1 files changed, 144 insertions, 0 deletions
diff --git a/board/keyborg/encode_segment.c b/board/keyborg/encode_segment.c
new file mode 100644
index 0000000000..49eaec64c9
--- /dev/null
+++ b/board/keyborg/encode_segment.c
@@ -0,0 +1,144 @@
+/* Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* Touch data encoding/decoding */
+
+/*
+ * This removes the "whitespace" (i.e. cells below the threshold) and
+ * group the remaining active cells into "segments". By only storing
+ * the segments, we can fit a single frame in RAM in most cases.
+ */
+
+#include "common.h"
+#include "debug.h"
+#include "touch_scan.h"
+#include "util.h"
+
+#define BUF_SIZE 6000
+static uint8_t encoded[BUF_SIZE];
+static int encoded_size;
+
+void encode_reset(void)
+{
+	/* Just clear the encoded data */
+	encoded_size = 0;
+}
+
+void encode_add_column(const uint8_t *dptr)
+{
+	uint8_t *seg_count_ptr;
+	int p, p_start;
+	uint8_t *eptr = encoded + encoded_size, *e_seg_size;
+
+	seg_count_ptr = eptr;
+	eptr++;
+
+	*seg_count_ptr = 0;
+	p = 0;
+	while (p < ROW_COUNT * 2) {
+		if (dptr[p] < THRESHOLD) {
+			++p;
+			continue;
+		}
+
+		/* Give up on overflow */
+		if (eptr + 2 >= encoded + BUF_SIZE)
+			return;
+
+		/* Save current position */
+		*(eptr++) = p;
+
+		/* Leave a byte for storing segment size */
+		e_seg_size = eptr;
+		eptr++;
+
+		/* Record segment starting point */
+		p_start = p;
+
+		/* Save the segment */
+		while (p < ROW_COUNT * 2 && dptr[p] >= THRESHOLD) {
+			if (eptr >= encoded + BUF_SIZE)
+				return;
+			*(eptr++) = dptr[p++];
+		}
+
+		/* Fill in the segment size now that we know it */
+		*e_seg_size = p - p_start;
+
+		(*seg_count_ptr)++;
+	}
+
+	/* Update encoded data size now that we're sure it fits */
+	encoded_size = eptr - encoded;
+}
+
+void encode_dump_matrix(void)
+{
+	uint8_t *dptr;
+	int row, col;
+	int seg_count;
+	int seg;
+	int seg_end;
+
+	debug_printf("Encoded size = %d\n", encoded_size);
+
+#ifdef CONFIG_ENCODE_DUMP_PYTHON
+	debug_printf("heat_map = [");
+	dptr = encoded;
+	for (col = 0; col < COL_COUNT * 2; ++col) {
+		debug_printf("[");
+		if (dptr >= encoded + encoded_size) {
+			debug_printf("0] * %d,\n", ROW_COUNT * 2);
+			continue;
+		}
+		seg_count = *(dptr++);
+		row = 0;
+		for (seg = 0; seg < seg_count; ++seg) {
+			if (row < *dptr) {
+				debug_printf("] + [0] * %d + [", *dptr - row);
+				row = *dptr;
+			}
+			dptr++;
+			seg_end = *dptr + row;
+			dptr++;
+			for (; row < seg_end; ++row, ++dptr)
+				debug_printf("%d,", *dptr);
+		}
+		if (row < ROW_COUNT * 2)
+			debug_printf("] + [0] * %d,\n", ROW_COUNT * 2 - row);
+		else
+			debug_printf("],\n");
+	}
+	debug_printf("]\n");
+#else
+	dptr = encoded;
+	for (col = 0; col < COL_COUNT * 2; ++col) {
+		if (dptr >= encoded + encoded_size) {
+			for (row = 0; row < ROW_COUNT * 2; ++row)
+				debug_printf("  - ");
+			debug_printf("\n");
+			continue;
+		}
+		seg_count = *(dptr++);
+		row = 0;
+		for (seg = 0; seg < seg_count; ++seg) {
+			while (row < *dptr) {
+				debug_printf("  - ");
+				row++;
+			}
+			dptr++;
+			seg_end = *dptr + row;
+			dptr++;
+			for (; row < seg_end; ++row, ++dptr)
+				debug_printf("%3d ", *dptr);
+		}
+		while (row < ROW_COUNT * 2) {
+			debug_printf("  - ");
+			row++;
+		}
+		debug_printf("\n");
+	}
+#endif
+}