From a9cfcb16d9705c813f0ba497fe6de155f8ba8091 Mon Sep 17 00:00:00 2001
From: Thomas Kolb <thomas@tkolb.de>
Date: Mon, 30 Dec 2019 12:18:04 +0100
Subject: [PATCH] Added "Matrix Code"-style animation

---
 include/Animation/AllAnimations.h       |  1 +
 include/Animation/AnimationController.h |  4 +-
 include/Animation/MatrixCodeAnimation.h | 37 ++++++++++++++++
 src/Animation/AnimationController.cpp   |  4 ++
 src/Animation/MatrixCodeAnimation.cpp   | 57 +++++++++++++++++++++++++
 5 files changed, 102 insertions(+), 1 deletion(-)
 create mode 100644 include/Animation/MatrixCodeAnimation.h
 create mode 100644 src/Animation/MatrixCodeAnimation.cpp

diff --git a/include/Animation/AllAnimations.h b/include/Animation/AllAnimations.h
index 3a2b3ca..bd0e38e 100644
--- a/include/Animation/AllAnimations.h
+++ b/include/Animation/AllAnimations.h
@@ -6,3 +6,4 @@
 #include "SnowfallAnimation.h"
 #include "FadeToColorAnimation.h"
 #include "ImageScrollerAnimation.h"
+#include "MatrixCodeAnimation.h"
diff --git a/include/Animation/AnimationController.h b/include/Animation/AnimationController.h
index aa2338f..1380d32 100644
--- a/include/Animation/AnimationController.h
+++ b/include/Animation/AnimationController.h
@@ -16,6 +16,7 @@ class AnimationController
             FIRE_COLD = 1,
             SNOWFALL = 2,
             FONT_TEST = 3,
+            MATRIX_CODE = 4,
 
             NUM_DEFAULT_ANIMATIONS
         };
@@ -24,7 +25,8 @@ class AnimationController
             "Hot Fire",
             "Cold Fire",
             "Snowfall",
-            "Font Test"
+            "Font Test",
+            "Matrix Code"
         };
 
         AnimationController(Fader *fader);
diff --git a/include/Animation/MatrixCodeAnimation.h b/include/Animation/MatrixCodeAnimation.h
new file mode 100644
index 0000000..8324f57
--- /dev/null
+++ b/include/Animation/MatrixCodeAnimation.h
@@ -0,0 +1,37 @@
+#pragma once
+
+#include <random>
+#include <list>
+
+#include "Animation.h"
+
+class MatrixCodeAnimation : public Animation
+{
+    public:
+        MatrixCodeAnimation(Fader *fader, int vspeed = 80, int spawn_rate = 8);
+
+        void loop(uint64_t frame) override;
+
+        void stop(void) override
+        {
+            m_stopping = true;
+        }
+
+        void reset(void) override;
+
+    private:
+        struct Pixel
+        {
+            int x; // position in 1/1 led
+            int y; // position in 1/256 led
+            int vspeed; // vertical speed in 1/256 leds per frame
+        };
+
+        std::default_random_engine m_gen;
+
+        std::list<Pixel> m_pixels;
+        int m_vspeed;
+        int m_spawnRate; // average pixels per second
+
+        bool m_stopping;
+};
diff --git a/src/Animation/AnimationController.cpp b/src/Animation/AnimationController.cpp
index 4a23da0..784fa44 100644
--- a/src/Animation/AnimationController.cpp
+++ b/src/Animation/AnimationController.cpp
@@ -49,6 +49,10 @@ void AnimationController::changeAnimation(AnimationController::DefaultAnimation
             changeAnimation(std::unique_ptr<Animation>(new SnowfallAnimation(m_fader)), transition);
             break;
 
+        case MATRIX_CODE:
+            changeAnimation(std::unique_ptr<Animation>(new MatrixCodeAnimation(m_fader)), transition);
+            break;
+
         case FONT_TEST:
             {
                 Bitmap bmp(0, 0);
diff --git a/src/Animation/MatrixCodeAnimation.cpp b/src/Animation/MatrixCodeAnimation.cpp
new file mode 100644
index 0000000..53adb0c
--- /dev/null
+++ b/src/Animation/MatrixCodeAnimation.cpp
@@ -0,0 +1,57 @@
+#include "Animation/MatrixCodeAnimation.h"
+
+#include <iostream>
+
+MatrixCodeAnimation::MatrixCodeAnimation(Fader *fader, int vspeed, int spawn_rate)
+    : Animation(fader),
+      m_vspeed(vspeed),
+      m_spawnRate(spawn_rate)
+{
+    reset();
+}
+
+void MatrixCodeAnimation::loop(uint64_t frame)
+{
+    int nled = m_fader->modules_per_strip();
+    int nstrip = m_fader->strips();
+
+    if(frame == 0) {
+        m_fader->set_fadestep(8);
+    }
+
+    // create new pixels
+    std::uniform_int_distribution<int> spawnRNG(0, (60*nstrip / m_spawnRate) - 1);
+    std::uniform_int_distribution<int> vspeedRNG(m_vspeed - 32, m_vspeed + 32);
+
+    if(!m_stopping) {
+        for(int i = 0; i < nstrip; i++) {
+            if(spawnRNG(m_gen) == 0) {
+                m_pixels.emplace_back(Pixel{i, 256*nled-1, vspeedRNG(m_gen)});
+            }
+        }
+    }
+
+    m_fader->fade_color(Fader::Color{0, 0, 0, 0});
+
+    // move all pixels down and render them
+    for(auto &px: m_pixels) {
+        px.y -= px.vspeed;
+        if(px.y >= 0) {
+            m_fader->set_color(px.x, px.y/256, Fader::Color{0, 192, 0, 16});
+        }
+    }
+
+    m_pixels.remove_if(
+        [](const Pixel &px) { return px.y < 0; });
+
+    m_fader->update();
+    m_running = !m_stopping || m_fader->something_changed();
+}
+
+void MatrixCodeAnimation::reset(void)
+{
+    m_pixels.clear();
+
+    m_stopping = false;
+    m_running = true;
+}