Move numeric arguments to the environment.

1 files changed, 14 insertions, 3 deletions

diff --git a/unpremultiply.c b/unpremultiply.c
index 8e6a25d..027477b 100644
--- a/unpremultiply.c
+++ b/unpremultiply.c
@@ -406,22 +406,33 @@ fill_empty(uint32_t *buf, size_t n)
     memset(buf, 0, 4*n);
 }
 
+static long
+getenvlong(char const *name, long default_value)
+{
+    char *val = getenv(name);
+    return val ? atol(val) : default_value;
+}
+
 int
 main(int argc, char **argv)
 {
-    long nloops = argc > 1 ? atol(argv[1]) : 1;
-    size_t n = 2*1024*1024*0 + (256*1024/4)/2;
+    long nloops = getenvlong("loops", 50);
+    size_t n = getenvlong("pixels", 2*1024*1024);
+    long ofs = getenvlong("offset", 0);
     uint32_t *dst = calloc(n, 4);
     uint32_t *src = calloc(n, 4);
     char const *method = "lut";
     int verify = 0;
     int i;
 
+    dst = (uint32_t*)((uintptr_t)dst + ofs);
+    src = (uint32_t*)((uintptr_t)src + ofs);
+
     make_division_table();
     make_reciprocal_table_A();
     make_reciprocal_table_B();
 
-    for (i=2; i<argc; i++) {
+    for (i=1; i<argc; i++) {
 	if (0 == strcmp(argv[i], "verify")) {
 	    verify = 1;
 	}