From 4fa7b4065b3c9630c638013f0fed7e2a36efd264 Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@member.fsf.org>
Date: Fri, 30 Aug 2019 21:13:56 +0300
Subject: [PATCH] fadeout

---
 src/main.c |   17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/main.c b/src/main.c
index 0807e5d..23b9878 100644
--- a/src/main.c
+++ b/src/main.c
@@ -122,17 +122,20 @@ void display(void)
 	long msec = glutGet(GLUT_ELAPSED_TIME) - start_time;
 	float t = (float)msec / 1000.0f;
 	float a[2], b[2], dt;
-	float anim;
+	float anim, alpha;
 
 	glClear(GL_COLOR_BUFFER_BIT);
 
 	glLineWidth(5.0);
 
 	anim = fmod(t / 6.0f, LOOPTIME);
+	alpha = 1.0f - ((anim - (LOOPTIME - 0.2)) / 0.2f);
+	if(alpha < 0.0f) alpha = 0.0f;
+	if(alpha > 1.0f) alpha = 1.0f;
 
 	dt = (anim > 1.0f ? 1.0f : anim) / (float)(nverts - 1);
 
-	glColor3f(1, 1, 1);
+	glColor4f(1, 1, 1, alpha);
 	for(i=0; i<nverts-1; i++) {
 		float t0 = (float)i * dt;
 		float t1 = (float)(i + 1) * dt;
@@ -156,6 +159,16 @@ void display(void)
 	glColor4f(0.8, 0, 0, 2.0 * (anim - 1.0f) / (LOOPTIME - 1.0f));
 	draw_disc(0, 0, 0.14, 24);
 
+	if(alpha < 1.0f) {
+		glBegin(GL_QUADS);
+		glColor4f(0, 0, 0, 1.0f - alpha);
+		glVertex2f(-1, -1);
+		glVertex2f(1, -1);
+		glVertex2f(1, 1);
+		glVertex2f(-1, 1);
+		glEnd();
+	}
+
 	glDisable(GL_BLEND);
 
 	glutSwapBuffers();
-- 
1.7.10.4