/* woodeneye-008.c ... */ /* * This code is public domain. Feel free to use it for any purpose! */ #define SDL_MAIN_USE_CALLBACKS 1 /* use the callbacks instead of main() */ #include <SDL3/SDL.h> #include <SDL3/SDL_main.h> #define MAP_BOX_SCALE 16 #define MAP_BOX_EDGES_LEN (12 + MAP_BOX_SCALE * 2) #define MAX_PLAYER_COUNT 4 #define CIRCLE_DRAW_SIDES 32 #define CIRCLE_DRAW_SIDES_LEN (CIRCLE_DRAW_SIDES + 1) typedef struct { SDL_MouseID mouse; SDL_KeyboardID keyboard; double pos[3]; double vel[3]; unsigned int yaw; int pitch; float radius, height; unsigned char color[3]; unsigned char wasd; } Player; typedef struct { SDL_Window *window; SDL_Renderer *renderer; int player_count; Player players[MAX_PLAYER_COUNT]; float edges[MAP_BOX_EDGES_LEN][6]; } AppState; static const struct { const char *key; const char *value; } extended_metadata[] = { { SDL_PROP_APP_METADATA_URL_STRING, "https://examples.libsdl.org/SDL3/game/02-woodeneye-008/" }, { SDL_PROP_APP_METADATA_CREATOR_STRING, "SDL team" }, { SDL_PROP_APP_METADATA_COPYRIGHT_STRING, "Placed in the public domain" }, { SDL_PROP_APP_METADATA_TYPE_STRING, "game" } }; static int whoseMouse(SDL_MouseID mouse, const Player players[], int players_len) { int i; for (i = 0; i < players_len; i++) { if (players[i].mouse == mouse) return i; } return -1; } static int whoseKeyboard(SDL_KeyboardID keyboard, const Player players[], int players_len) { int i; for (i = 0; i < players_len; i++) { if (players[i].keyboard == keyboard) return i; } return -1; } static void shoot(int shooter, Player players[], int players_len) { int i, j; double x0 = players[shooter].pos[0]; double y0 = players[shooter].pos[1]; double z0 = players[shooter].pos[2]; double bin_rad = SDL_PI_D / 2147483648.0; double yaw_rad = bin_rad * players[shooter].yaw; double pitch_rad = bin_rad * players[shooter].pitch; double cos_yaw = SDL_cos( yaw_rad); double sin_yaw = SDL_sin( yaw_rad); double cos_pitch = SDL_cos(pitch_rad); double sin_pitch = SDL_sin(pitch_rad); double vx = -sin_yaw*cos_pitch; double vy = sin_pitch; double vz = -cos_yaw*cos_pitch; for (i = 0; i < players_len; i++) { if (i == shooter) continue; Player *target = &(players[i]); int hit = 0; for (j = 0; j < 2; j++) { double r = target->radius; double h = target->height; double dx = target->pos[0] - x0; double dy = target->pos[1] - y0 + (j == 0 ? 0 : r - h); double dz = target->pos[2] - z0; double vd = vx*dx + vy*dy + vz*dz; double dd = dx*dx + dy*dy + dz*dz; double vv = vx*vx + vy*vy + vz*vz; double rr = r * r; if (vd < 0) continue; if (vd * vd >= vv * (dd - rr)) hit += 1; } if (hit) { target->pos[0] = (double)(MAP_BOX_SCALE * (SDL_rand(256) - 128)) / 256; target->pos[1] = (double)(MAP_BOX_SCALE * (SDL_rand(256) - 128)) / 256; target->pos[2] = (double)(MAP_BOX_SCALE * (SDL_rand(256) - 128)) / 256; } } } static void update(Player *players, int players_len, Uint64 dt_ns) { int i; for (i = 0; i < players_len; i++) { Player *player = &players[i]; double rate = 6.0; double time = (double)dt_ns * 1e-9; double drag = SDL_exp(-time * rate); double diff = 1.0 - drag; double mult = 60.0; double grav = 25.0; double yaw = (double)player->yaw; double rad = yaw * SDL_PI_D / 2147483648.0; double cos = SDL_cos(rad); double sin = SDL_sin(rad); unsigned char wasd = player->wasd; double dirX = (wasd & 8 ? 1.0 : 0.0) - (wasd & 2 ? 1.0 : 0.0); double dirZ = (wasd & 4 ? 1.0 : 0.0) - (wasd & 1 ? 1.0 : 0.0); double norm = dirX * dirX + dirZ * dirZ; double accX = mult * (norm == 0 ? 0 : ( cos*dirX + sin*dirZ) / SDL_sqrt(norm)); double accZ = mult * (norm == 0 ? 0 : (-sin*dirX + cos*dirZ) / SDL_sqrt(norm)); double velX = player->vel[0]; double velY = player->vel[1]; double velZ = player->vel[2]; player->vel[0] -= velX * diff; player->vel[1] -= grav * time; player->vel[2] -= velZ * diff; player->vel[0] += diff * accX / rate; player->vel[2] += diff * accZ / rate; player->pos[0] += (time - diff/rate) * accX / rate + diff * velX / rate; player->pos[1] += -0.5 * grav * time * time + velY * time; player->pos[2] += (time - diff/rate) * accZ / rate + diff * velZ / rate; double scale = (double)MAP_BOX_SCALE; double bound = scale - player->radius; double posX = SDL_max(SDL_min(bound, player->pos[0]), -bound); double posY = SDL_max(SDL_min(bound, player->pos[1]), player->height - scale); double posZ = SDL_max(SDL_min(bound, player->pos[2]), -bound); if (player->pos[0] != posX) player->vel[0] = 0; if (player->pos[1] != posY) player->vel[1] = (wasd & 16) ? 8.4375 : 0; if (player->pos[2] != posZ) player->vel[2] = 0; player->pos[0] = posX; player->pos[1] = posY; player->pos[2] = posZ; } } static void drawCircle(SDL_Renderer *renderer, float r, float x, float y) { float ang; SDL_FPoint points[CIRCLE_DRAW_SIDES_LEN]; int i; for (i = 0; i < CIRCLE_DRAW_SIDES_LEN; i++) { ang = 2.0f * SDL_PI_F * (float)i / (float)CIRCLE_DRAW_SIDES; points[i].x = x + r * SDL_cosf(ang); points[i].y = y + r * SDL_sinf(ang); } SDL_RenderLines(renderer, (const SDL_FPoint*)&points, CIRCLE_DRAW_SIDES_LEN); } static void drawClippedSegment( SDL_Renderer *renderer, float ax, float ay, float az, float bx, float by, float bz, float x, float y, float z, float w) { if (az >= -w && bz >= -w) return; float dx = ax - bx; float dy = ay - by; if (az > -w) { float t = (-w - bz) / (az - bz); ax = bx + dx * t; ay = by + dy * t; az = -w; } else if (bz > -w) { float t = (-w - az) / (bz - az); bx = ax - dx * t; by = ay - dy * t; bz = -w; } ax = -z * ax / az; ay = -z * ay / az; bx = -z * bx / bz; by = -z * by / bz; SDL_RenderLine(renderer, x + ax, y - ay, x + bx, y - by); } static char debug_string[32]; static void draw(SDL_Renderer *renderer, const float (*edges)[6], const Player players[], int players_len) { int w, h, i, j, k; if (!SDL_GetRenderOutputSize(renderer, &w, &h)) { return; } SDL_SetRenderDrawColor(renderer, 0, 0, 0, SDL_ALPHA_OPAQUE); SDL_RenderClear(renderer); if (players_len > 0) { float wf = (float)w; float hf = (float)h; int part_hor = players_len > 2 ? 2 : 1; int part_ver = players_len > 1 ? 2 : 1; float size_hor = wf / ((float)part_hor); float size_ver = hf / ((float)part_ver); for (i = 0; i < players_len; i++) { const Player *player = &players[i]; float mod_x = (float)(i % part_hor); float mod_y = (float)(i / part_hor); float hor_origin = (mod_x + 0.5f) * size_hor; float ver_origin = (mod_y + 0.5f) * size_ver; float cam_origin = (float)(0.5 * SDL_sqrt(size_hor * size_hor + size_ver * size_ver)); float hor_offset = mod_x * size_hor; float ver_offset = mod_y * size_ver; SDL_Rect rect; rect.x = (int)hor_offset; rect.y = (int)ver_offset; rect.w = (int)size_hor; rect.h = (int)size_ver; SDL_SetRenderClipRect(renderer, &rect); double x0 = player->pos[0]; double y0 = player->pos[1]; double z0 = player->pos[2]; double bin_rad = SDL_PI_D / 2147483648.0; double yaw_rad = bin_rad * player->yaw; double pitch_rad = bin_rad * player->pitch; double cos_yaw = SDL_cos( yaw_rad); double sin_yaw = SDL_sin( yaw_rad); double cos_pitch = SDL_cos(pitch_rad); double sin_pitch = SDL_sin(pitch_rad); double mat[9] = { cos_yaw , 0, -sin_yaw , sin_yaw*sin_pitch, cos_pitch, cos_yaw*sin_pitch, sin_yaw*cos_pitch, -sin_pitch, cos_yaw*cos_pitch }; SDL_SetRenderDrawColor(renderer, 64, 64, 64, 255); for (k = 0; k < MAP_BOX_EDGES_LEN; k++) { const float *line = edges[k]; float ax = (float)(mat[0] * (line[0] - x0) + mat[1] * (line[1] - y0) + mat[2] * (line[2] - z0)); float ay = (float)(mat[3] * (line[0] - x0) + mat[4] * (line[1] - y0) + mat[5] * (line[2] - z0)); float az = (float)(mat[6] * (line[0] - x0) + mat[7] * (line[1] - y0) + mat[8] * (line[2] - z0)); float bx = (float)(mat[0] * (line[3] - x0) + mat[1] * (line[4] - y0) + mat[2] * (line[5] - z0)); float by = (float)(mat[3] * (line[3] - x0) + mat[4] * (line[4] - y0) + mat[5] * (line[5] - z0)); float bz = (float)(mat[6] * (line[3] - x0) + mat[7] * (line[4] - y0) + mat[8] * (line[5] - z0)); drawClippedSegment(renderer, ax, ay, az, bx, by, bz, hor_origin, ver_origin, cam_origin, 1); } for (j = 0; j < players_len; j++) { if (i == j) continue; const Player *target = &players[j]; SDL_SetRenderDrawColor(renderer, target->color[0], target->color[1], target->color[2], 255); for (k = 0; k < 2; k++) { double rx = target->pos[0] - player->pos[0]; double ry = target->pos[1] - player->pos[1] + (target->radius - target->height) * (float)k; double rz = target->pos[2] - player->pos[2]; double dx = mat[0] * rx + mat[1] * ry + mat[2] * rz; double dy = mat[3] * rx + mat[4] * ry + mat[5] * rz; double dz = mat[6] * rx + mat[7] * ry + mat[8] * rz; double r_eff = target->radius * cam_origin / dz; if (!(dz < 0)) continue; drawCircle(renderer, (float)(r_eff), (float)(hor_origin - cam_origin*dx/dz), (float)(ver_origin + cam_origin*dy/dz)); } } SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255); SDL_RenderLine(renderer, hor_origin, ver_origin-10, hor_origin, ver_origin+10); SDL_RenderLine(renderer, hor_origin-10, ver_origin, hor_origin+10, ver_origin); } } SDL_SetRenderClipRect(renderer, 0); SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255); SDL_RenderDebugText(renderer, 0, 0, debug_string); SDL_RenderPresent(renderer); } static void initPlayers(Player *players, int len) { int i; for (i = 0; i < len; i++) { players[i].pos[0] = 8.0 * (i & 1 ? -1.0 : 1.0); players[i].pos[1] = 0; players[i].pos[2] = 8.0 * (i & 1 ? -1.0 : 1.0) * (i & 2 ? -1.0 : 1.0); players[i].vel[0] = 0; players[i].vel[1] = 0; players[i].vel[2] = 0; players[i].yaw = 0x20000000 + (i & 1 ? 0x80000000 : 0) + (i & 2 ? 0x40000000 : 0); players[i].pitch = -0x08000000; players[i].radius = 0.5f; players[i].height = 1.5f; players[i].wasd = 0; players[i].mouse = 0; players[i].keyboard = 0; players[i].color[0] = (1 << (i / 2)) & 2 ? 0 : 0xff; players[i].color[1] = (1 << (i / 2)) & 1 ? 0 : 0xff; players[i].color[2] = (1 << (i / 2)) & 4 ? 0 : 0xff; players[i].color[0] = (i & 1) ? players[i].color[0] : ~players[i].color[0]; players[i].color[1] = (i & 1) ? players[i].color[1] : ~players[i].color[1]; players[i].color[2] = (i & 1) ? players[i].color[2] : ~players[i].color[2]; } } static void initEdges(int scale, float (*edges)[6], int edges_len) { int i, j; const float r = (float)scale; const int map[24] = { 0,1 , 1,3 , 3,2 , 2,0 , 7,6 , 6,4 , 4,5 , 5,7 , 6,2 , 3,7 , 0,4 , 5,1 }; for(i = 0; i < 12; i++) { for (j = 0; j < 3; j++) { edges[i][j+0] = (map[i*2+0] & (1 << j) ? r : -r); edges[i][j+3] = (map[i*2+1] & (1 << j) ? r : -r); } } for(i = 0; i < scale; i++) { float d = (float)(i * 2); for (j = 0; j < 2; j++) { edges[i+12][3*j+0] = j ? r : -r; edges[i+12][3*j+1] = -r; edges[i+12][3*j+2] = d-r; edges[i+12+scale][3*j+0] = d-r; edges[i+12+scale][3*j+1] = -r; edges[i+12+scale][3*j+2] = j ? r : -r; } } } SDL_AppResult SDL_AppInit(void **appstate, int argc, char *argv[]) { if (!SDL_SetAppMetadata("Example splitscreen shooter game", "1.0", "com.example.woodeneye-008")) { return SDL_APP_FAILURE; } int i; for (i = 0; i < SDL_arraysize(extended_metadata); i++) { if (!SDL_SetAppMetadataProperty(extended_metadata[i].key, extended_metadata[i].value)) { return SDL_APP_FAILURE; } } AppState *as = SDL_calloc(1, sizeof(AppState)); if (!as) { return SDL_APP_FAILURE; } else { *appstate = as; } if (!SDL_Init(SDL_INIT_VIDEO)) { return SDL_APP_FAILURE; } if (!SDL_CreateWindowAndRenderer("examples/game/woodeneye-008", 640, 480, 0, &as->window, &as->renderer)) { return SDL_APP_FAILURE; } as->player_count = 1; initPlayers(as->players, MAX_PLAYER_COUNT); initEdges(MAP_BOX_SCALE, as->edges, MAP_BOX_EDGES_LEN); debug_string[0] = 0; SDL_SetRenderVSync(as->renderer, false); SDL_SetWindowRelativeMouseMode(as->window, true); SDL_SetHintWithPriority(SDL_HINT_WINDOWS_RAW_KEYBOARD, "1", SDL_HINT_OVERRIDE); return SDL_APP_CONTINUE; } SDL_AppResult SDL_AppEvent(void *appstate, SDL_Event *event) { AppState *as = appstate; Player *players = as->players; int player_count = as->player_count; int i; switch (event->type) { case SDL_EVENT_QUIT: return SDL_APP_SUCCESS; break; case SDL_EVENT_MOUSE_REMOVED: for (i = 0; i < player_count; i++) { if (players[i].mouse == event->mdevice.which) { players[i].mouse = 0; } } break; case SDL_EVENT_KEYBOARD_REMOVED: for (i = 0; i < player_count; i++) { if (players[i].keyboard == event->kdevice.which) { players[i].keyboard = 0; } } break; case SDL_EVENT_MOUSE_MOTION: { SDL_MouseID id = event->motion.which; int index = whoseMouse(id, players, player_count); if (index >= 0) { players[index].yaw -= ((int)event->motion.xrel) * 0x00080000; players[index].pitch = SDL_max(-0x40000000, SDL_min(0x40000000, players[index].pitch - ((int)event->motion.yrel) * 0x00080000)); } else if (id) { for (i = 0; i < MAX_PLAYER_COUNT; i++) { if (players[i].mouse == 0) { players[i].mouse = id; as->player_count = SDL_max(as->player_count, i + 1); break; } } } break; } case SDL_EVENT_MOUSE_BUTTON_DOWN: { SDL_MouseID id = event->button.which; int index = whoseMouse(id, players, player_count); if (index >= 0) { shoot(index, players, player_count); } break; } case SDL_EVENT_KEY_DOWN: { SDL_Keycode sym = event->key.key; SDL_KeyboardID id = event->key.which; int index = whoseKeyboard(id, players, player_count); if (index >= 0) { if (sym == SDLK_W) players[index].wasd |= 1; if (sym == SDLK_A) players[index].wasd |= 2; if (sym == SDLK_S) players[index].wasd |= 4; if (sym == SDLK_D) players[index].wasd |= 8; if (sym == SDLK_SPACE) players[index].wasd |= 16; } else if (id) { for (i = 0; i < MAX_PLAYER_COUNT; i++) { if (players[i].keyboard == 0) { players[i].keyboard = id; as->player_count = SDL_max(as->player_count, i + 1); break; } } } break; } case SDL_EVENT_KEY_UP: { SDL_Keycode sym = event->key.key; SDL_KeyboardID id = event->key.which; if (sym == SDLK_ESCAPE) return SDL_APP_SUCCESS; int index = whoseKeyboard(id, players, player_count); if (index >= 0) { if (sym == SDLK_W) players[index].wasd &= 30; if (sym == SDLK_A) players[index].wasd &= 29; if (sym == SDLK_S) players[index].wasd &= 27; if (sym == SDLK_D) players[index].wasd &= 23; if (sym == SDLK_SPACE) players[index].wasd &= 15; } break; } } return SDL_APP_CONTINUE; } SDL_AppResult SDL_AppIterate(void *appstate) { AppState *as = appstate; static Uint64 accu = 0; static Uint64 last = 0; static Uint64 past = 0; Uint64 now = SDL_GetTicksNS(); Uint64 dt_ns = now - past; update(as->players, as->player_count, dt_ns); draw(as->renderer, (const float (*)[6])as->edges, as->players, as->player_count); if (now - last > 999999999) { last = now; SDL_snprintf(debug_string, sizeof(debug_string), "%" SDL_PRIu64 " fps", accu); accu = 0; } past = now; accu += 1; Uint64 elapsed = SDL_GetTicksNS() - now; if (elapsed < 999999) { SDL_DelayNS(999999 - elapsed); } return SDL_APP_CONTINUE; } void SDL_AppQuit(void *appstate, SDL_AppResult result) { SDL_free(appstate); // just free the memory, SDL will clean up the window/renderer for us. }