From d867b905a80fad3f20725e5434c0ff233f11305f Mon Sep 17 00:00:00 2001
From: tth <tth@fubar.tetalab.org>
Date: Tue, 23 Feb 2021 03:49:24 +0100
Subject: [PATCH] tracking a math bug in filters3x3

---
 Fonderie/crapulator.c | 16 +++++++++++-----
 floatimg.h            |  2 +-
 funcs/filtrage.c      |  9 ++++-----
 funcs/tests.c         | 33 +++++++++++++++++++++++++--------
 4 files changed, 41 insertions(+), 19 deletions(-)

diff --git a/Fonderie/crapulator.c b/Fonderie/crapulator.c
index 62fca29..d6b103b 100644
--- a/Fonderie/crapulator.c
+++ b/Fonderie/crapulator.c
@@ -14,6 +14,8 @@
 #include  "glitches.h"
 #include  "sfx.h"
 
+extern int		verbosity;
+
 /* -------------------------------------------------------------- */
 static int trier_les_pixels(FloatImg *pimg)
 {
@@ -76,7 +78,7 @@ return 0;
 static int insitu_filtre3x3(FloatImg *pimg, int typef)
 {
 FloatImg		img;
-int 			retval;
+int 			foo, retval;
 FimgFilter3x3		*pfiltre;
 
 FimgFilter3x3	lowpass = {
@@ -103,7 +105,7 @@ FimgFilter3x3	diagonal = {
 		1.0,	0.0,	-1.0,
 		0.0,	-1.0,	-2.0,
 		},
-	1.0,	0.0
+	1.0,	4.0
 	};
 
 switch (typef) {
@@ -124,8 +126,12 @@ if (retval) {
 	fprintf(stderr, "%s error %d on filter\n", __func__, retval);
 	exit(1);
 	}
-/*
- *	may be, here, we can check for negative values ? */
+/**	may be, we can check for negative values ? */
+if (verbosity) {
+	foo = fimg_count_negativ(&img);
+	fprintf(stderr, "%s -> %d negs\n", __func__, foo);
+	}
+
 fimg_killborders(&img);
 fimg_copy_data(&img, pimg);
 fimg_destroy(&img);
@@ -206,7 +212,7 @@ switch (idFx) {
 		break;
 	case CR_liss2x2:
 		retval = fimg_lissage_2x2(image);
-		(void)fimg_killborders(image);
+		// (void)fimg_killborders(image);
 		break;
 	case CR_liss3x3:
 				/* smooth filter */
diff --git a/floatimg.h b/floatimg.h
index 4b0acbc..826ae7d 100644
--- a/floatimg.h
+++ b/floatimg.h
@@ -3,7 +3,7 @@
  *			ugly code from tTh
  */
 
-#define		FIMG_VERSION	118
+#define		FIMG_VERSION	119
 
 /*
  *	in memory descriptor
diff --git a/funcs/filtrage.c b/funcs/filtrage.c
index 5f46c38..7e7c6a4 100644
--- a/funcs/filtrage.c
+++ b/funcs/filtrage.c
@@ -15,7 +15,7 @@ float		*M;			/* alias of filter matrix */
 double		dval;
 
 #if DEBUG_LEVEL
-fprintf(stderr, ">>> %s ( %p %p %p)\n", __func__, src, dst, filtr);
+fprintf(stderr, ">>> %s ( %p %p %p )\n", __func__, src, dst, filtr);
 #endif
 
 if (src->type != FIMG_TYPE_RGB) {
@@ -48,7 +48,7 @@ for (y=1; y < h-1; y++) {
 		M[7] * pr[of+w]		+
 		M[8] * pr[of+(w-1)]	;
 
-	dst->R[of] = dval;
+	dst->R[of] = dval + filtr->offset;
 
 	dval =	M[0] * pg[of-(w+1)]	+
 		M[1] * pg[of-w]		+
@@ -60,7 +60,7 @@ for (y=1; y < h-1; y++) {
 		M[7] * pg[of+w]		+
 		M[8] * pg[of+(w-1)]	;
 
-	dst->G[of] = dval;
+	dst->G[of] = dval + filtr->offset;
 
 	dval =	M[0] * pb[of-(w+1)]	+
 		M[1] * pb[of-w]		+
@@ -72,7 +72,7 @@ for (y=1; y < h-1; y++) {
 		M[7] * pb[of+w]		+
 		M[8] * pb[of+(w-1)]	;
 
-	dst->B[of] = dval;
+	dst->B[of] = dval + filtr->offset;
 	}
 }
 
@@ -189,7 +189,6 @@ if (foo) {
 	return foo;
 	}
 
-/* XXX */
 fimg_killborders(img);
 
 return foo;
diff --git a/funcs/tests.c b/funcs/tests.c
index 3d61ee4..df327ad 100644
--- a/funcs/tests.c
+++ b/funcs/tests.c
@@ -323,7 +323,7 @@ FimgFilter3x3	filter_a =  {
 	{	1.0,	1.0,	1.0,
 		1.0,   -3.0,	1.0,
 		1.0,	1.0,	1.0 },
-		8.0, 0.0
+		9.0,	0.0
 
 	};
 
@@ -332,10 +332,19 @@ FimgFilter3x3	filter_b =  {
 	{	-2.0,	-1.0,	0.0,
 		-1.0,    3.0,	1.0,
 		0.0,	 1.0,	2.0 },
-		8.0, 0.0
+		8.0,	0.0
 
 	};
 
+FimgFilter3x3	filter_c = {
+		{
+		2.0,	1.0,	0.0,
+		1.0,	0.0,	-1.0,
+		0.0,	-1.0,	-2.0,
+		},
+	1.0,	8.0
+	};
+
 if (NULL != infile) {
 	fprintf(stderr, "%s: loading %s\n", __func__, infile);
 	foo = fimg_create_from_dump(infile, &src);
@@ -351,6 +360,8 @@ else	{
 	}
 
 // fimg_save_as_png(&src, "test.png", 0);
+foo = fimg_count_negativ(&src);
+fprintf(stderr, "%s: source have %d negs\n", __func__, foo);
 
 foo = fimg_clone(&src, &dst, 0);
 if (foo) {
@@ -359,21 +370,27 @@ if (foo) {
 	}
 
 fimg_filter_3x3(&src, &dst, &filter_a);
-
 foo = fimg_clamp_negativ(&dst);
-
 if (foo) {
-	fprintf(stderr, "clamped %d negative pixels\n", foo);
+	fprintf(stderr, "A clamped %d negative pixels\n", foo);
 	}
-// foo = fimg_save_as_png(&dst, "f3x3a.png", 0);
+foo = fimg_save_as_png(&dst, "f3x3a.png", 0);
 // foo = fimg_save_as_pnm(&dst, "f3x3a.pnm", 0);
 
 fimg_filter_3x3(&src, &dst, &filter_b);
 foo = fimg_clamp_negativ(&dst);
 if (foo) {
-	fprintf(stderr, "clamped %d negative pixels\n", foo);
+	fprintf(stderr, "B clamped %d negative pixels\n", foo);
 	}
-// foo = fimg_save_as_png(&dst, "f3x3b.png", 0);
+foo = fimg_save_as_png(&dst, "f3x3b.png", 0);
+// foo = fimg_save_as_pnm(&dst, "f3x3a.pnm", 0);
+
+fimg_filter_3x3(&src, &dst, &filter_c);
+foo = fimg_clamp_negativ(&dst);
+if (foo) {
+	fprintf(stderr, "C clamped %d negative pixels\n", foo);
+	}
+foo = fimg_save_as_png(&dst, "f3x3b.png", 0);
 // foo = fimg_save_as_pnm(&dst, "f3x3a.pnm", 0);
 
 fimg_destroy(&src);	fimg_destroy(&dst);