added a new function : fimg_rotate_90, need more tests

funcs/rotate.c

@@ -0,0 +1,65 @@
+/*
+ *		FLOATIMG
+ *	rotation matricielle des images
+ *	#coronamaison  Mon 23 Mar 2020 11:45:59 AM CET
+ */
+
+#include  <stdio.h>
+#include  <string.h>
+
+#include  "../floatimg.h"
+
+extern int		verbosity;
+
+/* --------------------------------------------------------------------- */
+int fimg_rotate_90(FloatImg *src, FloatImg *dst, int notused)
+{
+int			foo;
+int			x, y;
+float			rgb[3];
+
+#if DEBUG_LEVEL
+fprintf(stderr, ">>> %s ( %p %p %d )\n", __func__,
+				src, dst, notused);
+#endif
+
+if (src->type != FIMG_TYPE_RGB) {
+	fprintf(stderr, "%s: src type %d not valid\n", __func__,
+					src->type);
+	return -6;
+	}
+
+/* check if dst pic is not allocated */
+if ( 0 == (dst->type | dst->width | dst->height) ) {
+	fprintf(stderr, "in %s, %p is empty\n", __func__, dst);
+	/* OK allocate a new fpic */
+	foo = fimg_create(dst, src->height, src->width, src->type);
+	if (foo) {
+		fprintf(stderr, "%s: err %d create new pic\n", __func__, foo);
+		return -887;
+		}
+	if (verbosity) fimg_describe(dst, "new pic");
+	}
+
+/* check if dst and src are conpatibles */
+if ( (src->type != dst->type)    ||
+     (src->width != dst->height) || (src->height != dst->width) ) {
+	fprintf(stderr, "%s: src & dst not compatibles\n", __func__);
+	return -888;
+	}
+
+/*
+ *		THIS IS A CRUDE IMPLEMENTATION
+*/
+for (y=0; y<src->height; y++) {
+	for (x=0; x<src->width; x++) {
+		fimg_get_rgb(src, x, y, rgb);
+		fimg_plot_rgb(dst, y, x, rgb[0], rgb[1], rgb[2]);
+		}
+	}
+
+/* we don't have any cleanup to make */
+
+return 0;
+}
+/* --------------------------------------------------------------------- */