internal void ApplyToSKPaint(SKPaint skPaint, GraphicsUnit targetUnit, float dpi)
{
skPaint.Typeface = skTypeface;
float sizePixel = GraphicsUnitConverter.Convert(Unit, targetUnit, Size, dpi); //注意:转换单位
skPaint.TextSize = sizePixel; //TODO: 转换与System.Drawing不一致 20 -> 15，待修改
skPaint.IsAntialias = true;
skPaint.SubpixelText = true;
}
public void DrawString(string str, Font font, Color color, RectangleF rect, StringFormat format)
{
//TODO: 暂用TextLayout实现
var layout = new TextLayout(str, font, format, DpiX)
{
Width = GraphicsUnitConverter.Convert(PageUnit, GraphicsUnit.Pixel, rect.Width, DpiX),
Height = GraphicsUnitConverter.Convert(PageUnit, GraphicsUnit.Pixel, rect.Height, DpiY)
};
DrawTextLayout(layout, color, rect.X, rect.Y);
}
public void DrawString(string str, Font font, Color color, float x, float y)
{
font.ApplyToSKPaint(skPaint, PageUnit, DpiX);
skPaint.Color = new SKColor((uint)color.Value);
skPaint.Style = SKPaintStyle.Fill;
skPaint.TextEncoding = SKTextEncoding.Utf16;
unsafe
{
fixed(char *ptr = str)
{
SkiaApi.sk_canvas_draw_text(skCanvas.Handle, ptr, new IntPtr(str.Length * 2),
x, y + GraphicsUnitConverter.Convert(GraphicsUnit.Pixel, PageUnit, -font.FontMetrics.Ascent, DpiY),
skPaint.Handle);
}
}
skPaint.Reset();
}
public unsafe void DrawTextLayout(TextLayout layout, Color color, float x, float y)
{
layout.Run();
layout.Font.ApplyToSKPaint(skPaint, PageUnit, DpiX);
skPaint.Color = new SKColor((uint)color.Value);
skPaint.Style = SKPaintStyle.Fill;
skPaint.TextEncoding = SKTextEncoding.Utf16;
skPaint.IsAntialias = true;
var cy = y + GraphicsUnitConverter.Convert(GraphicsUnit.Pixel, PageUnit, layout.OffsetY, DpiY);
fixed(char *ptr = layout.Text)
{
for (int i = 0; i < layout.lines.Count; i++)
{
cy += GraphicsUnitConverter.Convert(GraphicsUnit.Pixel, PageUnit, -layout.Font.FontMetrics.Ascent, DpiY);
var length = layout.lines[i].widths.Length;
SKPoint *pos = stackalloc SKPoint[length];
var cx = x + GraphicsUnitConverter.Convert(GraphicsUnit.Pixel, PageUnit, layout.lines[i].offsetX, DpiX);
for (int j = 0; j < length; j++)
{
pos[j].X = cx;
pos[j].Y = cy;
cx += GraphicsUnitConverter.Convert(GraphicsUnit.Pixel, PageUnit, layout.lines[i].widths[j], DpiX);
}
SkiaApi.sk_canvas_draw_pos_text(skCanvas.Handle, ((byte *)ptr) + layout.lines[i].startByteIndex,
new IntPtr(layout.lines[i].byteLength), pos, skPaint.Handle);
cy += GraphicsUnitConverter.Convert(GraphicsUnit.Pixel, PageUnit,
layout.Font.FontMetrics.Descent + layout.Font.FontMetrics.Leading, DpiX);
}
}
//System.Diagnostics.Debug.WriteLine("Graphics.DrawTextLayout at {0},{1} with: {2}",x,y,layout.Text);
}