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#include <SDL2/SDL.h>
#include <iostream>
#include "lua/lua.hpp"
#define WIDTH 1280
#define HEIGHT 720
#define KEYSYM event.key.keysym.sym
SDL_Rect rect = {WIDTH/2, HEIGHT/2, 50, 50};
constexpr char* LUA_FILE = R"(
movementSpeed = 3;
function Setup()
end
function Update()
if keys[getKeycodeByName("RIGHT")] or keys[getKeycodeByName("D")] then
movePlayer(movementSpeed, 0)
end
if keys[getKeycodeByName("LEFT")] or keys[getKeycodeByName("A")] then
movePlayer(movementSpeed * -1, 0)
end
if keys[getKeycodeByName("DOWN")] or keys[getKeycodeByName("S")] then
movePlayer(0, movementSpeed)
end
if keys[getKeycodeByName("UP")] or keys[getKeycodeByName("W")] then
movePlayer(0, movementSpeed * -1)
end
end
)";
int l_move_rect(lua_State* L) {
int dx = luaL_checkinteger(L, 1);
int dy = luaL_checkinteger(L, 2);
rect.x += dx;
rect.y += dy;
return 0;
}
int l_keycode_from_string(lua_State* L) {
const char* keystr = luaL_checkstring(L, 1);
int scancode = -2;
if (strcmp(keystr, "RIGHT") == 0) scancode = SDL_SCANCODE_RIGHT;
else if (strcmp(keystr, "LEFT") == 0) scancode = SDL_SCANCODE_LEFT;
else if (strcmp(keystr, "UP") == 0) scancode = SDL_SCANCODE_UP;
else if (strcmp(keystr, "DOWN") == 0) scancode = SDL_SCANCODE_DOWN;
else if (strcmp(keystr, "D") == 0) scancode = SDL_SCANCODE_D;
else if (strcmp(keystr, "A") == 0) scancode = SDL_SCANCODE_A;
else if (strcmp(keystr, "S") == 0) scancode = SDL_SCANCODE_S;
else if (strcmp(keystr, "W") == 0) scancode = SDL_SCANCODE_W;
scancode += 1;
lua_pushinteger(L, scancode);
return 1;
}
void push_keys_to_lua(lua_State* L, bool keys[SDL_NUM_SCANCODES]) {
lua_newtable(L); // create a new table on the stack
for (int i = 0; i < SDL_NUM_SCANCODES; i++) {
lua_pushinteger(L, i + 1);
lua_pushboolean(L, keys[i]);
lua_settable(L, -3);
}
}
void call_lua_function(lua_State* L, const char* func_name) {
lua_getglobal(L, func_name);
if (lua_isfunction(L, -1)) {
if (lua_pcall(L, 0, 0, 0) != LUA_OK) {
std::cerr << "Lua Error in " << func_name << ": " << lua_tostring(L, -1) << std::endl;
lua_pop(L, 1);
}
} else {
lua_pop(L, 1);
}
}
int main() {
lua_State* L = luaL_newstate();
luaL_openlibs(L);
lua_register(L, "movePlayer", l_move_rect);
lua_register(L, "getKeycodeByName", l_keycode_from_string);
luaL_dostring(L, LUA_FILE);
SDL_Window* window = nullptr;
SDL_Renderer* renderer = nullptr;
SDL_Event event;
bool keys[SDL_NUM_SCANCODES] = {false};
bool running = true;
push_keys_to_lua(L, keys);
lua_setglobal(L, "keys");
SDL_Init(SDL_INIT_EVERYTHING);
SDL_CreateWindowAndRenderer(WIDTH, HEIGHT, 0, &window, &renderer);
SDL_SetWindowTitle(window, "Showdown of the Sticks");
call_lua_function(L, "Setup");
while (running) {
while (SDL_PollEvent(&event)) {
if (event.type == SDL_QUIT) {
running = false;
}
if (event.type == SDL_KEYDOWN) {
keys[event.key.keysym.scancode] = true;
}
if (event.type == SDL_KEYUP) {
keys[event.key.keysym.scancode] = false;
}
}
push_keys_to_lua(L, keys);
lua_setglobal(L, "keys");
call_lua_function(L, "Update");
SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
SDL_RenderClear(renderer);
SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255);
SDL_RenderFillRect(renderer, &rect);
SDL_RenderPresent(renderer);
SDL_Delay(10);
}
lua_close(L);
return 0;
}
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