Move the demo camera code into its own module

demo/common/src/camera.rs

@@ -0,0 +1,195 @@
+// pathfinder/demo/common/src/camera.rs
+//
+// Copyright © 2019 The Pathfinder Project Developers.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Camera management code for the demo.
+
+// TODO(#140, pcwalton): Move some of this out of the demo and into the library
+// proper.
+
+use crate::window::{OcularTransform, View};
+use pathfinder_geometry::basic::point::{Point2DF32, Point2DI32, Point3DF32};
+use pathfinder_geometry::basic::rect::RectF32;
+use pathfinder_geometry::basic::transform2d::Transform2DF32;
+use pathfinder_geometry::basic::transform3d::{Perspective, Transform3DF32};
+use std::f32::consts::FRAC_PI_4;
+
+const NEAR_CLIP_PLANE: f32 = 0.01;
+const FAR_CLIP_PLANE: f32 = 10.0;
+
+// Half of the eye separation distance.
+const DEFAULT_EYE_OFFSET: f32 = 0.025;
+
+pub enum Camera {
+    TwoD(Transform2DF32),
+    ThreeD {
+        // The ocular transform used for rendering of the scene to the scene framebuffer. If we are
+        // performing stereoscopic rendering, this is then reprojected according to the eye
+        // transforms below.
+        scene_transform: OcularTransform,
+        // For each eye, the perspective from camera coordinates to display coordinates,
+        // and the view transform from world coordinates to camera coordinates.
+        eye_transforms: Vec<OcularTransform>,
+        // The modelview transform from world coordinates to SVG coordinates
+        modelview_transform: CameraTransform3D,
+        // The camera's velocity (in world coordinates)
+        velocity: Point3DF32,
+    },
+}
+
+impl Camera {
+    pub fn new(mode: Mode, view_box: RectF32, viewport_size: Point2DI32) -> Camera {
+        if mode == Mode::TwoD {
+            Camera::new_2d(view_box, viewport_size)
+        } else {
+            Camera::new_3d(mode, view_box, viewport_size)
+        }
+    }
+
+    fn new_2d(view_box: RectF32, viewport_size: Point2DI32) -> Camera {
+        let scale = i32::min(viewport_size.x(), viewport_size.y()) as f32
+            * scale_factor_for_view_box(view_box);
+        let origin = viewport_size.to_f32().scale(0.5) - view_box.size().scale(scale * 0.5);
+        Camera::TwoD(Transform2DF32::from_scale(&Point2DF32::splat(scale)).post_translate(origin))
+    }
+
+    fn new_3d(mode: Mode, view_box: RectF32, viewport_size: Point2DI32) -> Camera {
+        let viewport_count = mode.viewport_count();
+
+        let fov_y = FRAC_PI_4;
+        let aspect = viewport_size.x() as f32 / viewport_size.y() as f32;
+        let projection =
+            Transform3DF32::from_perspective(fov_y, aspect, NEAR_CLIP_PLANE, FAR_CLIP_PLANE);
+        let perspective = Perspective::new(&projection, viewport_size);
+
+        // Create a scene transform by moving the camera back from the center of the eyes so that
+        // its field of view encompasses the field of view of both eyes.
+        let z_offset = -DEFAULT_EYE_OFFSET * projection.c0.x();
+        let scene_transform = OcularTransform {
+            perspective,
+            modelview_to_eye: Transform3DF32::from_translation(0.0, 0.0, z_offset),
+        };
+
+        // For now, initialize the eye transforms as copies of the scene transform.
+        let eye_offset = DEFAULT_EYE_OFFSET;
+        let eye_transforms = (0..viewport_count)
+            .map(|viewport_index| {
+                let this_eye_offset = if viewport_index == 0 {
+                    eye_offset
+                } else {
+                    -eye_offset
+                };
+                OcularTransform {
+                    perspective,
+                    modelview_to_eye: Transform3DF32::from_translation(this_eye_offset, 0.0, 0.0),
+                }
+            })
+            .collect();
+
+        Camera::ThreeD {
+            scene_transform,
+            eye_transforms,
+            modelview_transform: CameraTransform3D::new(view_box),
+            velocity: Point3DF32::default(),
+        }
+    }
+
+    pub fn is_3d(&self) -> bool {
+        match *self {
+            Camera::ThreeD { .. } => true,
+            Camera::TwoD { .. } => false,
+        }
+    }
+
+    pub fn mode(&self) -> Mode {
+        match *self {
+            Camera::ThreeD {
+                ref eye_transforms, ..
+            } if eye_transforms.len() >= 2 => Mode::VR,
+            Camera::ThreeD { .. } => Mode::ThreeD,
+            Camera::TwoD { .. } => Mode::TwoD,
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug)]
+pub struct CameraTransform3D {
+    position: Point3DF32,
+    pub yaw: f32,
+    pub pitch: f32,
+    scale: f32,
+}
+
+impl CameraTransform3D {
+    fn new(view_box: RectF32) -> CameraTransform3D {
+        let scale = scale_factor_for_view_box(view_box);
+        CameraTransform3D {
+            position: Point3DF32::new(
+                0.5 * view_box.max_x(),
+                -0.5 * view_box.max_y(),
+                1.5 / scale,
+                1.0,
+            ),
+            yaw: 0.0,
+            pitch: 0.0,
+            scale,
+        }
+    }
+
+    pub fn offset(&mut self, vector: Point3DF32) -> bool {
+        let update = !vector.is_zero();
+        if update {
+            let rotation = Transform3DF32::from_rotation(-self.yaw, -self.pitch, 0.0);
+            self.position = self.position + rotation.transform_point(vector);
+        }
+        update
+    }
+
+    pub fn to_transform(&self) -> Transform3DF32 {
+        let mut transform = Transform3DF32::from_rotation(self.yaw, self.pitch, 0.0);
+        transform = transform.post_mul(&Transform3DF32::from_uniform_scale(2.0 * self.scale));
+        transform = transform.post_mul(&Transform3DF32::from_translation(
+            -self.position.x(),
+            -self.position.y(),
+            -self.position.z(),
+        ));
+
+        // Flip Y.
+        transform = transform.post_mul(&Transform3DF32::from_scale(1.0, -1.0, 1.0));
+
+        transform
+    }
+}
+
+#[derive(Clone, Copy, PartialEq)]
+pub enum Mode {
+    TwoD = 0,
+    ThreeD = 1,
+    VR = 2,
+}
+
+impl Mode {
+    pub fn viewport_count(self) -> usize {
+        match self {
+            Mode::TwoD | Mode::ThreeD => 1,
+            Mode::VR => 2,
+        }
+    }
+
+    pub fn view(self, viewport: u32) -> View {
+        match self {
+            Mode::TwoD | Mode::ThreeD => View::Mono,
+            Mode::VR => View::Stereo(viewport),
+        }
+    }
+}
+
+pub fn scale_factor_for_view_box(view_box: RectF32) -> f32 {
+    1.0 / f32::min(view_box.size().x(), view_box.size().y())
+}

demo/common/src/lib.rs

@@ -13,16 +13,16 @@
 #[macro_use]
 extern crate log;
 
+use crate::camera::{Camera, Mode};
 use crate::concurrent::DemoExecutor;
 use crate::device::{GroundProgram, GroundVertexArray};
 use crate::ui::{DemoUI, UIAction};
-use crate::window::{Event, Keycode, OcularTransform, SVGPath, View, Window, WindowSize};
+use crate::window::{Event, Keycode, SVGPath, View, Window, WindowSize};
 use clap::{App, Arg};
 use image::ColorType;
-use pathfinder_geometry::basic::point::{Point2DF32, Point2DI32, Point3DF32};
+use pathfinder_geometry::basic::point::{Point2DF32, Point2DI32};
 use pathfinder_geometry::basic::rect::RectF32;
-use pathfinder_geometry::basic::transform2d::Transform2DF32;
+use pathfinder_geometry::basic::transform3d::Transform3DF32;
-use pathfinder_geometry::basic::transform3d::{Perspective, Transform3DF32};
 use pathfinder_geometry::color::{ColorF, ColorU};
 use pathfinder_gl::GLDevice;
 use pathfinder_gpu::resources::ResourceLoader;
@@ -36,7 +36,6 @@ use pathfinder_renderer::post::{DEFRINGING_KERNEL_CORE_GRAPHICS, STEM_DARKENING_
 use pathfinder_renderer::scene::Scene;
 use pathfinder_svg::BuiltSVG;
 use pathfinder_ui::{MousePosition, UIEvent};
-use std::f32::consts::FRAC_PI_4;
 use std::fs::File;
 use std::io::Read;
 use std::path::PathBuf;
@@ -54,9 +53,6 @@ const CAMERA_SCALE_SPEED_2D: f32 = 6.0;
 // How much the scene is scaled when a zoom button is clicked.
 const CAMERA_ZOOM_AMOUNT_2D: f32 = 0.1;
 
-const NEAR_CLIP_PLANE: f32 = 0.01;
-const FAR_CLIP_PLANE: f32 = 10.0;
-
 const LIGHT_BG_COLOR: ColorU = ColorU {
     r: 248,
     g: 248,
@@ -93,13 +89,11 @@ const APPROX_FONT_SIZE: f32 = 16.0;
 
 const MESSAGE_TIMEOUT_SECS: u64 = 5;
 
-// Half of the eye separation distance.
-const DEFAULT_EYE_OFFSET: f32 = 0.025;
-
 pub const GRIDLINE_COUNT: i32 = 10;
 
 pub mod window;
 
+mod camera;
 mod concurrent;
 mod device;
 mod ui;
@@ -401,7 +395,8 @@ impl<W> DemoApp<W> where W: Window {
                         ref mut velocity, ..
                     } = self.camera
                     {
-                        let scale_factor = scale_factor_for_view_box(self.scene_metadata.view_box);
+                        let scale_factor =
+                            camera::scale_factor_for_view_box(self.scene_metadata.view_box);
                         velocity.set_z(-CAMERA_VELOCITY / scale_factor);
                         self.dirty = true;
                     }
@@ -411,7 +406,8 @@ impl<W> DemoApp<W> where W: Window {
                         ref mut velocity, ..
                     } = self.camera
                     {
-                        let scale_factor = scale_factor_for_view_box(self.scene_metadata.view_box);
+                        let scale_factor =
+                            camera::scale_factor_for_view_box(self.scene_metadata.view_box);
                         velocity.set_z(CAMERA_VELOCITY / scale_factor);
                         self.dirty = true;
                     }
@@ -421,7 +417,8 @@ impl<W> DemoApp<W> where W: Window {
                         ref mut velocity, ..
                     } = self.camera
                     {
-                        let scale_factor = scale_factor_for_view_box(self.scene_metadata.view_box);
+                        let scale_factor =
+                            camera::scale_factor_for_view_box(self.scene_metadata.view_box);
                         velocity.set_x(-CAMERA_VELOCITY / scale_factor);
                         self.dirty = true;
                     }
@@ -431,7 +428,8 @@ impl<W> DemoApp<W> where W: Window {
                         ref mut velocity, ..
                     } = self.camera
                     {
-                        let scale_factor = scale_factor_for_view_box(self.scene_metadata.view_box);
+                        let scale_factor =
+                            camera::scale_factor_for_view_box(self.scene_metadata.view_box);
                         velocity.set_x(CAMERA_VELOCITY / scale_factor);
                         self.dirty = true;
                     }
@@ -976,29 +974,6 @@ impl Options {
     }
 }
 
-#[derive(Clone, Copy, PartialEq)]
-pub enum Mode {
-    TwoD = 0,
-    ThreeD = 1,
-    VR = 2,
-}
-
-impl Mode {
-    pub fn viewport_count(self) -> usize {
-        match self {
-            Mode::TwoD | Mode::ThreeD => 1,
-            Mode::VR => 2,
-        }
-    }
-
-    pub fn view(self, viewport: u32) -> View {
-        match self {
-            Mode::TwoD | Mode::ThreeD => View::Mono,
-            Mode::VR => View::Stereo(viewport),
-        }
-    }
-}
-
 #[derive(Clone, Copy, PartialEq)]
 pub enum UIVisibility {
     None,
@@ -1024,151 +999,6 @@ fn center_of_window(window_size: &WindowSize) -> Point2DF32 {
     window_size.device_size().to_f32().scale(0.5)
 }
 
-enum Camera {
-    TwoD(Transform2DF32),
-    ThreeD {
-        // The ocular transform used for rendering of the scene to the scene framebuffer. If we are
-        // performing stereoscopic rendering, this is then reprojected according to the eye
-        // transforms below.
-        scene_transform: OcularTransform,
-        // For each eye, the perspective from camera coordinates to display coordinates,
-        // and the view transform from world coordinates to camera coordinates.
-        eye_transforms: Vec<OcularTransform>,
-        // The modelview transform from world coordinates to SVG coordinates
-        modelview_transform: CameraTransform3D,
-        // The camera's velocity (in world coordinates)
-        velocity: Point3DF32,
-    },
-}
-
-impl Camera {
-    fn new(mode: Mode, view_box: RectF32, viewport_size: Point2DI32) -> Camera {
-        if mode == Mode::TwoD {
-            Camera::new_2d(view_box, viewport_size)
-        } else {
-            Camera::new_3d(mode, view_box, viewport_size)
-        }
-    }
-
-    fn new_2d(view_box: RectF32, viewport_size: Point2DI32) -> Camera {
-        let scale = i32::min(viewport_size.x(), viewport_size.y()) as f32
-            * scale_factor_for_view_box(view_box);
-        let origin = viewport_size.to_f32().scale(0.5) - view_box.size().scale(scale * 0.5);
-        Camera::TwoD(Transform2DF32::from_scale(&Point2DF32::splat(scale)).post_translate(origin))
-    }
-
-    fn new_3d(mode: Mode, view_box: RectF32, viewport_size: Point2DI32) -> Camera {
-        let viewport_count = mode.viewport_count();
-
-        let fov_y = FRAC_PI_4;
-        let aspect = viewport_size.x() as f32 / viewport_size.y() as f32;
-        let projection =
-            Transform3DF32::from_perspective(fov_y, aspect, NEAR_CLIP_PLANE, FAR_CLIP_PLANE);
-        let perspective = Perspective::new(&projection, viewport_size);
-
-        // Create a scene transform by moving the camera back from the center of the eyes so that
-        // its field of view encompasses the field of view of both eyes.
-        let z_offset = -DEFAULT_EYE_OFFSET * projection.c0.x();
-        let scene_transform = OcularTransform {
-            perspective,
-            modelview_to_eye: Transform3DF32::from_translation(0.0, 0.0, z_offset),
-        };
-
-        // For now, initialize the eye transforms as copies of the scene transform.
-        let eye_offset = DEFAULT_EYE_OFFSET;
-        let eye_transforms = (0..viewport_count)
-            .map(|viewport_index| {
-                let this_eye_offset = if viewport_index == 0 {
-                    eye_offset
-                } else {
-                    -eye_offset
-                };
-                OcularTransform {
-                    perspective,
-                    modelview_to_eye: Transform3DF32::from_translation(this_eye_offset, 0.0, 0.0),
-                }
-            })
-            .collect();
-
-        Camera::ThreeD {
-            scene_transform,
-            eye_transforms,
-            modelview_transform: CameraTransform3D::new(view_box),
-            velocity: Point3DF32::default(),
-        }
-    }
-
-    fn is_3d(&self) -> bool {
-        match *self {
-            Camera::ThreeD { .. } => true,
-            Camera::TwoD { .. } => false,
-        }
-    }
-
-    fn mode(&self) -> Mode {
-        match *self {
-            Camera::ThreeD {
-                ref eye_transforms, ..
-            } if eye_transforms.len() >= 2 => Mode::VR,
-            Camera::ThreeD { .. } => Mode::ThreeD,
-            Camera::TwoD { .. } => Mode::TwoD,
-        }
-    }
-}
-
-#[derive(Clone, Copy, Debug)]
-struct CameraTransform3D {
-    position: Point3DF32,
-    yaw: f32,
-    pitch: f32,
-    scale: f32,
-}
-
-impl CameraTransform3D {
-    fn new(view_box: RectF32) -> CameraTransform3D {
-        let scale = scale_factor_for_view_box(view_box);
-        CameraTransform3D {
-            position: Point3DF32::new(
-                0.5 * view_box.max_x(),
-                -0.5 * view_box.max_y(),
-                1.5 / scale,
-                1.0,
-            ),
-            yaw: 0.0,
-            pitch: 0.0,
-            scale,
-        }
-    }
-
-    fn offset(&mut self, vector: Point3DF32) -> bool {
-        let update = !vector.is_zero();
-        if update {
-            let rotation = Transform3DF32::from_rotation(-self.yaw, -self.pitch, 0.0);
-            self.position = self.position + rotation.transform_point(vector);
-        }
-        update
-    }
-
-    fn to_transform(&self) -> Transform3DF32 {
-        let mut transform = Transform3DF32::from_rotation(self.yaw, self.pitch, 0.0);
-        transform = transform.post_mul(&Transform3DF32::from_uniform_scale(2.0 * self.scale));
-        transform = transform.post_mul(&Transform3DF32::from_translation(
-            -self.position.x(),
-            -self.position.y(),
-            -self.position.z(),
-        ));
-
-        // Flip Y.
-        transform = transform.post_mul(&Transform3DF32::from_scale(1.0, -1.0, 1.0));
-
-        transform
-    }
-}
-
-fn scale_factor_for_view_box(view_box: RectF32) -> f32 {
-    1.0 / f32::min(view_box.size().x(), view_box.size().y())
-}
-
 fn get_svg_building_message(built_svg: &BuiltSVG) -> String {
     if built_svg.result_flags.is_empty() {
         return String::new();

demo/common/src/ui.rs

@@ -8,8 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use crate::camera::Mode;
 use crate::window::Window;
-use crate::{BackgroundColor, Mode, Options};
+use crate::{BackgroundColor, Options};
 use pathfinder_geometry::basic::point::Point2DI32;
 use pathfinder_geometry::basic::rect::RectI32;
 use pathfinder_gpu::resources::ResourceLoader;