From 585fdc3a7e1c9ee0dc67ca253003b1a91f556dbd Mon Sep 17 00:00:00 2001
From: dvdrw <admin@dvdrw.dev>
Date: Tue, 26 Nov 2024 00:08:47 +0100
Subject: [PATCH] feat: add support for centering the screen around
 best/midpoint

Pressing 'c' will center the screen around the average position of the
particles. Pressing 'f' will center the screen on each frame.

Pressing 'b' will center the screen around the best found point.
---
 include/screen.hpp |  7 ++++---
 src/main.cpp       | 31 +++++++++++++++++++++++++++++++
 src/screen.cpp     |  9 ++++-----
 3 files changed, 39 insertions(+), 8 deletions(-)

diff --git a/include/screen.hpp b/include/screen.hpp
index 74f40f3..5b788a3 100644
--- a/include/screen.hpp
+++ b/include/screen.hpp
@@ -40,14 +40,15 @@ struct Screen {
     Symbol &at(int x, int y);
     Symbol &at(float x, float y);
 
-    void resize(std::size_t n);
     void resize(std::size_t x, std::size_t y);
 
+    void move_to(float x, float y);
+
     std::pair<float, float> screen_to_xy(int w, int h);
     std::pair<int, int> xy_to_screen(float x, float y);
 
-    Screen(std::size_t n) : buf(nullptr) { resize(n); }
-    Screen(std::size_t x, std::size_t y) : buf(nullptr) { resize(x, y); }
+    Screen(std::size_t x, std::size_t y) : buf(nullptr)
+    { resize(x, y); move_to(0, 0); }
     ~Screen() { delete[] buf; }
 
     std::vector<const vec<2>*> points;
diff --git a/src/main.cpp b/src/main.cpp
index 3eab687..abf19e7 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -8,6 +8,7 @@ static constexpr int   kFPS = 60;
 static constexpr float kDT  = 1.0 / kFPS;
 
 float f(vec<2> x) {
+    // return std::pow(x.x, 2) + std::pow(x.y, 2);
     return  50 * (std::pow(std::sin((x.x - 10)/2),2) + std::pow(std::sin(x.y/2),2)) +
 	std::pow(std::abs(x.x - 3.141592653589), 1.2) + std::pow(std::abs(x.y), 1.2);
 }
@@ -65,6 +66,7 @@ main(int argc, char **argv) {
 
     bool pause = false;
     bool frame_step = false;
+    bool auto_follow = false;
 
     // initialize colorizer scale/translate
     scr.draw();
@@ -79,6 +81,15 @@ main(int argc, char **argv) {
 	       255, 255, 255, x.x, x.y, y);
     };
 
+    auto center_screen = [&]() -> void {
+	vec<2> pos = 0;
+	for(const auto &p : swarm.get_particles()) {
+	    pos += p.get_position();
+	}
+	pos /= swarm.get_particles().size();
+	scr.move_to(pos.x, pos.y);
+    };
+
     // We draw to the screen at a rate of `kFPS', but step()ing the swarm at
     // this rate would be far too fast to be interesting to look at. On the
     // other hand, step()ing once a second is too slow.
@@ -102,6 +113,8 @@ main(int argc, char **argv) {
 	    printf("Current iteration: %d\nCurrent frame: %d\n", i * 4 / kFPS, i);
 	}
 
+	if(auto_follow) center_screen();
+
 	if(frame_step) {
 	    pause = true;
 	    frame_step = false;
@@ -178,6 +191,24 @@ main(int argc, char **argv) {
 	    update_and_draw();
 	    break;
 
+	case 'v':
+	    scr.draw_vecs = !scr.draw_vecs;
+	    break;
+
+	case 'b': {
+	    const auto [_, b] = swarm.best();
+	    scr.move_to(b.x, b.y);
+	    break;
+	}
+
+	case 'c':
+	    center_screen();
+	    break;
+
+	case 'f':
+	    auto_follow = !auto_follow;
+	    break;
+
 	case 'h':
 	    printf("  movement  zoom  coloring  pause step \n"
 		   "     W       io    IK LO     SPC   .,  \n"
diff --git a/src/screen.cpp b/src/screen.cpp
index 8035570..1c64f9f 100644
--- a/src/screen.cpp
+++ b/src/screen.cpp
@@ -4,11 +4,6 @@
 
 /* Screen */
 
-void Screen::resize(std::size_t n) {
-    w = n; h = 1;
-    buf = (Symbol *)realloc(buf, n * sizeof(Symbol));
-}
-
 void Screen::resize(std::size_t x, std::size_t y) {
     w = x; h = y;
     buf = (Symbol *)realloc(buf, x * y * sizeof(Symbol));
@@ -41,6 +36,10 @@ std::pair<int, int> Screen::xy_to_screen(float x, float y) {
     };
 }
 
+void Screen::move_to(float x, float y) {
+    dx = x - w*sx/2;
+    dy = y - h*sy/2;
+}
 
 void Screen::clear() {
     static const Symbol s {' ', {0,0,0}};