/// <summary>
/// Renders the text.
/// </summary>
/// <param name="text">The text.</param>
/// <param name="style">The style.</param>
/// <param name="dpi">The dpi.</param>
public void RenderText(string text, FontSpan style, Vector2 dpi)
{
var glyphsToRender = this.layoutEngine.GenerateLayout(text, style);
foreach (var g in glyphsToRender)
{
g.Glyph.RenderTo(this.renderer, g.Location, dpi);
}
}
/// <summary>
/// Measures the text.
/// </summary>
/// <param name="text">The text.</param>
/// <param name="style">The style.</param>
/// <param name="dpi">The dpi.</param>
/// <returns>The size of the text if it was to be rendered.</returns>
public Size MeasureText(string text, FontSpan style, Vector2 dpi)
{
var glyphsToRender = this.layoutEngine.GenerateLayout(text, style);
var left = glyphsToRender.Min(x => x.Location.X);
var right = glyphsToRender.Max(x => x.Location.X + x.Width);
var top = glyphsToRender.Min(x => x.Location.Y);
var bottom = glyphsToRender.Max(x => x.Location.Y + x.Height);
var topLeft = new Vector2(left, top) * dpi;
var bottomRight = new Vector2(right, bottom) * dpi;
return(new Size(bottomRight.X - topLeft.X, bottomRight.Y - topLeft.Y));
}
/// <summary>
/// Measures the text.
/// </summary>
/// <param name="text">The text.</param>
/// <param name="style">The style.</param>
/// <param name="dpi">The dpi.</param>
/// <returns>The size of the text if it was to be rendered.</returns>
public Size MeasureText(string text, FontSpan style, float dpi)
{
return(this.MeasureText(text, style, new Vector2(dpi)));
}
/// <summary>
/// Generates the layout.
/// </summary>
/// <param name="text">The text.</param>
/// <param name="style">The style.</param>
/// <returns>A collection of layout that describe all thats needed to measure or render a series of glyphs.</returns>
public ImmutableArray <GlyphLayout> GenerateLayout(string text, FontSpan style)
{
AppliedFontStyle spanStyle = style.GetStyle(0, text.Length);
List <GlyphLayout> layout = new List <GlyphLayout>(text.Length);
float lineHeight = 0f;
Vector2 location = Vector2.Zero;
float lineHeightOfFirstLine = 0;
bool firstLine = true;
GlyphInstance previousGlyph = null;
float scale = 0;
for (var i = 0; i < text.Length; i++)
{
if (spanStyle.End < i)
{
spanStyle = style.GetStyle(i, text.Length);
previousGlyph = null;
}
if (spanStyle.Font.LineHeight > lineHeight)
{
// get the larget lineheight thus far
scale = spanStyle.Font.EmSize * 72;
lineHeight = (spanStyle.Font.LineHeight * spanStyle.PointSize) / scale;
}
if (firstLine && lineHeight > lineHeightOfFirstLine)
{
lineHeightOfFirstLine = lineHeight;
}
var c = text[i];
switch (c)
{
case '\r':
// carrage return resets the XX coordinate to 0
location.X = 0;
previousGlyph = null;
break;
case '\n':
// carrage return resets the XX coordinate to 0
location.X = 0;
location.Y += lineHeight;
lineHeight = 0; // reset line height tracking for next line
previousGlyph = null;
firstLine = false;
break;
case '\t':
{
var glyph = spanStyle.Font.GetGlyph(c);
var width = (glyph.AdvanceWidth * spanStyle.PointSize) / scale;
var tabStop = width * spanStyle.TabWidth;
// advance to a position > width away that
var dist = tabStop - ((location.X + width) % tabStop);
location.X += dist;
previousGlyph = null;
}
break;
case ' ':
{
var glyph = spanStyle.Font.GetGlyph(c);
var width = (glyph.AdvanceWidth * spanStyle.PointSize) / scale;
location.X += width;
previousGlyph = null;
}
break;
default:
{
var glyph = spanStyle.Font.GetGlyph(c);
var width = (glyph.AdvanceWidth * spanStyle.PointSize) / scale;
var height = (glyph.Height * spanStyle.PointSize) / scale;
var glyphLocation = location;
if (spanStyle.ApplyKerning && previousGlyph != null)
{
// if there is special instructions for this glyph pair use that width
var scaledOffset = (spanStyle.Font.GetOffset(glyph, previousGlyph) * spanStyle.PointSize) / scale;
glyphLocation += scaledOffset;
// only fix the 'X' of the current tracked location but use the actual 'X'/'Y' of the offset
location.X = glyphLocation.X;
}
layout.Add(new GlyphLayout(new Glyph(glyph, spanStyle.PointSize), glyphLocation, width, height));
// move foraward the actual with of the glyph, we are retaining the baseline
location.X += width;
previousGlyph = glyph;
}
break;
}
}
var offset = new Vector2(0, lineHeightOfFirstLine);
for (var i = 0; i < layout.Count; i++)
{
var glyphLayout = layout[i];
layout[i] = new GlyphLayout(glyphLayout.Glyph, glyphLayout.Location + offset, glyphLayout.Width, glyphLayout.Height);
}
return(layout.ToImmutableArray());
}
/// <summary>
/// Renders the text.
/// </summary>
/// <param name="text">The text.</param>
/// <param name="style">The style.</param>
/// <param name="dpi">The dpi.</param>
public void RenderText(string text, FontSpan style, float dpi)
{
this.RenderText(text, style, new Vector2(dpi));
}
