expose some window api

src/api/api.c

@@ -3,11 +3,13 @@
 
 int luaopen_system(lua_State *L);
 int luaopen_renderer(lua_State *L);
+int luaopen_window(lua_State *L);
 
 
 static const luaL_Reg libs[] = {
   { "system",    luaopen_system     },
   { "renderer",  luaopen_renderer   },
+  { "window",    luaopen_window     },
   { NULL, NULL }
 };
 
@@ -16,3 +18,4 @@ void api_load_libs(lua_State *L) {
     luaL_requiref(L, libs[i].name, libs[i].func, 1);
   }
 }
+

src/api/window.c

@@ -0,0 +1,95 @@
+#include <SDL2/SDL.h>
+#include <stdbool.h>
+#include "api.h"
+#ifdef _WIN32
+  #include <windows.h>
+#endif
+
+extern SDL_Window *window;
+
+
+static const char *window_opts[] = { "normal", "maximized", "fullscreen", 0 };
+
+static int f_get_window_mode(lua_State *L) {
+  unsigned flags = SDL_GetWindowFlags(window);
+  bool isFullscreen = flags & SDL_WINDOW_FULLSCREEN_DESKTOP;
+  bool isMaximized = flags & SDL_WINDOW_MAXIMIZED;
+  int index = 0;
+  if (isFullscreen) {
+    index = 2;
+  } else if (isMaximized) {
+    index = 1;
+  }
+  lua_pushstring(L, window_opts[index]);
+  return 1;
+}
+
+
+static int f_get_window_position(lua_State *L) {
+  int x, y;
+  SDL_GetWindowPosition(window, &x, &y);
+  lua_pushnumber(L, x);
+  lua_pushnumber(L, y);
+  return 2;
+}
+
+
+static int f_get_window_size(lua_State *L) {
+  int w = 0;
+  int h = 0;
+  SDL_GetWindowSize(window, &w, &h);
+  lua_pushnumber(L, w);
+  lua_pushnumber(L, h);
+  return 2;
+}
+
+// does not seem to work on Fedora Gnome Wayland
+// it returns true but visually nothing changes
+// possibly bc the view paints solid?
+static int f_set_window_opacity(lua_State *L) {
+  double n = luaL_checknumber(L, 1);
+  int r = SDL_SetWindowOpacity(window, n);
+  lua_pushboolean(L, r > -1);
+  return 1;
+}
+
+
+static int f_set_window_position(lua_State *L) {
+  int x = luaL_checknumber(L, 1);
+  int y = luaL_checknumber(L, 1);
+  SDL_SetWindowPosition(window, x, y);
+  return 0;
+}
+
+
+static int f_set_window_size(lua_State *L) {
+  int w = luaL_checknumber(L, 1);
+  int h = luaL_checknumber(L, 1);
+  if ((0 >= w) || (0 >= h)) {
+    lua_pushboolean(L, false);
+    lua_pushstring(L, "Width and height must be bigger than 0");
+    return 2;
+  }
+  SDL_SetWindowSize(window, w, h);
+  lua_pushboolean(L, true);
+  lua_pushnil(L);
+  return 2;
+}
+
+
+static const luaL_Reg lib[] = {
+  { "get_mode",          f_get_window_mode     },
+  { "get_position",      f_get_window_position },
+  { "get_size",          f_get_window_size     },
+  { "set_opacity",       f_set_window_opacity  },
+  { "set_position",      f_set_window_position },
+  { "set_size",          f_set_window_size     },
+  { NULL, NULL }
+};
+
+
+int luaopen_window(lua_State *L) {
+  luaL_newlib(L, lib);
+  return 1;
+}
+