1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "ui/gfx/gdi_util.h" 6 7 #include "base/logging.h" 8 #include "base/memory/scoped_ptr.h" 9 10 namespace gfx { 11 12 void CreateBitmapHeader(int width, int height, BITMAPINFOHEADER* hdr) { 13 CreateBitmapHeaderWithColorDepth(width, height, 32, hdr); 14 } 15 16 void CreateBitmapHeaderWithColorDepth(int width, int height, int color_depth, 17 BITMAPINFOHEADER* hdr) { 18 // These values are shared with gfx::PlatformDevice 19 hdr->biSize = sizeof(BITMAPINFOHEADER); 20 hdr->biWidth = width; 21 hdr->biHeight = -height; // minus means top-down bitmap 22 hdr->biPlanes = 1; 23 hdr->biBitCount = color_depth; 24 hdr->biCompression = BI_RGB; // no compression 25 hdr->biSizeImage = 0; 26 hdr->biXPelsPerMeter = 1; 27 hdr->biYPelsPerMeter = 1; 28 hdr->biClrUsed = 0; 29 hdr->biClrImportant = 0; 30 } 31 32 void CreateBitmapV4Header(int width, int height, BITMAPV4HEADER* hdr) { 33 // Because bmp v4 header is just an extension, we just create a v3 header and 34 // copy the bits over to the v4 header. 35 BITMAPINFOHEADER header_v3; 36 CreateBitmapHeader(width, height, &header_v3); 37 memset(hdr, 0, sizeof(BITMAPV4HEADER)); 38 memcpy(hdr, &header_v3, sizeof(BITMAPINFOHEADER)); 39 40 // Correct the size of the header and fill in the mask values. 41 hdr->bV4Size = sizeof(BITMAPV4HEADER); 42 hdr->bV4RedMask = 0x00ff0000; 43 hdr->bV4GreenMask = 0x0000ff00; 44 hdr->bV4BlueMask = 0x000000ff; 45 hdr->bV4AlphaMask = 0xff000000; 46 } 47 48 // Creates a monochrome bitmap header. 49 void CreateMonochromeBitmapHeader(int width, 50 int height, 51 BITMAPINFOHEADER* hdr) { 52 hdr->biSize = sizeof(BITMAPINFOHEADER); 53 hdr->biWidth = width; 54 hdr->biHeight = -height; 55 hdr->biPlanes = 1; 56 hdr->biBitCount = 1; 57 hdr->biCompression = BI_RGB; 58 hdr->biSizeImage = 0; 59 hdr->biXPelsPerMeter = 1; 60 hdr->biYPelsPerMeter = 1; 61 hdr->biClrUsed = 0; 62 hdr->biClrImportant = 0; 63 } 64 65 void SubtractRectanglesFromRegion(HRGN hrgn, 66 const std::vector<gfx::Rect>& cutouts) { 67 if (cutouts.size()) { 68 HRGN cutout = ::CreateRectRgn(0, 0, 0, 0); 69 for (size_t i = 0; i < cutouts.size(); i++) { 70 ::SetRectRgn(cutout, 71 cutouts[i].x(), 72 cutouts[i].y(), 73 cutouts[i].right(), 74 cutouts[i].bottom()); 75 ::CombineRgn(hrgn, hrgn, cutout, RGN_DIFF); 76 } 77 ::DeleteObject(cutout); 78 } 79 } 80 81 HRGN ConvertPathToHRGN(const gfx::Path& path) { 82 #if defined(USE_AURA) 83 int point_count = path.getPoints(NULL, 0); 84 scoped_ptr<SkPoint[]> points(new SkPoint[point_count]); 85 path.getPoints(points.get(), point_count); 86 scoped_ptr<POINT[]> windows_points(new POINT[point_count]); 87 for (int i = 0; i < point_count; ++i) { 88 windows_points[i].x = SkScalarRound(points[i].fX); 89 windows_points[i].y = SkScalarRound(points[i].fY); 90 } 91 92 return ::CreatePolygonRgn(windows_points.get(), point_count, ALTERNATE); 93 #elif defined(OS_WIN) 94 return path.CreateNativeRegion(); 95 #endif 96 } 97 98 99 double CalculatePageScale(HDC dc, int page_width, int page_height) { 100 int dc_width = GetDeviceCaps(dc, HORZRES); 101 int dc_height = GetDeviceCaps(dc, VERTRES); 102 103 // If page fits DC - no scaling needed. 104 if (dc_width >= page_width && dc_height >= page_height) 105 return 1.0; 106 107 double x_factor = 108 static_cast<double>(dc_width) / static_cast<double>(page_width); 109 double y_factor = 110 static_cast<double>(dc_height) / static_cast<double>(page_height); 111 return std::min(x_factor, y_factor); 112 } 113 114 // Apply scaling to the DC. 115 bool ScaleDC(HDC dc, double scale_factor) { 116 SetGraphicsMode(dc, GM_ADVANCED); 117 XFORM xform = {0}; 118 xform.eM11 = xform.eM22 = scale_factor; 119 return !!ModifyWorldTransform(dc, &xform, MWT_LEFTMULTIPLY); 120 } 121 122 void StretchDIBits(HDC hdc, int dest_x, int dest_y, int dest_w, int dest_h, 123 int src_x, int src_y, int src_w, int src_h, void* pixels, 124 const BITMAPINFO* bitmap_info) { 125 // When blitting a rectangle that touches the bottom, left corner of the 126 // bitmap, StretchDIBits looks at it top-down! For more details, see 127 // http://wiki.allegro.cc/index.php?title=StretchDIBits. 128 int rv; 129 int bitmap_h = -bitmap_info->bmiHeader.biHeight; 130 int bottom_up_src_y = bitmap_h - src_y - src_h; 131 if (bottom_up_src_y == 0 && src_x == 0 && src_h != bitmap_h) { 132 rv = ::StretchDIBits(hdc, 133 dest_x, dest_h + dest_y - 1, dest_w, -dest_h, 134 src_x, bitmap_h - src_y + 1, src_w, -src_h, 135 pixels, bitmap_info, DIB_RGB_COLORS, SRCCOPY); 136 } else { 137 rv = ::StretchDIBits(hdc, 138 dest_x, dest_y, dest_w, dest_h, 139 src_x, bottom_up_src_y, src_w, src_h, 140 pixels, bitmap_info, DIB_RGB_COLORS, SRCCOPY); 141 } 142 DCHECK(rv != GDI_ERROR); 143 } 144 145 } // namespace gfx 146
