public void Dispose()
{
if (graphics != IntPtr.Zero)
{
GdiPlusAPI.CheckStatus(GdiPlusAPI.GdipDeleteGraphics(graphics));
graphics = IntPtr.Zero;
}
if (defaultStringFormat != IntPtr.Zero)
{
GdiPlusAPI.CheckStatus(GdiPlusAPI.GdipDeleteStringFormat(defaultStringFormat));
graphics = IntPtr.Zero;
}
if (originalPen != IntPtr.Zero)
{
Gdi32API.SelectObjectChecked(hdc, originalPen);
}
if (originalBrush != IntPtr.Zero)
{
Gdi32API.SelectObjectChecked(hdc, originalBrush);
}
if (originalFont != IntPtr.Zero)
{
Gdi32API.SelectObjectChecked(hdc, originalFont);
}
}
private void DrawStringGDI(Color color, FontConfig font, int x, int y, string text)
{
if (color.IsFullyOpaque())
{
DrawOpaqueStringGDI(color, font, x, y, text);
return;
}
SelectGDIFont(font);
Gdi32API.GetTextExtentPoint32W(hdc, text, text.Length, out var size);
int leftPadding, rightPadding;
if (font.IsItalic)
{
int infFontSize = Convert.ToInt32(font.Size);
leftPadding = 1 + (4 * infFontSize + 199) / 200;
rightPadding = 1 + (11 * infFontSize + 199) / 200;
}
else
{
leftPadding = 0;
rightPadding = 0;
}
WithTransparentCanvas(
new Rectangle(x - leftPadding, y, size.cx + leftPadding + rightPadding, size.cy),
color.A, true,
canvas => canvas.DrawOpaqueStringGDI(color, font, leftPadding, 0, text)
);
}
private void DrawOpaqueStringGDI(Color color, FontConfig font, int x, int y, string text)
{
SelectGDIFont(font);
Gdi32API.SetBkModeChecked(hdc, Gdi32BackgroundMode.TRANSPARENT);
Gdi32API.SetTextColorChecked(hdc, Gdi32API.ToCOLORREF(color));
Gdi32API.TextOutW(hdc, x, y, text, text.Length);
}
public void DrawImage(INativeImage image, int x, int y)
{
x += offset.X;
y += offset.Y;
// todo: allow null?
Win32Image win32Image = (Win32Image)image;
var bitmap = Gdi32API.CreateDIBSectionChecked(hdc, new BITMAPINFO(win32Image.Width, win32Image.Height), out IntPtr buffer);
IntPtr hdcMem = IntPtr.Zero;
try
{
Marshal.Copy(win32Image.Pixels, 0, buffer, win32Image.Pixels.Length);
hdcMem = Gdi32API.CreateCompatibleDCChecked(hdc);
var oldBitmap = Gdi32API.SelectObjectChecked(hdcMem, bitmap);
Gdi32API.GdiAlphaBlend
(
hdc,
x, y, win32Image.Width, win32Image.Height,
hdcMem,
0, 0, win32Image.Width, win32Image.Height,
BLENDFUNCTION.SourceAlpha()
);
Gdi32API.SelectObjectChecked(hdcMem, oldBitmap);
}
finally
{
Gdi32API.SafeDeleteObject(hdcMem);
Gdi32API.DeleteObject(bitmap);
}
}
public static Win32Bitmap Create(IntPtr hdc, int width, int height)
{
IntPtr bitmapPtr = IntPtr.Zero;
IntPtr bitmapHdc = IntPtr.Zero;
try
{
bitmapPtr = Gdi32API.CreateCompatibleBitmapChecked(hdc, width, height);
bitmapHdc = Gdi32API.CreateCompatibleDCChecked(hdc);
Gdi32API.SelectObjectChecked(bitmapHdc, bitmapPtr);
var bitmap = new Win32Bitmap(bitmapPtr, bitmapHdc, width, height);
bitmapPtr = IntPtr.Zero;
bitmapHdc = IntPtr.Zero;
return(bitmap);
}
finally
{
if (bitmapHdc != IntPtr.Zero)
{
Gdi32API.DeleteDC(bitmapHdc);
}
if (bitmapPtr != IntPtr.Zero)
{
Gdi32API.DeleteObject(bitmapPtr);
}
}
}
public Size MeasureString(FontConfig font, string text)
{
IntPtr hdc = Win32API.GetDCChecked(IntPtr.Zero);
try
{
IntPtr fontPtr = objectCache.GetFont(font);
IntPtr oldFont = Gdi32API.SelectObjectChecked(hdc, fontPtr);
try
{
Gdi32API.GetTextExtentPoint32W(hdc, text, text.Length, out var size);
return(new Size(size.cx, size.cy));
}
finally
{
if (oldFont != IntPtr.Zero)
{
Gdi32API.SelectObjectChecked(hdc, fontPtr);
}
}
}
finally
{
Win32API.ReleaseDCChecked(IntPtr.Zero, hdc);
}
}
private void SelectGDIFont(FontConfig fontConfig)
{
IntPtr font = objectCache.GetFont(fontConfig);
IntPtr oldFont = Gdi32API.SelectObjectChecked(hdc, font);
if (originalFont == IntPtr.Zero)
{
originalFont = oldFont;
}
}
private void SelectSolidBrush(Color color)
{
IntPtr brush = objectCache.GetSolidBrush(color);
IntPtr oldBrush = Gdi32API.SelectObjectChecked(hdc, brush);
if (originalBrush == IntPtr.Zero)
{
originalBrush = oldBrush;
}
}
private void SelectSolidPen(Color color, int width)
{
IntPtr pen = objectCache.GetSolidPen(color, width);
IntPtr oldPen = Gdi32API.SelectObjectChecked(hdc, pen);
if (originalPen == IntPtr.Zero)
{
originalPen = oldPen;
}
}
private void WithTransparentCanvas(Rectangle rect, byte alpha, bool copySource, Action <Win32Canvas> action)
{
if (rect.Width <= 0 || rect.Height <= 0 || alpha == 0)
{
return;
}
IntPtr memoryHdc = Gdi32API.CreateCompatibleDCChecked(hdc);
try
{
IntPtr memoryBitmap = Gdi32API.CreateCompatibleBitmapChecked(hdc, rect.Width, rect.Height);
try
{
var originalBitmap = Gdi32API.SelectObjectChecked(memoryHdc, memoryBitmap);
try
{
if (copySource)
{
Gdi32API.BitBlt(memoryHdc, 0, 0, rect.Width, rect.Height, hdc, rect.X, rect.Y, GDI32RasterOperation.SRCCOPY);
}
using (Win32Canvas memoryCanvas = new Win32Canvas(memoryHdc, offset, objectCache))
{
action(memoryCanvas);
}
Gdi32API.GdiAlphaBlend
(
hdc,
rect.X, rect.Y, rect.Width, rect.Height,
memoryHdc,
0, 0, rect.Width, rect.Height,
BLENDFUNCTION.ConstantAlpha(alpha)
);
}
finally
{
Gdi32API.SelectObjectChecked(memoryHdc, originalBitmap);
}
}
finally
{
Gdi32API.DeleteObject(memoryBitmap);
}
}
finally
{
Gdi32API.DeleteDC(memoryHdc);
}
}
public void SetClipRectangle(int x, int y, int width, int height)
{
x += offset.X;
y += offset.Y;
var region = Gdi32API.CreateRectRgnChecked(x, y, x + width, y + height);
try
{
Gdi32API.SelectClipRgn(hdc, region);
}
finally
{
Gdi32API.DeleteObject(region);
}
}
private void FillOpaqueRectangleGDI(Color color, int x, int y, int width, int height)
{
// todo: check that width and height are exact
var region = Gdi32API.CreateRectRgnChecked(x, y, x + width, y + height);
try
{
// todo: pick FillRgn or PaintRgn
Gdi32API.FillRgn(hdc, region, objectCache.GetSolidBrush(color));
// SelectSolidBrush(color);
// Gdi32API.PaintRgn(hdc, region);
}
finally
{
Gdi32API.DeleteObject(region);
}
}
public void FillOpaqueEllipseGDI(Color color, int x, int y, int width, int height)
{
SelectSolidPen(color, 0);
SelectSolidBrush(color);
Gdi32API.Ellipse(hdc, x, y, x + width, y + height);
}
private void DrawOpaquePathGDI(Color color, int width, Point[] points)
{
SelectSolidPen(color, width);
// todo: unlike X11, GDI does not paint last pixel
Gdi32API.Polyline(hdc, points.Select(p => new POINT(p.X, p.Y)).ToArray(), points.Length);
}
public void CopyTo(IntPtr hdc, int x, int y)
{
Gdi32API.BitBlt(hdc, x, y, width, height, bitmapHdc, 0, 0, GDI32RasterOperation.SRCCOPY);
}
public void Dispose()
{
Gdi32API.DeleteDC(bitmapHdc);
Gdi32API.DeleteObject(bitmapPtr);
}
