#include "screen_fade.hpp"
#include "timer.hpp"
#include "player_status.hpp"
+#include "random_generator.hpp"
// the engine will be run with a logical framerate of 64fps.
// We chose 64fps here because it is a power of 2, so 1/64 gives an "even"
// binary fraction...
static const float LOGICAL_FPS = 64.0;
+/** ticks (as returned from SDL_GetTicks) per frame */
+static const Uint32 TICKS_PER_FRAME = (Uint32) (1000.0 / LOGICAL_FPS);
+/** don't skip more than every 2nd frame */
+static const int MAX_FRAME_SKIP = 2;
+
+float game_speed = 1.0f;
MainLoop* main_loop = NULL;
MainLoop::MainLoop()
- : speed(1.0), nextpop(false), nextpush(false)
+ : speed(1.0), nextpop(false), nextpush(false), fps(0), screenshot_requested(false)
{
using namespace Scripting;
TimeScheduler::instance = new TimeScheduler();
{
this->next_screen.reset(screen);
this->screen_fade.reset(screen_fade);
- if(nextpop)
- nextpush = false;
- else
- nextpush = true;
+ nextpush = !nextpop;
nextpop = false;
speed = 1.0;
}
this->speed = speed;
}
+float
+MainLoop::get_speed() const
+{
+ return speed;
+}
+
void
MainLoop::draw_fps(DrawingContext& context, float fps_fps)
{
char str[60];
snprintf(str, sizeof(str), "%3.1f", fps_fps);
const char* fpstext = "FPS";
- context.draw_text(white_text, fpstext, Vector(SCREEN_WIDTH - white_text->get_text_width(fpstext) - gold_text->get_text_width(" 99999") - BORDER_X, BORDER_Y + 20), LEFT_ALLIGN, LAYER_FOREGROUND1);
- context.draw_text(gold_text, str, Vector(SCREEN_WIDTH - BORDER_X, BORDER_Y + 20), RIGHT_ALLIGN, LAYER_FOREGROUND1);
+ context.draw_text(white_text, fpstext, Vector(SCREEN_WIDTH - white_text->get_text_width(fpstext) - gold_text->get_text_width(" 99999") - BORDER_X, BORDER_Y + 20), ALIGN_LEFT, LAYER_HUD);
+ context.draw_text(gold_text, str, Vector(SCREEN_WIDTH - BORDER_X, BORDER_Y + 20), ALIGN_RIGHT, LAYER_HUD);
}
void
-MainLoop::run()
+MainLoop::draw(DrawingContext& context)
{
- DrawingContext context;
-
- unsigned int frame_count = 0;
- float fps_fps = 0;
- Uint32 fps_ticks = SDL_GetTicks();
- Uint32 fps_nextframe_ticks = SDL_GetTicks();
- Uint32 ticks;
- bool skipdraw = false;
-
- running = true;
- while(running) {
- while( (next_screen.get() != NULL || nextpop == true) &&
- (screen_fade.get() == NULL || screen_fade->done())) {
- if(current_screen.get() != NULL) {
- current_screen->leave();
- }
+ static Uint32 fps_ticks = SDL_GetTicks();
+ static int frame_count = 0;
- if(nextpop) {
- if(screen_stack.empty()) {
- running = false;
- break;
- }
- next_screen.reset(screen_stack.back());
- screen_stack.pop_back();
- }
- if(nextpush && current_screen.get() != NULL) {
- screen_stack.push_back(current_screen.release());
+ current_screen->draw(context);
+ if(Menu::current() != NULL)
+ Menu::current()->draw(context);
+ if(screen_fade.get() != NULL)
+ screen_fade->draw(context);
+ Console::instance->draw(context);
+
+ if(config->show_fps)
+ draw_fps(context, fps);
+
+ // if a screenshot was requested, pass request on to drawing_context
+ if (screenshot_requested) {
+ context.take_screenshot();
+ screenshot_requested = false;
+ }
+ context.do_drawing();
+
+ /* Calculate frames per second */
+ if(config->show_fps)
+ {
+ ++frame_count;
+
+ if(SDL_GetTicks() - fps_ticks >= 500)
+ {
+ fps = (float) frame_count / .5;
+ frame_count = 0;
+ fps_ticks = SDL_GetTicks();
+ }
+ }
+}
+
+void
+MainLoop::update_gamelogic(float elapsed_time)
+{
+ Scripting::update_debugger();
+ Scripting::TimeScheduler::instance->update(game_time);
+ current_screen->update(elapsed_time);
+ if(screen_fade.get() != NULL)
+ screen_fade->update(elapsed_time);
+ Console::instance->update(elapsed_time);
+}
+
+void
+MainLoop::process_events()
+{
+ main_controller->update();
+ SDL_Event event;
+ while(SDL_PollEvent(&event)) {
+ main_controller->process_event(event);
+ if(Menu::current() != NULL)
+ Menu::current()->event(event);
+ if(event.type == SDL_QUIT)
+ quit();
+ else if (event.type == SDL_KEYDOWN && event.key.keysym.sym == SDLK_F11) {
+ config->use_fullscreen = !config->use_fullscreen;
+ init_video();
+ }
+ else if (event.type == SDL_KEYDOWN && event.key.keysym.sym == SDLK_PRINT) {
+ take_screenshot();
+ }
+ }
+}
+
+void
+MainLoop::handle_screen_switch()
+{
+ while( (next_screen.get() != NULL || nextpop) &&
+ (screen_fade.get() == NULL || screen_fade->done())) {
+ if(current_screen.get() != NULL) {
+ current_screen->leave();
+ }
+
+ if(nextpop) {
+ if(screen_stack.empty()) {
+ running = false;
+ break;
}
-
- nextpush = false;
- nextpop = false;
- speed = 1.0;
- if(next_screen.get() != NULL)
- next_screen->setup();
- current_screen.reset(next_screen.release());
- screen_fade.reset(NULL);
-
- waiting_threads.wakeup();
+ next_screen.reset(screen_stack.back());
+ screen_stack.pop_back();
+ }
+ if(nextpush && current_screen.get() != NULL) {
+ screen_stack.push_back(current_screen.release());
}
+ nextpush = false;
+ nextpop = false;
+ speed = 1.0;
+ if(next_screen.get() != NULL)
+ next_screen->setup();
+ current_screen.reset(next_screen.release());
+ screen_fade.reset(NULL);
+
+ waiting_threads.wakeup();
+ }
+}
+
+void
+MainLoop::run(DrawingContext &context)
+{
+ Uint32 last_ticks = 0;
+ Uint32 elapsed_ticks = 0;
+
+ running = true;
+ while(running) {
+
+ handle_screen_switch();
if(!running || current_screen.get() == NULL)
break;
-
- float elapsed_time = 1.0 / LOGICAL_FPS;
- ticks = SDL_GetTicks();
- if(ticks > fps_nextframe_ticks) {
- if(skipdraw == true) {
- // already skipped last frame? we have to slow down the game then...
- skipdraw = false;
- fps_nextframe_ticks -= (Uint32) (1000.0 / LOGICAL_FPS);
- } else {
- // don't draw all frames when we're getting too slow
- skipdraw = true;
- }
- } else {
- skipdraw = false;
- while(fps_nextframe_ticks > ticks) {
- /* just wait */
- // If we really have to wait long, then do an imprecise SDL_Delay()
- Uint32 diff = fps_nextframe_ticks - ticks;
- if(diff > 10) {
- SDL_Delay(diff - 2);
- }
- ticks = SDL_GetTicks();
- }
- }
- fps_nextframe_ticks = ticks + (Uint32) (1000.0 / LOGICAL_FPS);
- if(!skipdraw) {
- current_screen->draw(context);
- if(Menu::current() != NULL)
- Menu::current()->draw(context);
- if(screen_fade.get() != NULL)
- screen_fade->draw(context);
- Console::instance->draw(context);
+ Uint32 ticks = SDL_GetTicks();
+ elapsed_ticks += ticks - last_ticks;
+ last_ticks = ticks;
- if(config->show_fps)
- draw_fps(context, fps_fps);
+ Uint32 ticks_per_frame = TICKS_PER_FRAME * game_speed;
- context.do_drawing();
+ if (elapsed_ticks > ticks_per_frame*4) {
+ // when the game loads up or levels are switched the
+ // elapsed_ticks grows extremly large, so we just ignore those
+ // large time jumps
+ elapsed_ticks = 0;
+ }
- /* Calculate frames per second */
- if(config->show_fps)
+ int frames = 0;
+
+ if (elapsed_ticks > ticks_per_frame)
{
- ++frame_count;
-
- if(SDL_GetTicks() - fps_ticks >= 500)
- {
- fps_fps = (float) frame_count / .5;
- frame_count = 0;
- fps_ticks = SDL_GetTicks();
- }
- }
- }
+ while(elapsed_ticks > ticks_per_frame && frames < MAX_FRAME_SKIP)
+ {
+ elapsed_ticks -= ticks_per_frame;
+ float timestep = 1.0 / LOGICAL_FPS;
+ real_time += timestep;
+ timestep *= speed;
+ game_time += timestep;
- real_time += elapsed_time;
- elapsed_time *= speed;
- game_time += elapsed_time;
-
- Scripting::update_debugger();
- Scripting::TimeScheduler::instance->update(game_time);
- current_screen->update(elapsed_time);
- if(screen_fade.get() != NULL)
- screen_fade->update(elapsed_time);
- Console::instance->update(elapsed_time);
-
- main_controller->update();
- SDL_Event event;
- while(SDL_PollEvent(&event)) {
- main_controller->process_event(event);
- if(Menu::current() != NULL)
- Menu::current()->event(event);
- if(event.type == SDL_QUIT)
- quit();
- }
+ process_events();
+ update_gamelogic(timestep);
+ frames += 1;
+ }
+
+ draw(context);
+ }
sound_manager->update();
+
+ SDL_Delay(0);
}
}
+void
+MainLoop::take_screenshot()
+{
+ screenshot_requested = true;
+}
+