new example "resize"

examples/resize.c

@@ -0,0 +1,59 @@
+#include "gd.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+int main (int argc, char *argv[]) {
+	FILE *fp;
+	gdImagePtr in, out;
+	int w, h;
+
+	/* Help */
+	if (argc<=4) {
+		printf("%s  input.jpg  output.jpg  width  height\n", argv[0]);
+		return 1;
+	}
+
+	/* Size */
+	w = atoi(argv[3]);
+	h = atoi(argv[4]);
+	if (w<=0 || h<=0) {
+		fprintf(stderr, "Bad size %dx%d\n", h, w);
+		return 2;
+	}
+
+	/* Input */
+	fp = fopen(argv[1], "rb");
+	if (!fp) {
+		fprintf(stderr, "Can't read image %s\n", argv[1]);
+		return 3;
+	}
+	in = gdImageCreateFromJpeg(fp);
+	fclose(fp);
+	if (!in) {
+		fprintf(stderr, "Can't create image from %s\n", argv[1]);
+		return 4;
+	}
+
+	/* Resize */
+	gdImageSetInterpolationMethod(in, GD_BILINEAR_FIXED);
+	out = gdImageScale(in, w, h);
+	if (!out) {
+		fprintf(stderr, "gdImageScale fails\n");
+		return 5;
+	}
+
+	/* Output */
+	fp = fopen(argv[2], "wb");
+	if (!fp) {
+		fprintf(stderr, "Can't save image %s\n", argv[2]);
+		return 6;
+	}
+	gdImageJpeg(out, fp, 90);
+	fclose(fp);
+
+	/* Cleanups */
+	gdImageDestroy(in);
+	gdImageDestroy(out);
+
+	return 0;
+}