From 7244b4c8296b1aefa4b61979bd02fc4e586b7e64 Mon Sep 17 00:00:00 2001
From: tTh <tth@redlady.dinorama.fr>
Date: Sat, 1 Jul 2023 00:48:50 +0200
Subject: [PATCH] NEED MORE DEBUG

---
 experiment/mnt.c | 131 +++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 116 insertions(+), 15 deletions(-)

diff --git a/experiment/mnt.c b/experiment/mnt.c
index 304110f..f0e1df9 100644
--- a/experiment/mnt.c
+++ b/experiment/mnt.c
@@ -1,5 +1,5 @@
 /*
- *	Modeles Numeriques de Terrain
+ *	Modeles Numeriques de Terrain  --  UGLY CODE INSIDE !!
  *
  */
 
@@ -7,51 +7,145 @@
 #include   <math.h>
 #include   <stdlib.h>
 #include   <stdint.h>
+#include   <string.h>
 
 #include   "../floatimg.h"
 
 int		verbosity;
 
+/* ------------------------------------------------------------------- */
+/* for debug purpose */
+int calcul_histo_gray(FloatImg *img, char *fname, int nbslots, float *pmax)
+{
+int		offset, nbpix, ival;
+FILE		*fp;
+float		pixel, minp, maxp;
+
+int		*counts;
+
+#if DEBUG_LEVEL
+fprintf(stderr, ">>> %s ( %p '%s' %d )\n", __func__,
+				img, fname, nbslots);
+#endif
+
+if (FIMG_TYPE_GRAY != img->type) {
+	return -2;
+	}
+
+/* allocate memory for histogram computation */
+counts = calloc(nbslots, sizeof(int));
+if (NULL == counts) {
+	fprintf(stderr, "malloc fail in %s\n", __func__);
+	abort();
+	}
+
+nbpix = img->width * img->height;
+minp = 1e10, maxp = -1e10;
+
+for (offset=0; offset<nbpix; offset++) {
+	pixel = img->R[offset];
+	if (pixel < minp)	minp = pixel;
+	if (pixel > maxp)	maxp = pixel;
+	}
+fprintf(stderr, "    values =   %g  <  %g\n", minp, maxp);
+
+*pmax = maxp;		/* copy value for the caller */
+
+/* calcul de l'histogramme avec scaling */
+for (offset=0; offset<nbpix; offset++) {
+	pixel = img->R[offset];
+	ival = (int)((pixel * (float)nbslots) / maxp);
+	counts[ival]++;
+	// fprintf(stderr, "%6d    %10.6f    %i\n", offset, pixel, ival);
+	}
+
+if (NULL == (fp = fopen(fname, "w"))) {
+	perror(fname);
+	exit(1);
+	}
+for (ival=0; ival<nbslots; ival++) {
+	fprintf(fp, "%6d  %6d\n", ival, counts[ival]);
+	}
+fclose(fp);
+
+/* garbage collect stuff */
+free(counts);
+
+return 0;
+}
 /* ------------------------------------------------------------------- */
 /*
- *		First try
+ *		Second try - ahem?
  */
 int brotche_mnt_style(FloatImg *src, FloatImg *dst)
 {
-int		x, y;
+FloatImg	tmp;
+int		x, y, foo;
 int		offset;
 float		z1, z2, z3, z4;
 float		a, b, c;
-float		pente;
+float		pente, minp, maxp, seuil;
 
+#if DEBUG_LEVEL
 fprintf(stderr, ">>> %s ( %p %p )\n", __func__, src, dst);
+#endif
 
 #define W    (src->width)
 #define DX   1.0
 #define DY   1.0
 
+/* allocate a graylevel image for storing la 'pente'		*/
+memset(&tmp, 0, sizeof(FloatImg));
+foo = fimg_create(&tmp, src->width, src->height, FIMG_TYPE_GRAY);
+if (foo) {
+	fprintf(stderr, "create tmp pic --> %d\n", foo);
+	return foo;
+	}
+/* calcul de la pente : a vérifier ! */
 for (y=0; y<(src->height-1); y++) {
 	for (x=0; x<(src->width-1); x++) {
-		offset = (y * src->width) + x;
+		offset = (y * W) + x;
 		z1 = src->R[offset];
 		z2 = src->R[offset+1];
 		z3 = src->R[offset+W];
 		z4 = src->R[offset+W+1];
-
 		a = ( z1 + z2 + z3 + z4) / 4.0;
 		b = (-z1 + z2 - z3 + z4) / 2.0 / DX;
 		c = (-z1 - z2 + z3 + z4) / 2.0 / DY;
-
 		pente = atanf(sqrt(b*b + c*c));
-
-		dst->R[offset] = 0;
-		if (pente < 0.0) dst->G[offset] = pente;
-		else		 dst->B[offset] = pente;
-
-
+		tmp.R[offset] = pente;
 		}
 	}
 
+foo = calcul_histo_gray(&tmp, "histogramme.data", 499, &maxp);
+if (foo) fprintf(stderr, "<<< calcul histo -> %d\n", foo);
+
+
+minp = 1e10;
+seuil = 0.640 * maxp;
+fprintf(stderr, "seuil = %f\n", seuil);
+
+for (offset=0; offset<(src->width*src->height); offset++) {
+	pente = tmp.R[offset];
+	if (pente > seuil) {
+		if (pente < minp)	minp = pente;
+		}
+	if (pente > maxp)		maxp = pente;
+	}
+fprintf(stderr, "minp --> %f      maxp --> %f\n", minp, maxp);
+
+/* recopie dans l'image destination avec translation hauteur */
+for (offset=0; offset<(src->width*src->height); offset++) {
+	pente = tmp.R[offset] - minp;
+	if (pente < 0.0)  pente = 0.0;
+	dst->R[offset] = pente;
+	dst->G[offset] = pente;
+	dst->B[offset] = pente;
+	}
+
+/* clean the memory */
+fimg_destroy(&tmp);
+
 return 0;
 }
 /* ------------------------------------------------------------------- */
@@ -61,15 +155,17 @@ FloatImg	src, dst;
 char		*infile, *outfile;
 int		foo;
 
+verbosity = 1;		/* FIXME */
+
 if (3 != argc) {
-	fprintf(stderr, "%s need 2 args : infile & outfile\n", argv[0]);
+	fprintf(stderr, "'%s' need 2 args : infile & outfile\n", argv[0]);
 	fimg_print_version(0);
 	exit(1);
 	}
 
 infile = argv[1];	outfile = argv[2];
 
-fprintf(stderr,"--- working on %s\n", infile);
+if (verbosity) fprintf(stderr,"*** MNT    %s -> %s\n", infile, outfile);
 
 foo = fimg_create_from_dump(infile, &src);
 if (foo) {
@@ -82,6 +178,7 @@ if (foo) {
 	fprintf(stderr, "err %d cloning image\n", foo);
 	exit(1);
 	}
+fimg_clear(&dst);
 
 foo = brotche_mnt_style(&src, &dst);
 if (foo) {
@@ -95,6 +192,10 @@ if (foo) {
 	exit(1);
 	}
 
+/* clean the memory */
+fimg_destroy(&src);
+fimg_destroy(&dst);
+
 return 0;
 }
 /* ------------------------------------------------------------------- */