/* 
 * Copyright (c) 1999, Not a Number / NeoGeo b.v. 
 * 
 */

#include "plugin.h"

/* ******************** GLOBAL VARIABLES ***************** */


char name[24]= "scatter";

/* structure for buttons, 
 *  butcode      name           default  min  max  0
 */

VarStruct varstr[]= {
	LABEL,		"Input: 1 strip", 0.0, 0.0, 0.0, "", 
	NUM|INT,	"seed: ",		1.0,	0.0, 10.0, "Offset in random table", 
	NUMSLI|FLO,	"swing: ",		1.0,	0.0, 3.0, "The amplitude, width of the effect", 
	TOG|INT,	"wrap",			0.0,	0.0, 1.0, "Cyclic wrap around the left/right edges", 
	NUM|INT,	"type: ",		1.0,	0.0, 1.0, "Type 1 is random for each frame", 
};

/* The cast struct is for input in the main doit function
   Varstr and Cast must have the same variables in the same order */ 

typedef struct Cast {
	int dummy;			/* because of the 'label' button */
	int seed;
	float swing;
	int wrap;
	int type;
} Cast;

/* cfra: the current frame */

float cfra;

void plugin_seq_doit(Cast *, float, float, int, int, ImBuf *, ImBuf *, ImBuf *, ImBuf *);


/* ******************** Fixed functions ***************** */

int plugin_seq_getversion(void) 
{
	return B_PLUGIN_VERSION;
}

void plugin_but_changed(int but) 
{
}

void plugin_init()
{
}

void plugin_getinfo(PluginInfo *info)
{
	info->name= name;
	info->nvars= sizeof(varstr)/sizeof(VarStruct);
	info->cfra= &cfra;

	info->varstr= varstr;

	info->init= plugin_init;
	info->seq_doit= (SeqDoit) plugin_seq_doit;
	info->callback= plugin_but_changed;
}


/* ************************************************************
	Scatter
	
	with usage of ImBuf rect operation.
	
   ************************************************************ */

static void ibufrectop(ImBuf *dbuf, ImBuf *sbuf,	
				int destx, int desty, 
				int srcx, int srcy, int width, int height,
				void (*operation)(), 
				int value)
{
	uint *drect,*srect;

	if (dbuf == 0) return;
	if (operation == 0) return;

	if (destx < 0){
		srcx -= destx ;
		width += destx ;
		destx = 0;
	}
	if (srcx < 0){
		destx -= srcx ;
		width += destx ;
		srcx = 0;
	}
	if (desty < 0){
		srcy -= desty ;
		height += desty ;
		desty = 0;
	}
	if (srcy < 0){
		desty -= srcy ;
		height += desty ;
		srcy = 0;
	}

	if (width > dbuf->x - destx) width = dbuf->x - destx;
	if (height > dbuf->y - desty) height = dbuf->y - desty;
	if (sbuf){
		if (width > sbuf->x - srcx) width = sbuf->x - srcx;
		if (height > sbuf->y - srcy) height = sbuf->y - srcy;
	}

	if (width <= 0) return;
	if (height <= 0) return;

	drect = dbuf->rect;
	if (sbuf) srect = sbuf->rect;

	drect += desty * dbuf->x;
	drect += destx;
	destx = dbuf->x;

	if (sbuf) {
		srect += srcy * sbuf->x;
		srect += srcx;
		srcx = sbuf->x;
	} else{
		srect = drect;
		srcx = destx;
	}

	for (;height > 0; height--){
		operation(drect, srect, width, value);
		drect += destx;
		srect += srcx;
	}
}

static void rectcpy(uint *drect, uint *srect, int x) {
	memcpy(drect,srect, x * sizeof(int));
}

static void rectfill(uint *drect, uint *srect, int x, int value)
{
	for (;x > 0; x--) *drect++ = value;
}


void plugin_seq_doit(Cast *cast, float facf0, float facf1, int sx, int sy, ImBuf *ibuf1, ImBuf *ibuf2, ImBuf *out, ImBuf *use)
{
	float f1, f2, t1, t2, t3;
	int x, y, lr;
	
	/* fill imbuf 'out' with black */
	rectop(out, 0,0,0,0,0,32767,32767,rectfill, 0);

	switch (cast->type) {
		case 0:
			srand48(cast->seed);
			break;
		case 1:
			srand48(cast->seed + facf0 * 1000);
			break;
	}

	for (y = 0; y < sy; y++) {
		switch (cast->type) {
			case 0:
				if ((y & 1) == 0) {
					f1 = drand48() - 0.5;
					f2 = drand48() - 0.5;
					f1 = cast->swing * f1;
					f2 = cast->swing * f2;
					if (cast->wrap) f2 += 1.0;
					lr = drand48()>0.5;
					t1 = facf0;
				} else t1 = facf1;
				
				t2 = 1.0 - t1;
				t3 = 3.0 * (f1 * t1 * t1 * t2 + f2 * t1 * t2 * t2);
				if (cast->wrap) t3 += t2 * t2 * t2;
				x = sx * t3;
				if (lr) x = -x;
				break;
			case 1:
				f1 = drand48() - 0.5;
				f1 = f1 * cast->swing;
				if ((y & 1) == 0) f1 *= facf0;
				else f1 *= facf1;
				x = f1 * sx;
				break;
		}
		
		rectop(out, ibuf1, 0, y, x, y, 32767, 1, rectcpy, 0);
		if (cast->wrap) {
			rectop(out, ibuf1, 0, y, x + sx, y, 32767, 1, rectcpy, 0);
			rectop(out, ibuf1, 0, y, x + sx + sx, y, 32767, 1, rectcpy, 0);
			rectop(out, ibuf1, 0, y, x - sx, y, 32767, 1, rectcpy, 0);
			rectop(out, ibuf1, 0, y, x - sx - sx, y, 32767, 1, rectcpy, 0);
		}
	}
}

