macro for tilesize

1 files changed, 8 insertions, 7 deletions

diff --git a/src/main.c b/src/main.c
index 665d3c8..a5f3514 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2,14 +2,15 @@
 #include "stb_image.h"
 #include <stdio.h>
 
+#define TSIZE 8
 #define RGB(r, g, b) (((r) << 11) | ((g) << 5) | (b))
 
 static void
 output_tile(const uint8_t *data, int x, int y, int w)
 {
-	for (int iy = 0; iy < 16; iy += 1) {
+	for (int iy = 0; iy < TSIZE; iy += 1) {
 		putchar('\t');
-		for (int ix = 0; ix < 16; ix += 1) {
+		for (int ix = 0; ix < TSIZE; ix += 1) {
 			const int i = (ix + x + (iy + y) * w) * 3;
 			const int v = RGB(data[i]/8, data[i+1]/4, data[i+2]/8);
 			printf("%04x ", v);
@@ -34,10 +35,10 @@ main(int argc, char **argv)
 		return 1;
 	}
 
-	if ((w & 15) || (h & 15)) {
+	if (w % TSIZE || h % TSIZE) {
 		fprintf(stderr, "invalid dimensions %dx%d, "
-		                "expected dimensions divisible by 16\n",
-		                w, h);
+		                "expected dimensions divisible by %d\n",
+		                w, h, TSIZE);
 		goto panic;
 	}
 	if (chans != 3) {
@@ -47,8 +48,8 @@ main(int argc, char **argv)
 		goto panic;
 	}
 
-	for (int y = 0; y < h; y += 16)
-		for (int x = 0; x < w; x += 16)
+	for (int y = 0; y < h; y += TSIZE)
+		for (int x = 0; x < w; x += TSIZE)
 			output_tile(data, x, y, w);
 
 	stbi_image_free(data);