Basic GUI support

.travis.yml

@@ -7,7 +7,6 @@ os:
   - linux
   - osx
   - windows
-cache: cargo
 before_install:
   - |
     if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then

CHANGELOG.md

@@ -6,6 +6,21 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 ### Added
+- __Responsive GUI support!__ The new `ui` module can be used to extend a `Game`
+  and build a user interface. [#35]
+  - GUI runtime based on [Elm] and [The Elm Architecture].
+  - Layouting based on Flexbox and powered by [`stretch`].
+  - Built-in GUI widgets. Specifically: buttons, sliders, checkboxes, radio
+    buttons, rows, and columns.
+  - Built-in GUI renderer. It is capable of rendering all the built-in GUI
+    widgets.
+  - Customization. The `ui::core` module can be used to implement custom widgets
+    and renderers.
+- `Input` trait. It allows to implement reusable input handlers. [#35]
+- `KeyboardAndMouse` input handler. Useful to quickstart development and have
+  easy access to the keyboard and the mouse from the get-go. [#35]
+- `CursorTaken` and `CursorReturned` input events. They are fired when the cursor
+  is used/freed by the user interface.
 - Off-screen text rendering support. `Font::draw` now supports any `Target`
   instead of a window `Frame`. [#25]
 - `Game::debug` performance tracking. Time spent on this method is now shown in
@@ -18,17 +33,49 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Implementation of `ParallelExtend` for `Batch`. A `Batch` can now be populated
   using multiple threads, useful to improve performance when dealing with many
   thousands of quads. [#37]
+- `Text` alignment. It can be defined using the new `HorizontalAlignment` and
+- `VerticalAlignment` types in the `graphics` module. [#35]
+- `Font::measure`. It allows to measure the dimensions of any `Text`. [#35]
+- `Rectangle::contains`. It returns whether or not a `Rectangle` contains a
+  given `Point`. [#35]
+- `Sprite::scale`. It can be used to change the `Sprite` size when drawed.
+- `Default` implementation for `Sprite`. [#35]
+- `Debug::ui_duration`. It returns the average time spent running the UI runtime.
 - Multiple gravity centers based on mouse clicks in the particles example. [#30]
 
 ### Changed
+- The `View` associated type has been removed. Thus, implementors of the `Game`
+  trait are also meant to hold the game assets. This simplifies the API
+  considerably, and it helps model your game state-view relationship with
+  precision, avoiding inconsistencies. [#35]
+- The `Game::Input` associated type now has to implement the new `Input` trait.
+  This splits code quite nicely, as the `on_input` method moves away from `Game`.
+  It also makes `Input` implementors reusable. For instance, a `KeyboardAndMouse`
+  type has been implemented that can be used out of the box! [#35]
+- The `Game::LoadingScreen` associated type has been introduced. Given that all
+  the `Game` associated types implement a trait with a `load` method, wiring a
+  loading screen now is as simple as writing its name. Because of this, the
+  `Game::new` method is no longer necessary and it is dropped. [#35]
+- `Game::draw` now takes a `Frame` directly instead of a `Window`. [#35]
+- `LoadingScreen::on_progress` has been renamed to `LoadingScreen::draw` and it
+  now receives a `Frame` instead of a `Window`. [#35]
 - The performance of the particles example has been improved considerably on all
   platforms. [#37]
 
+### Removed
+- `Game::new`. `Game::load` should be used instead. [#35]
+- `Game::on_input`. Input handlers now must be implemented using the new `Input`
+  trait. [#35]
+
 [#25]: https://github.com/hecrj/coffee/pull/25
 [#26]: https://github.com/hecrj/coffee/pull/26
 [#28]: https://github.com/hecrj/coffee/pull/28
 [#30]: https://github.com/hecrj/coffee/pull/30
+[#35]: https://github.com/hecrj/coffee/pull/35
 [#37]: https://github.com/hecrj/coffee/pull/37
+[Elm]: https://elm-lang.org
+[The Elm Architecture]: https://guide.elm-lang.org/architecture/
+[`stretch`]: https://github.com/vislyhq/stretch
 
 
 ## [0.2.0] - 2019-04-28

Cargo.toml

@@ -31,6 +31,8 @@ debug = []
 image = "0.21"
 nalgebra = "0.18"
 rayon = "1.0"
+stretch = "0.2"
+twox-hash = "1.3"
 
 # gfx (OpenGL)
 gfx = { version = "0.18", optional = true }

README.md

@@ -18,6 +18,7 @@ bugs. [Feel free to contribute!]
 [Feel free to contribute!]: #contributing--feedback
 
 ## Features
+  * Responsive, customizable GUI with built-in widgets
   * Declarative, type-safe asset loading
   * Loading screens with progress tracking
   * Built-in [debug view with performance metrics]
@@ -49,43 +50,43 @@ performance:
 opt-level = 2
 ```
 
+__Coffee moves fast and the `master` branch can contain breaking changes!__ If
+you want to learn about a specific release, check out [the release list].
+
+[the release list]: https://github.com/hecrj/coffee/releases
+
 ## Overview
 Here is a minimal example that will open a window:
 
 ```rust
+use coffee::graphics::{Color, Frame, Window, WindowSettings};
+use coffee::load::Task;
 use coffee::{Game, Result, Timer};
-use coffee::graphics::{Color, Window, WindowSettings};
 
 fn main() -> Result<()> {
     MyGame::run(WindowSettings {
         title: String::from("A caffeinated game"),
         size: (1280, 1024),
         resizable: true,
+        fullscreen: false,
     })
 }
 
 struct MyGame {
-    // Your game state goes here...
+    // Your game state and assets go here...
 }
 
 impl Game for MyGame {
-    type View = (); // No view data.
-    type Input = (); // No input data.
-
-    const TICKS_PER_SECOND: u16 = 60; // Update rate
+    type Input = (); // No input data
+    type LoadingScreen = (); // No loading screen
 
-    fn new(_window: &mut Window) -> Result<(MyGame, Self::View, Self::Input)> {
+    fn load(_window: &Window) -> Task<MyGame> {
         // Load your game assets here. Check out the `load` module!
-        Ok((MyGame { /* ... */ }, (), ()))
-    }
-
-    fn update(&mut self, _view: &Self::View, _window: &Window) {
-        // Update your game here
+        Task::new(|| MyGame { /* ... */ })
     }
 
-    fn draw(&self, _view: &mut Self::View, window: &mut Window, _timer: &Timer) {
+    fn draw(&mut self, frame: &mut Frame, _timer: &Timer) {
         // Clear the current frame
-        let mut frame = window.frame();
         frame.clear(Color::BLACK);
 
         // Draw your game here. Check out the `graphics` module!
@@ -104,13 +105,15 @@ Coffee builds upon
   * [`winit`] for windowing and mouse/keyboard events.
   * [`gfx` pre-ll] for OpenGL support, based heavily on the [`ggez`] codebase.
   * [`wgpu`] for _experimental_ Vulkan, Metal, D3D11 and D3D12 support.
+  * [`stretch`] for responsive GUI layouting based on Flexbox.
   * [`glyph_brush`] for TrueType font rendering.
   * [`nalgebra`] for the `Point`, `Vector`, and `Transformation` types.
   * [`image`] for image loading and texture array building.
 
 [`winit`]: https://github.com/rust-windowing/winit
 [`gfx` pre-ll]: https://github.com/gfx-rs/gfx/tree/pre-ll
 [`wgpu`]: https://github.com/gfx-rs/wgpu
+[`stretch`]: https://github.com/vislyhq/stretch
 [`glyph_brush`]: https://github.com/alexheretic/glyph-brush/tree/master/glyph-brush
 [`nalgebra`]: https://github.com/rustsim/nalgebra
 [`image`]: https://github.com/image-rs/image
@@ -134,7 +137,10 @@ the [Rust Community Discord]. I go by `@lone_scientist` there.
 
 ## Credits / Thank you
   * [`ggez`], an awesome, easy-to-use, good game engine that introduced me to
-    Rust a month ago. Its graphics implementation served me as a guide to
-    implement OpenGL support for Coffee.
+    Rust. Its graphics implementation served me as a guide to implement OpenGL
+    support for Coffee.
+  * [Kenney], creators of amazing free game assets with no strings attached. The
+    built-in GUI renderer in Coffee uses a modified version of their UI sprites.
 
 [`ggez`]: https://github.com/ggez/ggez
+[Kenney]: https://kenney.nl

examples/README.md

@@ -8,6 +8,11 @@ OpenGL, we run:
 cargo run --example <example> --features opengl
 ```
 
+__Coffee moves fast and the `master` branch can contain breaking changes!__ If
+you want to learn about a specific release, check out [the release list].
+
+[the release list]: https://github.com/hecrj/coffee/releases
+
 ## Particles
 
 A particle gravity simulator that showcases a loading screen, input handling,
@@ -26,3 +31,14 @@ cargo run --example particles --features opengl,debug --release
 ![Particles example][particles]
 
 [particles]: https://github.com/hecrj/coffee/blob/master/images/examples/particles.png?raw=true
+
+## User Interface
+
+A tour showcasing the different built-in widgets available for building
+responsive user interfaces in Coffee.
+
+```
+cargo run --example ui --features opengl,debug --release
+```
+
+[![GUI](https://thumbs.gfycat.com/LivelyOnlyHypacrosaurus-size_restricted.gif)](https://gfycat.com/livelyonlyhypacrosaurus)

examples/color.rs

@@ -2,7 +2,7 @@ use coffee::graphics::{
     Color, Font, Frame, Image, Point, Quad, Rectangle, Text, Window,
     WindowSettings,
 };
-use coffee::load::{loading_screen, Join, LoadingScreen, Task};
+use coffee::load::{loading_screen::ProgressBar, Join, Task};
 use coffee::{Game, Result, Timer};
 
 fn main() -> Result<()> {
@@ -14,31 +14,47 @@ fn main() -> Result<()> {
     })
 }
 
-struct Colors;
-
-impl Game for Colors {
-    type View = View;
-    type Input = ();
+struct Colors {
+    palette: Image,
+    font: Font,
+}
 
-    const TICKS_PER_SECOND: u16 = 10;
+impl Colors {
+    const PRUSSIAN_BLUE: Color = Color {
+        r: 0.0,
+        g: 0.1922,
+        b: 0.3255,
+        a: 1.0,
+    };
 
-    fn new(window: &mut Window) -> Result<(Self, Self::View, Self::Input)> {
-        let load = Task::stage("Loading view...", View::load());
+    fn load() -> Task<Colors> {
+        (
+            Task::using_gpu(|gpu| {
+                Image::from_colors(gpu, &[Self::PRUSSIAN_BLUE])
+            }),
+            Font::load(include_bytes!(
+                "../resources/font/Inconsolata-Regular.ttf"
+            )),
+        )
+            .join()
+            .map(|(palette, font)| Colors { palette, font })
+    }
+}
 
-        let mut loading_screen = loading_screen::ProgressBar::new(window.gpu());
-        let view = loading_screen.run(load, window)?;
+impl Game for Colors {
+    type Input = ();
+    type LoadingScreen = ProgressBar;
 
-        Ok((Colors, view, ()))
+    fn load(_window: &Window) -> Task<Self> {
+        Task::stage("Loading view...", Colors::load())
     }
 
-    fn update(&mut self, _view: &Self::View, _window: &Window) {}
-
-    fn draw(&self, view: &mut Self::View, frame: &mut Frame, _timer: &Timer) {
+    fn draw(&mut self, frame: &mut Frame, _timer: &Timer) {
         frame.clear(Color::new(0.5, 0.5, 0.5, 1.0));
 
         let target = &mut frame.as_target();
 
-        view.palette.draw(
+        self.palette.draw(
             Quad {
                 source: Rectangle {
                     x: 0.0,
@@ -52,41 +68,14 @@ impl Game for Colors {
             target,
         );
 
-        view.font.add(Text {
-            content: String::from("Prussian blue"),
+        self.font.add(Text {
+            content: "Prussian blue",
             position: Point::new(20.0, 500.0),
             size: 50.0,
-            color: View::PRUSSIAN_BLUE,
+            color: Self::PRUSSIAN_BLUE,
             ..Text::default()
         });
 
-        view.font.draw(target);
-    }
-}
-
-struct View {
-    palette: Image,
-    font: Font,
-}
-
-impl View {
-    const PRUSSIAN_BLUE: Color = Color {
-        r: 0.0,
-        g: 0.1922,
-        b: 0.3255,
-        a: 1.0,
-    };
-
-    fn load() -> Task<View> {
-        (
-            Task::using_gpu(|gpu| {
-                Image::from_colors(gpu, &[Self::PRUSSIAN_BLUE])
-            }),
-            Font::load(include_bytes!(
-                "../resources/font/Inconsolata-Regular.ttf"
-            )),
-        )
-            .join()
-            .map(|(palette, font)| View { palette, font })
+        self.font.draw(target);
     }
 }