/// <summary>
/// Special draw logic to draw transparent text using GDI.<br/>
/// 1. Create in-memory DC<br/>
/// 2. Copy background to in-memory DC<br/>
/// 3. Draw the text to in-memory DC<br/>
/// 4. Copy the in-memory DC to the proper location with alpha blend<br/>
/// </summary>
static void DrawTransparentText(IntPtr hdc, string str, Font font, Point point, Size size, Color color)
{
IntPtr dib;
var memoryHdc = Win32Utils.CreateMemoryHdc(hdc, size.Width, size.Height, out dib);
try
{
// copy target background to memory HDC so when copied back it will have the proper background
Win32Utils.BitBlt(memoryHdc, 0, 0, size.Width, size.Height, hdc, point.X, point.Y, Win32Utils.BitBltCopy);
// Create and select font
Win32Utils.SelectObject(memoryHdc, FontStore.GetCachedHFont(font.InnerFont as System.Drawing.Font));
Win32Utils.SetTextColor(memoryHdc, (color.B & 0xFF) << 16 | (color.G & 0xFF) << 8 | color.R);
// Draw text to memory HDC
NativeTextWin32.TextOut(memoryHdc, 0, 0, str, str.Length);
// copy from memory HDC to normal HDC with alpha blend so achieve the transparent text
Win32Utils.AlphaBlend(hdc, point.X, point.Y, size.Width, size.Height, memoryHdc, 0, 0, size.Width, size.Height, new BlendFunction(color.A));
}
finally
{
Win32Utils.ReleaseMemoryHdc(memoryHdc, dib);
}
}
public override void DrawText(char[] buffer, Rectangle logicalTextBox, int textAlignment)
{
ReleaseHdc();
IntPtr gxdc = gx.GetHdc();
var clipRect = System.Drawing.Rectangle.Intersect(logicalTextBox.ToRect(), currentClipRect);
clipRect.Offset(canvasOriginX, canvasOriginY);
MyWin32.SetRectRgn(hRgn,
clipRect.Left,
clipRect.Top,
clipRect.Right,
clipRect.Bottom);
MyWin32.SelectClipRgn(gxdc, hRgn);
NativeTextWin32.TextOut(gxdc, CanvasOrgX + logicalTextBox.X, CanvasOrgY + logicalTextBox.Y, buffer, buffer.Length);
MyWin32.SelectClipRgn(gxdc, IntPtr.Zero);
gx.ReleaseHdc();
//ReleaseHdc();
//IntPtr gxdc = gx.GetHdc();
//MyWin32.SetViewportOrgEx(gxdc, CanvasOrgX, CanvasOrgY, IntPtr.Zero);
//System.Drawing.Rectangle clipRect =
// System.Drawing.Rectangle.Intersect(logicalTextBox.ToRect(), currentClipRect);
//clipRect.Offset(CanvasOrgX, CanvasOrgY);
//MyWin32.SetRectRgn(hRgn, clipRect.X, clipRect.Y, clipRect.Right, clipRect.Bottom);
//MyWin32.SelectClipRgn(gxdc, hRgn);
//NativeTextWin32.TextOut(gxdc, logicalTextBox.X, logicalTextBox.Y, buffer, buffer.Length);
//MyWin32.SelectClipRgn(gxdc, IntPtr.Zero);
//MyWin32.SetViewportOrgEx(gxdc, -CanvasOrgX, -CanvasOrgY, IntPtr.Zero);
//gx.ReleaseHdc();
}
void PrepareCharacterMapWhiteOnBlack(char[] buffer)
{
//-----------------------------------------------------------------------
IntPtr gxdc = gx.GetHdc();
int len = buffer.Length;
//draw each character
int curX = 0;
int curY = 0;
//1. clear with white color,
MyWin32.PatBlt(gxdc, 0, 0, width, height, MyWin32.BLACKNESS);
//2. transparent background
MyWin32.SetBkMode(gxdc, MyWin32._SetBkMode_TRANSPARENT);
//3. white brush
//set user font to dc
MyWin32.SelectObject(gxdc, this.hFont);
int rgb = ((255 & 0xFF) << 16 | (255 & 0xFF) << 8 | 255);
MyWin32.SetTextColor(gxdc, rgb);
//TODO:correct white text on black bg for subpixel rendering
//when draw with subpixel rendering
//on white bg -> red come first from left ,end with blue
//on black bg -> blue come first from left, end with red
int fontHeight = fontInfo.FontHeight;
int maxLineHeight = fontHeight;
for (int i = 0; i < len; ++i)
{
//-----------------------------------------------------------------------
//measure string
//and make simple character map
//-----------------------------------------------------------------------
//measure each character ***
//not adjust kerning***
char c = buffer[i];
FontABC abcWidth = fontInfo.GetCharABCWidth(c);
int glyphBoxWidth = Math.Abs(abcWidth.a) + (int)abcWidth.b + abcWidth.c;
if (abcWidth.Sum + curX > this.width)
{
//start newline
curX = 0;
curY += maxLineHeight;
maxLineHeight = fontHeight;
}
NativeTextWin32.TextOut(gxdc, curX, curY, new char[] { c }, 1);
charMap.Add(c, new PixelFarm.Drawing.RectangleF(curX, curY, glyphBoxWidth, fontHeight));
curX += glyphBoxWidth; //move next
}
gx.ReleaseHdc(gxdc);
//myTextBoardBmp = new Bitmap(width, height, new LazyGdiBitmapBufferProvider(this.textBoardBmp));
//myTextBoardBmp.InnerImage = GLBitmapTextureHelper.CreateBitmapTexture(this.textBoardBmp);
}
//public override float GetCharWidth(RequestFont f, char c)
//{
// WinGdiFont winFont = WinGdiFontSystem.GetWinGdiFont(f);
// return winFont.GetGlyph(c).horiz_adv_x >> 6;
//}
public override void DrawText(char[] buffer, int x, int y)
{
var clipRect = currentClipRect;
clipRect.Offset(canvasOriginX, canvasOriginY);
//1.
win32MemDc.SetClipRect(clipRect.Left, clipRect.Top, clipRect.Width, clipRect.Height);
//2.
NativeTextWin32.TextOut(win32MemDc.DC, CanvasOrgX + x, CanvasOrgY + y, buffer, buffer.Length);
//3
win32MemDc.ClearClipRect();
}
void PrepareCharacterMapBlackOnWhite(char[] buffer)
{
//-----------------------------------------------------------------------
IntPtr gxdc = gx.GetHdc();
int len = buffer.Length;
//draw each character
int curX = 0;
int curY = 0;
//1. clear with white color,
MyWin32.PatBlt(gxdc, 0, 0, width, height, MyWin32.WHITENESS);
//2. transparent background
MyWin32.SetBkMode(gxdc, MyWin32._SetBkMode_TRANSPARENT);
//set user font to dc
MyWin32.SelectObject(gxdc, this.hFont);
int fontHeight = fontInfo.FontHeight;
int maxLineHeight = fontHeight;
for (int i = 0; i < len; ++i)
{
//-----------------------------------------------------------------------
//measure string
//and make simple character map
//-----------------------------------------------------------------------
//measure each character ***
//not adjust kerning***
char c = buffer[i];
FontABC abcWidth = fontInfo.GetCharABCWidth(c);
int glyphBoxWidth = Math.Abs(abcWidth.a) + (int)abcWidth.b + abcWidth.c;
if (abcWidth.Sum + curX > this.width)
{
//start newline
curX = 0;
curY += maxLineHeight;
maxLineHeight = fontHeight;
}
NativeTextWin32.TextOut(gxdc, curX, curY, new char[] { c }, 1);
charMap.Add(c, new PixelFarm.Drawing.RectangleF(curX, curY, glyphBoxWidth, fontHeight));
curX += glyphBoxWidth; //move next
}
gx.ReleaseHdc(gxdc);
//myTextBoardBmp = new Bitmap(width, height, new LazyGdiBitmapBufferProvider(this.textBoardBmp));
//myTextBoardBmp.InnerImage = GLBitmapTextureHelper.CreateBitmapTexture(this.textBoardBmp);
}
//==============================================
public override void DrawText(char[] buffer, int x, int y)
{
ReleaseHdc();
IntPtr gxdc = gx.GetHdc();
var clipRect = currentClipRect;
clipRect.Offset(canvasOriginX, canvasOriginY);
MyWin32.SetRectRgn(hRgn,
clipRect.Left,
clipRect.Top,
clipRect.Right,
clipRect.Bottom);
MyWin32.SelectClipRgn(gxdc, hRgn);
NativeTextWin32.TextOut(gxdc, CanvasOrgX + x, CanvasOrgY + y, buffer, buffer.Length);
MyWin32.SelectClipRgn(gxdc, IntPtr.Zero);
gx.ReleaseHdc();
}
