Add data structures and functions

Signed-off-by: Tyrolyean <tyrolyean@tyrolyean.net>

shadermeh.c

@@ -85,6 +85,27 @@ static int write_retry(int fd, const void *buffer, size_t size)
 	return 0;
 }
 
+#define SND_BUFFER_SIZE   512
+
+static int read_audio_buffers(int fd, float buffer[SND_BUFFER_SIZE], 
+	unsigned int sampling_rate){
+	
+	return 0;
+}
+
+static void normalize_audio_buffers(float buffer_in[SND_BUFFER_SIZE], 
+	float buffer_out[SND_BUFFER_SIZE]){
+	
+	if(buffer_in == NULL || buffer_out == NULL){
+		return;
+	}
+
+	for(size_t i = 0; i < SND_BUFFER_SIZE; i++){
+		buffer_out[i] = (buffer_in[i]+1.0)/2.0;
+	}
+	return;
+}
+
 static const struct option long_opts[] = {
 	{ "width", required_argument, NULL, 'w' },
  	{ "height", required_argument, NULL, 'h' },
@@ -110,7 +131,6 @@ static const char *usage_str =
 "  --shader, -s <shader file>\n"
 "\n";
 
-#define SND_BUFFER_SIZE   512
 
 int main(int argc, char **argv)
 {
@@ -125,7 +145,7 @@ int main(int argc, char **argv)
 	float iTime, iTimeDelta;
 	bool to_stdout = false;
 	window *wnd;
-	int i;
+	int i, ret;
 	unsigned int sampling_rate = 0; /* Leaving this at 0 disables audio 
 	                                 * input 
 					 */
@@ -220,6 +240,15 @@ int main(int argc, char **argv)
 		fputs("Sampling rate specified and STDIN not a tty! "
 			"You habe been warnded!\n", stderr);
 	}
+	if(sampling_rate != 0){
+		ret = fcntl(STDIN_FILENO, F_SETFL,
+			fcntl(STDIN_FILENO,F_GETFL)
+			|(O_NONBLOCK));
+		if(ret == -1){
+			perror("Failed to set STDIN_FILENO to non-blocking "
+				"mode! This will likely mean failure");
+		}
+	}
 
 	/********** create window and make context current **********/
 	wnd = window_create(width, height, "shader meh...");
@@ -332,6 +361,13 @@ int main(int argc, char **argv)
 				break;
 			}
 		}
+		if(sampling_rate != 0){
+			if(read_audio_buffers(STDIN_FILENO, in_samples,
+				sampling_rate) < 0){
+				break;
+			}
+			normalize_audio_buffers(in_samples, norm_samples);
+		}
 
 		/* update timers */
 		clock_gettime(CLOCK_MONOTONIC_RAW, &frame_end);