From 54269cc007f75cf38f9b6b476716187b71903943 Mon Sep 17 00:00:00 2001
From: tth <sigfood@dinorama.fr>
Date: Wed, 25 Sep 2019 09:21:00 +0200
Subject: [PATCH] counting negative values

---
 floatimg.h        |  1 +
 lib/fimg-math.c   | 21 +++++++++++++++++++++
 tools/fimgstats.c |  7 ++++++-
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/floatimg.h b/floatimg.h
index afb0829..a3e5d03 100644
--- a/floatimg.h
+++ b/floatimg.h
@@ -79,6 +79,7 @@ int   fimg_to_gray(FloatImg *head);
 void  fimg_add_cste(FloatImg *fi, float value);
 void  fimg_mul_cste(FloatImg *fi, float value);
 void  fimg_drand48(FloatImg *fi, float kmul);
+int   fimg_count_negativ(FloatImg *fi);
 
 /*	various funcs modules		*/
 int   fimg_load_from_png(char *filename, FloatImg *fimg);
diff --git a/lib/fimg-math.c b/lib/fimg-math.c
index d8513b0..873f322 100644
--- a/lib/fimg-math.c
+++ b/lib/fimg-math.c
@@ -108,6 +108,27 @@ for (idx=0; idx<nbre; idx++) {
 	}
 }
 /* ---------------------------------------------------------------- */
+int fimg_count_negativ(FloatImg *fi)
+{
+int		nbre, idx;
+int		count;
+
+if (fi->type != FIMG_TYPE_RGB) {
+	fprintf(stderr, "%s : type %d invalide\n",
+				__func__, fi->type);
+	return -1;
+	}
+
+nbre = fi->width * fi->height * fi->type;
+
+count = 0;
+for (idx=0; idx<nbre; idx++) {
+	if (fi->R[idx] < 0.0) count++;
+	}
+
+return count;
+}
+/* ---------------------------------------------------------------- */
 void  fimg_mul_cste(FloatImg *fi, float value)
 {
 int		nbre, idx;
diff --git a/tools/fimgstats.c b/tools/fimgstats.c
index d530602..8642e46 100644
--- a/tools/fimgstats.c
+++ b/tools/fimgstats.c
@@ -31,7 +31,12 @@ for (foo=0; foo<4; foo++)
 	printf("      %c   %14.6f\n", "RGBA"[foo], moyennes[foo]);
 
 fvalue = fimg_get_maxvalue(fimg);
-printf("max value     %f\n", fvalue);
+printf("max value       %f\n", fvalue);
+
+foo = fimg_count_negativ(fimg);
+if (foo) {
+	fprintf(stderr, "%d negative values\n", foo);
+	}
 
 return 0;
 }