blob: 8cdff0a8bff578b886b5a3def676a10ebf70ecf3 [file] [log] [blame]
// Copyright (c) 2012 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 "ui/gfx/gdi_util.h"
#include <algorithm>
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
namespace {
void CreateBitmapHeaderWithColorDepth(LONG width,
LONG height,
WORD color_depth,
BITMAPINFOHEADER* hdr) {
// These values are shared with gfx::PlatformDevice
hdr->biSize = sizeof(BITMAPINFOHEADER);
hdr->biWidth = width;
hdr->biHeight = -height; // minus means top-down bitmap
hdr->biPlanes = 1;
hdr->biBitCount = color_depth;
hdr->biCompression = BI_RGB; // no compression
hdr->biSizeImage = 0;
hdr->biXPelsPerMeter = 1;
hdr->biYPelsPerMeter = 1;
hdr->biClrUsed = 0;
hdr->biClrImportant = 0;
}
} // namespace
namespace gfx {
void CreateBitmapHeader(int width, int height, BITMAPINFOHEADER* hdr) {
CreateBitmapHeaderWithColorDepth(width, height, 32, hdr);
}
void CreateBitmapV4Header(int width, int height, BITMAPV4HEADER* hdr) {
// Because bmp v4 header is just an extension, we just create a v3 header and
// copy the bits over to the v4 header.
BITMAPINFOHEADER header_v3;
CreateBitmapHeader(width, height, &header_v3);
memset(hdr, 0, sizeof(BITMAPV4HEADER));
memcpy(hdr, &header_v3, sizeof(BITMAPINFOHEADER));
// Correct the size of the header and fill in the mask values.
hdr->bV4Size = sizeof(BITMAPV4HEADER);
hdr->bV4RedMask = 0x00ff0000;
hdr->bV4GreenMask = 0x0000ff00;
hdr->bV4BlueMask = 0x000000ff;
hdr->bV4AlphaMask = 0xff000000;
}
// Creates a monochrome bitmap header.
void CreateMonochromeBitmapHeader(int width,
int height,
BITMAPINFOHEADER* hdr) {
CreateBitmapHeaderWithColorDepth(width, height, 1, hdr);
}
void SubtractRectanglesFromRegion(HRGN hrgn,
const std::vector<gfx::Rect>& cutouts) {
if (cutouts.size()) {
HRGN cutout = ::CreateRectRgn(0, 0, 0, 0);
for (size_t i = 0; i < cutouts.size(); i++) {
::SetRectRgn(cutout,
cutouts[i].x(),
cutouts[i].y(),
cutouts[i].right(),
cutouts[i].bottom());
::CombineRgn(hrgn, hrgn, cutout, RGN_DIFF);
}
::DeleteObject(cutout);
}
}
HRGN ConvertPathToHRGN(const gfx::Path& path) {
int point_count = path.getPoints(NULL, 0);
scoped_ptr<SkPoint[]> points(new SkPoint[point_count]);
path.getPoints(points.get(), point_count);
scoped_ptr<POINT[]> windows_points(new POINT[point_count]);
for (int i = 0; i < point_count; ++i) {
windows_points[i].x = SkScalarRoundToInt(points[i].fX);
windows_points[i].y = SkScalarRoundToInt(points[i].fY);
}
return ::CreatePolygonRgn(windows_points.get(), point_count, ALTERNATE);
}
float CalculatePageScale(HDC dc, int page_width, int page_height) {
int dc_width = GetDeviceCaps(dc, HORZRES);
int dc_height = GetDeviceCaps(dc, VERTRES);
// If page fits DC - no scaling needed.
if (dc_width >= page_width && dc_height >= page_height)
return 1.0;
float x_factor =
static_cast<float>(dc_width) / static_cast<float>(page_width);
float y_factor =
static_cast<float>(dc_height) / static_cast<float>(page_height);
return std::min(x_factor, y_factor);
}
// Apply scaling to the DC.
bool ScaleDC(HDC dc, float scale_factor) {
SetGraphicsMode(dc, GM_ADVANCED);
XFORM xform = {0};
xform.eM11 = xform.eM22 = scale_factor;
return !!ModifyWorldTransform(dc, &xform, MWT_LEFTMULTIPLY);
}
void StretchDIBits(HDC hdc, int dest_x, int dest_y, int dest_w, int dest_h,
int src_x, int src_y, int src_w, int src_h, void* pixels,
const BITMAPINFO* bitmap_info) {
// When blitting a rectangle that touches the bottom, left corner of the
// bitmap, StretchDIBits looks at it top-down! For more details, see
// http://wiki.allegro.cc/index.php?title=StretchDIBits.
int rv;
int bitmap_h = -bitmap_info->bmiHeader.biHeight;
int bottom_up_src_y = bitmap_h - src_y - src_h;
if (bottom_up_src_y == 0 && src_x == 0 && src_h != bitmap_h) {
rv = ::StretchDIBits(hdc,
dest_x, dest_h + dest_y - 1, dest_w, -dest_h,
src_x, bitmap_h - src_y + 1, src_w, -src_h,
pixels, bitmap_info, DIB_RGB_COLORS, SRCCOPY);
} else {
rv = ::StretchDIBits(hdc,
dest_x, dest_y, dest_w, dest_h,
src_x, bottom_up_src_y, src_w, src_h,
pixels, bitmap_info, DIB_RGB_COLORS, SRCCOPY);
}
DCHECK(rv != static_cast<int>(GDI_ERROR));
}
} // namespace gfx