fix #75 by computing evolution during frameRender

instead of pre-computing the entire evolution during preFrameRender, it creates 60 ticks' worth of grid data at a time during the rendering process, deleting old data as it goes. This works with the current render process and should still work if the render process changes, as long as render threads don't become extremely de-synchronized (which would probably be an issue anyway)

1 files changed, 12 insertions, 24 deletions

diff --git a/src/components/life.py b/src/components/life.py
index a2a3a30..e19ed36 100644
--- a/src/components/life.py
+++ b/src/components/life.py
@@ -121,30 +121,8 @@ class Component(Component):
         return self.drawGrid(self.startingGrid)
 
     def preFrameRender(self, *args, **kwargs):
-        '''
-        Evolution must be computed before frameRender begins
-        because frameRender may be called non-sequentially.
-        '''
         super().preFrameRender(*args, **kwargs)
-        self.progressBarSetText.emit("Computing evolution...")
         self.tickGrids = {0: self.startingGrid}
-        tick = 0
-        for frameNo in range(
-                self.tickRate, self.audioArrayLen, self.sampleSize
-                ):
-            if self.parent.canceled:
-                break
-            if frameNo % self.tickRate == 0:
-                tick += 1
-                self.tickGrids[tick] = self.gridForTick(tick)
-
-                # update progress bar
-                progress = int(100*(frameNo/self.audioArrayLen))
-                if progress >= 100:
-                    progress = 100
-                pStr = "Computing evolution: "+str(progress)+'%'
-                self.progressBarSetText.emit(pStr)
-                self.progressBarUpdate.emit(int(progress))
 
     def properties(self):
         if self.customImg and (
@@ -158,7 +136,15 @@ class Component(Component):
 
     def frameRender(self, frameNo):
         tick = math.floor(frameNo / self.tickRate)
+
+        # Compute grid evolution on this frame if it hasn't been computed yet
+        if tick not in self.tickGrids:
+            self.tickGrids[tick] = self.gridForTick(tick)
         grid = self.tickGrids[tick]
+
+        # Delete old evolution data which we shouldn't need anymore
+        if tick - 60 in self.tickGrids:
+            del self.tickGrids[tick - 60]
         return self.drawGrid(grid)
 
     def drawGrid(self, grid):
@@ -361,9 +347,11 @@ class Component(Component):
     def gridForTick(self, tick):
         '''
         Given a tick number over 0, returns a new grid (a set of tuples).
-        This depends on the previous tick's grid already being computed,
-        so it must be called sequentially.
+        This must compute the previous ticks' grids if not already computed
         '''
+        if tick - 1 not in self.tickGrids:
+            self.tickGrids[tick - 1] = self.gridForTick(tick - 1)
+        
         lastGrid = self.tickGrids[tick - 1]
 
         def neighbours(x, y):