Bump version to v0.5.

This should help to better visualize the velocity of the ship.

CHANGELOG

@@ -1,10 +0,0 @@
-v0.1: First Release
- - Basic simulation.
- - Information printing.
-
-v0.2: Menu Bar
- - Added a menu bar.
- - Can reset the simulation.
-
-v0.3: Port to C
- - Codebase ported to C for better performance.

CHANGELOG.md

@@ -0,0 +1,27 @@
+# Change Log
+
+## v0.5: Effects
+
+- Added stars in background for a better sense of velocity.
+- Viewport follows ship at center.
+- Zoom functionality.
+
+## v0.4: More functionality
+
+- Fix acceleration.
+- Add fullscreen support.
+- Pause functionality.
+
+## v0.3: Port to C
+
+- Codebase ported to C for better performance.
+
+## v0.2: Menu Bar
+
+- Added a menu bar.
+- Can reset the simulation.
+
+## v1.0: First Release
+
+- Basic simulation.
+- Information printing.

CMakeLists.txt

@@ -1,5 +1,5 @@
-# Copyright (C) 2018  Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
-# Author: Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
+# Copyright (C) 2026  Ortega Froysa, Nicolás <nicolas@ortegas.org>
+# Author: Ortega Froysa, Nicolás <nicolas@ortegas.org>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -14,11 +14,11 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-cmake_minimum_required(VERSION 2.8)
+cmake_minimum_required(VERSION 3.10)
 project(SpaceShipSim C)
 
 set(TARGET_NAME "spaceshipsim")
-set(TARGET_VERSION "0.3")
+set(TARGET_VERSION "0.5")
 
 if(NOT CMAKE_BUILD_TYPE)
 	set(CMAKE_BUILD_TYPE "release")
@@ -34,7 +34,7 @@ set(CMAKE_C_FLAGS_RELWITHDEBINFO "-g -O3 -ffast-math")
 set(CMAKE_C_FLAGS_MINSIZEREL "-Os")
 
 find_package(PkgConfig REQUIRED)
-pkg_check_modules(ALLEG5 REQUIRED allegro-5)
+pkg_check_modules(ALLEG5 REQUIRED allegro-5>=5.1.9)
 pkg_check_modules(ALLEG5-PRIM REQUIRED allegro_primitives-5)
 pkg_check_modules(ALLEG5-FONT REQUIRED allegro_font-5)
 
@@ -44,12 +44,12 @@ include_directories(
 set(SRCS
 	src/event_manager.c
 	src/main.c
-	src/ship.c)
+	src/ship.c
+	src/starfield.c)
 
 add_definitions(-DVERSION="${TARGET_VERSION}")
 
-if(${CMAKE_BUILD_TYPE} STREQUAL "debug" OR
-		${CMAKE_BUILD_TYPE} STREQUAL "relwithdebinfo")
+if(${CMAKE_BUILD_TYPE} STREQUAL "debug" OR ${CMAKE_BUILD_TYPE} STREQUAL "relwithdebinfo")
 	add_definitions(-DDEBUG)
 else()
 	add_definitions(-DNDEBUG)

README.md

@@ -1,39 +1,40 @@
-====================
-*** SpaceShipSim ***
-====================
+# SpaceShipSim
+
 This is a small simulation program of a space ship (with infinite fuel) in a
 frictionless environment (space). The idea is to use it for educational
 purposes.
 
-# Compiling
------------
+## Compiling
+
 In order to build this program you will require the following dependencies:
 
- - GNU GCC (https://gcc.gnu.org/)
- - CMake (https://cmake.org/)
- - Allegro 5 (http://liballeg.org/)
+- A C compiler that supports C99 or higher
+- CMake 3.10 or higher
+- Allegro 5
 
 You can then compile the program via the following commands:
 
-  cd build/
-  cmake ..
-  make
+```bash
+cd build/
+cmake ..
+make
+```
 
 This will create a release build with compiler optimizations. If you would like
-a debug build then pass the `-DCMAKE_BUILD_TYPE=debug' flag to the `cmake'
-command. If you would like to install then run `cmake' with the additional flag
-`-DCMAKE_INSTALL_PREFIX=<install_dir>'. If you are installing as a user then
-you may want to set the installation prefix to `/usr/local/', and if you're
+a debug build then pass the `-DCMAKE_BUILD_TYPE=debug` flag to the `cmake`
+command. If you would like to install then run `cmake` with the additional flag
+`-DCMAKE_INSTALL_PREFIX=<install_dir>`. If you are installing as a user then
+you may want to set the installation prefix to `/usr/local/`, and if you're
 packaging then please consult your distribution's policies. With this you
 should be able to run the `make install' target and install the binary.
 
-# Contributing
---------------
-If you would like to contribute to the project, send a patch file to my e-mail
-address: <nortega@themusicinnoise.net>.
+## Contributing
+
+If you would like to contribute to the project, send a patch file to my e-mail
+address: [nicolas@ortegas.org](mailto:nicolas@ortegas.org).
+
+## License
 
-# License
----------
 As educational software, unless otherwise noted, all files are licensed under
 the terms & conditions of the GNU General Public License version 3 or greater
-(see `LICENSE' file for more information).
+(see the [license file](LICENSE) for more information).

TODO

@@ -0,0 +1,2 @@
+TODO:
+ - Add presets with stellar masses (for gravity simulation).

src/event_manager.c

@@ -1,6 +1,6 @@
 /*
- * Copyright (C) 2018  Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
- * Author: Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
+ * Copyright (C) 2018,2026  Ortega Froysa, Nicolás <nicolas@ortegas.org>
+ * Author: Ortega Froysa, Nicolás <nicolas@ortegas.org>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -101,6 +101,16 @@ void set_key(int keycode, int value) {
 		case ALLEGRO_KEY_F:
 			keys[KEY_FULLSCREEN] = value;
 			break;
+		case ALLEGRO_KEY_P:
+			keys[KEY_PAUSE] = value;
+			break;
+		case ALLEGRO_KEY_LSHIFT:
+		case ALLEGRO_KEY_RSHIFT:
+			keys[KEY_SHIFT] = value;
+			break;
+		case ALLEGRO_KEY_Z:
+			keys[KEY_ZOOM] = value;
+			break;
 		default:
 			break;
 	}
@@ -110,29 +120,32 @@ void handle_event() {
 	ALLEGRO_EVENT evnt;
 	al_wait_for_event(event_queue, &evnt);
 
-	switch(evnt.type)
+	do
 	{
-		case ALLEGRO_EVENT_TIMER:
-			redraw = 1;
-			break;
-		case ALLEGRO_EVENT_DISPLAY_CLOSE:
-			run = 0;
-			break;
-		case ALLEGRO_EVENT_KEY_DOWN:
-			if(evnt.keyboard.keycode == ALLEGRO_KEY_H)
-				show_help = !show_help;
-			else if(evnt.keyboard.keycode == ALLEGRO_KEY_I)
-				show_info = !show_info;
-			else if(evnt.keyboard.keycode == ALLEGRO_KEY_Q ||
-					evnt.keyboard.keycode == ALLEGRO_KEY_ESCAPE)
+		switch(evnt.type)
+		{
+			case ALLEGRO_EVENT_TIMER:
+				redraw = 1;
+				break;
+			case ALLEGRO_EVENT_DISPLAY_CLOSE:
 				run = 0;
-			else
-				set_key(evnt.keyboard.keycode, 1);
-			break;
-		case ALLEGRO_EVENT_KEY_UP:
-			set_key(evnt.keyboard.keycode, 0);
-			break;
-	}
+				break;
+			case ALLEGRO_EVENT_KEY_DOWN:
+				if(evnt.keyboard.keycode == ALLEGRO_KEY_H)
+					show_help = !show_help;
+				else if(evnt.keyboard.keycode == ALLEGRO_KEY_I)
+					show_info = !show_info;
+				else if(evnt.keyboard.keycode == ALLEGRO_KEY_Q ||
+						evnt.keyboard.keycode == ALLEGRO_KEY_ESCAPE)
+					run = 0;
+				else
+					set_key(evnt.keyboard.keycode, 1);
+				break;
+			case ALLEGRO_EVENT_KEY_UP:
+				set_key(evnt.keyboard.keycode, 0);
+				break;
+		}
+	} while(al_get_next_event(event_queue, &evnt));
 }
 
 int key_is_down(int code) {

src/event_manager.h

@@ -1,6 +1,6 @@
 /*
- * Copyright (C) 2018  Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
- * Author: Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
+ * Copyright (C) 2018,2026  Ortega Froysa, Nicolás <nicolas@ortegas.org>
+ * Author: Ortega Froysa, Nicolás <nicolas@ortegas.org>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -27,7 +27,10 @@ enum {
 	KEY_RIGHT       = 0x3,
 	KEY_RESET       = 0x4,
 	KEY_FULLSCREEN  = 0x5,
-	KEY_MAX         = 0x6
+	KEY_PAUSE       = 0x6,
+	KEY_ZOOM        = 0x7,
+	KEY_SHIFT       = 0x8,
+	KEY_MAX         = 0x9
 };
 
 /**

src/globals.h

@@ -1,6 +1,6 @@
 /*
- * Copyright (C) 2018  Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
- * Author: Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
+ * Copyright (C) 2018,2026  Ortega Froysa, Nicolás <nicolas@ortegas.org>
+ * Author: Ortega Froysa, Nicolás <nicolas@ortegas.org>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -26,7 +26,7 @@
 #	define FPS 60.0f
 #endif
 #ifndef ACCEL
-#	define ACCEL 0.5f
+#	define ACCEL 0.1f
 #endif
 #ifndef TURN_ACCEL
 #	define TURN_ACCEL (M_PI / FPS)  // turn at pi radians / sec
@@ -39,6 +39,16 @@
 #	define WINDOW_HEIGHT 600
 #endif
 
+#ifndef ZOOM_MIN
+#	define ZOOM_MIN 0.25f
+#endif
+#ifndef ZOOM_MAX
+#	define ZOOM_MAX 4.0f
+#endif
+#ifndef ZOOM_STEP
+#	define ZOOM_STEP 0.1f
+#endif
+
 #include <math.h>
 #ifndef M_PI
 #	define M_PI 3.14159265f

src/main.c

@@ -1,6 +1,6 @@
 /*
- * Copyright (C) 2018  Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
- * Author: Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
+ * Copyright (C) 2018,2026  Ortega Froysa, Nicolás <nicolas@ortegas.org>
+ * Author: Ortega Froysa, Nicolás <nicolas@ortegas.org>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -19,6 +19,7 @@
 #include "globals.h"
 #include "event_manager.h"
 #include "ship.h"
+#include "starfield.h"
 
 int run;
 int redraw;
@@ -33,10 +34,14 @@ int show_info;
 const char *help =
 	"HELP:\n"
 	"LEFT/RIGHT - turn the ship\n"
-	"UP/DOWN - accelerate/decelerate\n"
+	"UP/DOWN - accelerate/reverse accelerate\n"
 	"R - reset the simulation\n"
+	"P - pause/unpause the simulation\n"
 	"I - show/hide simulation information\n"
 	"H - show/hide this help information\n"
+	"F - toggle fullscreen\n"
+	"Z - zoom in\n"
+	"SHIFT+Z - zoom out\n"
 	"Q/ESC - quit";
 
 const char *info_format =
@@ -44,11 +49,17 @@ const char *info_format =
 	"x: %f\n"
 	"y: %f\n"
 	"angle: %f (%f degrees)\n"
-	"velX: %f\n"
-	"velY: %f";
+	"velX: %f px/sec\n"
+	"velY: %f px/sec";
 
 int main() {
-	printf("SpaceShipSim v%s\n", VERSION);
+	char title[32];
+	float zoom = 1.0f;
+	float display_width = WINDOW_WIDTH;
+	float display_height = WINDOW_HEIGHT;
+
+	sprintf(title, "SpaceShipSim v%s", VERSION);
+	puts(title);
 
 	if(!al_init())
 	{
@@ -79,6 +90,7 @@ int main() {
 		fprintf(stderr, "alleg5: failed to initialize display.\n");
 		return 1;
 	}
+	al_set_window_title(display, title);
 #ifdef DEBUG
 	puts("Created display.");
 #endif
@@ -101,6 +113,10 @@ int main() {
 	redraw = 1;
 	show_help = 1;
 	show_info = 1;
+	int paused = 0;
+	int old_paused = 0;
+	int just_toggled_fullscreen = 0;
+	int zoom_pressed = 0;
 	while(run)
 	{
 		handle_event();
@@ -108,16 +124,77 @@ int main() {
 		// only redraw or run simulation if the timer event has occurred
 		if(redraw)
 		{
-			if(key_is_down(KEY_RESET))
-				ship_init(&ship, WINDOW_WIDTH / 2, WINDOW_HEIGHT / 2);
-			/*
-			 * We only run the simulation when the timer goes off so it's
-			 * running at a consistent rate, rather than dependent on random
-			 * events.
-			 */
-			ship_update(&ship);
+			if(just_toggled_fullscreen)
+			{
+				display_width = al_get_display_width(display);
+				display_height = al_get_display_height(display);
+			}
+
+			if(paused == old_paused && key_is_down(KEY_PAUSE))
+				paused = !paused;
+			else if(paused != old_paused && !key_is_down(KEY_PAUSE))
+				old_paused = paused;
+
+			if(!paused)
+			{
+				if(key_is_down(KEY_RESET))
+					ship_init(&ship, WINDOW_WIDTH / 2, WINDOW_HEIGHT / 2);
+				else
+					ship_update(&ship);
+			}
+
+			if (key_is_down(KEY_FULLSCREEN) && !just_toggled_fullscreen)
+			{
+				if(al_get_display_flags(display) & ALLEGRO_FULLSCREEN_WINDOW)
+				{
+					al_set_display_flag(display, ALLEGRO_FULLSCREEN_WINDOW, 0);
+				}
+				else
+				{
+					al_set_display_flag(display, ALLEGRO_FULLSCREEN_WINDOW, 1);
+				}
+				just_toggled_fullscreen = 1;
+			}
+			else if (!key_is_down(KEY_FULLSCREEN) && just_toggled_fullscreen)
+			{
+				just_toggled_fullscreen = 0;
+			}
+
+			if(key_is_down(KEY_SHIFT) && key_is_down(KEY_ZOOM) && !zoom_pressed)
+			{
+				zoom -= ZOOM_STEP;
+				if(zoom < ZOOM_MIN)
+					zoom = ZOOM_MIN;
+				zoom_pressed = 1;
+			}
+			else if(key_is_down(KEY_ZOOM) && !zoom_pressed)
+			{
+				zoom += ZOOM_STEP;
+				if(zoom > ZOOM_MAX)
+					zoom = ZOOM_MAX;
+				zoom_pressed = 1;
+			}
+			else if(!key_is_down(KEY_ZOOM) && zoom_pressed)
+			{
+				zoom_pressed = 0;
+			}
+
 			al_clear_to_color(al_map_rgb(0, 0, 0));
+
+			ALLEGRO_TRANSFORM transform;
+			al_identity_transform(&transform);
+			al_scale_transform(&transform, zoom, zoom);
+			al_translate_transform(&transform,
+					display_width / 2.0f - ship.x * zoom,
+					display_height / 2.0f - ship.y * zoom);
+			al_use_transform(&transform);
+
+			starfield_draw(ship.x, ship.y, zoom, display_width, display_height);
 			ship_draw(&ship);
+
+			al_identity_transform(&transform);
+			al_use_transform(&transform);
+
 			if(show_info)
 			{
 				char info[256];
@@ -125,10 +202,10 @@ int main() {
 						ship.x, ship.y,
 						ship.direction,
 						RAD_TO_DEG(ship.direction),
-						ship.velX, ship.velY);
+						ship.velX * FPS, ship.velY * FPS);
 				al_draw_multiline_text(font,
 						al_map_rgb(0xFF, 0xFF, 0xFF),
-						5, 5, WINDOW_WIDTH, 10.0f,
+						5, 5, (int)display_width, 10.0f,
 						ALLEGRO_ALIGN_LEFT,
 						info);
 			}
@@ -137,8 +214,8 @@ int main() {
 			{
 				al_draw_multiline_text(font,
 						al_map_rgb(0xFF, 0xFF, 0xFF),
-						WINDOW_WIDTH / 2, WINDOW_HEIGHT / 2,
-						WINDOW_WIDTH, 10.0f,
+						display_width / 2, display_height / 2 - 50,
+						(int)display_width, 10.0f,
 						ALLEGRO_ALIGN_CENTRE,
 						help);
 			}

src/ship.c

@@ -1,6 +1,6 @@
 /*
- * Copyright (C) 2018  Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
- * Author: Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
+ * Copyright (C) 2018,2026  Ortega Froysa, Nicolás <nicolas@ortegas.org>
+ * Author: Ortega Froysa, Nicolás <nicolas@ortegas.org>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -23,7 +23,6 @@
 #include <math.h>
 #include <assert.h>
 #include <allegro5/allegro_primitives.h>
-#include <stdio.h>
 
 #define SHIP_RADIUS 10.0f  // radius of the ship in pixels
 

src/ship.h

@@ -1,6 +1,6 @@
 /*
- * Copyright (C) 2018  Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
- * Author: Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
+ * Copyright (C) 2018,2026  Ortega Froysa, Nicolás <nicolas@ortegas.org>
+ * Author: Ortega Froysa, Nicolás <nicolas@ortegas.org>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

src/starfield.c

@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2026  Ortega Froysa, Nicolás <nicolas@ortegas.org>
+ * Author: Ortega Froysa, Nicolás <nicolas@ortegas.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "starfield.h"
+#include "globals.h"
+
+#include <stdlib.h>
+#include <math.h>
+#include <allegro5/allegro.h>
+#include <allegro5/allegro_primitives.h>
+
+#define CHUNK_SIZE 256
+#define STARS_PER_CHUNK 50
+#define STAR_COLOR al_map_rgb(255, 255, 255)
+
+static unsigned int hash_seed(int chunk_x, int chunk_y) {
+	unsigned int h = 5381;
+	h = ((h << 5) + h) ^ chunk_x;
+	h = ((h << 5) + h) ^ chunk_y;
+	return h;
+}
+
+static void generate_chunk_stars(int chunk_x, int chunk_y) {
+	unsigned int seed = hash_seed(chunk_x, chunk_y);
+	srand(seed);
+
+	float base_x = chunk_x * CHUNK_SIZE;
+	float base_y = chunk_y * CHUNK_SIZE;
+
+	for(int i = 0; i < STARS_PER_CHUNK; ++i)
+	{
+		float star_x = base_x + (float)(rand() % CHUNK_SIZE);
+		float star_y = base_y + (float)(rand() % CHUNK_SIZE);
+
+		al_draw_pixel(star_x, star_y, STAR_COLOR);
+	}
+}
+
+void starfield_draw(float camera_x, float camera_y, float zoom, float width, float height) {
+	float view_width = width / zoom;
+	float view_height = height / zoom;
+
+	float left = camera_x - view_width / 2.0f;
+	float right = camera_x + view_width / 2.0f;
+	float top = camera_y - view_height / 2.0f;
+	float bottom = camera_y + view_height / 2.0f;
+
+	int chunk_left = (int)floor(left / CHUNK_SIZE);
+	int chunk_right = (int)floor(right / CHUNK_SIZE);
+	int chunk_top = (int)floor(top / CHUNK_SIZE);
+	int chunk_bottom = (int)floor(bottom / CHUNK_SIZE);
+
+	for(int cy = chunk_top; cy <= chunk_bottom; ++cy)
+	{
+		for(int cx = chunk_left; cx <= chunk_right; ++cx)
+		{
+			generate_chunk_stars(cx, cy);
+		}
+	}
+}

src/starfield.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2026  Ortega Froysa, Nicolás <nicolas@ortegas.org>
+ * Author: Ortega Froysa, Nicolás <nicolas@ortegas.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+/**
+ * @brief Draw stars in the visible area of the starfield.
+ *
+ * @param camera_x The x position of the camera center.
+ * @param camera_y The y position of the camera center.
+ * @param zoom The zoom level (scale factor).
+ * @param width The display width in pixels.
+ * @param height The display height in pixels.
+ */
+void starfield_draw(float camera_x, float camera_y, float zoom, float width, float height);