feat: add support for stepping PSO iterations

Pressing ',' will now step entire PSO iterations, while '.' will step only
individual frames.

src/main.cpp

@@ -111,6 +111,14 @@ main(int argc, char **argv) {
 	case ' ':
 	    pause = !pause;
 	    break;
+	case ',':
+	    for(int j = 0; j < kFPS/4; ++j) {
+		swarm.move(kDT * 4);
+		if(i % (kFPS/4) == (kFPS/4)-1)
+		    swarm.step();
+
+		++i;
+	    }
 	case '.':
 	    pause = false;
 	    frame_step = true;
@@ -168,8 +176,8 @@ main(int argc, char **argv) {
 
 	case 'h':
 	    printf("  movement  zoom  coloring  pause step \n"
-		   "     W       i      I K      SPC   .   \n"
-		   "    ASD      o      O L                \n"
+		   "     W       io    IK LO     SPC   .,  \n"
+		   "    ASD                                \n"
 		   "                            quit:  q   \n");
 	    break;
 	}