1 files changed, 89 insertions, 0 deletions
diff --git a/debian/fireflies/fireflies-2.08/src/tail.cc b/debian/fireflies/fireflies-2.08/src/tail.cc
new file mode 100644
index 00000000..18e013b6
--- /dev/null
+++ b/debian/fireflies/fireflies-2.08/src/tail.cc
@@ -0,0 +1,89 @@
+#include "tail.h"
+#include "firefly.h"
+#include "scene.h"
+
+Tail::Tail(Firefly *_owner)
+    : owner(_owner)
+{
+}
+
+#define SET_COLOR(c, a)		glColor4f(c[0], c[1], c[2], a)
+#define SET_VERTEX(v, dx)	glVertex3d(v[0]+dx, v[1], v[2])
+#define DO_POINT(t, dx, a)\
+    SET_COLOR((t).color, a); SET_VERTEX((t).pos, dx)
+
+void Tail::draw()
+{
+    if (links.size() < 2) // need at least 2 links
+	return;
+
+    deque<Link>::iterator it = links.begin();
+    double glow_width = scene.glow_factor*scene.tail_width;
+    double stretch_factor = 2*scene.fsize*scene.wind[0];
+    double dx1, dx2;
+
+    dx2 = ((*it).glow ? glow_width : scene.tail_width);
+    for (; (it+1) != links.end(); it++) {
+	// half-width of the tail
+	dx1 = dx2;
+	dx2 = ((*(it+1)).glow ? glow_width : scene.tail_width);
+
+	// have the wind stretch the tail (greater effect on ends)
+	double age = (*it).age/scene.tail_length;
+	double stretch = stretch_factor*age*age;
+	double alpha = 0.9 - age;
+	if (alpha > scene.tail_opaq)
+	    alpha = scene.tail_opaq;
+
+	// two rectangles: outer vertices have alpha=0, inner two have
+	// alpha based on age. note: alpha goes negative, but opengl
+	// should clamp it to 0.
+	if (stretch > 0) { // stretch to the right
+	    glBegin(GL_QUAD_STRIP);
+	    DO_POINT(*it, -dx1, 0);
+	    DO_POINT(*(it+1), -dx2, 0);
+
+	    DO_POINT(*it, 0, alpha);
+	    DO_POINT(*(it+1), 0, alpha);
+
+	    DO_POINT(*it, dx1 + stretch, 0);
+	    DO_POINT(*(it+1), dx2 + stretch, 0);
+	}
+	else { // stretch to the left
+	    glBegin(GL_QUAD_STRIP);
+	    DO_POINT(*it, -dx1 + stretch, 0);
+	    DO_POINT(*(it+1), -dx2 + stretch, 0);
+
+	    DO_POINT(*it, 0, alpha);
+	    DO_POINT(*(it+1), 0, alpha);
+
+	    DO_POINT(*it, dx1, 0);
+	    DO_POINT(*(it+1), dx2, 0);
+	}
+	glEnd();
+    }
+}
+
+bool Tail::elapse(double t)
+{
+    // pop off the dead ones.
+    // note we only have to check the end, since that's where they're gonna
+    // be dying from.  deque is very nice for this, because it has constant
+    // time  insertion/removal from both ends.
+    while (!links.empty() && links.back().age >= scene.tail_length)
+	links.pop_back();
+
+    deque<Link>::iterator it = links.begin();
+    for (; it != links.end(); it++) {
+	(*it).age += t;
+	double age = (*it).age/scene.tail_length;
+	(*it).pos += scene.wind*age*age;
+    }
+
+    if (owner == 0) // my owner died! grow no longer
+	return links.empty(); // if we're empty, tell caller we're dead
+
+    links.push_front(Link(owner->pos, owner->color, owner->bait->glow));
+
+    return false;
+}