Use one texture with two channels for video

src/shrooms_vb_core.rs

@@ -113,7 +113,7 @@ impl CoreVB {
         unsafe { vb_emulate(self.sim, &mut cycles) };
     }
 
-    pub fn read_pixels(&mut self, buffers: &mut [Vec<u8>; 2]) -> bool {
+    pub fn read_pixels(&mut self, buffers: &mut [u8]) -> bool {
         // SAFETY: the *mut VB owns its userdata.
         // There is no way for the userdata to be null or otherwise invalid.
         let data: &mut VBState = unsafe { &mut *vb_get_user_data(self.sim).cast() };
@@ -122,17 +122,17 @@ impl CoreVB {
         }
         data.frame_seen = false;
 
-        assert_eq!(buffers[0].len(), 384 * 224);
-        assert_eq!(buffers[1].len(), 384 * 224);
+        // the buffer must be big enough for our data
+        assert!(buffers.len() >= 384 * 224 * 2);
         unsafe {
             vb_get_pixels(
                 self.sim,
-                buffers[0].as_mut_ptr().cast(),
-                1,
-                384,
-                buffers[1].as_mut_ptr().cast(),
-                1,
-                384,
+                buffers.as_mut_ptr().cast(),
+                2,
+                384 * 2,
+                buffers.as_mut_ptr().offset(1).cast(),
+                2,
+                384 * 2,
             );
         };
         true