✨ Add realtime preview

- Preview quality is crude but works good enough.
- Add scaling to render function. This helps to make the preview
  faster because we can use the same result for several pixels.
- You can move around the camera a bit with wasd, super basic.
- Press R to start/stop rendering the scene.

1 files changed, 4 insertions, 0 deletions

diff --git a/racer-tracer/src/error.rs b/racer-tracer/src/error.rs
index ac78c91..9254715 100644
--- a/racer-tracer/src/error.rs
+++ b/racer-tracer/src/error.rs
@@ -10,6 +10,9 @@ pub enum TracerError {
 
     #[error("Failed to update window: {0}")]
     FailedToUpdateWindow(String),
+
+    #[error("Resolution is not power of two.")]
+    ResolutionIsNotPowerOfTwo(),
 }
 
 impl From<TracerError> for i32 {
@@ -21,6 +24,7 @@ impl From<TracerError> for i32 {
             } => exit_code,
             TracerError::FailedToCreateWindow(_) => 2,
             TracerError::FailedToUpdateWindow(_) => 3,
+            TracerError::ResolutionIsNotPowerOfTwo() => 4,
         }
     }
 }