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#![deny(clippy::all, clippy::pedantic)]
use std::collections::BTreeMap;
use std::time::{Duration, Instant};
use glfw::window::KeyState;
use glfw::{Window, WindowBuilder};
use crate::camera::Camera;
use crate::object::{Id as ObjectId, Object};
use crate::renderer::Renderer;
use crate::vector::Vec2;
mod matrix;
mod opengl;
mod projection;
mod renderer;
mod transform;
pub mod camera;
pub mod color;
pub mod object;
pub mod texture;
pub mod vector;
pub mod vertex;
pub use glfw::window::Key;
pub use glfw::WindowSize;
#[derive(Debug)]
pub struct Engine
{
/// Objects have to be dropped before window. Otherwise, UB.
objects: BTreeMap<ObjectId, Object>,
window: Window,
renderer: Renderer,
delta_time: Duration,
}
impl Engine
{
/// Creates and initializes a new engine.
///
/// # Errors
/// Will return `Err` if window creation or window configuration fails.
pub fn new(window_size: &WindowSize, window_title: &str) -> Result<Self, Error>
{
let window_builder = WindowBuilder::new();
#[cfg(feature = "debug")]
let window_builder =
window_builder.hint(glfw::window::Hint::OpenGLDebugContext, 1);
let window = window_builder
.create(window_size, window_title)
.map_err(Error::CreateWindowFailed)?;
window
.make_context_current()
.map_err(Error::ConfigureWindowFailed)?;
window.set_framebuffer_size_callback(move |new_window_size| {
Renderer::set_viewport(&Vec2::ZERO, &new_window_size);
});
let renderer = Renderer::new(&window).map_err(Error::InitializeRendererFailed)?;
Ok(Self {
window,
renderer,
objects: BTreeMap::new(),
delta_time: Duration::ZERO,
})
}
pub fn add_object(&mut self, object: Object)
{
self.objects.insert(object.id(), object);
}
pub fn set_objecs(&mut self, objects: impl IntoIterator<Item = Object>)
{
self.objects
.extend(objects.into_iter().map(|object| (object.id(), object)));
}
#[must_use]
pub fn get_object_by_id(&self, id: ObjectId) -> Option<&Object>
{
self.objects.get(&id)
}
#[must_use]
pub fn get_object_by_id_mut(&mut self, id: ObjectId) -> Option<&mut Object>
{
self.objects.get_mut(&id)
}
/// Starts the engine.
///
/// # Errors
/// Will return `Err` if updating the window fails.
pub fn start(&mut self, mut func: impl FnMut(&mut Self)) -> Result<(), Error>
{
let mut prev_frame_start: Option<Instant> = None;
while !self.window.should_close() {
self.update_delta_time(&mut prev_frame_start);
func(self);
let window_size = self.window.size().map_err(Error::GetWindowSizeFailed)?;
self.renderer.render(self.objects.values(), &window_size);
self.window
.swap_buffers()
.map_err(Error::UpdateWindowFailed)?;
self.window
.poll_events()
.map_err(Error::UpdateWindowFailed)?;
}
Ok(())
}
#[must_use]
pub fn camera(&self) -> &Camera
{
self.renderer.camera()
}
pub fn camera_mut(&mut self) -> &mut Camera
{
self.renderer.camera_mut()
}
/// Returns the current delta time. Will be 0 if not called from the function
/// passed to [`start`].
#[must_use]
pub fn delta_time(&self) -> &Duration
{
&self.delta_time
}
/// Returns whether or not a keyboard key is currently pressed.
///
/// # Errors
/// Will return `Err` if getting the key state fails.
pub fn is_key_pressed(&self, key: Key) -> Result<bool, Error>
{
self.window
.get_key(key)
.map(|key_state| matches!(key_state, KeyState::Pressed))
.map_err(Error::GetKeyStateFailed)
}
/// Returns the cursor position.
///
/// # Errors
/// Will return `Err` if unable to get the cursor position from GLFW.
pub fn get_cursor_pos(&self) -> Result<Vec2<f64>, Error>
{
let pos = self
.window
.get_cursor_position()
.map_err(Error::GetCursorPosFailed)?;
Ok(Vec2 { x: pos.x, y: pos.y })
}
fn update_delta_time(&mut self, prev_frame_start: &mut Option<Instant>)
{
let frame_start_time = Instant::now();
if let Some(last_frame_start) = prev_frame_start {
self.delta_time = frame_start_time.duration_since(*last_frame_start);
}
*prev_frame_start = Some(frame_start_time);
}
}
/// Engine Error
#[derive(Debug, thiserror::Error)]
pub enum Error
{
#[error("Failed to create window")]
CreateWindowFailed(#[source] glfw::Error),
#[error("Failed to configure window")]
ConfigureWindowFailed(#[source] glfw::Error),
#[error("Failed to initialize renderer")]
InitializeRendererFailed(#[source] renderer::Error),
#[error("Failed to update window")]
UpdateWindowFailed(#[source] glfw::Error),
#[error("Failed to get window size")]
GetWindowSizeFailed(#[source] glfw::Error),
#[error("Failed to get key state")]
GetKeyStateFailed(#[source] glfw::Error),
#[error("Failed to get cursor position")]
GetCursorPosFailed(#[source] glfw::Error),
}
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