Limit FPS in JS by skipping iterations.

This commit is contained in:
Fabio Alessandrelli 2020-06-29 21:00:20 +02:00
parent c7d2767ab9
commit 399e2c1db0
2 changed files with 13 additions and 4 deletions

View File

@ -30,11 +30,12 @@
#include "core/io/resource_loader.h" #include "core/io/resource_loader.h"
#include "main/main.h" #include "main/main.h"
#include "os_javascript.h" #include "platform/javascript/os_javascript.h"
#include <emscripten/emscripten.h> #include <emscripten/emscripten.h>
static OS_JavaScript *os = NULL; static OS_JavaScript *os = NULL;
static uint64_t target_ticks = 0;
// Files drop (implemented in JS for now). // Files drop (implemented in JS for now).
extern "C" EMSCRIPTEN_KEEPALIVE void _drop_files_callback(char *p_filev[], int p_filec) { extern "C" EMSCRIPTEN_KEEPALIVE void _drop_files_callback(char *p_filev[], int p_filec) {
@ -58,10 +59,18 @@ void exit_callback() {
} }
void main_loop_callback() { void main_loop_callback() {
uint64_t current_ticks = os->get_ticks_usec();
bool force_draw = os->check_size_force_redraw(); bool force_draw = os->check_size_force_redraw();
if (force_draw) { if (force_draw) {
Main::force_redraw(); Main::force_redraw();
} else if (current_ticks < target_ticks && !force_draw) {
return; // Skip frame.
}
int target_fps = Engine::get_singleton()->get_target_fps();
if (target_fps > 0) {
target_ticks += (uint64_t)(1000000 / target_fps);
} }
if (os->main_loop_iterate()) { if (os->main_loop_iterate()) {
emscripten_cancel_main_loop(); // Cancel current loop and wait for finalize_async. emscripten_cancel_main_loop(); // Cancel current loop and wait for finalize_async.
@ -85,9 +94,6 @@ extern "C" EMSCRIPTEN_KEEPALIVE void cleanup_after_sync() {
} }
extern "C" EMSCRIPTEN_KEEPALIVE void main_after_fs_sync(char *p_idbfs_err) { extern "C" EMSCRIPTEN_KEEPALIVE void main_after_fs_sync(char *p_idbfs_err) {
OS_JavaScript *os = OS_JavaScript::get_singleton();
// Set IDBFS status // Set IDBFS status
String idbfs_err = String::utf8(p_idbfs_err); String idbfs_err = String::utf8(p_idbfs_err);
if (!idbfs_err.empty()) { if (!idbfs_err.empty()) {
@ -118,6 +124,8 @@ extern "C" EMSCRIPTEN_KEEPALIVE void main_after_fs_sync(char *p_idbfs_err) {
ResourceLoader::set_abort_on_missing_resources(false); ResourceLoader::set_abort_on_missing_resources(false);
Main::start(); Main::start();
os->get_main_loop()->init(); os->get_main_loop()->init();
// Immediately run the first iteration.
// We are inside an animation frame, we want to immediately draw on the newly setup canvas.
main_loop_callback(); main_loop_callback();
emscripten_resume_main_loop(); emscripten_resume_main_loop();
} }

View File

@ -163,6 +163,7 @@ public:
String get_executable_path() const; String get_executable_path() const;
virtual Error shell_open(String p_uri); virtual Error shell_open(String p_uri);
virtual String get_name() const; virtual String get_name() const;
virtual void add_frame_delay(bool p_can_draw) {}
virtual bool can_draw() const; virtual bool can_draw() const;
virtual String get_cache_path() const; virtual String get_cache_path() const;