aafont.pas

平滑特效字体控件包是一个基于平滑（Anti-aliasing）和特效（Effect）字体 技术的控件包

  p1.x := Round(-wCos + hSin); // 左下
  p1.y := Round(-wSin - hCos);
  p2.x := Round(wCos + hSin); // 右下
  p2.y := Round(wSin - hCos);
  p3.x := Round(-wCos - hSin); // 左上
  p3.y := Round(-wSin + hCos);
  p4.x := Round(wCos - hSin); // 右上
  p4.y := Round(wSin + hCos);

  // 计算包含矩形
  Rect.Left := MinIntValue([p1.x, p2.x, p3.x, p4.x]);
  Rect.Right := MaxIntValue([p1.x, p2.x, p3.x, p4.x]);
  Rect.Top := MinIntValue([p1.y, p2.y, p3.y, p4.y]);
  Rect.Bottom := MaxIntValue([p1.y, p2.y, p3.y, p4.y]);
  
  Result.cx := Rect.Right - Rect.Left;
  Result.cy := Rect.Bottom - Rect.Top;
  StartPoint.x := p1.x + Result.cx div 2;
  StartPoint.y := p1.y + Result.cy div 2;
end;

//文本高、宽，旋转后起始位置
function TAAMask.TextExtentEx(s: string; var Point: TPoint): TSize;
var
  LogFont: TLogFont;
  TempFont, SaveFont: HFONT;
  DC: HDC;
  Beta: Double;
begin
  Result.cx := 0;
  Result.cy := 0;
  if (AAFont = nil) or (AAFont.Canvas = nil) then
    Exit;
  DC := GetDC(0);
  try
    GetObject(AAFont.Canvas.Font.Handle, SizeOf(TLogFont), @LogFont);
    with LogFont do
    begin
      lfHeight := lfHeight * Scale;
      lfWidth := lfWidth * Scale;
      Beta := lfEscapement * Pi / 1800;
    end;
    TempFont := CreateFontIndirect(LogFont);
    try
      SaveFont := SelectObject(DC, TempFont);
      GetTextExtentPoint32(DC, PChar(s), Length(s), Result);
      Result.cx := (Result.cx + Scale - 1) div Scale;
      Result.cy := (Result.cy + Scale - 1) div Scale;
      if (fsItalic in AAFont.Canvas.Font.Style) and (Length(s) > 0) then
        Result.cx := Result.cx + Round(Result.cx / Length(s) * ItalicAdjust);
      SelectObject(DC, SaveFont);
      if Beta <> 0 then
      begin
        Result := GetRotateSize(Result, Beta, Point);
      end;
    finally
      DeleteObject(TempFont);
    end;
  finally
    ReleaseDC(0, DC);
  end;
end;

//文本高、宽
function TAAMask.TextExtent(s: string): TSize;
var
  Point: TPoint;
begin
  Result := TextExtentEx(s, Point);
end;

//文本高度
function TAAMask.TextHeight(s: string): Integer;
begin
  Result := TextExtent(s).cy;
end;

//文本宽度
function TAAMask.TextWidth(s: string): Integer;
begin
  Result := TextExtent(s).cx;
end;

{ TAABlend }

//--------------------------------------------------------//
//前景背景蒙板混合类                                      //
//--------------------------------------------------------//

//初始化
constructor TAABlend.Create(AOwner: TAAFont);
begin
  AAFont := AOwner;
  FForeBmp := TBitmap.Create;
  FForeBmp.PixelFormat := pf24bit;
  RGBBmp := TBitmap.Create;
  RGBBmp.PixelFormat := pf24bit;
end;

//释放
destructor TAABlend.Destroy;
begin
  ForeBmp.Free;
  RGBBmp.Free;
  inherited;
end;

//赋值
procedure TAABlend.Assign(Source: TPersistent);
begin
  if Source is TAABlend then
    ForeBmp.Assign(TAABlend(Source).ForeBmp)
  else
    inherited Assign(Source);
end;

//文本按前景色与背景混合
procedure TAABlend.Blend(x, y: Integer; AColor: TColor; Alpha: TAlpha;
  Mask: TAAMask);
var
  r, b, g: Byte;
  AAlpha: DWORD;
  pMask: PByteArray;
  pRGB: PRGBArray;
  Weight: Byte;
  i, j: Integer;
  Color: TColor;
begin
  if (AAFont = nil) or (AAFont.Canvas = nil) then
    Exit;

  RGBBmp.Width := Mask.Width;
  RGBBmp.Height := Mask.Height;
  Color := ColorToRGB(AColor);          //实际前景色
  r := GetRValue(Color);                //色彩分量
  g := GetGValue(Color);
  b := GetBValue(Color);
  AAlpha := Alpha * $100 div 100;       //透明度
  RGBBmp.Canvas.Brush.Assign(AAFont.Canvas.Brush);
  if RGBBmp.Canvas.Brush.Style <> bsSolid then
    Bitblt(RGBBmp.Canvas.Handle, 0, 0, RGBBmp.Width, RGBBmp.Height,
      AAFont.Canvas.Handle, x, y, SRCCOPY) //透明
  else
    FillRect(RGBBmp.Canvas.Handle, Bounds(0, 0, RGBBmp.Width, RGBBmp.Height), 0);

  for j := 0 to RGBBmp.Height - 1 do
  begin
    pMask := Mask.ScanLine(j);
    pRGB := RGBBmp.ScanLine[j];
    for i := 0 to RGBBmp.Width - 1 do
    begin
      Weight := pMask^[i] * AAlpha shr 8; //混合系数
      if Weight <> 0 then
      begin
        if Weight = 255 then
        begin                           //前景色
          pRGB^[i].rgbtBlue := b;
          pRGB^[i].rgbtGreen := g;
          pRGB^[i].rgbtRed := r;
        end
        else
        begin                           //混合
          Inc(pRGB^[i].rgbtBlue, Weight * (b - pRGB^[i].rgbtBlue) shr 8);
          Inc(pRGB^[i].rgbtGreen, Weight * (g - pRGB^[i].rgbtGreen) shr 8);
          Inc(pRGB^[i].rgbtRed, Weight * (r - pRGB^[i].rgbtRed) shr 8);
        end;
      end;
    end;
  end;

  Bitblt(AAFont.Canvas.Handle, x, y, RGBBmp.Width, RGBBmp.Height,
    RGBBmp.Canvas.Handle, 0, 0, SRCCOPY); //输出
end;

//文本按纹理与背景混合
procedure TAABlend.BlendEx(x, y: Integer; Alpha: TAlpha; Mask: TAAMask);
var
  AAlpha: WORD;
  pMask: PByteArray;
  pRGB: PRGBArray;
  pFore: PRGBArray;
  Weight: Byte;
  i, j: Integer;
begin
  if (AAFont = nil) or (AAFont.Canvas = nil) then
    Exit;
  if (ForeBmp.Width <> Mask.Width) or (ForeBmp.Height <> Mask.Height)
    or (ForeBmp.PixelFormat <> pf24bit) then
  begin                                 //错误的纹理图
    raise EInvalidForeBmp.Create('Invalid foreground bitmap!');
    Exit;
  end;

  RGBBmp.Width := Mask.Width;
  RGBBmp.Height := Mask.Height;
  AAlpha := Alpha * $100 div 100;       //透明度
  RGBBmp.Canvas.Brush.Assign(AAFont.Canvas.Brush);
  if RGBBmp.Canvas.Brush.Style <> bsSolid then
    Bitblt(RGBBmp.Canvas.Handle, 0, 0, RGBBmp.Width, RGBBmp.Height,
      AAFont.Canvas.Handle, x, y, SRCCOPY) //透明
  else
    FillRect(RGBBmp.Canvas.Handle, Bounds(0, 0, RGBBmp.Width, RGBBmp.Height), 0);

  for j := 0 to RGBBmp.Height - 1 do
  begin
    pMask := Mask.ScanLine(j);
    pRGB := RGBBmp.ScanLine[j];
    pFore := ForeBmp.ScanLine[j];
    for i := 0 to RGBBmp.Width - 1 do
    begin
      Weight := pMask^[i] * AAlpha shr 8; //混合系数
      if Weight = 255 then
      begin
        pRGB^[i].rgbtBlue := pFore^[i].rgbtBlue;
        pRGB^[i].rgbtGreen := pFore^[i].rgbtGreen;
        pRGB^[i].rgbtRed := pFore^[i].rgbtRed;
      end
      else if Weight <> 0 then          //混合
      begin
        Inc(pRGB^[i].rgbtBlue, Weight * (pFore^[i].rgbtBlue - pRGB^[i].rgbtBlue) shr
          8);
        Inc(pRGB^[i].rgbtGreen, Weight * (pFore^[i].rgbtGreen - pRGB^[i].rgbtGreen) shr
          8);
        Inc(pRGB^[i].rgbtRed, Weight * (pFore^[i].rgbtRed - pRGB^[i].rgbtRed) shr 8);
      end;
    end;
  end;

  Bitblt(AAFont.Canvas.Handle, x, y, RGBBmp.Width, RGBBmp.Height,
    RGBBmp.Canvas.Handle, 0, 0, SRCCOPY); //输出
end;

//设置前景纹理图
procedure TAABlend.SetForeBmp(const Value: TBitmap);
begin
  FForeBmp.Assign(Value);
end;

{ TAAFont }

//--------------------------------------------------------//
//平滑字体类                                              //
//--------------------------------------------------------//

//初始化
constructor TAAFont.Create(ACanvas: TCanvas);
begin
  FCanvas := ACanvas;
  Mask := TAAMask.Create(Self);
  Blend := TAABlend.Create(Self);
end;

//释放
destructor TAAFont.Destroy;
begin
  Mask.Free;
  Blend.Free;
  inherited;
end;

//取显示精度
function TAAFont.GetQuality: TAAQuality;
begin
  Result := Mask.Quality;
end;

//设置显示精度
procedure TAAFont.SetQuality(const Value: TAAQuality);
begin
  Mask.Quality := Value;
end;

//文本高、宽
function TAAFont.TextExtent(s: string): TSize;
begin
  Result := Mask.TextExtent(s);
end;

//文本高度
function TAAFont.TextHeight(s: string): Integer;
begin
  Result := TextExtent(s).cy;
end;

//文本宽度
function TAAFont.TextWidth(s: string): Integer;
begin
  Result := TextExtent(s).cx;
end;

//平滑文本输出
procedure TAAFont.TextOut(x, y: Integer; s: string; Alpha: TAlpha;
  Blur: TBlurStrength);
begin
  if (Canvas = nil) or (s = '') then
    Exit;

  Mask.DrawMask(s);                     //创建字体蒙板
  if Blur > 0 then
    Mask.Blur(Blur);                    //模糊
  Blend.Blend(x, y, Canvas.Font.Color, Alpha, Mask); //与前景色混合
end;

{ TAAFontEx }

//--------------------------------------------------------//
//增强平滑字体类                                          //
//--------------------------------------------------------//

//初始化
constructor TAAFontEx.Create(ACanvas: TCanvas);
begin
  inherited Create(ACanvas);
  FEffect := TAAEffect.Create(nil);
end;

//释放
destructor TAAFontEx.Destroy;
begin
  FEffect.Free;
  inherited;
end;

//设置显示风格
procedure TAAFontEx.SetEffect(const Value: TAAEffect);
begin
  FEffect.Assign(Value);
end;

//计算阴影偏移
function TAAFontEx.GetShadowPoint: TPoint;
begin
  if Effect.Shadow.Enabled then
  begin
    if Effect.Shadow.OffsetX > 0 then
      Result.x := Effect.Shadow.OffsetX
    else
      Result.x := 0;
    if Effect.Shadow.OffsetY > 0 then
      Result.y := Effect.Shadow.OffsetY
    else
      Result.y := 0;
  end
  else
  begin
    Result.x := 0;
    Result.y := 0;
  end;
end;

//计算文本偏移
function TAAFontEx.GetTextPoint: TPoint;
begin
  if Effect.Shadow.Enabled then
  begin
    if Effect.Shadow.OffsetX < 0 then
      Result.x := Abs(Effect.Shadow.OffsetX)
    else
      Result.x := 0;
    if Effect.Shadow.OffsetY < 0 then
      Result.y := Abs(Effect.Shadow.OffsetY)
    else
      Result.y := 0;
  end
  else
  begin
    Result.x := 0;
    Result.y := 0;
  end;
end;

//文本高、宽
function TAAFontEx.TextExtent(s: string): TSize;
var
  LogFont: TLogFont;
  TempFont: HFONT;
  SaveFont: TFont;
begin
  if Effect.Angle <> 0 then
  begin
    GetObject(Canvas.Font.Handle, SizeOf(TLogFont), @LogFont);
    LogFont.lfEscapement := Effect.Angle * 10;
    SaveFont := TFont.Create;
    try
      SaveFont.Assign(Canvas.Font);
      TempFont := CreateFontIndirect(LogFont);
      Canvas.Font.Handle := TempFont;
      Result := inherited TextExtent(s);
      Canvas.Font.Assign(SaveFont);
      DeleteObject(TempFont);
    finally
      SaveFont.Free;
    end;
  end
  else
    Result := inherited TextExtent(s);
    
  if Effect.Shadow.Enabled then