public void DrawInto(Batcher batcher, ref FontCharacterSource text, Vector2 position, Color color,
float rotation, Vector2 origin, Vector2 scale, SpriteEffects effect, float depth)
{
var flipAdjustment = Vector2.Zero;
var flippedVert = (effect & SpriteEffects.FlipVertically) == SpriteEffects.FlipVertically;
var flippedHorz = (effect & SpriteEffects.FlipHorizontally) == SpriteEffects.FlipHorizontally;
if (flippedVert || flippedHorz)
{
Vector2 size;
MeasureString(ref text, out size);
if (flippedHorz)
{
origin.X *= -1;
flipAdjustment.X = -size.X;
}
if (flippedVert)
{
origin.Y *= -1;
flipAdjustment.Y = _font.LineSpacing - size.Y;
}
}
// TODO: This looks excessive... i suspect we could do most of this with simple vector math and avoid this much matrix work.
var requiresTransformation = flippedHorz || flippedVert || rotation != 0f || scale != Vector2.One;
if (requiresTransformation)
{
Matrix2D temp;
Matrix2D.CreateTranslation(-origin.X, -origin.Y, out _transformationMatrix);
Matrix2D.CreateScale((flippedHorz ? -scale.X : scale.X), (flippedVert ? -scale.Y : scale.Y), out temp);
Matrix2D.Multiply(ref _transformationMatrix, ref temp, out _transformationMatrix);
Matrix2D.CreateTranslation(flipAdjustment.X, flipAdjustment.Y, out temp);
Matrix2D.Multiply(ref temp, ref _transformationMatrix, out _transformationMatrix);
Matrix2D.CreateRotation(rotation, out temp);
Matrix2D.Multiply(ref _transformationMatrix, ref temp, out _transformationMatrix);
Matrix2D.CreateTranslation(position.X, position.Y, out temp);
Matrix2D.Multiply(ref _transformationMatrix, ref temp, out _transformationMatrix);
}
// Get the default glyph here once.
SpriteFont.Glyph?defaultGlyph = null;
if (_font.DefaultCharacter.HasValue)
{
defaultGlyph = _glyphs[_font.DefaultCharacter.Value];
}
var currentGlyph = SpriteFont.Glyph.Empty;
var offset = requiresTransformation ? Vector2.Zero : position - origin;
var firstGlyphOfLine = true;
for (var i = 0; i < text.Length; ++i)
{
var c = text[i];
if (c == '\r')
{
continue;
}
if (c == '\n')
{
offset.X = requiresTransformation ? 0f : position.X - origin.X;
offset.Y += _font.LineSpacing;
firstGlyphOfLine = true;
continue;
}
if (!_glyphs.TryGetValue(c, out currentGlyph))
{
if (!defaultGlyph.HasValue)
{
throw new ArgumentException("Errors.TextContainsUnresolvableCharacters", "text");
}
currentGlyph = defaultGlyph.Value;
}
// The first character on a line might have a negative left side bearing.
// In this scenario, SpriteBatch/SpriteFont normally offset the text to the right,
// so that text does not hang off the left side of its rectangle.
if (firstGlyphOfLine)
{
offset.X += Math.Max(currentGlyph.LeftSideBearing, 0);
firstGlyphOfLine = false;
}
else
{
offset.X += _font.Spacing + currentGlyph.LeftSideBearing;
}
var p = offset;
if (flippedHorz)
{
p.X += currentGlyph.BoundsInTexture.Width;
}
p.X += currentGlyph.Cropping.X;
if (flippedVert)
{
p.Y += currentGlyph.BoundsInTexture.Height - _font.LineSpacing;
}
p.Y += currentGlyph.Cropping.Y;
// transform our point if we need to
if (requiresTransformation)
{
Vector2Ext.Transform(ref p, ref _transformationMatrix, out p);
}
var destRect = RectangleExt.FromFloats(p.X, p.Y,
currentGlyph.BoundsInTexture.Width * scale.X,
currentGlyph.BoundsInTexture.Height * scale.Y);
batcher.Draw(_font.Texture, destRect, currentGlyph.BoundsInTexture, color, rotation, Vector2.Zero,
effect, depth);
offset.X += currentGlyph.Width + currentGlyph.RightSideBearing;
}
}