add missing files for gfx

src/gfx/camera.rs

@@ -0,0 +1,191 @@
+use cgmath::*;
+use std::f32::consts::FRAC_PI_2;
+use std::time::Duration;
+use winit::dpi::PhysicalPosition;
+use winit::event::*;
+
+#[rustfmt::skip]
+pub const OPENGL_TO_WGPU_MATRIX: cgmath::Matrix4<f32> = cgmath::Matrix4::new(
+    1.0, 0.0, 0.0, 0.0,
+    0.0, 1.0, 0.0, 0.0,
+    0.0, 0.0, 0.5, 0.0,
+    0.0, 0.0, 0.5, 1.0,
+);
+
+#[derive(Debug)]
+pub struct Camera {
+    pub position: Point3<f32>,
+    yaw: Rad<f32>,
+    pitch: Rad<f32>,
+}
+
+impl Camera {
+    pub fn new<V: Into<Point3<f32>>, Y: Into<Rad<f32>>, P: Into<Rad<f32>>>(
+        position: V,
+        yaw: Y,
+        pitch: P,
+    ) -> Self {
+        Self {
+            position: position.into(),
+            yaw: yaw.into(),
+            pitch: pitch.into(),
+        }
+    }
+
+    pub fn calc_matrix(&self) -> Matrix4<f32> {
+        Matrix4::look_at_dir(
+            self.position,
+            Vector3::new(self.yaw.0.cos(), self.pitch.0.sin(), self.yaw.0.sin()).normalize(),
+            Vector3::unit_y(),
+        )
+    }
+}
+
+pub struct Projection {
+    aspect: f32,
+    fovy: Rad<f32>,
+    znear: f32,
+    zfar: f32,
+}
+
+impl Projection {
+    pub fn new<F: Into<Rad<f32>>>(width: u32, height: u32, fovy: F, znear: f32, zfar: f32) -> Self {
+        Self {
+            aspect: width as f32 / height as f32,
+            fovy: fovy.into(),
+            znear,
+            zfar,
+        }
+    }
+
+    pub fn resize(&mut self, width: u32, height: u32) {
+        self.aspect = width as f32 / height as f32;
+    }
+
+    pub fn calc_matrix(&self) -> Matrix4<f32> {
+        OPENGL_TO_WGPU_MATRIX * perspective(self.fovy, self.aspect, self.znear, self.zfar)
+    }
+}
+
+#[derive(Debug)]
+pub struct CameraController {
+    amount_left: f32,
+    amount_right: f32,
+    amount_forward: f32,
+    amount_backward: f32,
+    amount_up: f32,
+    amount_down: f32,
+    rotate_horizontal: f32,
+    rotate_vertical: f32,
+    scroll: f32,
+    speed: f32,
+    sensitivity: f32,
+}
+
+impl CameraController {
+    pub fn new(speed: f32, sensitivity: f32) -> Self {
+        Self {
+            amount_left: 0.0,
+            amount_right: 0.0,
+            amount_forward: 0.0,
+            amount_backward: 0.0,
+            amount_up: 0.0,
+            amount_down: 0.0,
+            rotate_horizontal: 0.0,
+            rotate_vertical: 0.0,
+            scroll: 0.0,
+            speed,
+            sensitivity,
+        }
+    }
+
+    pub fn process_keyboard(&mut self, key: VirtualKeyCode, state: ElementState) -> bool {
+        let amount = if state == ElementState::Pressed {
+            1.0
+        } else {
+            0.0
+        };
+        match key {
+            VirtualKeyCode::W | VirtualKeyCode::Up => {
+                self.amount_forward = amount;
+                true
+            }
+            VirtualKeyCode::S | VirtualKeyCode::Down => {
+                self.amount_backward = amount;
+                true
+            }
+            VirtualKeyCode::A | VirtualKeyCode::Left => {
+                self.amount_left = amount;
+                true
+            }
+            VirtualKeyCode::D | VirtualKeyCode::Right => {
+                self.amount_right = amount;
+                true
+            }
+            VirtualKeyCode::Space => {
+                self.amount_up = amount;
+                true
+            }
+            VirtualKeyCode::LShift => {
+                self.amount_down = amount;
+                true
+            }
+            _ => false,
+        }
+    }
+
+    pub fn process_mouse(&mut self, mouse_dx: f64, mouse_dy: f64) {
+        self.rotate_horizontal = mouse_dx as f32;
+        self.rotate_vertical = mouse_dy as f32;
+    }
+
+    pub fn process_scroll(&mut self, delta: &MouseScrollDelta) {
+        self.scroll = match delta {
+            // I'm assuming a line is about 100 pixels
+            MouseScrollDelta::LineDelta(_, scroll) => -scroll * 0.5,
+            MouseScrollDelta::PixelDelta(PhysicalPosition { y: scroll, .. }) => -*scroll as f32,
+        };
+    }
+
+    pub fn update_camera(&mut self, camera: &mut Camera, dt: Duration) {
+        let dt = dt.as_secs_f32();
+
+        // Move forward/backward and left/right
+        let (yaw_sin, yaw_cos) = camera.yaw.0.sin_cos();
+        let forward = Vector3::new(yaw_cos, 0.0, yaw_sin).normalize();
+        let right = Vector3::new(-yaw_sin, 0.0, yaw_cos).normalize();
+        camera.position += forward * (self.amount_forward - self.amount_backward) * self.speed * dt;
+        camera.position += right * (self.amount_right - self.amount_left) * self.speed * dt;
+
+        // Move in/out (aka. "zoom")
+        // Note: this isn't an actual zoom. The camera's position
+        // changes when zooming. I've added this to make it easier
+        // to get closer to an object you want to focus on.
+        let (pitch_sin, pitch_cos) = camera.pitch.0.sin_cos();
+        let scrollward =
+            Vector3::new(pitch_cos * yaw_cos, pitch_sin, pitch_cos * yaw_sin).normalize();
+        camera.position += scrollward * self.scroll * self.speed * self.sensitivity * dt;
+        self.scroll = 0.0;
+
+        // Move up/down. Since we don't use roll, we can just
+        // modify the y coordinate directly.
+        camera.position.y += (self.amount_up - self.amount_down) * self.speed * dt;
+
+        // Rotate
+        camera.yaw += Rad(self.rotate_horizontal) * self.sensitivity * dt;
+        camera.pitch += Rad(-self.rotate_vertical) * self.sensitivity * dt;
+
+        // If process_mouse isn't called every frame, these values
+        // will not get set to zero, and the camera will rotate
+        // when moving in a non cardinal direction.
+        self.rotate_horizontal = 0.0;
+        self.rotate_vertical = 0.0;
+
+        // Keep the camera's angle from going too high/low.
+        if camera.pitch < -Rad(FRAC_PI_2) {
+            camera.pitch = -Rad(FRAC_PI_2);
+        } else if camera.pitch > Rad(FRAC_PI_2) {
+            camera.pitch = Rad(FRAC_PI_2);
+        }
+    }
+}