From 663443055c826b8c9d12485c318ba3b8af29191b Mon Sep 17 00:00:00 2001
From: Christian Kroll <chris@das-labor.org>
Date: Wed, 15 Aug 2012 04:05:04 +0000
Subject: [PATCH] Added basic square pattern animation. Unfortunately, it did
 not turn out to be as beautiful as intended. Borg displays can be limiting at
 times...

---
 animations/Makefile  |  4 +++
 animations/config.in |  2 ++
 animations/squares.c | 67 ++++++++++++++++++++++++++++++++++++++++++++
 animations/squares.h | 19 +++++++++++++
 display_loop.c       |  7 +++++
 5 files changed, 99 insertions(+)
 create mode 100644 animations/squares.c
 create mode 100644 animations/squares.h

diff --git a/animations/Makefile b/animations/Makefile
index 88b1a80..c775a28 100644
--- a/animations/Makefile
+++ b/animations/Makefile
@@ -69,6 +69,10 @@ ifeq ($(ANIMATION_BLACKHOLE),y)
   SRC += blackhole.c
 endif
 
+ifeq ($(ANIMATION_SQUARES),y)
+  SRC += squares.c
+endif
+
 ifeq ($(ANIMATION_TIME),y)
   SRC += borg_time.c
 endif
diff --git a/animations/config.in b/animations/config.in
index d8992d2..9f49617 100644
--- a/animations/config.in
+++ b/animations/config.in
@@ -70,6 +70,8 @@ comment "Animations"
 
 	bool     "Black Hole"       ANIMATION_BLACKHOLE
 
+	dep_bool "Squares"          ANIMATION_SQUARES       $RANDOM_SUPPORT
+
 	comment  "Special Animations"
 	bool     "Test Animations"  ANIMATION_TESTS
 	bool     "Display off mode" ANIMATION_OFF
diff --git a/animations/squares.c b/animations/squares.c
new file mode 100644
index 0000000..c915bc7
--- /dev/null
+++ b/animations/squares.c
@@ -0,0 +1,67 @@
+/**
+ * \defgroup squares Square patterns for the Borg.
+ * @{
+ */
+
+
+/**
+ * @file squares.c
+ * @brief Moves layers of translucent checker boards over each other.
+ * @author Christian Kroll
+ */
+
+
+#include <assert.h>
+#include <stdint.h>
+#include "../config.h"
+#include "../util.h"
+#include "../pixel.h"
+#include "../random/prng.h"
+#include "squares.h"
+
+#define STEP_WIDTH (NUMPLANE * 2u)
+#define TICK 150
+#define CYCLES 200u
+
+/**
+ * Moves layers of translucent checker boards over each other.
+ */
+void squares(void) {
+	// add a rotating color map for smooth transitions
+	uint8_t nColorMap[NUMPLANE * 2];
+	for (uint8_t i = 0; i < (((NUMPLANE + 1) * 2) - 1); ++i) {
+		if (i < (NUMPLANE + 1)) {
+			nColorMap[i] = i;
+		} else {
+			nColorMap[i] = (NUMPLANE * 2) - i;
+		}
+	}
+
+	uint8_t nOffsets[NUMPLANE] = {0};
+	uint8_t nColOffset = 0;
+	for (uint8_t nCount = CYCLES; nCount--;) {
+		for (uint8_t x = 0; x < NUM_COLS ; ++x) {
+			for (uint8_t y = 0; y < NUM_ROWS; ++y) {
+				uint8_t nColor = 0;
+				for (uint8_t nLayer = 0; nLayer < NUMPLANE; ++nLayer) {
+					nColor += (((x + nOffsets[nLayer]) / STEP_WIDTH) + ((y +
+							nOffsets[nLayer] + STEP_WIDTH) / STEP_WIDTH)) % 2u;
+				}
+				setpixel((pixel){x, y},
+						nColorMap[(nColOffset + nColor) % (2* NUMPLANE)]);
+			}
+		}
+
+		// add randomly calculated offsets to each layer starting points
+		for (uint8_t i = 0; i < NUMPLANE; ++i) {
+			nOffsets[i] = (nOffsets[i] + random8()) & STEP_WIDTH;
+		}
+		// rotate color map
+		nColOffset = (nColOffset + 1) % (NUMPLANE * 2);
+
+		// pause for a moment to ensure that frame transitions are visible
+		wait(TICK);
+	}
+}
+
+/*@}*/
diff --git a/animations/squares.h b/animations/squares.h
new file mode 100644
index 0000000..6c211c4
--- /dev/null
+++ b/animations/squares.h
@@ -0,0 +1,19 @@
+/**
+ * \addtogroup squares
+ * @{
+ */
+
+/**
+ * @file squares.h
+ * @brief Moves layers of translucent checker boards over each other.
+ * @author Christian Kroll
+ */
+
+#ifndef SQUARES_H_
+#define SQUARES_H_
+
+void squares(void);
+
+#endif /* SQUARES_H_ */
+
+/*@}*/
diff --git a/display_loop.c b/display_loop.c
index 4549def..db3e36f 100644
--- a/display_loop.c
+++ b/display_loop.c
@@ -20,6 +20,7 @@
 #include "animations/fpmath_patterns.h"
 #include "animations/mherweg.h"
 #include "animations/blackhole.h"
+#include "animations/squares.h"
 #ifdef ANIMATION_TIME
 #include "animations/borg_time.h"
 #endif
@@ -240,6 +241,12 @@ void display_loop(){
 			break;
 #endif
 
+#ifdef ANIMATION_SQUARES
+		case 25:
+			squares();
+			break;
+#endif
+
 #ifdef ANIMATION_TESTS
 		case 31:
 			test_level(1);