1 files changed, 52 insertions, 8 deletions

diff --git a/glslview.c b/glslview.c
index 4ff4dd3..b0b5d1b 100644
--- a/glslview.c
+++ b/glslview.c
@@ -46,6 +46,12 @@
 #endif
 
 
+static int init_param0 = 0;
+static int init_param1 = 0;
+static int init_param2 = 0;
+static float init_time = 0;
+static float init_speed = 1.0;
+
 static bool paused = false;
 static float speed = 1.0;
 static unsigned previous_ticks = 0;
@@ -124,11 +130,13 @@ static void handle_input(const char *input) {
 			break;
 
 		case 'r':
-			current_time = 0;
+			current_time = init_time;
 			break;
 
 		case 'R':
-			param0 = param1 = param2 = 0;
+			param0 = init_param0;
+			param1 = init_param1;
+			param2 = init_param2;
 			print_params();
 			break;
 
@@ -142,9 +150,9 @@ static void handle_input(const char *input) {
 
 		case '=':
 			if (speed < 0)
-				set_speed(-1.0);
+				set_speed(-init_speed);
 			else
-				set_speed(1.0);
+				set_speed(init_speed);
 			break;
 
 		case '<':
@@ -163,12 +171,48 @@ static void handle_input(const char *input) {
 	}
 }
 
+static void usage(void) {
+	fprintf(stderr, "Usage: glslview [-t <time>] [-s <speed>] [-0 <param0>] [-1 <param1>] [-2 <param2>] <shader>\n");
+	exit(1);
+}
+
 int main(int argc, char *argv[]) {
-	if (argc != 2) {
-		fprintf(stderr, "Usage: glslview <shader>\n");
-		exit(1);
+	while (true) {
+		int c = getopt(argc, argv, "t:s:0:1:2:");
+		if (c == -1)
+			break;
+
+		switch (c) {
+		case 't':
+			current_time = init_time = atof(optarg);
+			break;
+
+		case 's':
+			speed = atof(optarg);
+			init_speed = fabsf(speed);
+			break;
+
+		case '0':
+			param0 = init_param0 = atoi(optarg);
+			break;
+
+		case '1':
+			param1 = init_param1 = atoi(optarg);
+			break;
+
+		case '2':
+			param2 = init_param2 = atoi(optarg);
+			break;
+
+		default:
+			fprintf(stderr, "Invalid option '%c'\n", optopt);
+			usage();
+		}
 	}
 
+	if (argc - optind != 1)
+		usage();
+
 	SDL_Init(SDL_INIT_VIDEO);
 
 	SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 8);
@@ -179,7 +223,7 @@ int main(int argc, char *argv[]) {
 	SDL_Window *window = SDL_CreateWindow("glslview", 0, 0, 800, 800, SDL_WINDOW_OPENGL|SDL_WINDOW_RESIZABLE);
 	SDL_GLContext ctx = SDL_GL_CreateContext(window);
 
-	filename = argv[1];
+	filename = argv[optind];
 
 	init_watch();
 	init();