>` in the tree to capture
 the input.
 
 .. image:: img/input.png
 
-For more information on how Godot handles input please read the :ref:`Input Event Tutorial<doc_inputevent>`.
+For more information on how Godot handles input, please read the :ref:`Input Event Tutorial<doc_inputevent>`.
 
 Listener
 --------
 
-Godot supports 3D sound (in both 2D and 3D nodes), more on this can be
+Godot supports 3D sound (in both 2D and 3D nodes); more on this can be
 found in the :ref:`Audio Streams Tutorial<doc_audio-streams>`. For this type of sound to be
 audible, the :ref:`Viewport <class_Viewport>` needs to be enabled as a listener (for 2D or 3D).
 If you are using a custom :ref:`Viewport <class_Viewport>` to display your :ref:`World <class_World>`, don't forget
@@ -83,17 +83,17 @@ or make it the current camera by calling:
 Scale & stretching
 ------------------
 
-:ref:`Viewports <class_Viewport>` have a "size" property which represents the size of the :ref:`Viewport <class_Viewport>`
+:ref:`Viewports <class_Viewport>` have a "size" property, which represents the size of the :ref:`Viewport <class_Viewport>`
 in pixels. For :ref:`Viewports <class_Viewport>` which are children of :ref:`ViewportContainers <class_viewportcontainer>`,
-these values are overridden, but for all others this sets their resolution.
+these values are overridden, but for all others, this sets their resolution.
 
 It is also possible to scale the 2D content and make the :ref:`Viewport <class_Viewport>` resolution
-different than the one specified in size, by calling:
+different from the one specified in size, by calling:
 
 ::
 
-    viewport.set_size_override(w, h) # Custom size for 2D
-    viewport.set_size_override_stretch(true) # Enable stretch for custom size
+    viewport.set_size_override(true, Vector2(width, height)) # Custom size for 2D
+    viewport.set_size_override_stretch(true) # Enable stretch for custom size.
 
 The root :ref:`Viewport <class_Viewport>` uses this for the stretch options in the project
 settings. For more information on scaling and stretching visit the :ref:`Multiple Resolutions Tutorial <doc_multiple_resolutions>`
@@ -105,7 +105,7 @@ For 3D, a :ref:`Viewport <class_Viewport>` will contain a :ref:`World <class_Wor
 is basically the universe that links physics and rendering together.
 Spatial-base nodes will register using the :ref:`World <class_World>` of the closest
 :ref:`Viewport <class_Viewport>`. By default, newly created :ref:`Viewports <class_Viewport>` do not contain a :ref:`World <class_World>` but
-use the same as their parent :ref:`Viewport <class_Viewport>` (root :ref:`Viewport <class_Viewport>` always contains a
+use the same as their parent :ref:`Viewport <class_Viewport>` (the root :ref:`Viewport <class_Viewport>` always contains a
 :ref:`World <class_World>`, which is the one objects are rendered to by default). A :ref:`World <class_World>` can
 be set in a :ref:`Viewport <class_Viewport>` using the "world" property, and that will separate
 all children nodes of that :ref:`Viewport <class_Viewport>` from interacting with the parent
@@ -122,41 +122,41 @@ For 2D, each :ref:`Viewport <class_Viewport>` always contains its own :ref:`Worl
 This suffices in most cases, but in case sharing them may be desired, it
 is possible to do so by setting the :ref:`Viewport's <class_Viewport>` :ref:`World2D <class_World2D>` manually.
 
-For an example of how this works see the demo projects `3D in 2D <https://github.com/godotengine/godot-demo-projects/tree/master/viewport/3d_in_2d>`_ and `2D in 3D <https://github.com/godotengine/godot-demo-projects/tree/master/viewport/2d_in_3d>`_ respectively.
+For an example of how this works, see the demo projects `3D in 2D <https://github.com/godotengine/godot-demo-projects/tree/master/viewport/3d_in_2d>`_ and `2D in 3D <https://github.com/godotengine/godot-demo-projects/tree/master/viewport/2d_in_3d>`_ respectively.
 
 Capture
 -------
 
 It is possible to query a capture of the :ref:`Viewport <class_Viewport>` contents. For the root
-:ref:`Viewport <class_Viewport>` this is effectively a screen capture. This is done with the
+:ref:`Viewport <class_Viewport>`, this is effectively a screen capture. This is done with the
 following code:
 
 ::
 
-   # Retrieve the captured Image using get_data()
+   # Retrieve the captured Image using get_data().
    var img = get_viewport().get_texture().get_data()
-   # Flip on the y axis
-   # You can also set "V Flip" to true if not on the Root Viewport
+   # Flip on the y axis.
+   # You can also set "V Flip" to true if not on the Root Viewport.
    img.flip_y()
-   # Convert Image to ImageTexture
+   # Convert Image to ImageTexture.
    var tex = ImageTexture.new()
    tex.create_from_image(img)
-   # Set Sprite Texture
+   # Set Sprite Texture.
    $sprite.texture = tex
 
-But if you use this in _ready() or from the first frame of the :ref:`Viewport's <class_Viewport>` initialization
-you will get an empty texture cause there is nothing to get as texture. You can deal with
+But if you use this in _ready() or from the first frame of the :ref:`Viewport's <class_Viewport>` initialization,
+you will get an empty texture because there is nothing to get as texture. You can deal with
 it using (for example):
 
 ::
 
-   # Let two frames pass to make sure the screen can be captured
+   # Let two frames pass to make sure the screen can be captured.
    yield(get_tree(), "idle_frame")
    yield(get_tree(), "idle_frame")
-   # You can get the image after this
+   # You can get the image after this.
 
 If the returned image is empty, capture still didn't happen, wait a
-little more, as Godot's rendering API is asynchronous. For a working example of this
+little more, as Godot's rendering API is asynchronous. For a working example of this,
 check out the `Screen Capture example <https://github.com/godotengine/godot-demo-projects/tree/master/viewport/screen_capture>`_ in the demo projects
 
 Viewport Container
@@ -174,12 +174,12 @@ Rendering
 ---------
 
 Due to the fact that the :ref:`Viewport <class_Viewport>` is an entryway into another rendering surface, it exposes a few
-rendering properties that can be different from the project settings. The first is MSAA, you can
-choose to use a different level of MSAA for each :ref:`Viewport <class_Viewport>`, the default behavior is DISABLED.
+rendering properties that can be different from the project settings. The first is MSAA; you can
+choose to use a different level of MSAA for each :ref:`Viewport <class_Viewport>`; the default behavior is DISABLED.
 You can also set the :ref:`Viewport <class_Viewport>` to use HDR, HDR is very useful for when you want to store values in the texture that are outside the range 0.0 - 1.0.
 
 If you know how the :ref:`Viewport <class_Viewport>` is going to be used, you can set its Usage to either 3D or 2D. Godot will then
-restrict how the :ref:`Viewport <class_Viewport>` is drawn to in accordance with your choice, default is 3D.
+restrict how the :ref:`Viewport <class_Viewport>` is drawn to in accordance with your choice; default is 3D.
 
 Godot also provides a way of customizing how everything is drawn inside :ref:`Viewports <class_Viewport>` using “Debug Draw”.
 Debug Draw allows you to specify one of four options for how the :ref:`Viewport <class_Viewport>` will display things drawn
@@ -209,13 +209,13 @@ this writing (v3.0.2), wireframe mode is not functional and currently renders th
 Render target
 -------------
 
-When rendering to a :ref:`Viewport <class_Viewport>` whatever is inside will not be
+When rendering to a :ref:`Viewport <class_Viewport>`, whatever is inside will not be
 visible in the scene editor. To display the contents, you have to draw the :ref:`Viewport's <class_Viewport>` :ref:`ViewportTexture <class_ViewportTexture>` somewhere.
 This can be requested via code using (for example):
 
 ::
 
-    #This gets us the  ViewportTexture
+    # This gives us the ViewportTexture.
     var rtt = viewport.get_texture()
     sprite.texture = rtt
 
@@ -227,14 +227,14 @@ and then selecting the :ref:`Viewport <class_Viewport>` you want to use.
 
 .. image:: img/texturepath.png
 
-Every frame the :ref:`Viewport <class_Viewport>`'s texture is cleared away with the default clear color (or a transparent
+Every frame, the :ref:`Viewport <class_Viewport>`'s texture is cleared away with the default clear color (or a transparent
 color if Transparent BG is set to true). This can be changed by setting Clear Mode to Never or Next Frame.
-As the name implies, Never means the texture will never be cleared while next frame will
+As the name implies, Never means the texture will never be cleared, while next frame will
 clear the texture on the next frame and then set itself to Never.
 
 By default, re-rendering of the :ref:`Viewport <class_Viewport>` happens when the
 :ref:`Viewport <class_Viewport>`'s :ref:`ViewportTexture <class_ViewportTexture>` has been drawn in a frame. If visible, it will be
-rendered, otherwise it will not. This behavior can be changed to manual
+rendered; otherwise, it will not. This behavior can be changed to manual
 rendering (once), or always render, no matter if visible or not. This flexibility
 allows users to render an image once and then use the texture without
 incurring the cost of rendering every frame.