From 334f26c84fc7583e5d889d8241076d51933bcae3 Mon Sep 17 00:00:00 2001
From: David Rowe <david@ctrlaltstudio.com>
Date: Fri, 6 Feb 2015 21:43:21 -0800
Subject: [PATCH] Display some progress while waiting at 0% and limit speed of
 advance

---
 examples/progress.js | 110 ++++++++++++++++++++++++-------------------
 1 file changed, 62 insertions(+), 48 deletions(-)

diff --git a/examples/progress.js b/examples/progress.js
index 7fb2a043e2..57a1fd1a07 100644
--- a/examples/progress.js
+++ b/examples/progress.js
@@ -13,9 +13,13 @@
 
 (function () {
 
-    var progress = 100,                             // %
+    var rawProgress = 100,                          // % raw value.
+        displayProgress = 100,                      // % smoothed value to display.
+        DISPLAY_PROGRESS_MINOR_MAXIMUM = 8,         // % displayed progress bar goes up to while 0% raw progress.
+        DISPLAY_PROGRESS_MINOR_INCREMENT = 0.1,     // % amount to increment display value each update when 0% raw progress.
+        DISPLAY_PROGRESS_MAJOR_INCREMENT = 5,       // % maximum amount to increment display value when >0% raw progress.
         alpha = 0.0,
-        alphaDelta = 0.0,                           // > 0 if fading in; < 0 if fading out/
+        alphaDelta = 0.0,                           // > 0 if fading in; < 0 if fading out.
         ALPHA_DELTA_IN = 0.15,
         ALPHA_DELTA_OUT = -0.02,
         fadeTimer = null,
@@ -90,56 +94,15 @@
     function onDownloadInfoChanged(info) {
         var i;
 
-        // Calculate progress
+        // Update raw progress value
         if (info.downloading.length + info.pending === 0) {
-            progress = 100;
+            rawProgress = 100;
         } else {
-            progress = 0;
+            rawProgress = 0;
             for (i = 0; i < info.downloading.length; i += 1) {
-                progress += info.downloading[i];
+                rawProgress += info.downloading[i];
             }
-            progress = progress / (info.downloading.length + info.pending);
-        }
-
-        // Update state
-        if (!visible) {  // Not visible because no recent downloads
-            if (progress < 100) {  // Have started downloading so fade in
-                visible = true;
-                alphaDelta = ALPHA_DELTA_IN;
-                fadeTimer = Script.setInterval(fade, FADE_INTERVAL);
-            }
-        } else if (alphaDelta !== 0.0) {  // Fading in or out
-            if (alphaDelta > 0) {
-                if (progress === 100) {  // Was donloading but now have finished so fade out
-                    alphaDelta = ALPHA_DELTA_OUT;
-                }
-            } else {
-                if (progress < 100) {  // Was finished downloading but have resumed so fade in
-                    alphaDelta = ALPHA_DELTA_IN;
-                }
-            }
-        } else {  // Fully visible because downloading or recently so
-            if (fadeWaitTimer === null) {
-                if (progress === 100) {  // Was downloading but have finished so fade out soon
-                    fadeWaitTimer = Script.setTimeout(function () {
-                        alphaDelta = ALPHA_DELTA_OUT;
-                        fadeTimer = Script.setInterval(fade, FADE_INTERVAL);
-                        fadeWaitTimer = null;
-                    }, FADE_OUT_WAIT);
-                }
-            } else {
-                if (progress < 100) {  // Was finished and waiting to fade out but have resumed downloading so don't fade out
-                    Script.clearInterval(fadeWaitTimer);
-                    fadeWaitTimer = null;
-                }
-            }
-        }
-
-        // Update progress bar
-        if (visible) {
-            Overlays.editOverlay(isOnHMD ? bar3D.overlay : bar2D.overlay, {
-                subImage: { x: BAR_WIDTH * (1 - progress / 100), y: 0, width: BAR_WIDTH, height: BAR_HEIGHT }
-            });
+            rawProgress = rawProgress / (info.downloading.length + info.pending);
         }
     }
 
@@ -201,7 +164,58 @@
             createOverlays();
         }
 
+        // Calculate progress value to display
+        if (rawProgress === 0 && displayProgress <= DISPLAY_PROGRESS_MINOR_MAXIMUM) {
+            displayProgress = Math.min(displayProgress + DISPLAY_PROGRESS_MINOR_INCREMENT, DISPLAY_PROGRESS_MINOR_MAXIMUM);
+        } else if (rawProgress < displayProgress) {
+            displayProgress = rawProgress;
+        } else if (rawProgress > displayProgress) {
+            displayProgress = Math.min(rawProgress, displayProgress + DISPLAY_PROGRESS_MAJOR_INCREMENT);
+        }  // else (rawProgress === displayProgress); do nothing.
+
+        // Update state
+        if (!visible) {  // Not visible because no recent downloads
+            if (displayProgress < 100) {  // Have started downloading so fade in
+                visible = true;
+                alphaDelta = ALPHA_DELTA_IN;
+                fadeTimer = Script.setInterval(fade, FADE_INTERVAL);
+            }
+        } else if (alphaDelta !== 0.0) {  // Fading in or out
+            if (alphaDelta > 0) {
+                if (displayProgress === 100) {  // Was downloading but now have finished so fade out
+                    alphaDelta = ALPHA_DELTA_OUT;
+                }
+            } else {
+                if (displayProgress < 100) {  // Was finished downloading but have resumed so fade in
+                    alphaDelta = ALPHA_DELTA_IN;
+                }
+            }
+        } else {  // Fully visible because downloading or recently so
+            if (fadeWaitTimer === null) {
+                if (displayProgress === 100) {  // Was downloading but have finished so fade out soon
+                    fadeWaitTimer = Script.setTimeout(function () {
+                        alphaDelta = ALPHA_DELTA_OUT;
+                        fadeTimer = Script.setInterval(fade, FADE_INTERVAL);
+                        fadeWaitTimer = null;
+                    }, FADE_OUT_WAIT);
+                }
+            } else {
+                if (displayProgress < 100) {  // Was finished and waiting to fade out but have resumed so don't fade out
+                    Script.clearInterval(fadeWaitTimer);
+                    fadeWaitTimer = null;
+                }
+            }
+        }
+
         if (visible) {
+
+            // Update progress bar
+            Overlays.editOverlay(isOnHMD ? bar3D.overlay : bar2D.overlay, {
+                visible: visible,
+                subImage: { x: BAR_WIDTH * (1 - displayProgress / 100), y: 0, width: BAR_WIDTH, height: BAR_HEIGHT }
+            });
+
+            // Update position
             if (isOnHMD) {
                 // Update 3D overlays to maintain positions relative to avatar
                 eyePosition = MyAvatar.getDefaultEyePosition();