add "cos01" contrast adjustement

Lib/Makefile

@@ -125,7 +125,6 @@ text1.o:	text1.c		$(DEPS)
 text16x24.o:	text16x24.c	$(DEPS)
 tga.o:		tga.c		$(DEPS)
 tools.o:	tools.c		$(DEPS)
-trigo.o:	trigo.c		$(DEPS)
 turtle.o:	turtle.c	$(DEPS)
 
 vignetize.o:	vignetize.c	$(DEPS)
@@ -174,7 +173,7 @@ OBJECTS =	7seg.o							\
 		scale.o	sobel4.o stereo.o				\
 		tamppool.o tele_2.o television.o			\
 		text0.o text1.o text16x24.o				\
-		tga.o tools.o trigo.o turtle.o				\
+		tga.o tools.o turtle.o					\
 		vignetize.o						\
 		warp0.o warp1.o warp2.o warp3.o				\
 		zoom.o
@@ -186,7 +185,7 @@ OBJECTS =	7seg.o							\
 #-----------------------------------------------------------------
 
 foo:		foo.c $(DEPS) ../libtthimage.a
-	gcc $(CFLAGS) $< ../libtthimage.a -o $@
+	gcc $(CFLAGS) $< ../libtthimage.a -lm -o $@
 
 t_png:	t_png.c $(DEPS)  ../libtthimage.a
 	gcc $(CFLAGS) $< ../libtthimage.a -lpng -lz -o $@

Lib/contrast.c

@@ -6,6 +6,48 @@
 #include  <math.h>
 #include  "../tthimage.h"
 
+
+/*::------------------------------------------------------------------::*/
+/*
+ *	new: Fri Sep 15 20:18:35 UTC 2023
+ *	inspired by the sam func in FloatImg
+ */
+int Image_egalise_cos01(Image_Desc *source, Image_Desc *but, int k)
+{
+unsigned char	lut[256], uc;
+int		idx, x, y, pix, foo;
+float		fidx;
+
+fprintf(stderr, ">>> %s ( %p  %p  %d )\n", __func__,
+		source, but, k);
+
+if ( (foo=Image_compare_desc(source, but)) ) {
+	fprintf(stderr, "%s: images not compatible, %d\n", __func__, foo);
+	return foo;
+	}
+
+for (idx=0; idx<256; idx++) {
+	fidx = (float)idx / 255.0;
+	uc = (unsigned char)(255.0*(0.5 - 0.5 * cos(3.141592654*fidx)));
+	lut[idx] = uc;
+	/* printf("%7d    %7d\n", idx, uc); */
+	}
+
+for (y=0; y<source->height; y++) {
+	for (x=0; x<source->width; x++) {
+
+		pix = source->Rpix[y][x];
+		but->Rpix[y][x] = lut[pix];
+		pix = source->Gpix[y][x];
+		but->Gpix[y][x] = lut[pix];
+		pix = source->Bpix[y][x];
+		but->Bpix[y][x] = lut[pix];
+
+		}
+	}
+
+return FULL_NUCKED;
+}
 /*::------------------------------------------------------------------::*/
 /*
  *	cette fonction peut etre utilisee avec la meme image
@@ -20,6 +62,10 @@ float	fr, fg, fb;
 fprintf(stderr, "%s : %p -> %p\n", __func__, source, but);
 #endif
 
+if (k)	{
+	fprintf(stderr, "In %s, k must be 0, was %d\n", __func__, k);
+	}
+
 if ( (foo=Image_compare_desc(source, but)) ) {
     fprintf(stderr, "%s : images are differents %d\n", __func__, foo);
     return foo;
@@ -55,6 +101,10 @@ float	fr, fg, fb;
 fprintf(stderr, "%s : %p -> %p\n", __func__, source, but);
 #endif
 
+if (k)	{
+	fprintf(stderr, "In %s, k must be 0, was %d\n", __func__, k);
+	}
+
 if ( (foo=Image_compare_desc(source, but)) ) {
     fprintf(stderr, "%s : images are differents %d\n", __func__, foo);
     return foo;

Lib/foo.c

@@ -2,6 +2,7 @@
 #include  <stdlib.h>
 #include  <unistd.h>
 #include   <stdint.h>
+#include  <math.h>
 
 #include  "../tthimage.h"
 
@@ -14,6 +15,20 @@ else
 	Image_t16x24_essai("16x24gruik", "0123456789abcdef", "16x24.tga");
 return 0;
 }
+
+/*		==============================				*/
+void mk_lut(unsigned char lut[])
+{
+int		idx, uc;
+float		fidx;
+
+for (idx=0; idx<256; idx++) {
+	fidx = (float)idx / 255.0;
+	uc = (unsigned char)(255.0*(0.5 - 0.5 * cos(3.141592654*fidx)));
+	lut[idx] = uc;
+	printf("%7d    %7d\n", idx, uc); 
+	}
+}
 /*		==============================				*/
 int essai_draw_paint_rect(char *outga)
 {
@@ -62,7 +77,11 @@ return OLL_KORRECT;
 int main(int argc, char *argv[])
 {
 int		foo;
+unsigned char	Lut[256];
 
+mk_lut(Lut);
+
+#if 0
 Image_print_version(2);
 Image_print_sizeof_structs("foo");
 
@@ -72,5 +91,8 @@ fprintf(stderr, "essai show t16x24 --> %d\n", foo);
 foo = essai_draw_paint_rect("foo.tga");
 fprintf(stderr, "essai draw rect --> %d\n", foo);
 
+Image_egalise_cos01(NULL, NULL, 0);
+#endif
+
 return 0;
 }