Camera2d fov modes

crates/geng-camera/src/camera_2d.rs

@@ -1,18 +1,52 @@
 use super::*;
 
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub enum Camera2dFov {
+    Vertical(f32),
+    Horizontal(f32),
+    MinSide(f32),
+    MaxSide(f32),
+}
+impl Camera2dFov {
+    pub fn value_mut(&mut self) -> &mut f32 {
+        match self {
+            Camera2dFov::Vertical(value) => value,
+            Camera2dFov::Horizontal(value) => value,
+            Camera2dFov::MinSide(value) => value,
+            Camera2dFov::MaxSide(value) => value,
+        }
+    }
+    pub fn value(&self) -> f32 {
+        match *self {
+            Camera2dFov::Vertical(value) => value,
+            Camera2dFov::Horizontal(value) => value,
+            Camera2dFov::MinSide(value) => value,
+            Camera2dFov::MaxSide(value) => value,
+        }
+    }
+}
+
 /// 2-dimensional camera.
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub struct Camera2d {
     pub center: vec2<f32>,
     pub rotation: Angle<f32>,
-    pub fov: f32,
+    pub fov: Camera2dFov,
 }
 
 impl AbstractCamera2d for Camera2d {
     fn view_matrix(&self) -> mat3<f32> {
         mat3::rotate(-self.rotation) * mat3::translate(-self.center)
     }
     fn projection_matrix(&self, framebuffer_size: vec2<f32>) -> mat3<f32> {
-        mat3::scale(vec2(2.0 * framebuffer_size.y / framebuffer_size.x, 2.0) / self.fov)
+        let aspect = framebuffer_size.aspect();
+        let (vertical, fov) = match self.fov {
+            Camera2dFov::Vertical(fov) => (true, fov),
+            Camera2dFov::Horizontal(fov) => (false, fov),
+            Camera2dFov::MinSide(fov) => (aspect > 1.0, fov),
+            Camera2dFov::MaxSide(fov) => (aspect < 1.0, fov),
+        };
+        let vertical_fov = if vertical { fov } else { fov / aspect };
+        mat3::scale(vec2(2.0 / aspect, 2.0) / vertical_fov)
     }
 }

examples/03_moving.rs

@@ -43,7 +43,7 @@ impl geng::State for State {
             &geng::Camera2d {
                 center: vec2(0.0, 0.0),
                 rotation: Angle::ZERO,
-                fov: 15.0,
+                fov: Camera2dFov::Vertical(15.0),
             },
             "Use arrow keys to move around\nPress Space to reset",
             vec2::splat(geng::TextAlign::CENTER),

examples/04_camera_controls.rs

@@ -18,7 +18,7 @@ impl State {
             camera: geng::Camera2d {
                 center: vec2(0.0, 0.0),
                 rotation: Angle::ZERO,
-                fov: 15.0,
+                fov: Camera2dFov::Vertical(15.0),
             },
             framebuffer_size: vec2(1.0, 1.0),
             prev_touch_distance: 0.0,
@@ -63,7 +63,8 @@ impl geng::State for State {
             }
             // Scrolling to zoom
             geng::Event::Wheel { delta } => {
-                self.camera.fov = (self.camera.fov * 1.01f32.powf(-delta as f32)).clamp(1.0, 30.0);
+                let fov = self.camera.fov.value_mut();
+                *fov = (*fov * 1.01f32.powf(-delta as f32)).clamp(1.0, 30.0);
             }
             // Drag start
             geng::Event::MousePress {
@@ -126,7 +127,7 @@ impl geng::State for State {
                 } else if self.touches.len() == 2 {
                     let diff = self.touches[0].position - self.touches[1].position;
                     let now_dist = diff.len() as f32;
-                    self.camera.fov /= now_dist / self.prev_touch_distance;
+                    *self.camera.fov.value_mut() /= now_dist / self.prev_touch_distance;
                     self.prev_touch_distance = now_dist;
                     let now_angle = diff.map(|x| x as f32).arg();
                     let angle_diff = (now_angle - self.prev_touch_angle).normalized_pi();

examples/crabrave/main.rs

@@ -55,7 +55,7 @@ impl geng::State for CrabRave {
         let camera = geng::Camera2d {
             center: vec2::ZERO,
             rotation: Angle::ZERO,
-            fov: 3.0,
+            fov: Camera2dFov::MinSide(3.0),
         };
         let x = (self.t / 10.0).cos();
         let body = mat3::translate(

examples/custom_font_shader.rs

@@ -113,7 +113,7 @@ impl geng::State for State {
                 geng::Camera2d {
                     center: size / 2.0,
                     rotation: Angle::ZERO,
-                    fov: 3.0,
+                    fov: Camera2dFov::Vertical(3.0),
                 }
                 .uniforms(framebuffer.size().map(|x| x as f32)),
             ),

examples/draw/main.rs

@@ -84,7 +84,7 @@ impl State {
             camera: geng::Camera2d {
                 center: vec2::ZERO,
                 rotation: Angle::ZERO,
-                fov: 10.0,
+                fov: Camera2dFov::Vertical(10.0),
             },
             objects: vec![],
         };

examples/line_texture/main.rs

@@ -77,7 +77,7 @@ impl geng::State for Example {
             &geng::Camera2d {
                 center: vec2(0.0, 2.5),
                 rotation: Angle::ZERO,
-                fov: 10.0,
+                fov: Camera2dFov::Vertical(10.0),
             },
             &draw2d::TexturedPolygon::strip(
                 izip![points, ts]

examples/pong/game_state.rs

@@ -43,7 +43,7 @@ impl GameState {
             camera: geng::Camera2d {
                 center: vec2(0.0, 0.0),
                 rotation: Angle::ZERO,
-                fov: 400.0,
+                fov: Camera2dFov::Vertical(400.0),
             },
             boundary: Aabb2::ZERO.extend_symmetric(vec2(ARENA_SIZE_X, ARENA_SIZE_Y) / 2.0),
             ball: Self::new_ball(),

examples/text_input.rs

@@ -22,7 +22,7 @@ impl geng::State for State {
             &geng::Camera2d {
                 center: vec2(0.0, 0.0),
                 rotation: Angle::ZERO,
-                fov: 15.0,
+                fov: Camera2dFov::Vertical(15.0),
             },
             &self.text,
             vec2::splat(geng::TextAlign::CENTER),

src/lib.rs

@@ -28,7 +28,7 @@
 
 pub mod prelude {
     pub use crate::{asset::Hot, draw2d, Geng};
-    pub use crate::{AbstractCamera2d, AbstractCamera3d, Camera2d};
+    pub use crate::{AbstractCamera2d, AbstractCamera3d, Camera2d, Camera2dFov};
     pub use ::batbox;
     pub use ::batbox::prelude::*;
     // pub use gilrs::{self, Gilrs};
@@ -50,7 +50,7 @@ pub use geng_async_state as async_state;
 #[cfg(feature = "audio")]
 pub use geng_audio::{self as audio, *};
 pub use geng_camera::{
-    self as camera, AbstractCamera2d, AbstractCamera3d, Camera2d, PixelPerfectCamera,
+    self as camera, AbstractCamera2d, AbstractCamera3d, Camera2d, Camera2dFov, PixelPerfectCamera,
 };
 pub use geng_draw2d::{self as draw2d, Draw2d};
 pub use geng_font::{self as font, Font, TextAlign};