Intial commit

src/timer.c

@@ -0,0 +1,87 @@
+/** 
+ * Copyright (c) 2014 rxi
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the MIT license. See LICENSE for details.
+ */
+
+#include <dos.h>
+#include <time.h>
+#include "luaobj.h"
+#include "image.h"
+#include "vga.h"
+
+long long timer_lastStep;
+double timer_lastDt;
+double timer_elapsed;
+
+double  timer_avgLastDt;
+double  timer_avgAcc = 1;
+int     timer_avgCount;
+double  timer_avgTimer;
+
+
+int l_timer_step(lua_State *L) {
+  /* Do delta */
+  long long now = uclock();
+  timer_lastDt = (now - timer_lastStep) / (double)UCLOCKS_PER_SEC;
+  timer_lastStep = now;
+  /* Do average */
+  timer_avgAcc += timer_lastDt;
+  timer_avgCount++;
+  timer_avgTimer -= timer_lastDt;
+  if (timer_avgTimer <= 0) {
+    timer_avgLastDt = (timer_avgAcc / timer_avgCount);
+    timer_avgTimer += 1;
+    timer_avgAcc = 0;
+    timer_avgCount = 0;
+  }
+  /* Do elapsed */
+  timer_elapsed += timer_lastDt;
+  return 0;
+}
+
+
+int l_timer_sleep(lua_State *L) {
+  delay(luaL_checknumber(L, 1) * 1000.);
+  return 1;
+}
+
+
+int l_timer_getDelta(lua_State *L) {
+  lua_pushnumber(L, timer_lastDt);
+  return 1;
+}
+
+
+int l_timer_getAverageDelta(lua_State *L) {
+  lua_pushnumber(L, timer_avgLastDt);
+  return 1;
+}
+
+
+int l_timer_getFPS(lua_State *L) {
+  lua_pushnumber(L, (int)(1. / timer_avgLastDt));
+  return 1;
+}
+
+
+int l_timer_getTime(lua_State *L) {
+  lua_pushnumber(L, timer_elapsed);
+  return 1;
+}
+
+
+int luaopen_timer(lua_State *L) {
+  luaL_Reg reg[] = {
+    { "step",             l_timer_step              },
+    { "sleep",            l_timer_sleep             },
+    { "getDelta",         l_timer_getDelta          },
+    { "getAverageDelta",  l_timer_getAverageDelta   },
+    { "getFPS",           l_timer_getFPS            },
+    { "getTime",          l_timer_getTime           },
+    { 0, 0 },
+  };
+  luaL_newlib(L, reg);
+  return 1;
+}