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
CreateBitmapHeader(int width,int height,BITMAPINFOHEADER * hdr)12 void CreateBitmapHeader(int width, int height, BITMAPINFOHEADER* hdr) {
13 CreateBitmapHeaderWithColorDepth(width, height, 32, hdr);
14 }
15
CreateBitmapHeaderWithColorDepth(int width,int height,int color_depth,BITMAPINFOHEADER * hdr)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
CreateBitmapV4Header(int width,int height,BITMAPV4HEADER * hdr)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.
CreateMonochromeBitmapHeader(int width,int height,BITMAPINFOHEADER * hdr)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
SubtractRectanglesFromRegion(HRGN hrgn,const std::vector<gfx::Rect> & cutouts)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
ConvertPathToHRGN(const gfx::Path & path)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 = SkScalarRoundToInt(points[i].fX);
89 windows_points[i].y = SkScalarRoundToInt(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
CalculatePageScale(HDC dc,int page_width,int page_height)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.
ScaleDC(HDC dc,double scale_factor)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
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)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