Saving/loading

README.md

@@ -8,11 +8,6 @@ The engine features full multithreading support when calculating forces.
 
 
 ## TODO:
-
-- Config files (instead of requiring recompilation)
-
-- Saving/restoring progress - Would also like autosaving for long runs, in case of a power failure or other issue.
-
 - Automatic video processing - Export X frames, turn them into a video, delete the frames. Repeat until the simulation is done, and then stick the videos together. At the moment, a long simulation can take hundreds of GB to store all of the images.
 
 - Allow processing over a distributed set of computers

main.c

@@ -204,6 +204,34 @@ void saveImage(double frame)
 	out = BMP_Create(w, h, 24);
 }
 
+void saveState(int it)
+{
+	FILE *fp;
+	char filename[300]; //lots of room
+	char buffer[15];
+	strcpy(filename, "saves/");
+	strcat(filename, s);
+	itoa(it, buffer);
+	strcat(filename, buffer);
+	strcat(filename, "-ID.sgs");
+	fp = fopen(filename, "wb");
+
+	//first, write the config parameters
+	config_t conf;
+	conf.nStars = nStars;
+	conf.imgW = w;
+	conf.imgH = h;
+	conf.savePeriod = a;
+	conf.iteration = it;
+	strcpy(conf.saveFile, s);
+	fwrite(&conf, sizeof(conf), 1, fp);
+	//then, write all the stars
+	fwrite(stars, sizeof(RigidMass_t), nStars, fp);
+
+	//close the file
+	fclose(fp);
+}
+
 void prnHelp(char *name)
 {
 	//TODO: iterations per frame
@@ -258,6 +286,7 @@ int main(int argc, char **argv)
 			else strcpy(s, optarg);
 			break;
 		case 'L':
+			load = true;
 			if(strlen(optarg) >= 255)
 			{
 				printf("ERROR: Load filename too long.\r\n");
@@ -298,30 +327,64 @@ int main(int argc, char **argv)
 		//allocate array
 		stars = malloc(sizeof(RigidMass_t) * nStars);
 
+		srand(time(NULL));
 		generateStars();
 		
 	}
 	else if(load) //technically redundant. can never be too sure
 	{
-		printf("Continuing %s...", l);
-		printf("%f stars loaded.", -1);
+		printf("Continuing %s...\r\n", l);
+
+		FILE *fp;
+		fp = fopen(l, "r");
+		//first, read the config parameters
+		config_t conf;
+		fread(&conf, sizeof(conf), 1, fp);
+		nStars = conf.nStars;
+		w = conf.imgW;
+		h = conf.imgH;
+		a = conf.savePeriod;
+		iteration = conf.iteration;
+		strcpy(s, conf.saveFile);
+
+		//second, read the stars
+		stars = malloc(sizeof(RigidMass_t) * nStars);
+		fread(stars, sizeof(RigidMass_t), nStars, fp);
+
+		//close the file
+		fclose(fp);
+		
+		printf("%d stars loaded.\r\n", nStars);
+		printf("Continuing from i=%d\r\n", iteration);
 	}
-	
-	srand(time(NULL));
 	out = BMP_Create(w, h, 24);
 
 
 	//Runs until CTRL+C
 	//TODO: CTRL+C should force autosave
+	bool justStarted = true;
 	while(1)
 	{
 		iterate();
 		addToImage();
-		if (iteration % 10 == 0)
+		//gives the next frame some iterations to build up
+		//without justStarted, the loaded iteration is rerendered, but only from
+		//a single iteration, which stands out quite a bit.
+		if(justStarted)
 		{
-			saveImage(iteration / 10);
+			justStarted = false;
+		}
+		else
+		{
+			if(iteration % 10 == 0)
+			{
+				saveImage(iteration / 10);
+			}
+			if(iteration % a == 0)
+			{
+				saveState(iteration);
+			}
 		}
-		
 		iteration++;
 	}