1 files changed, 82 insertions, 0 deletions
diff --git a/src/modules/sparkler/xplode.c b/src/modules/sparkler/xplode.c
new file mode 100644
index 0000000..24a436e
--- /dev/null
+++ b/src/modules/sparkler/xplode.c
@@ -0,0 +1,82 @@
+#include <stdlib.h>
+
+#include "draw.h"
+#include "particle.h"
+#include "particles.h"
+
+/* a "xplode" particle type, emitted by rockets in large numbers at the end of their lifetime */
+#define XPLODE_MAX_DECAY_RATE	10
+#define XPLODE_MIN_DECAY_RATE	5
+#define XPLODE_MAX_LIFETIME	150
+#define XPLODE_MIN_LIFETIME	5
+
+extern particle_ops_t spark_ops;
+particle_ops_t	xplode_ops;
+
+typedef struct _xplode_ctxt_t {
+	int		decay_rate;
+	int		longevity;
+	int		lifetime;
+} xplode_ctxt_t;
+
+
+static int xplode_init(particles_t *particles, particle_t *p)
+{
+	xplode_ctxt_t	*ctxt = p->ctxt;
+
+	ctxt->decay_rate = rand_within_range(XPLODE_MIN_DECAY_RATE, XPLODE_MAX_DECAY_RATE);
+	ctxt->lifetime = ctxt->longevity = rand_within_range(XPLODE_MIN_LIFETIME, XPLODE_MAX_LIFETIME);
+
+	p->props->drag = 10.9;
+	p->props->mass = 0.3;
+
+	return 1;
+}
+
+
+static particle_status_t xplode_sim(particles_t *particles, particle_t *p)
+{
+	xplode_ctxt_t	*ctxt = p->ctxt;
+
+	if (!ctxt->longevity || (ctxt->longevity -= ctxt->decay_rate) <= 0) {
+		ctxt->longevity = 0;
+		return PARTICLE_DEAD;
+	}
+
+	/* litter some small sparks behind the explosion particle */
+	if (!(ctxt->lifetime % 30)) {
+		particle_props_t	props = *p->props;
+
+		props.velocity = (float)rand_within_range(10, 50) / 10000.0;
+		particles_spawn_particle(particles, p, &props, &xplode_ops);
+	}
+
+	return PARTICLE_ALIVE;
+}
+
+
+static void xplode_draw(particles_t *particles, particle_t *p, int x, int y, fb_fragment_t *f)
+{
+	xplode_ctxt_t	*ctxt = p->ctxt;
+	uint32_t	color;
+
+	if (ctxt->longevity == ctxt->lifetime) {
+		color = makergb(0xff, 0xff, 0xa0, 1.0);
+	} else {
+		color = makergb(0xff, 0xff, 0x00, ((float)ctxt->longevity / ctxt->lifetime));
+	}
+
+	if (!draw_pixel(f, x, y, color)) {
+		/* offscreen */
+		ctxt->longevity = 0;
+	}
+}
+
+
+particle_ops_t	xplode_ops = {
+			.context_size = sizeof(xplode_ctxt_t),
+			.sim = xplode_sim,
+			.init = xplode_init,
+			.draw = xplode_draw,
+			.cleanup = NULL,
+		};