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// Copyright (c) 2010 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/capturer_gdi.h"
#include "remoting/host/differ.h"
#include "gfx/rect.h"
namespace remoting {
// 3780 pixels per meter is equivalent to 96 DPI, typical on desktop monitors.
static const int kPixelsPerMeter = 3780;
// 32 bit RGBA is 4 bytes per pixel.
static const int kBytesPerPixel = 4;
CapturerGdi::CapturerGdi()
: desktop_dc_(NULL),
memory_dc_(NULL),
capture_fullscreen_(true) {
memset(target_bitmap_, 0, sizeof(target_bitmap_));
memset(buffers_, 0, sizeof(buffers_));
}
CapturerGdi::~CapturerGdi() {
ReleaseBuffers();
}
void CapturerGdi::ReleaseBuffers() {
for (int i = kNumBuffers - 1; i >= 0; i--) {
if (target_bitmap_[i]) {
DeleteObject(target_bitmap_[i]);
target_bitmap_[i] = NULL;
}
if (buffers_[i]) {
DeleteObject(buffers_[i]);
buffers_[i] = NULL;
}
}
desktop_dc_ = NULL;
if (memory_dc_) {
DeleteDC(memory_dc_);
memory_dc_ = NULL;
}
}
void CapturerGdi::ScreenConfigurationChanged() {
ReleaseBuffers();
desktop_dc_ = GetDC(GetDesktopWindow());
memory_dc_ = CreateCompatibleDC(desktop_dc_);
// Create a bitmap to keep the desktop image.
width_ = GetSystemMetrics(SM_CXSCREEN);
height_ = GetSystemMetrics(SM_CYSCREEN);
int rounded_width = (width_ + 3) & (~3);
// Dimensions of screen.
bytes_per_row_ = rounded_width * kBytesPerPixel;
// Create a differ for this screen size.
differ_.reset(new Differ(width_, height_, 4, bytes_per_row_));
// Create a device independant bitmap (DIB) that is the same size.
BITMAPINFO bmi;
memset(&bmi, 0, sizeof(bmi));
bmi.bmiHeader.biHeight = height_;
bmi.bmiHeader.biWidth = width_;
bmi.bmiHeader.biPlanes = 1;
bmi.bmiHeader.biBitCount = kBytesPerPixel * 8;
bmi.bmiHeader.biSize = sizeof(bmi.bmiHeader);
bmi.bmiHeader.biSizeImage = bytes_per_row_ * height_;
bmi.bmiHeader.biXPelsPerMeter = kPixelsPerMeter;
bmi.bmiHeader.biYPelsPerMeter = kPixelsPerMeter;
// Create memory for the buffers.
for (int i = 0; i < kNumBuffers; i++) {
target_bitmap_[i] = CreateDIBSection(desktop_dc_, &bmi, DIB_RGB_COLORS,
static_cast<void**>(&buffers_[i]),
NULL, 0);
}
capture_fullscreen_ = true;
}
void CapturerGdi::CalculateInvalidRects() {
ClearInvalidRects();
CaptureImage();
if (capture_fullscreen_) {
InvalidateFullScreen();
} else {
// Calculate the difference between the previous and current screen.
int prev_buffer_id = current_buffer_ - 1;
if (prev_buffer_id < 0) {
prev_buffer_id = kNumBuffers - 1;
}
void* prev_buffer = buffers_[prev_buffer_id];
void* curr_buffer = buffers_[current_buffer_];
InvalidRects rects;
differ_->CalcDirtyRects(prev_buffer, curr_buffer, &rects);
InvalidateRects(rects);
}
capture_fullscreen_ = false;
}
void CapturerGdi::CaptureRects(const InvalidRects& rects,
CaptureCompletedCallback* callback) {
DataPlanes planes;
planes.data[0] = static_cast<uint8*>(buffers_[current_buffer_]);
planes.strides[0] = bytes_per_row_;
scoped_refptr<CaptureData> data(new CaptureData(planes,
width(),
height(),
pixel_format()));
data->mutable_dirty_rects() = rects;
FinishCapture(data, callback);
}
void CapturerGdi::CaptureImage() {
// Select the target bitmap into the memory dc.
SelectObject(memory_dc_, target_bitmap_[current_buffer_]);
// And then copy the rect from desktop to memory.
BitBlt(memory_dc_, 0, 0, width_, height_, desktop_dc_, 0, 0,
SRCCOPY | CAPTUREBLT);
}
} // namespace remoting
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