FloatImg/Fonderie/glitches.c

/*
 * 		glitches.c
 * 		----------
 *
 * 	initially developped for the interpolator
 */

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

#include  "../floatimg.h"

#include  "glitches.h"

extern int		verbosity;

/*   --------------------------------------------------------------   */
int kill_a_random_line(FloatImg *pvictime, float fval, int bits)
{
int		line, xpos, offset;
float		ftmp;

#if DEBUG_LEVEL
fprintf(stderr, ">>> %s ( %p %d )\n", __func__, pvictime, bits);
#endif

line = rand() % pvictime->height;

if (verbosity > 2) {
	fprintf(stderr, "%s: try to kill line %d\n", __func__, line);
	}

offset = pvictime->width * line;

for (xpos=0; xpos<pvictime->width; xpos++) {
	if (bits & 1)	{ ftmp = pvictime->R[offset+xpos] * fval;
			pvictime->R[offset+xpos] = sqrt(ftmp); }
	else		pvictime->R[offset+xpos] = 0.0;
	if (bits & 2)	{ ftmp = pvictime->G[offset+xpos] * fval;
			pvictime->G[offset+xpos] = sqrt(ftmp); }
	else		pvictime->G[offset+xpos] = 0.0;
	if (bits & 4)	{ ftmp = pvictime->B[offset+xpos] * fval;
			pvictime->B[offset+xpos] = sqrt(ftmp); }
	else		pvictime->B[offset+xpos] = 0.0;
	}

return 0;
}
/*   --------------------------------------------------------------   */
int kill_a_few_lines(FloatImg *who, float fval, int number)
{
int		idx, foo;

#if DEBUG_LEVEL
fprintf(stderr, ">>> %s ( %p %f %d )\n", __func__, who, fval, number);
#endif

/* Frag the pixels */
for (idx=0; idx<number; idx++) {
	foo = kill_a_random_line(who, fval, rand() & 0x07);
	if (foo)	abort();
	}

return foo;
}
/*   --------------------------------------------------------------   */
int un_petit_flou_8x8(FloatImg *picture, int xpos, int ypos)
{
float	sr, sg, sb;
int	x, y, off;

/*
 *  please add boundary check ?
 */
sr = sg = sb = 0.0;
for (y=0; y<8; y++) {
	off = xpos + (picture->width * (y+ypos));
	for (x=0; x<8; x++) {
		sr += picture->R[off];
		sg += picture->G[off];
		sb += picture->B[off];
		off++;
		}
	}
sr /= 64.0;	sg /= 64.0;	sb /= 64.0;
for (y=0; y<8; y++) {
	off = xpos + (picture->width * (y+ypos));
	for (x=0; x<8; x++) {
		picture->R[off] = sr;
		picture->G[off] = sg;
		picture->B[off] = sb;
		off++;
		}
	}
return 0;
}
/*   --------------------------------------------------------------   */
int un_moyen_flou_8x8(FloatImg *picture, int xpos, int ypos)
{
int	i, j, x, y;

/*
 *  please add boundary check ?
 */
for (i=y=0; i<8; i++, y+=8) {
	for (j=x=0; j<8; j++, x+=8 ) {
		un_petit_flou_8x8(picture, x+xpos, y+ypos);
		}
	}
return 0;
}
/*   --------------------------------------------------------------   */
int poke_a_random_pixel(FloatImg *picz, float fval, int kaboo)
{

return -1;
}
/*   --------------------------------------------------------------   */
/*
 *   used by vertical_singlitch()
 */
static int x_delta(float dy, float phy)
{
float	param, fv;
param = dy + phy;
fv = 9.999*sin(param) + 6.666*sin(param*3) + 3.333*sin(param*5);
return (int)fv;
}
/*   --------------------------------------------------------------   */
/*
 *     please explain arguments
 */
int vertical_singlitch(FloatImg *picz, int xpos, float fval, 
						float omega, float phi)
{
int		y, x, w, h;
float		dy;
float		fv;

#if DEBUG_LEVEL
fprintf(stderr, ">>> %s ( %p %d %f %f )\n", __func__, picz,
					xpos, omega, phi);
#endif

h = picz->height;		w = picz->width;
#define BB 4
for (y=BB; y<h-BB; y++) {

	dy = (float)y * omega;		/* normalize vertical position */

	x = xpos + x_delta(dy, phi);	/* add sinus deviation */

	/* compute bounding box */
	if ( (x>BB) && (x<w-BB) ) {
		/* an make the glitch */
		fimg_plot_rgb(picz, x, y, fval, fval, fval);
		fv = fval / 3.0;
		if (rand() & 8)
			fimg_plot_rgb(picz, x-1, y, fv, fv, fv);
		if (rand() & 8)
		// XXX else
			fimg_plot_rgb(picz, x+1, y, fv, fv, fv);
		}
	}
return 0;
}
/*   --------------------------------------------------------------   */