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https://github.com/Telecominfraproject/OpenCellular.git
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4cb6971daf
A single frame of the scanned heat map is too big to fit into RAM. Let's encode it so that we can get the whole frame. BUG=None TEST=Touch on various places on the panel and see corresponding results. BRANCH=None Change-Id: I8c7c72d5d4a83ebc2018c0abd57075697c931bef Signed-off-by: Vic Yang <victoryang@chromium.org> Reviewed-on: https://chromium-review.googlesource.com/199940 Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
115 lines
2.3 KiB
C
115 lines
2.3 KiB
C
/* Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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/* Touch data encoding/decoding */
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/*
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* This removes the "whitespace" (i.e. cells below the threshold) and
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* group the remaining active cells into "segments". By only storing
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* the segments, we can fit a single frame in RAM in most cases.
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*/
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#include "common.h"
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#include "debug.h"
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#include "touch_scan.h"
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#include "util.h"
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#define BUF_SIZE 6000
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static uint8_t encoded[BUF_SIZE];
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static int encoded_size;
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void encode_reset(void)
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{
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/* Just clear the encoded data */
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encoded_size = 0;
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}
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void encode_add_column(const uint8_t *dptr)
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{
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uint8_t *seg_count_ptr;
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int p, p_start;
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uint8_t *eptr = encoded + encoded_size, *e_seg_size;
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seg_count_ptr = eptr;
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eptr++;
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*seg_count_ptr = 0;
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p = 0;
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while (p < ROW_COUNT * 2) {
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if (dptr[p] < THRESHOLD) {
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++p;
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continue;
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}
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/* Give up on overflow */
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if (eptr + 2 >= encoded + BUF_SIZE)
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return;
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/* Save current position */
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*(eptr++) = p;
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/* Leave a byte for storing segment size */
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e_seg_size = eptr;
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eptr++;
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/* Record segment starting point */
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p_start = p;
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/* Save the segment */
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while (p < ROW_COUNT * 2 && dptr[p] >= THRESHOLD) {
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if (eptr >= encoded + BUF_SIZE)
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return;
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*(eptr++) = dptr[p++];
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}
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/* Fill in the segment size now that we know it */
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*e_seg_size = p - p_start;
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(*seg_count_ptr)++;
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}
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/* Update encoded data size now that we're sure it fits */
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encoded_size = eptr - encoded;
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}
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void encode_dump_matrix(void)
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{
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uint8_t *dptr;
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int row, col;
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int seg_count;
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int seg;
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int seg_end;
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debug_printf("Encoded size = %d\n", encoded_size);
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dptr = encoded;
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for (col = 0; col < COL_COUNT * 2; ++col) {
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if (dptr >= encoded + encoded_size) {
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for (row = 0; row < ROW_COUNT * 2; ++row)
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debug_printf(" - ");
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debug_printf("\n");
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continue;
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}
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seg_count = *(dptr++);
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row = 0;
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for (seg = 0; seg < seg_count; ++seg) {
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while (row < *dptr) {
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debug_printf(" - ");
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row++;
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}
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dptr++;
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seg_end = *dptr + row;
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dptr++;
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for (; row < seg_end; ++row, ++dptr)
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debug_printf("%3d ", *dptr);
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}
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while (row < ROW_COUNT * 2) {
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debug_printf(" - ");
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row++;
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}
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debug_printf("\n");
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}
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}
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