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Unified Diff: remoting/host/differ.cc

Issue 11470028: Move screen capturers to remoting/capturer. (Closed) Base URL: svn://svn.chromium.org/chrome/trunk/src
Patch Set: Created 8 years ago
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Index: remoting/host/differ.cc
diff --git a/remoting/host/differ.cc b/remoting/host/differ.cc
deleted file mode 100644
index 582521ced70e3229cc55a2972944cd1d112d3b07..0000000000000000000000000000000000000000
--- a/remoting/host/differ.cc
+++ /dev/null
@@ -1,211 +0,0 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "remoting/host/differ.h"
-
-#include "base/logging.h"
-#include "remoting/host/differ_block.h"
-
-namespace remoting {
-
-Differ::Differ(int width, int height, int bpp, int stride) {
- // Dimensions of screen.
- width_ = width;
- height_ = height;
- bytes_per_pixel_ = bpp;
- bytes_per_row_ = stride;
-
- // Calc number of blocks (full and partial) required to cover entire image.
- // One additional row/column is added as a boundary on the right & bottom.
- diff_info_width_ = ((width_ + kBlockSize - 1) / kBlockSize) + 1;
- diff_info_height_ = ((height_ + kBlockSize - 1) / kBlockSize) + 1;
- diff_info_size_ = diff_info_width_ * diff_info_height_ * sizeof(DiffInfo);
- diff_info_.reset(new DiffInfo[diff_info_size_]);
-}
-
-Differ::~Differ() {}
-
-void Differ::CalcDirtyRegion(const void* prev_buffer, const void* curr_buffer,
- SkRegion* region) {
- if (!region) {
- return;
- }
- region->setEmpty();
-
- if (!prev_buffer || !curr_buffer) {
- return;
- }
-
- // Identify all the blocks that contain changed pixels.
- MarkDirtyBlocks(prev_buffer, curr_buffer);
-
- // Now that we've identified the blocks that have changed, merge adjacent
- // blocks to minimize the number of rects that we return.
- MergeBlocks(region);
-}
-
-void Differ::MarkDirtyBlocks(const void* prev_buffer, const void* curr_buffer) {
- memset(diff_info_.get(), 0, diff_info_size_);
-
- // Calc number of full blocks.
- int x_full_blocks = width_ / kBlockSize;
- int y_full_blocks = height_ / kBlockSize;
-
- // Calc size of partial blocks which may be present on right and bottom edge.
- int partial_column_width = width_ - (x_full_blocks * kBlockSize);
- int partial_row_height = height_ - (y_full_blocks * kBlockSize);
-
- // Offset from the start of one block-column to the next.
- int block_x_offset = bytes_per_pixel_ * kBlockSize;
- // Offset from the start of one block-row to the next.
- int block_y_stride = (width_ * bytes_per_pixel_) * kBlockSize;
- // Offset from the start of one diff_info row to the next.
- int diff_info_stride = diff_info_width_ * sizeof(DiffInfo);
-
- const uint8* prev_block_row_start = static_cast<const uint8*>(prev_buffer);
- const uint8* curr_block_row_start = static_cast<const uint8*>(curr_buffer);
- DiffInfo* diff_info_row_start = static_cast<DiffInfo*>(diff_info_.get());
-
- for (int y = 0; y < y_full_blocks; y++) {
- const uint8* prev_block = prev_block_row_start;
- const uint8* curr_block = curr_block_row_start;
- DiffInfo* diff_info = diff_info_row_start;
-
- for (int x = 0; x < x_full_blocks; x++) {
- // Mark this block as being modified so that it gets incorporated into
- // a dirty rect.
- *diff_info = BlockDifference(prev_block, curr_block, bytes_per_row_);
- prev_block += block_x_offset;
- curr_block += block_x_offset;
- diff_info += sizeof(DiffInfo);
- }
-
- // If there is a partial column at the end, handle it.
- // This condition should rarely, if ever, occur.
- if (partial_column_width != 0) {
- *diff_info = DiffPartialBlock(prev_block, curr_block, bytes_per_row_,
- partial_column_width, kBlockSize);
- diff_info += sizeof(DiffInfo);
- }
-
- // Update pointers for next row.
- prev_block_row_start += block_y_stride;
- curr_block_row_start += block_y_stride;
- diff_info_row_start += diff_info_stride;
- }
-
- // If the screen height is not a multiple of the block size, then this
- // handles the last partial row. This situation is far more common than the
- // 'partial column' case.
- if (partial_row_height != 0) {
- const uint8* prev_block = prev_block_row_start;
- const uint8* curr_block = curr_block_row_start;
- DiffInfo* diff_info = diff_info_row_start;
- for (int x = 0; x < x_full_blocks; x++) {
- *diff_info = DiffPartialBlock(prev_block, curr_block,
- bytes_per_row_,
- kBlockSize, partial_row_height);
- prev_block += block_x_offset;
- curr_block += block_x_offset;
- diff_info += sizeof(DiffInfo);
- }
- if (partial_column_width != 0) {
- *diff_info = DiffPartialBlock(prev_block, curr_block, bytes_per_row_,
- partial_column_width, partial_row_height);
- diff_info += sizeof(DiffInfo);
- }
- }
-}
-
-DiffInfo Differ::DiffPartialBlock(const uint8* prev_buffer,
- const uint8* curr_buffer,
- int stride, int width, int height) {
- int width_bytes = width * bytes_per_pixel_;
- for (int y = 0; y < height; y++) {
- if (memcmp(prev_buffer, curr_buffer, width_bytes) != 0)
- return 1;
- prev_buffer += bytes_per_row_;
- curr_buffer += bytes_per_row_;
- }
- return 0;
-}
-
-void Differ::MergeBlocks(SkRegion* region) {
- DCHECK(region);
- region->setEmpty();
-
- uint8* diff_info_row_start = static_cast<uint8*>(diff_info_.get());
- int diff_info_stride = diff_info_width_ * sizeof(DiffInfo);
-
- for (int y = 0; y < diff_info_height_; y++) {
- uint8* diff_info = diff_info_row_start;
- for (int x = 0; x < diff_info_width_; x++) {
- if (*diff_info != 0) {
- // We've found a modified block. Look at blocks to the right and below
- // to group this block with as many others as we can.
- int left = x * kBlockSize;
- int top = y * kBlockSize;
- int width = 1;
- int height = 1;
- *diff_info = 0;
-
- // Group with blocks to the right.
- // We can keep looking until we find an unchanged block because we
- // have a boundary block which is never marked as having diffs.
- uint8* right = diff_info + 1;
- while (*right) {
- *right++ = 0;
- width++;
- }
-
- // Group with blocks below.
- // The entire width of blocks that we matched above much match for
- // each row that we add.
- uint8* bottom = diff_info;
- bool found_new_row;
- do {
- found_new_row = true;
- bottom += diff_info_stride;
- right = bottom;
- for (int x2 = 0; x2 < width; x2++) {
- if (*right++ == 0) {
- found_new_row = false;
- }
- }
-
- if (found_new_row) {
- height++;
-
- // We need to go back and erase the diff markers so that we don't
- // try to add these blocks a second time.
- right = bottom;
- for (int x2 = 0; x2 < width; x2++) {
- *right++ = 0;
- }
- }
- } while (found_new_row);
-
- // Add rect to list of dirty rects.
- width *= kBlockSize;
- if (left + width > width_) {
- width = width_ - left;
- }
- height *= kBlockSize;
- if (top + height > height_) {
- height = height_ - top;
- }
- region->op(SkIRect::MakeXYWH(left, top, width, height),
- SkRegion::kUnion_Op);
- }
-
- // Increment to next block in this row.
- diff_info++;
- }
-
- // Go to start of next row.
- diff_info_row_start += diff_info_stride;
- }
-}
-
-} // namespace remoting

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