├── LICENSE ├── README.md ├── asteroids ├── asteroids.c ├── asteroids.h ├── main.c ├── player.c ├── player.h ├── renderer.c ├── renderer.h ├── vector.c └── vector.h └── screenshot.png /LICENSE: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 2, June 1991 3 | 4 | Copyright (C) 1989, 1991 Free Software Foundation, Inc., 5 | 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 6 | Everyone is permitted to copy and distribute verbatim copies 7 | of this license document, but changing it is not allowed. 8 | 9 | Preamble 10 | 11 | The licenses for most software are designed to take away your 12 | freedom to share and change it. By contrast, the GNU General Public 13 | License is intended to guarantee your freedom to share and change free 14 | software--to make sure the software is free for all its users. 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If this is what you want to do, use the GNU Lesser General 339 | Public License instead of this License. 340 | 341 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # Asteroids 2 | 3 | This is a WebAssembly port of an [Asteroids game written in C](https://github.com/flightcrank/asteroids): 4 | 5 | **[Live Demo](http://www.levelupwasm.com/apps/asteroids/index.html)** | **[WebAssembly Tutorial](https://medium.com/@robaboukhalil/porting-games-to-the-web-with-webassembly-70d598e1a3ec?source=friends_link&sk=20c835664031227eae5690b8a12514f0)** 6 | 7 | ![Screenshot of asteroids game](https://raw.githubusercontent.com/robertaboukhalil/wasm-asteroids/master/screenshot.png) 8 | 9 | If you're looking for a practical guide to learning WebAssembly, check out my book [Level up with WebAssembly](http://www.levelupwasm.com/). 10 | 11 | ## Build 12 | 13 | Fetch Emscripten from DockerHub: 14 | 15 | ```bash 16 | docker pull robertaboukhalil/emsdk:1.38.26 17 | ``` 18 | 19 | Create a container from that image: 20 | 21 | ```bash 22 | # Create container from that image 23 | docker run -dt --name wasm robertaboukhalil/emsdk:1.38.26 24 | 25 | # Enter the container 26 | docker exec -it wasm bash 27 | ``` 28 | 29 | Within the container, fetch the code: 30 | 31 | ```bash 32 | git clone "https://github.com/robertaboukhalil/wasm-asteroids.git" 33 | cd wasm-asteroids 34 | ``` 35 | 36 | And compile it to WebAssembly: 37 | 38 | ```bash 39 | emcc \ 40 | -o app.html asteroids/*.c \ 41 | -Wall -g -lm \ 42 | -s USE_SDL=2 43 | ``` 44 | -------------------------------------------------------------------------------- /asteroids/asteroids.c: -------------------------------------------------------------------------------- 1 | 2 | //asteroids.c 3 | 4 | #include 5 | #include 6 | #include 7 | #include "renderer.h" 8 | #include "asteroids.h" 9 | 10 | void init_asteroids(struct asteroid asteroids[], int size) { 11 | 12 | int i = 0; 13 | int j = 0; 14 | struct vector2d translation = {SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2}; 15 | 16 | for (i = 0; i < size; i++) { 17 | 18 | int sign_x = rand() % 100; 19 | int sign_y = rand() % 100; 20 | 21 | //start asteroid in random location 22 | int lx = rand() % SCREEN_WIDTH / 2; 23 | int ly = rand() % SCREEN_HEIGHT / 2; 24 | 25 | //give asteroid random velocity 26 | float vx = (float) (rand() % 500) / 1000; 27 | float vy = (float) (rand() % 500) / 1000; 28 | 29 | float degrees = (float) (rand() % 100 + 1000) / 1000; 30 | 31 | //50% chance the sign of the variable will be switched to negative 32 | if (sign_x >= 50) { 33 | 34 | vx = -vx; 35 | lx = -lx; 36 | degrees = -degrees; 37 | } 38 | 39 | //50% chance the sign of the variable will be switched to negative 40 | if (sign_y >= 50) { 41 | 42 | vy = -vy; 43 | ly = -ly; 44 | } 45 | 46 | //firest 3 asteroids are alive 47 | if (i < 3) { 48 | 49 | asteroids[i].alive = 1; 50 | 51 | } else { 52 | 53 | asteroids[i].alive = 0; 54 | } 55 | 56 | asteroids[i].size = LARGE; 57 | asteroids[i].hit_radius = 35; 58 | asteroids[i].rotation = degrees; 59 | asteroids[i].location.x = lx; 60 | asteroids[i].location.y = ly; 61 | asteroids[i].velocity.x = vx; 62 | asteroids[i].velocity.y = vy; 63 | asteroids[i].obj_vert[0].x = .0; 64 | asteroids[i].obj_vert[0].y = .4; 65 | asteroids[i].obj_vert[1].x = .2; 66 | asteroids[i].obj_vert[1].y = .3; 67 | asteroids[i].obj_vert[2].x = .2; 68 | asteroids[i].obj_vert[2].y = .1; 69 | asteroids[i].obj_vert[3].x = .4; 70 | asteroids[i].obj_vert[3].y = .0; 71 | asteroids[i].obj_vert[4].x = .3; 72 | asteroids[i].obj_vert[4].y = -.2; 73 | asteroids[i].obj_vert[5].x = .1; 74 | asteroids[i].obj_vert[5].y = -.2; 75 | asteroids[i].obj_vert[6].x = .0; 76 | asteroids[i].obj_vert[6].y = -.3; 77 | asteroids[i].obj_vert[7].x = -.2; 78 | asteroids[i].obj_vert[7].y = -.2; 79 | asteroids[i].obj_vert[8].x = -.4; 80 | asteroids[i].obj_vert[8].y = 0; 81 | asteroids[i].obj_vert[9].x = -.3; 82 | asteroids[i].obj_vert[9].y = .3; 83 | 84 | for (j = 0; j < VERTS; j++) { 85 | 86 | //coverts verts from obj space to world space and traslate world space to screen space 87 | multiply_vector(&asteroids[i].obj_vert[j], 88); 88 | add_vector(&asteroids[i].world_vert[j], &asteroids[i].obj_vert[j]); 89 | add_vector(&asteroids[i].world_vert[j], &translation); 90 | } 91 | } 92 | } 93 | 94 | void update_asteroids(struct asteroid asteroids[], int size) { 95 | 96 | int i = 0; 97 | int j = 0; 98 | struct vector2d translation = {SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2}; 99 | 100 | for (i = 0; i < size; i++) { 101 | 102 | //updates each asteroids location based off its velicity vector 103 | add_vector(&asteroids[i].location, &asteroids[i].velocity); 104 | 105 | //update each vert of the asteroid to reflect the changes made to the asteroids location vector 106 | //and rotation amount, then translate the new vert location to screen space 107 | for (j = 0; j < VERTS; j++) { 108 | 109 | asteroids[i].world_vert[j] = add_vector_new(&asteroids[i].obj_vert[j], &asteroids[i].location); 110 | add_vector(&asteroids[i].world_vert[j], &translation); 111 | rotate_vector(&asteroids[i].obj_vert[j], asteroids[i].rotation); 112 | } 113 | } 114 | } 115 | 116 | void draw_asteroids(uint32_t* pixel_buffer, struct asteroid asteroids[], int size) { 117 | 118 | int i = 0; 119 | 120 | for (i = 0; i < size; i++) { 121 | 122 | if (asteroids[i].alive) { 123 | 124 | draw_line(pixel_buffer, asteroids[i].world_vert[0].x, asteroids[i].world_vert[0].y, asteroids[i].world_vert[1].x, asteroids[i].world_vert[1].y, 0xffffffff); 125 | draw_line(pixel_buffer, asteroids[i].world_vert[1].x, asteroids[i].world_vert[1].y, asteroids[i].world_vert[2].x, asteroids[i].world_vert[2].y, 0xffffffff); 126 | draw_line(pixel_buffer, asteroids[i].world_vert[2].x, asteroids[i].world_vert[2].y, asteroids[i].world_vert[3].x, asteroids[i].world_vert[3].y, 0xffffffff); 127 | draw_line(pixel_buffer, asteroids[i].world_vert[3].x, asteroids[i].world_vert[3].y, asteroids[i].world_vert[4].x, asteroids[i].world_vert[4].y, 0xffffffff); 128 | draw_line(pixel_buffer, asteroids[i].world_vert[4].x, asteroids[i].world_vert[4].y, asteroids[i].world_vert[5].x, asteroids[i].world_vert[5].y, 0xffffffff); 129 | draw_line(pixel_buffer, asteroids[i].world_vert[5].x, asteroids[i].world_vert[5].y, asteroids[i].world_vert[6].x, asteroids[i].world_vert[6].y, 0xffffffff); 130 | draw_line(pixel_buffer, asteroids[i].world_vert[6].x, asteroids[i].world_vert[6].y, asteroids[i].world_vert[7].x, asteroids[i].world_vert[7].y, 0xffffffff); 131 | draw_line(pixel_buffer, asteroids[i].world_vert[7].x, asteroids[i].world_vert[7].y, asteroids[i].world_vert[8].x, asteroids[i].world_vert[8].y, 0xffffffff); 132 | draw_line(pixel_buffer, asteroids[i].world_vert[8].x, asteroids[i].world_vert[8].y, asteroids[i].world_vert[9].x, asteroids[i].world_vert[9].y, 0xffffffff); 133 | draw_line(pixel_buffer, asteroids[i].world_vert[9].x, asteroids[i].world_vert[9].y, asteroids[i].world_vert[0].x, asteroids[i].world_vert[0].y, 0xffffffff); 134 | } 135 | 136 | /* 137 | //draw vert representing ships location 138 | struct vector2d cpy = {asteroids[i].location.x, asteroids[i].location.y}; 139 | struct vector2d translation = {SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2}; 140 | add_vector(&cpy, &translation); 141 | 142 | draw_pixel(pixel_buffer, cpy.x, cpy.y, 0x00ff00ff); 143 | */ 144 | } 145 | } 146 | 147 | int shrink_asteroid(struct asteroid* a, int size) { 148 | 149 | a->obj_vert[0].x = .0; 150 | a->obj_vert[0].y = .4; 151 | a->obj_vert[1].x = .2; 152 | a->obj_vert[1].y = .3; 153 | a->obj_vert[2].x = .2; 154 | a->obj_vert[2].y = .1; 155 | a->obj_vert[3].x = .4; 156 | a->obj_vert[3].y = .0; 157 | a->obj_vert[4].x = .3; 158 | a->obj_vert[4].y = -.2; 159 | a->obj_vert[5].x = .1; 160 | a->obj_vert[5].y = -.2; 161 | a->obj_vert[6].x = .0; 162 | a->obj_vert[6].y = -.3; 163 | a->obj_vert[7].x = -.2; 164 | a->obj_vert[7].y = -.2; 165 | a->obj_vert[8].x = -.4; 166 | a->obj_vert[8].y = 0; 167 | a->obj_vert[9].x = -.3; 168 | a->obj_vert[9].y = .3; 169 | 170 | int i = 0; 171 | 172 | for (i = 0; i < VERTS; i++) { 173 | 174 | multiply_vector(&a->obj_vert[i], 88); 175 | } 176 | 177 | if (size == LARGE) { 178 | 179 | //shrink asteroid 180 | for (i = 0; i < VERTS; i++) { 181 | 182 | divide_vector(&a->obj_vert[i], 2); 183 | } 184 | 185 | a->size = MEDIUM; 186 | 187 | return 0; 188 | } 189 | 190 | if (size == MEDIUM) { 191 | 192 | //shrink asteroid 193 | for (i = 0; i < VERTS; i++) { 194 | 195 | divide_vector(&a->obj_vert[i], 4); 196 | } 197 | 198 | a->size = SMALL; 199 | 200 | return 0; 201 | } 202 | 203 | if (size == SMALL) { 204 | 205 | //shrink asteroid 206 | for (i = 0; i < VERTS; i++) { 207 | 208 | divide_vector(&a->obj_vert[i], 8); 209 | } 210 | 211 | return 0; 212 | } 213 | 214 | return 1; 215 | } 216 | 217 | void spawn_asteroids(struct asteroid a[], int length, int size, struct vector2d v) { 218 | 219 | int i = 0; 220 | int count = 0; 221 | 222 | for (i = 0; i < length; i++) { 223 | 224 | if(a[i].alive == 0) { 225 | 226 | if (count == 3) { 227 | 228 | break; 229 | } 230 | 231 | a[i].location = v; 232 | a[i].hit_radius /= 2; 233 | a[i].alive = 1; 234 | count++; 235 | shrink_asteroid(&a[i], size); 236 | } 237 | } 238 | } 239 | 240 | void bounds_asteroids(struct asteroid asteroids[], int size) { 241 | 242 | int i = 0; 243 | 244 | for (i = 0 ; i < size; i++) { 245 | 246 | if (asteroids[i].location.x < -SCREEN_WIDTH / 2) { 247 | 248 | asteroids[i].location.x = SCREEN_WIDTH / 2; 249 | } 250 | 251 | if (asteroids[i].location.x > SCREEN_WIDTH / 2) { 252 | 253 | asteroids[i].location.x = -SCREEN_WIDTH / 2; 254 | } 255 | 256 | if (asteroids[i].location.y < -SCREEN_HEIGHT / 2) { 257 | 258 | asteroids[i].location.y = SCREEN_HEIGHT / 2; 259 | } 260 | 261 | if (asteroids[i].location.y > SCREEN_HEIGHT / 2) { 262 | 263 | asteroids[i].location.y = -SCREEN_HEIGHT / 2; 264 | } 265 | } 266 | } 267 | 268 | 269 | int collision_asteroids(struct asteroid asteroids[], int size, struct vector2d* v, float radius) { 270 | 271 | 272 | int i = 0; 273 | 274 | 275 | for (i = 0; i < size; i++) { 276 | 277 | //only check for collions for asteroids that are shown onscreen 278 | if (asteroids[i].alive == 1) { 279 | 280 | float sum = asteroids[i].hit_radius + radius; 281 | float a = pow(asteroids[i].location.x - v->x, 2); 282 | float b = pow(asteroids[i].location.y - v->y, 2); 283 | float distance = sqrt(a + b); 284 | 285 | if (distance < sum) { 286 | 287 | return i; 288 | } 289 | } 290 | } 291 | 292 | return -1; 293 | } 294 | -------------------------------------------------------------------------------- /asteroids/asteroids.h: -------------------------------------------------------------------------------- 1 | 2 | //asteroids.h 3 | #include "vector.h" 4 | #define VERTS 10 5 | 6 | enum sizes {SMALL, MEDIUM, LARGE}; 7 | 8 | struct asteroid { 9 | 10 | int alive; 11 | enum sizes size; 12 | float hit_radius; 13 | float rotation; 14 | struct vector2d location; 15 | struct vector2d velocity; 16 | struct vector2d obj_vert[VERTS]; 17 | struct vector2d world_vert[VERTS]; 18 | }; 19 | 20 | void init_asteroids(struct asteroid asteroids[], int size); 21 | void update_asteroids(struct asteroid asteroids[], int size); 22 | void draw_asteroids(uint32_t* pixel_buffer, struct asteroid asteroids[], int size); 23 | int shrink_asteroid(struct asteroid* a, int size); 24 | void spawn_asteroids(struct asteroid a[], int length, int size, struct vector2d v); 25 | void bounds_asteroids(struct asteroid asteroids[], int size); 26 | int collision_asteroids(struct asteroid asteroids[], int size, struct vector2d* v, float radius); 27 | -------------------------------------------------------------------------------- /asteroids/main.c: -------------------------------------------------------------------------------- 1 | 2 | //main.c 3 | 4 | //Using SDL and standard IO 5 | #include 6 | #include 7 | #include 8 | #include "renderer.h" 9 | #include "player.h" 10 | #include "asteroids.h" 11 | 12 | // Import "emscripten_set_main_loop()" and "emscripten_cancel_main_loop()" 13 | #include "emscripten.h" 14 | 15 | #define ASTEROIDS 27 16 | #define LIVES 3 17 | 18 | int init(int width, int height); 19 | 20 | SDL_Window* window = NULL; //The window we'll be rendering to 21 | SDL_Renderer *renderer; //The renderer SDL will use to draw to the screen 22 | SDL_Texture *screen; //The texture representing the screen 23 | uint32_t* pixels = NULL; //The pixel buffer to draw to 24 | struct asteroid asteroids[ASTEROIDS]; //The asteroids 25 | struct player p; //The player 26 | struct player lives[LIVES]; //Player lives left 27 | 28 | 29 | // Main game loop 30 | void mainloop() 31 | { 32 | // Moved these variables 33 | int sleep = 0; 34 | int quit = 0; 35 | SDL_Event event; 36 | Uint32 next_game_tick = SDL_GetTicks(); 37 | 38 | // Main loop code 39 | //check for new events every frame 40 | SDL_PumpEvents(); 41 | 42 | const Uint8 *state = SDL_GetKeyboardState(NULL); 43 | 44 | if (state[SDL_SCANCODE_ESCAPE]) { 45 | quit = 1; 46 | } 47 | 48 | if (state[SDL_SCANCODE_UP]) { 49 | struct vector2d thrust = get_direction(&p); 50 | multiply_vector(&thrust, .06); 51 | apply_force(&p.velocity, thrust); 52 | } 53 | 54 | if (state[SDL_SCANCODE_LEFT]) { 55 | rotate_player(&p, -4); 56 | } 57 | 58 | if (state[SDL_SCANCODE_RIGHT]) { 59 | rotate_player(&p, 4); 60 | } 61 | 62 | while (SDL_PollEvent(&event)) { 63 | switch(event.type) { 64 | case SDL_KEYDOWN: 65 | switch( event.key.keysym.sym ) { 66 | case SDLK_SPACE: 67 | if (p.lives > 0) { 68 | shoot_bullet(&p); 69 | } 70 | break; 71 | } 72 | } 73 | } 74 | 75 | //draw to the pixel buffer 76 | clear_pixels(pixels, 0x00000000); 77 | draw_asteroids(pixels, asteroids, ASTEROIDS); 78 | update_player(&p); 79 | bounds_player(&p); 80 | bounds_asteroids(asteroids, ASTEROIDS); 81 | 82 | int res = collision_asteroids(asteroids, ASTEROIDS, &p.location, p.hit_radius); 83 | 84 | if (res != -1) { 85 | p.lives--; 86 | p.location.x = 0; 87 | p.location.y = 0; 88 | p.velocity.x = 0; 89 | p.velocity.y = 0; 90 | 91 | int i = LIVES - 1; 92 | for ( i = LIVES; i >= 0; i--) { 93 | if(lives[i].lives > 0) { 94 | lives[i].lives = 0; 95 | break; 96 | } 97 | } 98 | } 99 | draw_player(pixels, &p); 100 | draw_player(pixels, &lives[0]); 101 | draw_player(pixels, &lives[1]); 102 | draw_player(pixels, &lives[2]); 103 | 104 | int i = 0; 105 | struct vector2d translation = {-SCREEN_WIDTH / 2, -SCREEN_HEIGHT / 2}; 106 | 107 | for (i = 0; i < BULLETS; i++) { 108 | //only check for collision for bullets that are shown on screen 109 | if (p.bullets[i].alive == TRUE) { 110 | //convert bullet screen space location to world space to compare 111 | //with asteroids world space to detect a collision 112 | struct vector2d world = add_vector_new(&p.bullets[i].location, &translation); 113 | int index = collision_asteroids(asteroids, ASTEROIDS, &world, 1); 114 | 115 | //collision occured 116 | if (index != -1) { 117 | asteroids[index].alive = 0; 118 | p.bullets[i].alive = FALSE; 119 | 120 | if (asteroids[index].size != SMALL) { 121 | spawn_asteroids(asteroids, ASTEROIDS, asteroids[index].size, asteroids[index].location); 122 | } 123 | } 124 | } 125 | } 126 | 127 | update_asteroids(asteroids, ASTEROIDS); 128 | 129 | //draw buffer to the texture representing the screen 130 | SDL_UpdateTexture(screen, NULL, pixels, SCREEN_WIDTH * sizeof (Uint32)); 131 | 132 | //draw to the screen 133 | SDL_RenderClear(renderer); 134 | SDL_RenderCopy(renderer, screen, NULL, NULL); 135 | SDL_RenderPresent(renderer); 136 | 137 | if(quit == 1) { 138 | emscripten_cancel_main_loop(); 139 | 140 | //free the screen buffer 141 | free(pixels); 142 | 143 | //Destroy window 144 | SDL_DestroyWindow(window); 145 | 146 | //Quit SDL subsystems 147 | SDL_Quit(); 148 | } 149 | } 150 | 151 | int main (int argc, char* args[]) { 152 | 153 | //SDL Window setup 154 | if (init(SCREEN_WIDTH, SCREEN_HEIGHT) == 1) { 155 | 156 | return 0; 157 | } 158 | 159 | int i = 0; 160 | int j = 0; 161 | int offset = 0; 162 | struct vector2d translation = {-SCREEN_WIDTH / 2, -SCREEN_HEIGHT / 2}; 163 | 164 | //set up icons used to represent player lives 165 | for (i = 0; i < LIVES; i++) { 166 | 167 | init_player(&lives[i]); 168 | lives[i].lives = 1; 169 | 170 | //shrink lives 171 | for (j = 0; j < P_VERTS; j++) { 172 | 173 | divide_vector(&lives[i].obj_vert[j], 2); 174 | } 175 | 176 | //convert screen space vector into world space 177 | struct vector2d top_left = {20 + offset, 20}; 178 | add_vector(&top_left, &translation); 179 | lives[i].location = top_left; 180 | update_player(&lives[i]); 181 | offset += 20; 182 | } 183 | 184 | //set up player and asteroids in world space 185 | init_player(&p); 186 | init_asteroids(asteroids, ASTEROIDS); 187 | 188 | emscripten_set_main_loop(mainloop, 0, 1); 189 | 190 | return 0; 191 | } 192 | 193 | int init(int width, int height) { 194 | 195 | //Initialize SDL 196 | if (SDL_Init(SDL_INIT_VIDEO) < 0) { 197 | 198 | printf("SDL could not initialize! SDL_Error: %s\n", SDL_GetError()); 199 | 200 | return 1; 201 | } 202 | 203 | //Create window 204 | SDL_CreateWindowAndRenderer(SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN, &window, &renderer); 205 | 206 | //set up screen texture 207 | screen = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_RGBA8888, SDL_TEXTUREACCESS_STREAMING, SCREEN_WIDTH, SCREEN_HEIGHT); 208 | 209 | //allocate pixel buffer 210 | pixels = (Uint32*) malloc((SCREEN_WIDTH * SCREEN_HEIGHT) * sizeof(Uint32)); 211 | 212 | 213 | if (window == NULL) { 214 | 215 | printf ("Window could not be created! SDL_Error: %s\n", SDL_GetError()); 216 | 217 | return 1; 218 | } 219 | 220 | if (screen == NULL) { 221 | 222 | printf ("Texture could not be created! SDL_Error: %s\n", SDL_GetError()); 223 | 224 | return 1; 225 | } 226 | 227 | if (pixels == NULL) { 228 | 229 | printf ("Error allocating pixel buffer"); 230 | 231 | return 1; 232 | } 233 | 234 | return 0; 235 | } 236 | -------------------------------------------------------------------------------- /asteroids/player.c: -------------------------------------------------------------------------------- 1 | 2 | //player.c 3 | 4 | #include 5 | #include "renderer.h" 6 | #include "player.h" 7 | 8 | void init_player(struct player* p) { 9 | 10 | int i = 0; 11 | struct vector2d translation = {SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2}; 12 | 13 | p->hit_radius = 15; 14 | p->lives = 3; 15 | p->location.x = 0; 16 | p->location.y = 0; 17 | p->velocity.x = 0; 18 | p->velocity.y = 0; 19 | p->obj_vert[0].x = 0; 20 | p->obj_vert[0].y = 1.5; 21 | p->obj_vert[1].x = -1; 22 | p->obj_vert[1].y = -1; 23 | p->obj_vert[2].x = 1; 24 | p->obj_vert[2].y = -1; 25 | 26 | //convert player verts from object space to world space 27 | for(i = 0; i < P_VERTS; i++) { 28 | 29 | multiply_vector(&p->obj_vert[i], -1); 30 | multiply_vector(&p->obj_vert[i], 12); 31 | add_vector(&p->world_vert[i], &p->obj_vert[i]); 32 | add_vector(&p->world_vert[i], &translation); 33 | } 34 | 35 | for(i = 0; i < BULLETS; i++) { 36 | 37 | p->bullets[i].alive = FALSE; 38 | } 39 | } 40 | 41 | void apply_force(struct vector2d* velocity, struct vector2d v) { 42 | 43 | add_vector(velocity, &v); 44 | } 45 | 46 | struct vector2d get_direction(struct player* p) { 47 | 48 | struct vector2d direction = p->obj_vert[0]; 49 | normalise_vector(&direction); 50 | 51 | return direction; 52 | } 53 | 54 | void shoot_bullet(struct player* p) { 55 | 56 | int i = 0; 57 | 58 | for (i = 0; i < BULLETS; i++) { 59 | 60 | if (p->bullets[i].alive == FALSE) { 61 | 62 | p->bullets[i].alive = TRUE; 63 | p->bullets[i].location = p->world_vert[0]; 64 | p->bullets[i].velocity = get_direction(p); 65 | multiply_vector(&p->bullets[i].velocity, 4.1); 66 | break; 67 | } 68 | } 69 | } 70 | 71 | void draw_player(uint32_t* pixel_buffer, struct player* p) { 72 | 73 | int i = 0; 74 | 75 | if (p->lives > 0) { 76 | 77 | draw_line(pixel_buffer, p->world_vert[0].x, p->world_vert[0].y, p->world_vert[1].x, p->world_vert[1].y, 0xffffffff); 78 | draw_line(pixel_buffer, p->world_vert[1].x, p->world_vert[1].y, p->world_vert[2].x, p->world_vert[2].y, 0xffffffff); 79 | draw_line(pixel_buffer, p->world_vert[2].x, p->world_vert[2].y, p->world_vert[0].x, p->world_vert[0].y, 0xffffffff); 80 | } 81 | 82 | /* 83 | //draw vers representing the player 84 | for (i = 0; i < P_VERTS; i++) { 85 | 86 | draw_pixel(pixel_buffer, p->world_vert[i].x, p->world_vert[i].y, 0xff00ffff); 87 | } 88 | */ 89 | 90 | //draw verts representing the bullets 91 | for (i = 0; i < BULLETS; i++) { 92 | 93 | if (p->bullets[i].alive == TRUE) { 94 | 95 | draw_pixel(pixel_buffer, p->bullets[i].location.x, p->bullets[i].location.y, 0xffffffff); 96 | } 97 | } 98 | 99 | /* 100 | //draw vert representing ships location 101 | struct vector2d cpy = {p->location.x, p->location.y}; 102 | struct vector2d translation = {SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2}; 103 | add_vector(&cpy, &translation); 104 | 105 | draw_pixel(pixel_buffer, cpy.x, cpy.y, 0x00ff00ff); 106 | */ 107 | } 108 | 109 | void update_player(struct player* p) { 110 | 111 | limit_vector(&p->velocity, 2); 112 | add_vector(&p->location, &p->velocity); 113 | 114 | struct vector2d translation = {SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2}; 115 | 116 | int i = 0; 117 | 118 | for (i =0; i < P_VERTS; i++) { 119 | 120 | p->world_vert[i] = add_vector_new(&p->obj_vert[i], &p->location); 121 | add_vector(&p->world_vert[i], &translation); 122 | } 123 | 124 | for (i = 0; i < BULLETS; i++) { 125 | 126 | add_vector(&p->bullets[i].location, &p->bullets[i].velocity); 127 | } 128 | } 129 | 130 | void rotate_player(struct player* p, float degrees) { 131 | 132 | int i = 0; 133 | 134 | for (i =0; i < P_VERTS; i++) { 135 | 136 | rotate_vector(&p->obj_vert[i], degrees); 137 | } 138 | } 139 | 140 | void bounds_player(struct player* p) { 141 | 142 | int i = 0; 143 | 144 | if (p->location.x < -SCREEN_WIDTH / 2) { 145 | 146 | p->location.x = SCREEN_WIDTH / 2; 147 | } 148 | 149 | if (p->location.x > SCREEN_WIDTH / 2) { 150 | 151 | p->location.x = -SCREEN_WIDTH / 2; 152 | } 153 | 154 | if (p->location.y < -SCREEN_HEIGHT / 2) { 155 | 156 | p->location.y = SCREEN_HEIGHT / 2; 157 | } 158 | 159 | if (p->location.y > SCREEN_HEIGHT / 2) { 160 | 161 | p->location.y = -SCREEN_HEIGHT / 2; 162 | } 163 | 164 | //bullet is out of bounds, reset bullet to be shot again 165 | //bullets are in world space 166 | for (i = 0; i < BULLETS; i++) { 167 | 168 | if (p->bullets[i].location.x < 0 || p->bullets[i].location.x >= SCREEN_WIDTH) { 169 | 170 | p->bullets[i].alive = FALSE; 171 | } 172 | 173 | if (p->bullets[i].location.y < 0 || p->bullets[i].location.y >= SCREEN_HEIGHT) { 174 | 175 | p->bullets[i].alive = FALSE; 176 | } 177 | } 178 | } 179 | 180 | -------------------------------------------------------------------------------- /asteroids/player.h: -------------------------------------------------------------------------------- 1 | 2 | //player.h 3 | 4 | #include "vector.h" 5 | 6 | #define P_VERTS 3 7 | #define BULLETS 3 8 | 9 | enum boolean {TRUE, FALSE}; 10 | 11 | struct bullet { 12 | 13 | struct vector2d location; 14 | struct vector2d velocity; 15 | enum boolean alive; 16 | }; 17 | 18 | struct player { 19 | 20 | float hit_radius; 21 | int lives; 22 | struct vector2d location; 23 | struct vector2d velocity; 24 | struct vector2d obj_vert[P_VERTS]; 25 | struct vector2d world_vert[P_VERTS]; 26 | struct bullet bullets[BULLETS]; 27 | }; 28 | 29 | void init_player(struct player* p); 30 | 31 | void draw_player(uint32_t* pixel_buffer, struct player* p); 32 | 33 | void shoot_bullet(struct player* p); 34 | 35 | void update_player(struct player* p); 36 | 37 | void bounds_player(struct player* p); 38 | 39 | void apply_force(struct vector2d* velocity, struct vector2d v); 40 | 41 | void rotate_player(struct player* p, float degrees); 42 | 43 | struct vector2d get_direction(struct player* p); 44 | 45 | -------------------------------------------------------------------------------- /asteroids/renderer.c: -------------------------------------------------------------------------------- 1 | 2 | //renderer.c 3 | 4 | #include "renderer.h" 5 | 6 | int draw_line(uint32_t* pixel_buffer, int x1, int y1, int x2, int y2, uint32_t colour) { 7 | 8 | 9 | //plot the first point 10 | draw_pixel(pixel_buffer, x1, y1, colour); 11 | 12 | //make sure we draw the line always from left to right 13 | if (x1 > x2) { 14 | 15 | int temp_x = x1; 16 | int temp_y = y1; 17 | 18 | x1 = x2; 19 | y1 = y2; 20 | 21 | x2 = temp_x; 22 | y2 = temp_y; 23 | } 24 | 25 | int dx = x2 - x1; 26 | int dy = y2 - y1; 27 | 28 | //the length of the line is greater along the X axis 29 | if (dx >= fabs(dy)) { 30 | 31 | float slope = (float) dy / dx; 32 | 33 | //line travels from top to bottom 34 | if (y1 <= y2) { 35 | 36 | float ideal_y = y1 + slope; 37 | int y = (int) round(ideal_y); 38 | float error = ideal_y - y; 39 | 40 | int i = 0; 41 | 42 | //loop through all the X values 43 | for(i = 1; i <= dx; i++) { 44 | 45 | int x = x1 + i; 46 | 47 | draw_pixel(pixel_buffer, x, y, colour); 48 | 49 | error += slope; 50 | 51 | if (error >= 0.5) { 52 | 53 | y++; 54 | error -= 1; 55 | } 56 | } 57 | } 58 | 59 | //line travels from bottom to top 60 | if (y1 > y2) { 61 | 62 | float ideal_y = y1 + slope; 63 | int y = (int) round(ideal_y); 64 | float error = ideal_y - y; 65 | 66 | int i = 0; 67 | 68 | //loop through all the x values 69 | for(i = 1; i <= dx; i++) { 70 | 71 | int x = x1 + i; 72 | 73 | draw_pixel(pixel_buffer, x, y, colour); 74 | 75 | error += slope; 76 | 77 | if (error <= -0.5) { 78 | 79 | y--; 80 | error += 1; 81 | } 82 | } 83 | } 84 | 85 | 86 | } 87 | 88 | //the length of the line is greater along the Y axis 89 | if (fabs(dy) > dx) { 90 | 91 | float slope = (float) dx / dy; 92 | 93 | //line travels from top to bottom 94 | if (y1 < y2) { 95 | 96 | float ideal_x = x1 + slope; 97 | int x = (int) round(ideal_x); 98 | float error = ideal_x - x; 99 | 100 | int i = 0; 101 | 102 | //loop through all the y values 103 | for(i = 1; i <= dy; i++) { 104 | 105 | int y = y1 + i; 106 | 107 | draw_pixel(pixel_buffer, x, y, colour); 108 | 109 | error += slope; 110 | 111 | if (error >= 0.5) { 112 | 113 | x++; 114 | error -= 1; 115 | } 116 | } 117 | } 118 | 119 | //draw line from bottom to top 120 | if (y1 > y2) { 121 | 122 | float ideal_x = x1 - slope; 123 | int x = (int) round(ideal_x); 124 | float error = ideal_x - x; 125 | 126 | int i = 0; 127 | 128 | //loop through all the y values 129 | for(i = 1; i <= fabs(dy); i++) { 130 | 131 | int y = y1 - i; 132 | 133 | draw_pixel(pixel_buffer, x, y, colour); 134 | 135 | error += slope; 136 | 137 | if (error <= -0.5) { 138 | 139 | x++; 140 | error += 1; 141 | } 142 | } 143 | } 144 | } 145 | 146 | return 0; 147 | } 148 | 149 | int draw_pixel(uint32_t* pixel_buffer, int x, int y, uint32_t colour) { 150 | 151 | //dont draw any pixels that are outside of the pixel buffer 152 | if (x < 0 || y < 0) { 153 | 154 | return 1; 155 | } 156 | 157 | //dont draw any pixels that are outside of the pixel buffer 158 | if (x >= SCREEN_WIDTH || y >= SCREEN_HEIGHT) { 159 | 160 | return 1; 161 | } 162 | 163 | uint32_t position = y * SCREEN_WIDTH + x; 164 | pixel_buffer[position] = colour; 165 | 166 | return 0; 167 | } 168 | 169 | void clear_pixels(uint32_t* pixel_buffer, uint32_t colour) { 170 | 171 | int i = 0; 172 | int buffer_size = SCREEN_WIDTH * SCREEN_HEIGHT; 173 | 174 | for (i = 0; i < buffer_size; i++) { 175 | 176 | pixel_buffer[i] = colour; 177 | } 178 | } 179 | 180 | -------------------------------------------------------------------------------- /asteroids/renderer.h: -------------------------------------------------------------------------------- 1 | 2 | //renderer.h 3 | 4 | #include 5 | #include 6 | 7 | //Screen dimension constants 8 | #define SCREEN_WIDTH 640 9 | #define SCREEN_HEIGHT 480 10 | 11 | //assing a colour to a single pixel 12 | int draw_pixel(uint32_t* pixel_buffer, int x, int y, uint32_t colour); 13 | 14 | int draw_line(uint32_t* pixel_buffer, int x1, int y1, int x2, int y2, uint32_t colour); 15 | 16 | //assign a colour to all pixels 17 | void clear_pixels(uint32_t* pixel_buffer, uint32_t colour); 18 | 19 | -------------------------------------------------------------------------------- /asteroids/vector.c: -------------------------------------------------------------------------------- 1 | 2 | //vector.c 3 | 4 | #include 5 | #include 6 | #include "vector.h" 7 | 8 | void add_vector(struct vector2d* a, struct vector2d* b) { 9 | 10 | a->x += b->x; 11 | a->y += b->y; 12 | } 13 | 14 | struct vector2d add_vector_new(struct vector2d* a, struct vector2d* b) { 15 | 16 | struct vector2d new = {a->x + b->x, a->y + b->y}; 17 | 18 | return new; 19 | } 20 | 21 | void multiply_vector(struct vector2d* v, float n) { 22 | 23 | v->x *= n; 24 | v->y *= n; 25 | } 26 | 27 | void divide_vector(struct vector2d* v, float n) { 28 | 29 | v->x /= n; 30 | v->y /= n; 31 | } 32 | 33 | void print_vector(struct vector2d* a) { 34 | 35 | printf("x = %f\n y = %f\n", a->x, a->y); 36 | } 37 | 38 | float magnitude_vector(struct vector2d* v) { 39 | 40 | float c2 = pow(v->x, 2) + pow(v->y, 2); 41 | 42 | return sqrt(c2); 43 | } 44 | 45 | void normalise_vector(struct vector2d* v) { 46 | 47 | float mag = magnitude_vector(v); 48 | 49 | divide_vector(v, mag); 50 | } 51 | 52 | void limit_vector(struct vector2d* v, float limit) { 53 | 54 | float mag = magnitude_vector(v); 55 | 56 | if (mag > limit) { 57 | 58 | float ratio = limit / mag; 59 | v->x *= ratio; 60 | v->y *= ratio; 61 | } 62 | } 63 | 64 | void rotate_vector(struct vector2d* v, float degrees) { 65 | 66 | //calculate radians 67 | float angle = degrees * M_PI / 180; 68 | float sine = sin(angle); 69 | float cosine = cos(angle); 70 | 71 | //rotation matix 72 | float matrix[2][2] = {{cosine, -sine}, {sine, cosine}}; 73 | 74 | float x = v->x; 75 | float y = v->y; 76 | 77 | v->x = matrix[0][0] * x + matrix[0][1] * y; 78 | v->y = matrix[1][0] * x + matrix[1][1] * y; 79 | } 80 | 81 | -------------------------------------------------------------------------------- /asteroids/vector.h: -------------------------------------------------------------------------------- 1 | 2 | //vector.h 3 | 4 | #ifndef VECTOR_H 5 | #define VECTOR_H 6 | 7 | struct vector2d { 8 | 9 | float x; 10 | float y; 11 | }; 12 | 13 | void add_vector(struct vector2d* a, struct vector2d* b); 14 | 15 | struct vector2d add_vector_new(struct vector2d* a, struct vector2d* b); 16 | 17 | void multiply_vector(struct vector2d* v, float n); 18 | 19 | void divide_vector(struct vector2d* v, float n); 20 | 21 | void print_vector(struct vector2d* a); 22 | 23 | void rotate_vector(struct vector2d* v, float degrees); 24 | 25 | float magnitude_vector(struct vector2d* v); 26 | 27 | void normalise_vector(struct vector2d* v); 28 | 29 | void limit_vector(struct vector2d* v, float limit); 30 | 31 | #endif //VECTOR_H 32 | -------------------------------------------------------------------------------- /screenshot.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/robertaboukhalil/wasm-asteroids/d9b08b1f0d16053d86c3353922d390bfb881f8f0/screenshot.png --------------------------------------------------------------------------------