Force a render if a frame takes longer than half a second to run

1 files changed, 6 insertions, 0 deletions

diff --git a/bedrock.js b/bedrock.js
index bdb4062..3db4372 100644
--- a/bedrock.js
+++ b/bedrock.js
@@ -1118,6 +1118,7 @@ function Bedrock(e) {
         this.paused = true;   // true when program is paused for the user.
         this.asleep = false;  // true when program is waiting for input.
         this.halted = false;  // true when program has halted.
+        this.frameLag = 0;    // time since runLoop started
     }
 
     // Reset the emulator and load in a new program.
@@ -1194,6 +1195,7 @@ function Bedrock(e) {
             let image = new ImageData(scr.pixels, scr.width, scr.height);
             scr.ctx.putImageData(image, 0, 0, scr.dx0, scr.dy0, scr.dx1, scr.dy1);
             scr.unmark();
+            this.frameLag = performance.now();
         }
     }
 
@@ -1212,12 +1214,16 @@ function Bedrock(e) {
                     default:                       // NORMAL
                 }
                 this.update();
+                // Force a render if the frame has been running for >500ms.
+                if (performance.now() - this.frameLag > 500) {
+                    this.render(); }
                 setTimeout(this.runLoop.bind(this), 0);
             }
         }
     }
 
     this.sleepLoop = () => {
+        this.frameLag = performance.now();
         if (!this.halted) {
             if (!this.asleep) {
                 setTimeout(this.runLoop.bind(this), 0);