From 3746bb1e6d70fc6bac921cf45b71e31181b4561b Mon Sep 17 00:00:00 2001
From: Dan Ballard <dan@mindstab.net>
Date: Wed, 30 Dec 2020 16:59:45 -0800
Subject: [PATCH] game of life implementation... cripplingly slow

---
 src/main.rs | 127 +++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 116 insertions(+), 11 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 4a03781..89db7d0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -8,52 +8,157 @@ use opengl_graphics::{GlGraphics, OpenGL};
 use piston::event_loop::{EventSettings, Events};
 use piston::input::{RenderArgs, RenderEvent, UpdateArgs, UpdateEvent};
 use piston::window::WindowSettings;
+use graphics::Rectangle;
+
+use std::cmp;
+
+pub const SCREEN_SIZE: u32 = 800;
+pub const BLACK: [f32; 4] = [0.0, 0.0, 0.0, 1.0];
+pub const WHITE: [f32; 4] = [1.0, 1.0, 1.0, 1.0];
+
+pub trait Cell {
+    fn color(&self) -> [f32; 4];
+}
+
+#[derive(Clone)]
+pub struct ConwayCell {
+    color: [f32; 4],
+    alive: bool,
+}
+
+/*
+impl Cell {
+    pub fn clone(&self) -> Cell {
+        Cell{color: self.color}
+    }
+}*/
 
 pub struct App {
     gl: GlGraphics,
-    steps_per_sec: u32,
+    steps_per_sec: f64,
+    px_size: u32,
+    dt_last: f64,
+    grid: Vec<Vec<ConwayCell>>,
 }
 
 impl App {
     fn render (&mut self, args: &RenderArgs) {
         use graphics::*;
 
-        const BLACK: [f32; 4] = [0.0, 0.0, 0.0, 1.0];
+        let grid = &self.grid;
+        let px_size = self.px_size;
 
         self.gl.draw(args.viewport(), |c, gl| {
             // Clear the screen.
             clear(BLACK, gl);
+
+            for y in 0..grid.len() {
+                for x in 0..grid[y].len() {
+                    if grid[y][x].alive {
+                        rectangle(grid[y][x].color, rectangle::square((x as u32 * px_size) as f64, (y as u32 * px_size) as f64, px_size as f64), c.transform, gl)
+                    }
+                }
+            }
+
+            /*
+            for (y, row) in grid.iter().enumerate() {
+                for (x, cell) in row.iter().enumerate() {
+                    rectangle( cell.color, rectangle::square((x as u32 * px_size) as f64, (y as u32 * px_size) as f64, px_size as f64), c.transform, gl)
+                }
+            }*/
         });
     }
 
     fn update(&mut self, args: &UpdateArgs) {
+        //println!("update and update.dt: {} with self.dt_last: {}", args.dt, self.dt_last);
+        if args.dt + self.dt_last > (1.0 / self.steps_per_sec) {
+            self.dt_last = 0.0;
+            print!(">");
+            self.evolve();
+        } else {
+            print!(".");
+            self.dt_last += args.dt;
+        }
+    }
 
+    fn evolve(&mut self) {
+        let mut new_grid = vec![vec![ConwayCell{color: BLACK, alive: false}; self.grid.len()]; self.grid.len()];
+
+        for y in 0..self.grid.len() {
+            for x in 0..self.grid[y].len() {
+                let mut nalive = 0;
+
+                let mut ylow = 0;
+                if y > 1 {
+                    ylow = y-1;
+                }
+                let yhigh = cmp::min(self.grid.len()-1, y+1);
+
+                let mut xlow = 0;
+                if x > 1 {
+                    xlow = x-1;
+                }
+                let xhigh =  cmp::min(self.grid.len()-1, x+1);
+
+                for i in ylow..yhigh+1 {
+                    for j in xlow..xhigh+1 {
+                        if i == y && j == x {
+                            continue;
+                        }
+                        if self.grid[i][j].alive {
+                            nalive += 1;
+                        }
+                    }
+                }
+
+                if self.grid[y][x].alive {
+                    if nalive == 2 || nalive == 3 {
+                        new_grid[y][x] = ConwayCell{color: WHITE, alive: true}
+                    }
+                } else if nalive == 3 {
+                    new_grid[y][x] = ConwayCell{color: WHITE, alive: true}
+                }
+            }
+        }
+        self.grid = new_grid;
     }
 }
 
 fn main() {
-    // Make window
-
     // Change this to OpenGL::V2_1 if not working.
     let opengl = OpenGL::V3_2;
 
     // Create an Glutin window.
-    let mut window: Window = WindowSettings::new("spinning-square", [800, 800])
+    let mut window: Window = WindowSettings::new("spinning-square", [SCREEN_SIZE, SCREEN_SIZE])
         .graphics_api(opengl)
         .exit_on_esc(true)
         .build()
         .unwrap();
 
+    let px_size = 2;
+    let size: usize = (SCREEN_SIZE/px_size) as usize;
+    let mut grid = vec![vec![ConwayCell{color: BLACK, alive: false}; size]; size];
+    // r pemento
+    println!("size:{} size/2:{}", size, size/2);
+    let centery = size/2;
+    let centerx = size/2;
+    println!("centery:{} centerx:{}", centery, centerx);
+    grid[centery][centerx] = ConwayCell{color: WHITE, alive: true};
+    grid[centery+1][centerx] = ConwayCell{color: WHITE, alive: true};
+    grid[centery-1][centerx] = ConwayCell{color: WHITE, alive: true};
+
+    grid[centery-1][centerx-1] = ConwayCell{color: WHITE, alive: true};
+    grid[centery][centerx+1] = ConwayCell{color: WHITE, alive: true};
+
     let mut app = App {
         gl: GlGraphics::new(opengl),
-        steps_per_sec: 2,
+        steps_per_sec: 30.0,
+        px_size: px_size,
+        dt_last: 0.0,
+        grid: grid,
     };
 
-    let mut events = Events::new(EventSettings::new());
-
-    // Make grid
-
-    // Quick life engine -> redraw
+    println!("{:?}", EventSettings::new());
 
     let mut events = Events::new(EventSettings::new());
     while let Some(e) = events.next(&mut window) {