pushrod/render/
texture_store.rs

1// Pushrod Rendering Library
2// Texture Store
3//
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at
7//
8// http://www.apache.org/licenses/LICENSE-2.0
9//
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15
16use sdl2::render::{Canvas, Texture};
17use sdl2::video::Window;
18
19/// This is a store used by the `TextureStore`.
20#[derive(Default)]
21pub struct TextureStore {
22    store: Option<Texture>,
23    width: u32,
24    height: u32,
25}
26
27/// This is a `TextureStore` that is used by `Widget`s to draw against.  It serves as a GPU-based
28/// `Texture` store that can be changed at any time during the drawing loop.
29impl TextureStore {
30    /// Retrieves a `&mut Texture` reference to the stored `Texture` object.
31    ///
32    /// Example use:
33    /// ```rust,no_run
34    /// c.with_texture_canvas(texture_store.get_mut_ref(), |texture| {
35    ///   texture.set_draw_color(base_color);
36    ///   texture.clear();
37    ///
38    ///   texture.set_draw_color(border_color);
39    ///   texture
40    ///     .draw_rect(Rect::new(0, 0, 200, 200))
41    ///     .unwrap();
42    /// })
43    ///   .unwrap();
44    /// ```
45    pub fn get_mut_ref(&mut self) -> &mut Texture {
46        self.store.as_mut().unwrap()
47    }
48
49    /// Retrieves a `Option<&Texture>` object for the `Texture` object store.  Use this as a shortcut
50    /// to the `Widget`'s return values (see `BaseWidget` for reference.)
51    pub fn get_optional_ref(&mut self) -> Option<&Texture> {
52        Some(self.store.as_ref().unwrap())
53    }
54
55    /// This is used to create a new `Texture` object that can be drawn against.  If the `Widget` is
56    /// ever redrawn, this function will automatically generate a new `Texture` to draw against, and
57    /// destroy the previously stored `Texture`.  If any changes are observed when calling this
58    /// function (ie. the width changes, height changes, or the store is lost), it is regenerated.
59    pub fn create_or_resize_texture(&mut self, c: &mut Canvas<Window>, width: u32, height: u32) {
60        if self.store.is_none() || self.width != width || self.height != height {
61            self.width = width;
62            self.height = height;
63            self.store = Some(c.create_texture_target(None, width, height).unwrap());
64
65            eprintln!("Created texture: size={}x{}", width, height);
66        }
67    }
68}
pushrod/render/texture_store.rs

pushrod/render/
texture_store.rs
