1 files changed, 63 insertions, 0 deletions
diff --git a/modules/sparkler/spark.c b/modules/sparkler/spark.c
new file mode 100644
index 0000000..ea68ac2
--- /dev/null
+++ b/modules/sparkler/spark.c
@@ -0,0 +1,63 @@
+#include <stdlib.h>
+
+#include "draw.h"
+#include "particle.h"
+#include "particles.h"
+
+/* a "spark" particle type, emitted from behind rockets */
+#define SPARK_MAX_DECAY_RATE	20
+#define SPARK_MIN_DECAY_RATE	2
+#define SPARK_MAX_LIFETIME	150
+#define SPARK_MIN_LIFETIME	1
+
+typedef struct _spark_ctxt_t {
+	int		decay_rate;
+	int		longevity;
+	int		lifetime;
+} spark_ctxt_t;
+
+
+static int spark_init(particles_t *particles, particle_t *p)
+{
+	spark_ctxt_t	*ctxt = p->ctxt;
+
+	p->props->drag = 20.0;
+	p->props->mass = 0.1;
+	ctxt->decay_rate = rand_within_range(SPARK_MIN_DECAY_RATE, SPARK_MAX_DECAY_RATE);
+	ctxt->lifetime = ctxt->longevity = rand_within_range(SPARK_MIN_LIFETIME, SPARK_MAX_LIFETIME);
+
+	return 1;
+}
+
+
+static particle_status_t spark_sim(particles_t *particles, particle_t *p)
+{
+	spark_ctxt_t	*ctxt = p->ctxt;
+
+	if (!ctxt->longevity || (ctxt->longevity -= ctxt->decay_rate) <= 0) {
+		ctxt->longevity = 0;
+		return PARTICLE_DEAD;
+	}
+
+	return PARTICLE_ALIVE;
+}
+
+
+static void spark_draw(particles_t *particles, particle_t *p, int x, int y, fb_fragment_t *f)
+{
+	spark_ctxt_t	*ctxt = p->ctxt;
+
+	if (!draw_pixel(f, x, y, makergb(0xff, 0xa0, 0x20, ((float)ctxt->longevity / ctxt->lifetime)))) {
+		/* offscreen */
+		ctxt->longevity = 0;
+	}
+}
+
+
+particle_ops_t	spark_ops = {
+			.context_size = sizeof(spark_ctxt_t),
+			.sim = spark_sim,
+			.init = spark_init,
+			.draw = spark_draw,
+			.cleanup = NULL,
+		};