From c735119367a02a5d39f19dd84592c83f45cfda86 Mon Sep 17 00:00:00 2001
From: Grant Sanderson <grant@3blue1brown.com>
Date: Sat, 12 Jan 2019 14:44:26 -0800
Subject: [PATCH] Began clacks solution animations (just for the recap scenes,
 so mostly carried over from clacks)

---
 active_projects/clacks.py           |   9 ++-
 active_projects/clacks_solution1.py | 106 ++++++++++++++++++++++++++--
 2 files changed, 106 insertions(+), 9 deletions(-)

diff --git a/active_projects/clacks.py b/active_projects/clacks.py
index 387cb647..575db8fb 100644
--- a/active_projects/clacks.py
+++ b/active_projects/clacks.py
@@ -3,9 +3,6 @@ import subprocess
 from pydub import AudioSegment
 
 
-MIN_TIME_BETWEEN_FLASHES = 0.004
-
-
 class SlidingBlocks(VGroup):
     CONFIG = {
         "block1_config": {
@@ -225,6 +222,7 @@ class ClackFlashes(ContinualAnimation):
             "flash_radius": 0.2,
         },
         "start_up_time": 0,
+        "min_time_between_flashes": 1 / 30,
     }
 
     def __init__(self, clack_data, **kwargs):
@@ -233,7 +231,7 @@ class ClackFlashes(ContinualAnimation):
         group = Group()
         last_time = 0
         for location, time in clack_data:
-            if (time - last_time) < MIN_TIME_BETWEEN_FLASHES:
+            if (time - last_time) < self.min_time_between_flashes:
                 continue
             last_time = time
             flash = Flash(location, **self.flash_config)
@@ -268,6 +266,7 @@ class BlocksAndWallScene(Scene):
         "counter_label": "\\# Collisions: ",
         "collision_sound": "clack.wav",
         "show_flash_animations": True,
+        "min_time_between_sounds": 0.004,
     }
 
     def setup(self):
@@ -359,7 +358,7 @@ class BlocksAndWallScene(Scene):
         total_time = max(times) + 1
         clacks = AudioSegment.silent(int(1000 * total_time))
         last_position = 0
-        min_diff = int(1000 * MIN_TIME_BETWEEN_FLASHES)
+        min_diff = int(1000 * self.min_time_between_sounds)
         for time in times:
             position = int(1000 * time)
             d_position = position - last_position
diff --git a/active_projects/clacks_solution1.py b/active_projects/clacks_solution1.py
index 4484583b..81b5676f 100644
--- a/active_projects/clacks_solution1.py
+++ b/active_projects/clacks_solution1.py
@@ -3,9 +3,47 @@ from active_projects.clacks import *
 
 
 
-class LastVideo(Scene):
+# TODO, add solution image
+class FromPuzzleToSolution(MovingCameraScene):
     def construct(self):
-        pass
+        big_rect = FullScreenFadeRectangle()
+        big_rect.set_fill(DARK_GREY, 0.5)
+        self.add(big_rect)
+
+        rects = VGroup(ScreenRectangle(), ScreenRectangle())
+        rects.set_height(3)
+        rects.arrange_submobjects(RIGHT, buff=2)
+
+        titles = VGroup(
+            TextMobject("Puzzle"),
+            TextMobject("Solution"),
+        )
+
+        images = Group(
+            ImageMobject("BlocksAndWallExampleMass16"),
+            ImageMobject("SphereSurfaceProof2"), # TODO
+        )
+        for title, rect, image in zip(titles, rects, images):
+            title.scale(1.5)
+            title.next_to(rect, UP)
+            image.replace(rect)
+            self.add(image, rect, title)
+
+        frame = self.camera_frame
+        frame.save_state()
+
+        self.play(
+            frame.replace, images[0],
+            run_time=3
+        )
+        self.wait()
+        self.play(Restore(frame, run_time=3))
+        self.play(
+            frame.replace, images[1],
+            run_time=3,
+        )
+        self.wait()
+
 
 
 class BlocksAndWallExampleMass16(BlocksAndWallExample):
@@ -20,7 +58,6 @@ class BlocksAndWallExampleMass16(BlocksAndWallExample):
     }
 
 
-
 class Mass16WithElasticLabel(Mass1e1WithElasticLabel):
     CONFIG = {
         "sliding_blocks_config": {
@@ -40,4 +77,65 @@ class BlocksAndWallExampleMass64(BlocksAndWallExample):
             },
         },
         "wait_time": 25,
-    }
\ No newline at end of file
+    }
+
+
+class BlocksAndWallExampleMass1e4(BlocksAndWallExample):
+    CONFIG = {
+        "sliding_blocks_config": {
+            "block1_config": {
+                "mass": 64,
+                "velocity": -1.5,
+            },
+        },
+        "wait_time": 25,
+    }
+
+
+class BlocksAndWallExampleMassMillion(BlocksAndWallExample):
+    CONFIG = {
+        "sliding_blocks_config": {
+            "block1_config": {
+                "mass": 1e6,
+                "velocity": -0.9,
+                "label_text": "$100^{3}$ kg"
+            },
+        },
+        "wait_time": 30,
+        "million_fade_time": 4,
+        "min_time_between_sounds": 0.002,
+    }
+
+    def setup(self):
+        super().setup()
+        self.add_million_label()
+
+    def add_million_label(self):
+        first_label = self.blocks.block1.label
+        brace = Brace(first_label[:-2], UP, buff=SMALL_BUFF)
+        new_label = TexMobject("1{,}000{,}000")
+        new_label.next_to(brace, UP, buff=SMALL_BUFF)
+        new_label.add(brace)
+        new_label.set_color(YELLOW)
+
+        def update_label(label):
+            d_time = self.get_time() - self.million_fade_time
+            opacity = smooth(d_time)
+            label.set_fill(opacity=d_time)
+
+        new_label.add_updater(update_label)
+        first_label.add(new_label)
+
+
+class BlocksAndWallExampleMassTrillion(BlocksAndWallExample):
+    CONFIG = {
+        "sliding_blocks_config": {
+            "block1_config": {
+                "mass": 1e12,
+                "velocity": -1,
+            },
+        },
+        "wait_time": 30,
+        "min_time_between_sounds": 0.001,
+    }
+