libtthimage/calcluts.c

/*
			calcluts.c
			----------

   voir aussi: luts15bits.c

*/

#include  <stdio.h>
#include  <stdlib.h>
#include  <string.h>

#ifdef NEED_ALLOCA_H
#include  <alloca.h> 
#endif

#include  "tthimage.h"

/*::------------------------------------------------------------------::*/
int
Image_calclut_lin(int *lut, int v0, int v255)
{
int foo, quux, delta;

#if DEBUG_LEVEL
fprintf(stderr, "calclut lin: v0 = %d  v255 = %d\n", v0, v255);
#endif

delta = v255 - v0;
if (delta == 0)
	{
	return DIVISOR_IS_0;
	}

#if DEBUG_LEVEL
fprintf(stderr, "calclut lin: delta = %d\n", delta);
#endif

for (foo=0; foo<256; foo++)
	{
	quux = (foo * delta / 255) + v0;
#if DEBUG_LEVEL
	printf("lut(%d) = %d\n", foo, quux);
#endif
	lut[foo] = quux;
	}

return FUNC_IS_ALPHA;
}
/*::------------------------------------------------------------------::*/
int
Image_calclut_foo(int *lut, int v0, int v255)
{
fprintf(stderr, "%s ( %p %d %d )\n", __func__, lut, v0, v255);

return FUNC_IS_ALPHA;
}
/*::------------------------------------------------------------------::*/
int
Image_print_lut(int *lut, char *fname, int flag)
{
FILE	*fp;
int	foo;

if (strcmp(fname, "-"))
	fp = fopen(fname, "w");
else
	fp = stdout;

for (foo=0; foo<256; foo++)
	{
	if (flag)
		printf("%d ", foo);
	printf("%d\n", lut[foo]);
	}

if (fp!=stdout)
	fclose(fp);

return FUNC_IS_ALPHA;
}
/*::------------------------------------------------------------------::*/
int
Image_load_lut(int *lut, char *fname, int flag)
{
FILE	*fp;
int	value, foo, idx;

if (flag) {
	fprintf(stderr, "in %s, flag must be O, was %d\n", __func__, flag);
	return WRONG_FLAG;
	}

#if DEBUG_LEVEL
fprintf(stderr, "load_lut %s in %p\n", fname, lut);
#endif

if (NULL==(fp=fopen(fname, "r")))
	{
	fprintf(stderr, "%s can't fopen %s\n", __func__, fname);
	return 666;
	}

/* WARNING : very crude code here (4 nov 1999) */
for (idx=0; idx<256; idx++)
	{
	foo = fscanf(fp, "%d", &value);
#if DEBUG_LEVEL
	fprintf(stderr, "load lut %3d %3d %d\n", idx, foo, value);
#endif
	if (1==foo)	lut[idx] = value;
	else		lut[idx] = -1;
	}

fclose(fp);

return FUNC_IS_ALPHA;
}
/*::------------------------------------------------------------------::*/