From 4993fe5194245f12d42881ee4b65e93543968755 Mon Sep 17 00:00:00 2001
From: Christian Kroll <chris@das-labor.org>
Date: Mon, 14 Mar 2011 10:34:16 +0000
Subject: [PATCH] simple plasma animation added

---
 animations/Makefile  |  4 ++++
 animations/config.in | 14 +++++++------
 animations/plasma.c  | 48 ++++++++++++++++++++++++++++++++++++++++++++
 animations/plasma.h  |  6 ++++++
 display_loop.c       |  8 ++++++++
 5 files changed, 74 insertions(+), 6 deletions(-)
 create mode 100644 animations/plasma.c
 create mode 100644 animations/plasma.h

diff --git a/animations/Makefile b/animations/Makefile
index 344b16f..1435566 100644
--- a/animations/Makefile
+++ b/animations/Makefile
@@ -53,4 +53,8 @@ ifeq ($(ANIMATION_LOGO_27C3),y)
   SRC += 27c3.c
 endif
 
+ifeq ($(ANIMATION_PLASMA),y)
+  SRC += plasma.c
+endif
+
 include $(TOPDIR)/rules.mk
diff --git a/animations/config.in b/animations/config.in
index d873666..332e142 100644
--- a/animations/config.in
+++ b/animations/config.in
@@ -14,14 +14,16 @@ comment "Animations"
 	dep_bool "Breakout Demo" ANIMATION_BREAKOUT      $GAME_BREAKOUT
 	bool     "Martin Herweg" ANIMATION_MHERWEG       $RANDOM_SUPPORT
 	dep_bool "Langton Ant"   ANIMATION_LTN_ANT       $RANDOM_SUPPORT
-	
+
 	dep_bool_menu "Bitmap Scroller" ANIMATION_BMSCROLLER y $RANDOM_SUPPORT
-		dep_bool "LABOR Logo" ANIMATION_LABORLOGO $ANIMATION_BMSCROLLER
-		dep_bool "Amphibian"  ANIMATION_AMPHIBIAN $ANIMATION_BMSCROLLER
-		dep_bool "27c3 Logo"  ANIMATION_LOGO_27C3 $ANIMATION_BMSCROLLER
+		dep_bool "LABOR Logo"    ANIMATION_LABORLOGO     $ANIMATION_BMSCROLLER
+		dep_bool "Amphibian"     ANIMATION_AMPHIBIAN     $ANIMATION_BMSCROLLER
+		dep_bool "27c3 Logo"     ANIMATION_LOGO_27C3     $ANIMATION_BMSCROLLER
 	endmenu
-	
+
+	bool "Plasma"            ANIMATION_PLASMA
+
 	comment  "Special Animations"
 	bool     "Test Animations"  ANIMATION_TESTS
 	bool     "Display off mode" ANIMATION_OFF
-endmenu
\ No newline at end of file
+endmenu
diff --git a/animations/plasma.c b/animations/plasma.c
new file mode 100644
index 0000000..b76d770
--- /dev/null
+++ b/animations/plasma.c
@@ -0,0 +1,48 @@
+#include <math.h>
+#include <stdint.h>
+#include "../config.h"
+#include "../pixel.h"
+#include "../util.h"
+#include "plasma.h"
+
+
+#define FRAME_TICK 80
+#define FRAME_COUNT 750
+#define PLASMA_X (1.0 / (NUM_COLS / (2.0 * M_PI)))
+
+
+/**
+ * calculates the distance between two points
+ * @param x1 x coordinate of the first point
+ * @param y1 y coordinate of the first point
+ * @param x2 x coordinate of the second point
+ * @param y2 y coordinate of the second point
+ * @return distance between the points
+ */
+static double dist(double x1, double y1, double x2, double y2)
+{
+	return sqrt(((x1 - x2) * (x1 - x2)) + ((y1 - y2) * (y1 - y2)));
+}
+
+
+/**
+ * draws a simple plasma effect
+ */
+void plasma(void)
+{
+	for (double t = 0; t < (FRAME_COUNT / 10.0); t = t + 0.1) {
+		for (unsigned char x = 0; x < NUM_COLS; ++x)
+		{
+			for (unsigned char y = 0; y < NUM_ROWS; ++y)
+			{
+				double nColor1 = sin(x * PLASMA_X + t) + 1;
+				double nColor2 = sin(dist(x, y,	NUM_COLS * sin(t) + NUM_COLS,
+					NUM_ROWS * cos(t) + NUM_ROWS) * PLASMA_X) + 1;
+				unsigned char nColor =
+						((nColor1 + nColor2) * (NUMPLANE - 1)) / 2;
+				setpixel((pixel){x, y}, nColor);
+			}
+		}
+		wait(FRAME_TICK);
+	}
+}
diff --git a/animations/plasma.h b/animations/plasma.h
new file mode 100644
index 0000000..40beb28
--- /dev/null
+++ b/animations/plasma.h
@@ -0,0 +1,6 @@
+#ifndef PLASMA_H_
+#define PLASMA_H_
+
+void plasma(void);
+
+#endif /* PLASMA_H_ */
diff --git a/display_loop.c b/display_loop.c
index 9b847a0..d65eedf 100644
--- a/display_loop.c
+++ b/display_loop.c
@@ -15,6 +15,7 @@
 #include "animations/amphibian.h"
 #include "animations/laborlogo.h"
 #include "animations/27c3.h"
+#include "animations/plasma.h"
 #include "animations/mherweg.h"
 #include "borg_hw/borg_hw.h"
 #include "can/borg_can.h"
@@ -171,6 +172,13 @@ void display_loop(){
 			break;
 #endif
 
+#ifdef ANIMATION_PLASMA
+		case 18:
+			plasma();
+			break;
+#endif
+
+
 #ifdef ANIMATION_TESTS
 		case 31:
 			test_level(1);