Perspective + orthographic cameras

camera.odin

@@ -6,27 +6,95 @@ import "core:math/linalg"
 Camera :: struct {
     position: [3]f32,
     forward, up, right: [3]f32,
-
-    fov_degrees: f32,
     near, far: f32,
+    yaw, pitch, roll: f32,
+
+    type: Camera_Type,
 }
 
-create_camera :: proc(renderer: ^Renderer, position: [3]f32, forward, up: [3]f32, fov_degrees, near, far: f32) -> Camera {
+Camera_Type :: union {
+    Camera_Perspective,
+    Camera_Orthographic,
+}
+
+Camera_Perspective :: struct {
+    fov_degrees: f32,
+}
+
+Camera_Orthographic :: struct {
+    height: f32,
+}
+
+@(private) create_camera_base :: proc(
+    renderer: ^Renderer,
+    position: [3]f32,
+    forward, up: [3]f32,
+    near, far: f32,
+    type: Camera_Type,
+    yaw: f32 = 0, pitch: f32 = 0, roll: f32 = 0
+) -> Camera
+{
     c: Camera
     c.position = position
     c.forward = forward
     c.up = up
-    c.fov_degrees = fov_degrees
     c.near = near
     c.far = far
+    c.type = type
+    c.yaw = yaw
+    c.pitch = pitch
+    c.roll = roll
 
     assert(c.forward != {})
     assert(c.up != {})
+    assert(c.near > 0)
+    assert(c.far > 0)
+
+    return c
+}
+
+create_camera_perspective :: proc(
+    renderer: ^Renderer,
+    position: [3]f32,
+    forward, up: [3]f32,
+    near, far: f32,
+    fov_degrees: f32,
+    yaw: f32 = 0, pitch: f32 = 0, roll: f32 = 0
+) -> Camera
+{
     assert(fov_degrees > 0)
     assert(near > 0)
     assert(far > 0)
 
-    return c
+    return create_camera_base(
+        renderer, position, forward, up,
+        near, far,
+        Camera_Perspective {
+            fov_degrees = fov_degrees,
+        },
+        yaw, pitch, roll
+    )
+}
+
+create_camera_orthographic :: proc(
+    renderer: ^Renderer,
+    position: [3]f32,
+    forward, up: [3]f32,
+    near, far: f32,
+    height: f32,
+    yaw: f32 = 0, pitch: f32 = 0, roll: f32 = 0
+) -> Camera
+{
+    assert(height > 0)
+
+    return create_camera_base(
+        renderer, position, forward, up,
+        near, far,
+        Camera_Orthographic {
+            height = height,
+        },
+        yaw, pitch, roll
+    )
 }
 
 get_camera_view_matrix :: proc(camera: ^Camera) -> (linalg.Matrix4f32, bool) {
@@ -48,23 +116,50 @@ get_camera_projection_matrix :: proc(renderer: ^Renderer, camera: ^Camera) -> (l
     }
 
     projection_matrix := linalg.MATRIX4F32_IDENTITY
-    projection_matrix *= linalg.matrix4_perspective(
-        linalg.to_radians(f32(camera.fov_degrees)),
-        get_aspect_ratio(renderer),
-        camera.near,
-        camera.far,
-        flip_z_axis = true,
-    )
 
+    switch t in camera.type {
+        case Camera_Perspective: {
+            projection_matrix *= linalg.matrix4_perspective(
+                linalg.to_radians(f32(t.fov_degrees)),
+                get_aspect_ratio(renderer),
+                camera.near,
+                camera.far,
+                flip_z_axis = true,
+            )
+        }
+        case Camera_Orthographic: {
+            half_h := t.height / 2
+            half_w := half_h * get_aspect_ratio(renderer)
+
+            projection_matrix *= linalg.matrix_ortho3d(
+                -half_w, half_w,
+                -half_h, half_h,
+                camera.near,
+                camera.far,
+                flip_z_axis = true,
+            )
+        }
+    }
+    
     return projection_matrix, true
 }
 
 rotate_camera :: proc(camera: ^Camera, yaw, pitch, roll: f32) {
-    pitch := clamp(pitch, -89.0, 89.0)
+    new_yaw   := camera.yaw   + yaw
+    new_pitch := camera.pitch + pitch
+    new_roll  := camera.roll  + roll
 
-    pitch_rad := linalg.to_radians(pitch)
-    yaw_rad   := linalg.to_radians(yaw)
-    roll_rad  := linalg.to_radians(roll)
+    set_camera_rotation(camera, new_yaw, new_pitch, new_roll)
+}
+
+set_camera_rotation :: proc(camera: ^Camera, yaw, pitch, roll: f32) {
+    camera.yaw   = yaw
+    camera.pitch = pitch
+    camera.roll  = roll
+
+    pitch_rad := linalg.to_radians(camera.pitch)
+    yaw_rad   := linalg.to_radians(camera.yaw)
+    roll_rad  := linalg.to_radians(camera.roll)
 
     camera.forward = [3]f32{
         math.cos(pitch_rad) * math.cos(yaw_rad),
@@ -73,9 +168,9 @@ rotate_camera :: proc(camera: ^Camera, yaw, pitch, roll: f32) {
     }
 
     WORLD_UP :: [3]f32{0, 1, 0}
+
     camera.right = linalg.normalize(linalg.cross(camera.forward, WORLD_UP))
     camera.up    = linalg.normalize(linalg.cross(camera.right, camera.forward))
-    // TODO: SS - Support 'roll'.
 }
 
 set_active_camera :: proc(renderer: ^Renderer, camera: ^Camera) {
@@ -83,5 +178,6 @@ set_active_camera :: proc(renderer: ^Renderer, camera: ^Camera) {
 }
 
 get_active_camera :: proc(renderer: ^Renderer) -> ^Camera {
+    assert(renderer != nil)
     return renderer.active_camera
 }