Initial commit

win/rfb_win32/DIBSectionBuffer.cxx

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+/* Copyright (C) 2002-2005 RealVNC Ltd.  All Rights Reserved.
+ * Copyright 2014 Pierre Ossman for Cendio AB
+ * 
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this software; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+ * USA.
+ */
+
+#include <rfb_win32/DIBSectionBuffer.h>
+#include <rfb_win32/DeviceContext.h>
+#include <rfb_win32/BitmapInfo.h>
+#include <rfb/LogWriter.h>
+
+using namespace rfb;
+using namespace win32;
+
+static LogWriter vlog("DIBSectionBuffer");
+
+
+DIBSectionBuffer::DIBSectionBuffer(HWND window_)
+  : bitmap(0), window(window_), device(0) {
+  memset(&format, 0, sizeof(format));
+}
+
+DIBSectionBuffer::DIBSectionBuffer(HDC device_)
+  : bitmap(0), window(0), device(device_) {
+  memset(&format, 0, sizeof(format));
+}
+
+DIBSectionBuffer::~DIBSectionBuffer() {
+  if (bitmap)
+    DeleteObject(bitmap);
+}
+
+
+void DIBSectionBuffer::setPF(const PixelFormat& pf) {
+  if (memcmp(&getPF(), &pf, sizeof(pf)) == 0) {
+    vlog.debug("pixel format unchanged by setPF()");
+    return;
+  }
+  if (!pf.trueColour)
+    throw rfb::Exception("palette format not supported");
+  format = pf;
+  recreateBuffer();
+}
+
+void DIBSectionBuffer::setSize(int w, int h) {
+  if (width_ == w && height_ == h) {
+    vlog.debug("size unchanged by setSize()");
+    return;
+  }
+  width_ = w;
+  height_ = h;
+  recreateBuffer();
+}
+
+
+inline void initMaxAndShift(DWORD mask, int* max, int* shift) {
+  for ((*shift) = 0; (mask & 1) == 0; (*shift)++) mask >>= 1;
+  (*max) = (rdr::U16)mask;
+}
+
+void DIBSectionBuffer::recreateBuffer() {
+  HBITMAP new_bitmap = 0;
+  rdr::U8* new_data = 0;
+
+  if (width_ && height_ && (format.depth != 0)) {
+    BitmapInfo bi;
+    memset(&bi, 0, sizeof(bi));
+    UINT iUsage = DIB_RGB_COLORS;
+    bi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
+    bi.bmiHeader.biBitCount = format.bpp;
+    bi.bmiHeader.biSizeImage = (format.bpp / 8) * width_ * height_;
+    bi.bmiHeader.biPlanes = 1;
+    bi.bmiHeader.biWidth = width_;
+    bi.bmiHeader.biHeight = -height_;
+    bi.bmiHeader.biCompression = (format.bpp > 8) ? BI_BITFIELDS : BI_RGB;
+    bi.mask.red = format.pixelFromRGB((rdr::U16)~0, 0, 0);
+    bi.mask.green = format.pixelFromRGB(0, (rdr::U16)~0, 0);
+    bi.mask.blue = format.pixelFromRGB(0, 0, (rdr::U16)~0);
+
+    // Create a DIBSection to draw into
+    if (device)
+      new_bitmap = ::CreateDIBSection(device, (BITMAPINFO*)&bi.bmiHeader, iUsage,
+                                      (void**)&new_data, NULL, 0);
+    else
+      new_bitmap = ::CreateDIBSection(WindowDC(window), (BITMAPINFO*)&bi.bmiHeader, iUsage,
+                                      (void**)&new_data, NULL, 0);
+
+    if (!new_bitmap) {
+      int err = GetLastError();
+      throw rdr::SystemException("unable to create DIB section", err);
+    }
+
+    vlog.debug("recreateBuffer()");
+  } else {
+    vlog.debug("one of area or format not set");
+  }
+
+  if (new_bitmap && bitmap) {
+    vlog.debug("preserving bitmap contents");
+
+    // Copy the contents across
+    if (device) {
+      BitmapDC src_dev(device, bitmap);
+      BitmapDC dest_dev(device, new_bitmap);
+      BitBlt(dest_dev, 0, 0, width_, height_, src_dev, 0, 0, SRCCOPY);
+    } else {
+      WindowDC wndDC(window);
+      BitmapDC src_dev(wndDC, bitmap);
+      BitmapDC dest_dev(wndDC, new_bitmap);
+      BitBlt(dest_dev, 0, 0, width_, height_, src_dev, 0, 0, SRCCOPY);
+    }
+  }
+  
+  if (bitmap) {
+    // Delete the old bitmap
+    DeleteObject(bitmap);
+    bitmap = 0;
+    data = 0;
+  }
+
+  if (new_bitmap) {
+    int bpp, depth;
+    int redMax, greenMax, blueMax;
+    int redShift, greenShift, blueShift;
+
+    // Set up the new bitmap
+    bitmap = new_bitmap;
+    data = new_data;
+
+    // Determine the *actual* DIBSection format
+    DIBSECTION ds;
+    if (!GetObject(bitmap, sizeof(ds), &ds))
+      throw rdr::SystemException("GetObject", GetLastError());
+
+    // Correct the "stride" of the DIB
+    // *** This code DWORD aligns each row - is that right???
+    stride = width_;
+    int bytesPerRow = stride * format.bpp/8;
+    if (bytesPerRow % 4) {
+      bytesPerRow += 4 - (bytesPerRow % 4);
+      stride = (bytesPerRow * 8) / format.bpp;
+      vlog.info("adjusting DIB stride: %d to %d", width_, stride);
+    }
+
+    // Calculate the PixelFormat for the DIB
+    bpp = depth = ds.dsBm.bmBitsPixel;
+
+    // Get the truecolour format used by the DIBSection
+    initMaxAndShift(ds.dsBitfields[0], &redMax, &redShift);
+    initMaxAndShift(ds.dsBitfields[1], &greenMax, &greenShift);
+    initMaxAndShift(ds.dsBitfields[2], &blueMax, &blueShift);
+
+    // Calculate the effective depth
+    depth = 0;
+    Pixel bits = ds.dsBitfields[0] | ds.dsBitfields[1] | ds.dsBitfields[2];
+    while (bits) {
+      depth++;
+      bits = bits >> 1;
+    }
+    if (depth > bpp)
+      throw Exception("Bad DIBSection format (depth exceeds bpp)");
+
+    format = PixelFormat(bpp, depth, false, true,
+                         redMax, greenMax, blueMax,
+                         redShift, greenShift, blueShift);
+  }
+}