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/**************************************************************
* _____ __ _____ *
* / _ \ | | ____ ___ ___ / | | *
* / /_\ \ | | _/ __ \ \ \/ / / | |_ *
* / | \| |__\ ___/ > < / ^ / *
* \____|__ /|____/ \___ >/__/\_ \ \____ | *
* \/ \/ \/ |__| *
* *
**************************************************************
* (c) Free Lunch Design 2003 *
* Written by Johan Peitz *
* http://www.freelunchdesign.com *
**************************************************************
* This source code is released under the The GNU *
* General Public License (GPL). Please refer to the *
* document license.txt in the source directory or *
* http://www.gnu.org for license information. *
**************************************************************/
#include "particle.h"
// pointer to datafile
DATAFILE *data;
// set datafile to use
void set_datafile(DATAFILE *d) {
data = d;
}
// inits variables in a particle
void set_particle(Tparticle *p, int x, int y, double dx, double dy, int color, int life, int bmp) {
p->x = x;
p->y = y;
p->dx = dx;
p->dy = dy;
p->color = color;
p->life = life;
p->bmp = bmp;
p->count = 0;
}
// draws particle depending on map offset (ox and oy)
void draw_particle(BITMAP *bmp, Tparticle*p, int ox, int oy) {
int x = p->x - ox;
int y = p->y - oy;
// is the particle inside the screen
if (x < -16 || x > bmp->w + 16 || y < -16 || y > bmp->h +16) return;
// draw it
if (p->bmp == -1)
putpixel(bmp, x, y, p->color);
else {
BITMAP *b = data[p->bmp + (p->color == -1 ? p->count>>1 : 0)].dat;
draw_sprite(bmp, b, x - b->w/2, y - b->h/2);
}
}
// updates the particle data (position etc)
void update_particle(Tparticle* p) {
p->x += p->dx;
p->y += p->dy;
if (p->bmp == -1) {
p->dy += 0.1;
}
p->life --;
p->count ++;
}
// resets all particles in an array
void reset_particles(Tparticle *p, int max) {
int i;
for(i = 0; i < max; i ++) {
p[i].life = 0;
}
}
// returns an unused particle from an array
Tparticle *get_free_particle(Tparticle *p, int max) {
int i = 0;
while(p[i].life && i<max) i++;
if (i == max) return NULL;
return &p[i];
}
// updates particle with map
void update_particle_with_map(Tparticle *p, Tmap *m) {
update_particle(p);
/* bouncing algo removed
p->y -= p->dy;
p->x -= p->dx;
if (is_ground(m, (int)p->x, (int)p->y)) {
p->dy = - 0.9 * p->dy;
//p->dx = - p->dx;
}
*/
}
// creates a little fireworks "bang"
void create_burst(Tparticle *ps, int x, int y, int spread, int num, int life, int bmp) {
int i;
Tparticle *p;
for(i = 0; i < num; i ++) {
p = get_free_particle(ps, MAX_PARTICLES);
if (p != NULL) {
set_particle(p, x + rand()%spread - spread/2, y + rand()%spread - spread/2, ((double)(rand()%100))/100.0 - 0.5, ((double)(rand()%100))/100.0 - 0.5, rand()%4 + 1, (life ? life : 70 - rand()%50), bmp);
}
}
}
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