public TextExtents MeasureText(ref TextBlock block, TextQuality quality)
{
// First, check if we have cached this text block. Do not use block_cache.TryGetValue, to avoid thrashing
// the user's TextBlockExtents struct.
int hashcode = block.GetHashCode();
if (block_cache.ContainsKey(hashcode))
{
return(block_cache[hashcode]);
}
// If this block is not cached, we have to measure it and (potentially) place it in the cache.
TextExtents extents = MeasureTextExtents(ref block, quality);
if ((block.Options & TextPrinterOptions.NoCache) == 0)
{
block_cache.Add(hashcode, extents);
}
return(extents);
}
static TextExtents()
{
Empty = new TextExtents();
}
public void Render(ref TextBlock block, Color color, IGlyphRasterizer rasterizer)
{
GL.PushAttrib(AttribMask.CurrentBit | AttribMask.TextureBit | AttribMask.EnableBit | AttribMask.ColorBufferBit | AttribMask.DepthBufferBit);
GL.Enable(EnableCap.Texture2D);
GL.Enable(EnableCap.Blend);
SetBlendFunction();
GL.Disable(EnableCap.DepthTest);
GL.TexEnv(TextureEnvTarget.TextureEnv, TextureEnvParameter.TextureEnvMode, (int)All.Modulate);
GL.TexEnv(TextureEnvTarget.TextureEnv, TextureEnvParameter.TextureEnvColor, new Color4(0, 0, 0, 0));
GL.Disable(EnableCap.TextureGenQ);
GL.Disable(EnableCap.TextureGenR);
GL.Disable(EnableCap.TextureGenS);
GL.Disable(EnableCap.TextureGenT);
RectangleF position;
SetColor(color);
int block_hash = block.GetHashCode();
if (block_cache.ContainsKey(block_hash))
{
GL.CallList(block_cache[block_hash]);
}
else
{
using (TextExtents extents = rasterizer.MeasureText(ref block))
{
// Build layout
int current = 0;
foreach (Glyph glyph in block)
{
// Do not render whitespace characters or characters outside the clip rectangle.
if (glyph.IsWhiteSpace || extents[current].Width == 0 || extents[current].Height == 0)
{
current++;
continue;
}
else if (!Cache.Contains(glyph))
{
Cache.Add(glyph, rasterizer, TextQuality);
}
CachedGlyphInfo info = Cache[glyph];
position = extents[current++];
// Use the real glyph width instead of the measured one (we want to achieve pixel perfect output).
position.Size = info.Rectangle.Size;
if (!active_lists.ContainsKey(info.Texture))
{
if (inactive_lists.Count > 0)
{
List <Vector2> list = inactive_lists.Dequeue();
list.Clear();
active_lists.Add(info.Texture, list);
}
else
{
active_lists.Add(info.Texture, new List <Vector2>());
}
}
{
// Interleaved array: Vertex, TexCoord, Vertex, ...
List <Vector2> current_list = active_lists[info.Texture];
current_list.Add(new Vector2(info.RectangleNormalized.Left, info.RectangleNormalized.Top));
current_list.Add(new Vector2(position.Left, position.Top));
current_list.Add(new Vector2(info.RectangleNormalized.Left, info.RectangleNormalized.Bottom));
current_list.Add(new Vector2(position.Left, position.Bottom));
current_list.Add(new Vector2(info.RectangleNormalized.Right, info.RectangleNormalized.Bottom));
current_list.Add(new Vector2(position.Right, position.Bottom));
current_list.Add(new Vector2(info.RectangleNormalized.Right, info.RectangleNormalized.Bottom));
current_list.Add(new Vector2(position.Right, position.Bottom));
current_list.Add(new Vector2(info.RectangleNormalized.Right, info.RectangleNormalized.Top));
current_list.Add(new Vector2(position.Right, position.Top));
current_list.Add(new Vector2(info.RectangleNormalized.Left, info.RectangleNormalized.Top));
current_list.Add(new Vector2(position.Left, position.Top));
}
}
}
// Render
int display_list = 0;
if ((block.Options & TextPrinterOptions.NoCache) == 0)
{
display_list = GL.GenLists(1);
// Mesa Indirect gerates an InvalidOperation error right after
// GL.EndList() when using ListMode.CompileAndExecute.
// Using ListMode.Compile as a workaround.
GL.NewList(display_list, ListMode.Compile);
}
foreach (Texture2D key in active_lists.Keys)
{
List <Vector2> list = active_lists[key];
key.Bind();
GL.Begin(BeginMode.Triangles);
for (int i = 0; i < list.Count; i += 2)
{
GL.TexCoord2(list[i]);
GL.Vertex2(list[i + 1]);
}
GL.End();
}
if ((block.Options & TextPrinterOptions.NoCache) == 0)
{
GL.EndList();
block_cache.Add(block_hash, display_list);
GL.CallList(display_list);
}
// Clean layout
foreach (List <Vector2> list in active_lists.Values)
{
//list.Clear();
inactive_lists.Enqueue(list);
}
active_lists.Clear();
}
GL.PopAttrib();
}
static TextExtents()
{
Empty = new TextExtents();
}
internal TextExtents Clone()
{
var extents = new TextExtents();
extents._glyphExtents.AddRange(GlyphExtents);
extents.BoundingBox = BoundingBox;
return extents;
}
TextExtents MeasureTextExtents(ref TextBlock block, TextQuality quality)
{
// TODO: Parse layout options:
var format = block.Font.Italic ? measure_string_format : measure_string_format_tight;
//StringFormat format = measure_string_format_tight;
if (block.Direction == TextDirection.Vertical)
{
format.FormatFlags |= StringFormatFlags.DirectionVertical;
}
else
{
format.FormatFlags &= ~StringFormatFlags.DirectionVertical;
}
if (block.Direction == TextDirection.RightToLeft)
{
format.FormatFlags |= StringFormatFlags.DirectionRightToLeft;
}
else
{
format.FormatFlags &= ~StringFormatFlags.DirectionRightToLeft;
}
if (block.Alignment == TextAlignment.Near)
{
format.Alignment = StringAlignment.Near;
}
else if (block.Alignment == TextAlignment.Center)
{
format.Alignment = StringAlignment.Center;
}
else
{
format.Alignment = StringAlignment.Far;
}
TextExtents extents = text_extents_pool.Acquire();
RectangleF rect = block.Bounds;
// Work around Mono/GDI+ bug, which causes incorrect
// text wraping when block.Bounds == SizeF.Empty.
if (block.Bounds.Size == SizeF.Empty)
{
rect.Size = MaximumGraphicsClipSize;
}
SetTextRenderingOptions(graphics, block.Font, quality);
IntPtr native_graphics = GdiPlus.GetNativeGraphics(graphics);
IntPtr native_font = GdiPlus.GetNativeFont(block.Font);
IntPtr native_string_format = GdiPlus.GetNativeStringFormat(format);
float max_width = 0, max_height = 0;
// It seems that the mere presence of \n and \r characters
// is enough for Mono to botch the layout (even if these
// characters are not processed.) We'll need to find a
// different way to perform layout on Mono, probably
// through Pango.
// TODO: This workaround allocates memory.
//if (Configuration.RunningOnMono)
{
string[] lines = block.Text.Replace("\r", String.Empty).Split('\n');
foreach (string s in lines)
{
float width, height;
extents.AddRange(MeasureGlyphExtents(
ref block, s,
native_graphics, native_font, native_string_format,
ref rect, out width, out height));
if ((block.Direction & TextDirection.Vertical) == 0)
{
rect.Y += block.Font.Height;
}
else
{
rect.X += block.Font.Height;
}
if (width > max_width)
{
max_width = width;
}
if (height > max_height)
{
max_height = height;
}
}
}
if (extents.Count > 0)
{
extents.BoundingBox = new RectangleF(extents[0].X, extents[0].Y, max_width, max_height);
}
else
{
extents.BoundingBox = RectangleF.Empty;
}
return(extents);
}
