public TextPipeline(FontDevice fontDevice)
{
Contract.Requires(fontDevice != null);
_FontDevice = fontDevice;
_TextAnalyzer = new Analyzer(_FontDevice.Factory);
_AggregatorSink = new AggregatorSink();
_Aggregator = new Aggregator(_AggregatorSink);
_ShaperSink = new ShaperSink();
_Shaper = new Shaper(_FontDevice, _ShaperSink);
_FormatterSink = new FormatterSink();
_Formatter = new Formatter(_FormatterSink);
_TypesetterSink = new TypesetterSink();
_Typesetter = new Typesetter(_TypesetterSink);
_GeometryCache = new TextGeometryCache();
}
/// <summary>
/// This method produces the bidi formatted cluster runs.
/// </summary>
/// <param name="input"> This parameter references the input sink. </param>
/// <returns> This method returns an enumeration of the results. </returns>
private static IEnumerable<FormattedRun> ProduceBidiRuns(TypesetterSink input)
{
Contract.Requires(input != null);
FormattedRun activeRun;
activeRun.BidiLevel = input.Clusters[0].BidiLevel;
activeRun.Clusters = IndexedRange.Empty;
activeRun.EmSize = input.Clusters[0].Advance.Height;
activeRun.Font = input.Clusters[0].Font;
activeRun.PointSize = input.Clusters[0].PointSize;
activeRun.TextRange = IndexedRange.Empty;
activeRun.LineNumber = input.Clusters[0].LineNumber;
for(int i = 0; i < input.Clusters.Count; ++i)
{
FormattedRun currentRun;
currentRun.BidiLevel = input.Clusters[i].BidiLevel;
currentRun.Clusters = activeRun.Clusters;
currentRun.EmSize = activeRun.EmSize;
currentRun.Font = activeRun.Font;
currentRun.PointSize = activeRun.PointSize;
currentRun.TextRange = activeRun.TextRange;
currentRun.LineNumber = input.Clusters[i].LineNumber;
if(currentRun == activeRun)
{
// extend the current cluster range by one cluster
activeRun.Clusters = activeRun.Clusters.Extend(1);
}
else
{
yield return activeRun;
activeRun = currentRun;
activeRun.Clusters = new IndexedRange(i, 1);
}
}
yield return activeRun;
}
/// <summary>
/// This method formats the input clusters and glyphs.
/// </summary>
/// <param name="input"> This parameter references the input sink. </param>
public void Format(TypesetterSink input)
{
Contract.Requires(input != null);
Contract.Ensures(_OutputSink.Clusters.Count == input.Clusters.Count);
Contract.Ensures(_OutputSink.Glyphs.Count == input.Glyphs.Count);
_Clusters = new FormattedCluster[input.Clusters.Count];
_OutputSink.Reset(input.FullText);
_OutputSink.LayoutRegion = input.LayoutRegion;
_OutputSink.LineHeight = input.LineHeight;
_OutputSink.Leading = input.Leading;
_OutputSink.PreallocateGlyphs(input.Glyphs.Count);
_OutputSink.PreallocateClusters(input.Clusters.Count);
OutputGlyphs(input);
ProduceLines(input);
DetermineBaselines();
}
/// <summary>
/// This method produces formatted lines of clusters.
/// </summary>
/// <param name="input"> This parameter references the input sink. </param>
private void ProduceLines(TypesetterSink input)
{
Contract.Requires(input != null);
int lineNumber = -1;
int lineBidiLevel = -1;
float penPosition = 0.0f;
foreach(FormattedRun run in ProduceBidiRuns(input))
{
if(run.LineNumber != lineNumber)
{
lineNumber = run.LineNumber;
if(lineNumber == 0)
{
// the first run determines the line bidi level
lineBidiLevel = run.BidiLevel;
if(input.Alignment == Alignment.Leading)
{
// reverse the bidi level for leading alignment
lineBidiLevel++;
}
}
bool isLeftToRight = lineBidiLevel % 2 == 0;
if(input.Alignment != Alignment.Center)
{
penPosition = 0.0f;
if(!isLeftToRight)
{
// position relative to the right edge
penPosition = input.Lines[lineNumber].Right;
}
// indent only the first line in the paragraph
if(lineNumber == 0)
{
if(isLeftToRight)
{
// position relative to the left edge
penPosition = input.Indentation;
}
else
{
// position relative to the right edge
penPosition = penPosition - input.Indentation;
}
}
}
else
{
float lineWidth = input.Lines[lineNumber].Width;
// determine unused space on the line
lineWidth -= input.LineLengths[lineNumber];
// divide the unused space in half
lineWidth /= 2.0f;
// distribute the halved space to center the line
penPosition = lineWidth;
if(!isLeftToRight)
{
// position relative to the right edge
penPosition = input.Lines[lineNumber].Right - penPosition;
}
}
}
ProduceClusters(run, lineBidiLevel, ref penPosition, input);
}
_OutputSink.Clusters.AddRange(_Clusters);
_OutputSink.Runs.AddRange(ProduceFinalRuns(input));
}
/// <summary>
/// This method produces the formatted clusters for each line from each run.
/// </summary>
/// <param name="run"> This parameter contains the formatted run. </param>
/// <param name="lineBidiLevel"> This parameter indicates the bidi level of the line. </param>
/// <param name="penPosition"> This parameter indicates the pen position. </param>
/// <param name="input"> This parameter references the input sink. </param>
private void ProduceClusters(
FormattedRun run, int lineBidiLevel, ref float penPosition, TypesetterSink input)
{
Contract.Requires(input != null);
// the run and the line have the same direction
if((run.BidiLevel % 2 == 0) == (lineBidiLevel % 2 == 0))
{
foreach(int clusterIndex in run.Clusters)
{
FormattedCluster newCluster;
newCluster.Region = input.Lines[run.LineNumber];
TypesetCluster cluster = input.Clusters[clusterIndex];
newCluster.Characters = cluster.Characters;
newCluster.Glyphs = cluster.Glyphs;
newCluster.Display = cluster.Display;
float clusterWidth = cluster.Advance.Width;
float clusterHeight = newCluster.Region.Height;
Size clusterSize = new Size(clusterWidth, clusterHeight);
newCluster.Region = newCluster.Region.Resize(clusterSize);
// the line reads from left to right
if(lineBidiLevel % 2 == 0)
{
Size amount = new Size(penPosition, 0.0f);
newCluster.Region = newCluster.Region.Translate(amount);
penPosition += newCluster.Region.Width;
}
// the line reads from right to left
else
{
float x = penPosition - newCluster.Region.Width;
Point location = new Point(x, newCluster.Region.Y);
newCluster.Region = newCluster.Region.Relocate(location);
penPosition -= newCluster.Region.Width;
}
if(cluster.ContentType == ContentType.Floater)
{
newCluster.Region = cluster.Floater;
}
_Clusters[clusterIndex] = newCluster;
}
}
else
{
// iterate over the clusters in reverse
for(int i = run.Clusters.LastIndex; i >= run.Clusters.StartIndex; --i)
{
FormattedCluster newCluster;
newCluster.Region = input.Lines[run.LineNumber];
TypesetCluster cluster = input.Clusters[i];
newCluster.Characters = cluster.Characters;
newCluster.Glyphs = cluster.Glyphs;
newCluster.Display = cluster.Display;
float clusterWidth = cluster.Advance.Width;
float clusterHeight = newCluster.Region.Height;
Size clusterSize = new Size(clusterWidth, clusterHeight);
newCluster.Region = newCluster.Region.Resize(clusterSize);
// the line reads from left to right
if(lineBidiLevel % 2 == 0)
{
Size amount = new Size(penPosition, 0.0f);
newCluster.Region = newCluster.Region.Translate(amount);
penPosition += newCluster.Region.Width;
}
// the line reads from right to left
else
{
float x = penPosition - newCluster.Region.Width;
Point location = new Point(x, newCluster.Region.Y);
newCluster.Region = newCluster.Region.Relocate(location);
penPosition -= newCluster.Region.Width;
}
if(cluster.ContentType == ContentType.Floater)
{
newCluster.Region = cluster.Floater;
}
_Clusters[i] = newCluster;
}
}
}
/// <summary>
/// This method produces the formatted glyphs.
/// </summary>
/// <param name="input"> This parameter references the input sink. </param>
private void OutputGlyphs(TypesetterSink input)
{
Contract.Requires(input != null);
foreach(TypesetGlyph glyph in input.Glyphs)
{
FormattedGlyph newGlyph;
newGlyph.Advance = glyph.Advance;
newGlyph.Index = glyph.Index;
newGlyph.Offset = glyph.Offset;
_OutputSink.Glyphs.Add(newGlyph);
}
}
/// <summary>
/// This method produces the final formatted cluster runs.
/// </summary>
/// <param name="input"> This parameter references the input sink. </param>
/// <returns> This method returns an enumeration of the results. </returns>
private static IEnumerable<FormattedRun> ProduceFinalRuns(TypesetterSink input)
{
Contract.Requires(input != null);
FormattedRun activeRun;
activeRun.BidiLevel = input.Clusters[0].BidiLevel;
activeRun.Clusters = IndexedRange.Empty;
activeRun.EmSize = input.Clusters[0].Advance.Height;
activeRun.Font = input.Clusters[0].Font;
activeRun.TextRange = IndexedRange.Empty;
activeRun.PointSize = input.Clusters[0].PointSize;
activeRun.LineNumber = input.Clusters[0].LineNumber;
int start;
int end;
for(int i = 0; i < input.Clusters.Count; ++i)
{
FormattedRun currentRun;
currentRun.BidiLevel = input.Clusters[i].BidiLevel;
currentRun.Clusters = activeRun.Clusters;
currentRun.EmSize = input.Clusters[i].Advance.Height;
currentRun.Font = input.Clusters[i].Font;
currentRun.TextRange = activeRun.TextRange;
currentRun.PointSize = input.Clusters[i].PointSize;
currentRun.LineNumber = input.Clusters[i].LineNumber;
// the runs are identical
if(currentRun == activeRun)
{
// extend the current cluster range by one cluster
activeRun.Clusters = activeRun.Clusters.Extend(1);
}
else
{
// determine the text range from the clusters
start = input.Clusters[activeRun.Clusters.StartIndex].Characters.StartIndex;
end = input.Clusters[activeRun.Clusters.LastIndex].Characters.LastIndex;
// convert the valid index range to a length
activeRun.TextRange = new IndexedRange(start, (end - start) + 1);
yield return activeRun;
activeRun = currentRun;
activeRun.Clusters = new IndexedRange(i, 1);
}
}
// determine the text range from the clusters
start = input.Clusters[activeRun.Clusters.StartIndex].Characters.StartIndex;
end = input.Clusters[activeRun.Clusters.LastIndex].Characters.LastIndex;
// convert the valid index range to a length
activeRun.TextRange = new IndexedRange(start, (end - start) + 1);
yield return activeRun;
}