WiiDuktape/source/duktape/duktape_engine.c

#include <grrlib.h>
#include <duktape.h>
#include <stdio.h>
#include <stdlib.h>
#include <ogc/lwp_watchdog.h>

#include <data.h>
#include <wii_duk.h>
#include <game.h>
#include <microsecond.h>

static float deltatime = 1.0f/60;
static unsigned int green = RGBA(0, 255, 0, 255); 
static GRRLIB_ttfFont * font;

static void duk_fatal_error(void *udata, const char * msg) {
	const char * err_message_format = "a fatal error has occured: %s";
	size_t message_size = strlen(err_message_format) + strlen(msg) * sizeof(char *);
	char * message = malloc(message_size);
	snprintf(message, message_size, err_message_format, msg);
	while (1) {
		GRRLIB_PrintfTTF(0, 0, font, message, 12, green);
		GRRLIB_Render();
	}
}

static void duk_error_loop(duk_context * ctx, const char * msg) {
	const char * err_message_format = "an error has occured: %s";
	size_t message_size = strlen(err_message_format) + strlen(msg) * sizeof(char *);
	char * message = malloc(message_size);
	snprintf(message, message_size, err_message_format, msg);
	bool error_loop_running = true;

	while (error_loop_running) {
		PAD_ScanPads();
		unsigned int pressed = PAD_ButtonsDown(0);

		GRRLIB_PrintfTTF(0, 0, font, message, 12, green);
		GRRLIB_PrintfTTF(0, 20, font, "Press A to exit", 12, green);
		GRRLIB_Render();

		if (pressed & PAD_BUTTON_A) {
			error_loop_running = false;
		}
	}

	duk_destroy_heap(ctx);
}

void duktape(GRRLIB_ttfFont * global_font, bool * running) {
	font = global_font;	
	duk_context * ctx = duk_create_heap(NULL, NULL, NULL, NULL, duk_fatal_error);

	// create a wii object on the global object (globalThis)
	duk_define_wii_object(ctx, font, running, &deltatime);
	duk_put_global_string(ctx, "wii");

	// evaluate functions from game.js
	duk_eval_string_noresult(ctx, program);

	// call start function
	duk_get_global_string(ctx, "start");
	duk_int_t status = duk_pcall(ctx, 0);

	if (status == DUK_EXEC_ERROR) {
		duk_error_loop(ctx, duk_safe_to_string(ctx, -1));
		*running = false;
		return;
	}

	duk_pop(ctx);

	while (*running) {
		const unsigned int beginningOfFrame = ticks_to_microsecs(gettime());

		PAD_ScanPads();

		// call update function
		duk_get_global_string(ctx, "update");
		duk_int_t status = duk_pcall(ctx, 0);

		if (status == DUK_EXEC_ERROR) {
			duk_error_loop(ctx, duk_safe_to_string(ctx, -1));
			*running = false;
			return;
		}

		duk_pop(ctx);

		GRRLIB_Render();

		const unsigned int endOfFrame = ticks_to_microsecs(gettime());
		deltatime = (endOfFrame - beginningOfFrame) * MICROSECOND;
	}

	duk_destroy_heap(ctx);
}