Busy Mode|Fixed: Transition duration should be determined before the …

…worker begins

The transition style is configured by the caller prior to initiating
busy mode. Processing the work tasks may result in changes to the
default transition cvars. Therefore the transition duration must be
determined prior to starting the worker.

doomsday/engine/portable/src/con_busy.c

@@ -51,8 +51,8 @@ static void Con_BusyPrepareResources(void);
 static void deleteBusyTextures(void);
 static void seedDoomWipeSine(void);
 
-int rTransition = (int) TS_CROSSFADE;
-int rTransitionTics = 28;
+int rTransition = (int) TS_CROSSFADE; ///< cvar Default transition style.
+int rTransitionTics = 28; ///< cvar Default transition duration (in tics).
 
 static boolean busyInited;
 static BusyTask* busyTask; // Current task.
@@ -70,10 +70,15 @@ static mutex_t busy_Mutex; // To prevent Data races in the busy thread.
 static DGLuint texLoading[2];
 static DGLuint texScreenshot; // Captured screenshot of the latest frame.
 
-static boolean transitionInProgress = false;
-static transitionstyle_t transitionStyle = 0;
-static uint transitionStartTime = 0;
-static float transitionPosition;
+typedef struct {
+    boolean inProgress; /// @c true= a transition is presently being animated.
+    transitionstyle_t style; /// Style of transition (cross-fade, wipe, etc...).
+    uint startTime; /// Time at the moment the transition began (in 35hz tics).
+    uint tics; /// Time duration of the animation.
+    float position; /// Animation interpolation point [0..1].
+} transitionstate_t;
+
+static transitionstate_t transition;
 
 static float doomWipeSine[DOOMWIPESINE_NUMSAMPLES];
 static float doomWipeSamples[SCREENWIDTH+1];
@@ -119,17 +124,18 @@ void BusyTask_Begin(BusyTask* task)
     busyTaskEndedWithError = false;
     busyInited = true;
 
-    // Start the busy worker thread, which will proces things in the
+    // Start the busy worker thread, which will process the task in the
     // background while we keep the user occupied with nice animations.
     busyThread = Sys_StartThread(busyTask->worker, busyTask->workerData);
 
     // Are we doing a transition effect?
     if(task->_willAnimateTransition)
     {
-        transitionStyle = rTransition;
-        if(transitionStyle == TS_DOOM || transitionStyle == TS_DOOMSMOOTH)
+        transition.tics = rTransitionTics;
+        transition.style = rTransition;
+        if(transition.style == TS_DOOM || transition.style == TS_DOOMSMOOTH)
             seedDoomWipeSine();
-        transitionInProgress = true;
+        transition.inProgress = true;
     }
 
     // Switch the engine loop and window to the busy mode.
@@ -184,10 +190,10 @@ void BusyTask_End(BusyTask* task)
         Con_AbnormalShutdown(busyError);
     }
 
-    if(transitionInProgress)
+    if(transition.inProgress)
     {
-        transitionStartTime = Sys_GetTime();
-        transitionPosition = 0;
+        transition.startTime = Sys_GetTime();
+        transition.position = 0;
     }
 
     // Make sure that any remaining deferred content gets uploaded.
@@ -274,14 +280,13 @@ static void Con_BusyPrepareResources(void)
 
 static void deleteBusyTextures(void)
 {
-    if(novideo)
-        return;
+    if(novideo) return;
 
     glDeleteTextures(2, (const GLuint*) texLoading);
     texLoading[0] = texLoading[1] = 0;
 
-    // Don't release this yet if doing a transition.
-    if(!transitionInProgress)
+    // Don't release yet if doing a transition.
+    if(!transition.inProgress)
         Con_ReleaseScreenshotTexture();
 
     busyFont = 0;
@@ -817,23 +822,30 @@ static void BusyTask_Drawer(void)
 
 boolean Con_TransitionInProgress(void)
 {
-    return transitionInProgress;
+    return transition.inProgress;
+}
+
+static void Con_EndTransition(void)
+{
+    if(!transition.inProgress) return;
+
+    // Clear any input events that might have accumulated during the transition.
+    DD_ClearEvents();
+    B_ActivateContext(B_ContextByName(UI_BINDING_CONTEXT_NAME), false);
+
+    Con_ReleaseScreenshotTexture();
+    transition.inProgress = false;
 }
 
 void Con_TransitionTicker(timespan_t ticLength)
 {
     if(isDedicated) return;
     if(!Con_TransitionInProgress()) return;
 
-    transitionPosition = (float)(Sys_GetTime() - transitionStartTime) / rTransitionTics;
-    if(transitionPosition >= 1)
+    transition.position = (float)(Sys_GetTime() - transition.startTime) / transition.tics;
+    if(transition.position >= 1)
     {
-        // Clear any input events that might have accumulated during the transition.
-        DD_ClearEvents();
-        B_ActivateContext(B_ContextByName(UI_BINDING_CONTEXT_NAME), false);
-
-        Con_ReleaseScreenshotTexture();
-        transitionInProgress = false;
+        Con_EndTransition();
     }
 }
 
@@ -852,8 +864,8 @@ static void seedDoomWipeSine(void)
 static float sampleDoomWipeSine(float point)
 {
     float sample = doomWipeSine[(uint)ROUND((DOOMWIPESINE_NUMSAMPLES-1) * MINMAX_OF(0, point, 1))];
-    float offset = SCREENHEIGHT * transitionPosition * transitionPosition;
-    return offset + (SCREENHEIGHT/2) * (transitionPosition + sample) * transitionPosition * transitionPosition;
+    float offset = SCREENHEIGHT * transition.position * transition.position;
+    return offset + (SCREENHEIGHT/2) * (transition.position + sample) * transition.position * transition.position;
 }
 
 static void sampleDoomWipe(void)
@@ -881,15 +893,15 @@ void Con_DrawTransition(void)
     GL_BindTextureUnmanaged(texScreenshot, GL_LINEAR);
     glEnable(GL_TEXTURE_2D);
 
-    switch(transitionStyle)
+    switch(transition.style)
     {
     case TS_DOOMSMOOTH: {
         float topAlpha, s, div, colWidth = 1.f / SCREENWIDTH;
         int x, y, h, i;
 
         sampleDoomWipe();
-        div = 1 - .25f * transitionPosition;
-        topAlpha = 1 - transitionPosition;
+        div = 1 - .25f * transition.position;
+        topAlpha = 1 - transition.position;
         topAlpha *= topAlpha;
 
         h = SCREENHEIGHT * (1 - div);
@@ -945,7 +957,7 @@ void Con_DrawTransition(void)
         break;
       }
     case TS_CROSSFADE:
-        glColor4f(1, 1, 1, 1 - transitionPosition);
+        glColor4f(1, 1, 1, 1 - transition.position);
 
         glBegin(GL_QUADS);
             glTexCoord2f(0, 0); glVertex2f(0, 0);