diff --git a/glonkers.c b/glonkers.c
index fed3237..fe8bf60 100644
--- a/glonkers.c
+++ b/glonkers.c
@@ -28,22 +28,26 @@ double time_since_start() {
 int main(int argc, char *argv[]) {
     char *shader_path = NULL;
     int output_type = OUTPUT_WINDOW;
-    if (argc >= 2) {
-        shader_path = argv[1];
-    } else {
-        printf("need to supply path to shader\n");
-        exit(1);
-    }
-    if (argc >= 3) {
-        // xdg toplevel window (window) or wlr_layer_shell window (layer)
-        if (strcmp(argv[2], "window") == 0) {
+    // syntax: --window for a normal window or --layer for a wallpaper
+    for (int i = 1; i < argc; i++) {
+        if (strncmp("--window", argv[i], strlen("--window")) == 0) {
             output_type = OUTPUT_WINDOW;
-        } else if (strcmp(argv[2], "layer") == 0) {
-            output_type = OUTPUT_LAYER;
-        } else {
-            printf("argument 2 is either 'window' or 'layer' 🍰\n");
-            return 1;
         }
+        else if (strncmp("--layer", argv[i], strlen("--layer")) == 0) {
+            output_type = OUTPUT_LAYER;
+        }
+        else {
+            // path to fragment shader
+            if (shader_path != NULL) {
+                fprintf(stderr, "tried supplying '%s' as a shader file while one has already been selected\n", argv[i]);
+                return 1;
+            }
+            shader_path = argv[i];
+        }
+    }
+    if (shader_path == NULL) {
+        printf("need to supply path to shader\n");
+        return 1;
     }
 
     struct client_state state;
diff --git a/renderer.c b/renderer.c
index db03eca..67e27df 100644
--- a/renderer.c
+++ b/renderer.c
@@ -57,7 +57,7 @@ GLuint create_shader(const char *fragment_src) {
 GLuint load_shader(const char *path) {
     FILE *handle = fopen(path, "r");
     if (handle == NULL) {
-        printf("failed to open shader file\n");
+        printf("failed to open shader file: '%s'\n", path);
         exit(1);
     }
     fseek(handle, 0L, SEEK_END);
@@ -156,10 +156,6 @@ void render(Renderer *state, int w, int h, double time, char *shader_path, int r
     int uniform_time = glGetUniformLocation(state->shader, "time");
     glUniform1f(uniform_time, (float)time);
 
-    //glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, vVertices);
-    //glEnableVertexAttribArray(0);
-    //glDrawArrays(GL_TRIANGLES, 0, 6);
-
     glBindVertexArray(state->vao);
     glDrawArrays(GL_TRIANGLES, 0, 6);
 }
diff --git a/shm.c b/shm.c
deleted file mode 100644
index 6897a61..0000000
--- a/shm.c
+++ /dev/null
@@ -1,53 +0,0 @@
-#define _POSIX_C_SOURCE 200112L
-#include <errno.h>
-#include <fcntl.h>
-#include <sys/mman.h>
-#include <time.h>
-#include <unistd.h>
-#include "shm.h"
-
-static void
-randname(char *buf)
-{
-	struct timespec ts;
-	clock_gettime(CLOCK_REALTIME, &ts);
-	long r = ts.tv_nsec;
-	for (int i = 0; i < 6; ++i) {
-		buf[i] = 'A'+(r&15)+(r&16)*2;
-		r >>= 5;
-	}
-}
-
-static int
-create_shm_file(void)
-{
-	int retries = 100;
-	do {
-		char name[] = "/wl_shm-XXXXXX";
-		randname(name + sizeof(name) - 7);
-		--retries;
-		int fd = shm_open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
-		if (fd >= 0) {
-			shm_unlink(name);
-			return fd;
-		}
-	} while (retries > 0 && errno == EEXIST);
-	return -1;
-}
-
-int
-allocate_shm_file(size_t size)
-{
-	int fd = create_shm_file();
-	if (fd < 0)
-		return -1;
-	int ret;
-	do {
-		ret = ftruncate(fd, size);
-	} while (ret < 0 && errno == EINTR);
-	if (ret < 0) {
-		close(fd);
-		return -1;
-	}
-	return fd;
-}
diff --git a/shm.h b/shm.h
deleted file mode 100644
index 327f722..0000000
--- a/shm.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#ifndef SHM_H
-#define SHM_H
-
-#include <unistd.h>
-
-int allocate_shm_file(size_t size);
-
-#endif