From: Armaan Bhojwani <me@armaanb.net>
Date: Sat, 15 May 2021 21:29:01 +0000 (-0400)
Subject: Eliminate usleep and improve logic
X-Git-Url: https://git.armaanb.net/?p=pong.git;a=commitdiff_plain;h=c13d0ec4469557c988193022f08e7e334d77ad6a

Eliminate usleep and improve logic
---

diff --git a/pong.c b/pong.c
index e6b8f38..0be9fe3 100644
--- a/pong.c
+++ b/pong.c
@@ -2,6 +2,8 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <unistd.h>
+#include <sys/time.h>
+#include <time.h>
 
 int
 die(int code)
@@ -12,29 +14,34 @@ die(int code)
 
 int
 main(void) {
-	int x = 1, y = 0, aoff = 0, boff = 0;
-	int max_y = 0, max_x = 0;
+	int x, y, aoff = 0, boff = 0;
+	int max_y, max_x;
 	int max_y_new = 0, max_x_new = 0;
-	int direction = 1;
 	int pad_h = 5;
 	int a_score = 0, b_score = 0;
-	int slope_x = 5;
+	int slope_x = 8;
 	int slope_y = 1;
-	int index = 0;
 	int index_dir = 1;
+	int direction = 1;
+	double speed = 0.015;
+	struct timeval start, stop;
 
 	// Initialize curses
 	initscr();
 	noecho();
 	curs_set(0);
 	nodelay(stdscr, 1); // Don't wait for getch input
-	index = max_y/2;
+	getmaxyx(stdscr, max_y, max_x);
+	--max_x;
+	--max_y;
+	int index = (max_y/2)*(slope_x/slope_y);
 	x = max_x/2;
 
+	gettimeofday(&start, NULL);
 	while(1) {
 		getmaxyx(stdscr, max_y_new, max_x_new);
 		--max_x_new;
-		--max_y_new; 
+		--max_y_new;
 		pad_h = 0.2 * max_y;
 		if (max_y_new != max_y || max_x_new != max_x) {
 			clear();
@@ -42,8 +49,6 @@ main(void) {
 			max_y = max_y_new;
 		}
 
-		index += index_dir;
-
 		// Parse keypresses
 		int key = getch();
 		if (key == 'q') {
@@ -59,9 +64,11 @@ main(void) {
 		}
 
 		// Draw paddles
-		for (int i = 0; i < max_y; i++) {
+		for (int i = 0; i < max_y + 1; i++) {
 			mvprintw(i, 0, " ");
+			mvprintw(i, 1, " ");
 			mvprintw(i, max_x, " ");
+			mvprintw(i, max_x - 1, " ");
 		}
 		for (int i = aoff; i < aoff + pad_h; i++) {
 			mvprintw(i, 0, "|");
@@ -79,34 +86,42 @@ main(void) {
 		mvprintw(0, max_x - 1, "%d", b_score);
 
 		// Move ball
-		mvprintw(y, x, " ");
-
-		x += direction;
-		y = index / slope_x * slope_y;
-		mvprintw(y, x, "o");
+		gettimeofday(&stop, NULL);
+		if ((double)(stop.tv_usec - start.tv_usec) / 1000000 +
+				(double)(stop.tv_sec - start.tv_sec) > speed) {
+			gettimeofday(&start, NULL);
+			index += index_dir;
+			mvprintw(y, x, " ");
+			x += direction;
+			y = slope_y * index / slope_x;
+			mvprintw(y, x, "o");
+		}
 
-		// Check if touching paddle
-		if (x == max_x) {
+		// Check if touching paddle or edges
+		if (x >= max_x - 1) {
 			if (y >= boff && y <= boff + pad_h) {
 				direction *= -1;
+				x += direction;
 			} else {
 				a_score += 1;
-				usleep(600000);
 				x = max_x/2;
-				index = max_y/2;
+				index = (max_y/2)*(slope_x/slope_y);
+				speed /= 0.8;
+				sleep(1);
 			}
-		} else if (x == 0) {
+		} else if (x <= 1) {
 			if (y >= aoff && y <= aoff + pad_h) {
 				direction *= -1;
+				x += direction;
 			} else {
 				b_score += 1;
-				usleep(600000);
 				x = max_x/2;
-				index = max_y/2;
+				index = (max_y/2)*(slope_x/slope_y);
+				speed /= 0.8;
+				sleep(1);
 			}
-		} else if (y < 0 || y > max_y) {
+		} else if (y == 0 || y == max_y) {
 			index_dir *= -1;
 		}
-		usleep(3000000 * (1.0/((double)max_x + (double)max_y)));
 	}
 }