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PdfTextExtractor: Keep basic graphics state for correct matrix calculations

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This commit is contained in:
Valeriano A.R.
2016-06-21 11:24:39 +02:00
parent c41c541149
commit 44f6cb3d0c
1 changed files with 141 additions and 43 deletions
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184
VAR.PdfTools/PdfTextExtractor.cs
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@@ -5,10 +5,20 @@ namespace VAR.PdfTools
{
public class Vector3D
{
#region Declarations
public double[] _vector = new double[3];
#endregion
#region Properties
public double[] Vector { get { return _vector; } }
#endregion
#region Creator
public Vector3D()
{
Init();
@@ -20,19 +30,35 @@ namespace VAR.PdfTools
_vector[1] = 0.0;
_vector[2] = 1.0;
}
#endregion
}
public class Matrix3x3
{
#region Declarations
public double[,] _matrix = new double[3, 3];
#endregion
#region Properties
public double[,] Matrix { get { return _matrix; } }
#endregion
#region Creator
public Matrix3x3()
{
Idenity();
}
#endregion
#region Public methods
public void Idenity()
{
_matrix[0, 0] = 1.0;
@@ -91,8 +117,9 @@ namespace VAR.PdfTools
return newMatrix;
}
#endregion
}
public class PdfTextElement
{
public PdfFont Font { get; set; }
@@ -115,13 +142,19 @@ namespace VAR.PdfTools
private PdfDocumentPage _page = null;
private List<PdfTextElement> _textElements = new List<PdfTextElement>();
// Graphics state
private List<Matrix3x3> _graphicsMatrixStack = new List<Matrix3x3>();
private Matrix3x3 _graphicsMatrix = new Matrix3x3();
// Text state
private PdfFont _font = null;
private double _fontSize = 1;
private double _textLeading = 0;
// Text object state
private bool inText = false;
private Matrix3x3 _matrix = new Matrix3x3();
private Matrix3x3 _textMatrix = new Matrix3x3();
private StringBuilder _sbText = new StringBuilder();
private double _textWidth = 0;
@@ -202,11 +235,11 @@ namespace VAR.PdfTools
}
PdfTextElement textElem = new PdfTextElement();
textElem.Matrix = _matrix.Copy();
textElem.Matrix = _textMatrix.Multiply(_graphicsMatrix);
textElem.Font = _font;
textElem.RawText = _sbText.ToString();
textElem.VisibleText = PdfString_ToUnicode(textElem.RawText, _font);
textElem.VisibleWidth = _textWidth;
textElem.VisibleWidth = _textWidth * textElem.Matrix.Matrix[0, 0];
_textElements.Add(textElem);
_sbText = new StringBuilder();
@@ -217,59 +250,83 @@ namespace VAR.PdfTools
#region Operations
private void OpBT()
private void OpPushGraphState()
{
_matrix.Idenity();
_graphicsMatrixStack.Add(_graphicsMatrix.Copy());
}
private void OpPopGraphState()
{
_graphicsMatrix = _graphicsMatrixStack[_graphicsMatrixStack.Count - 1];
_graphicsMatrixStack.RemoveAt(_graphicsMatrixStack.Count - 1);
}
private void OpSetGraphMatrix(double a, double b, double c, double d, double e, double f)
{
_graphicsMatrix.Matrix[0, 0] = a;
_graphicsMatrix.Matrix[1, 0] = b;
_graphicsMatrix.Matrix[2, 0] = 0;
_graphicsMatrix.Matrix[0, 1] = c;
_graphicsMatrix.Matrix[1, 1] = d;
_graphicsMatrix.Matrix[2, 1] = 0;
_graphicsMatrix.Matrix[0, 2] = e;
_graphicsMatrix.Matrix[1, 2] = f;
_graphicsMatrix.Matrix[2, 2] = 1;
}
private void OpBeginText()
{
_textMatrix.Idenity();
inText = true;
}
private void OpET()
private void OpEndText()
{
FlushTextElement();
inText = false;
}
private void OpTf(string fontName, double size)
private void OpTextFont(string fontName, double size)
{
FlushTextElement();
_font = _page.Fonts[fontName];
_fontSize = size;
}
private void OpTL(double textLeading)
private void OpTextLeading(double textLeading)
{
_textLeading = textLeading;
}
private void OpTd(double x, double y)
private void OpTesDisplace(double x, double y)
{
FlushTextElement();
var newMatrix = new Matrix3x3();
newMatrix.Matrix[0, 2] = x;
newMatrix.Matrix[1, 2] = y;
_matrix = newMatrix.Multiply(_matrix);
_textMatrix = newMatrix.Multiply(_textMatrix);
}
private void OpTStar()
private void OpTextLineFeed()
{
OpTd(0, -_textLeading);
OpTesDisplace(0, -_textLeading);
}
private void OpTm(double a, double b, double c, double d, double e, double f)
private void OpSetTextMatrix(double a, double b, double c, double d, double e, double f)
{
FlushTextElement();
_matrix.Matrix[0, 0] = a;
_matrix.Matrix[1, 0] = b;
_matrix.Matrix[2, 0] = 0;
_matrix.Matrix[0, 1] = c;
_matrix.Matrix[1, 1] = d;
_matrix.Matrix[2, 1] = 0;
_matrix.Matrix[0, 2] = e;
_matrix.Matrix[1, 2] = f;
_matrix.Matrix[2, 2] = 1;
_textMatrix.Matrix[0, 0] = a;
_textMatrix.Matrix[1, 0] = b;
_textMatrix.Matrix[2, 0] = 0;
_textMatrix.Matrix[0, 1] = c;
_textMatrix.Matrix[1, 1] = d;
_textMatrix.Matrix[2, 1] = 0;
_textMatrix.Matrix[0, 2] = e;
_textMatrix.Matrix[1, 2] = f;
_textMatrix.Matrix[2, 2] = 1;
}
private void OpTj(string text)
private void OpTextPut(string text)
{
if (inText == false) { return; }
_sbText.Append(text);
@@ -282,14 +339,14 @@ namespace VAR.PdfTools
}
}
private void OpTJ(PdfArray array)
private void OpTextPutMultiple(PdfArray array)
{
if (inText == false) { return; }
foreach (IPdfElement elem in array.Values)
{
if(elem is PdfString)
{
OpTj(((PdfString)elem).Value);
OpTextPut(((PdfString)elem).Value);
}
else if(elem is PdfInteger || elem is PdfReal)
{
@@ -298,7 +355,7 @@ namespace VAR.PdfTools
}
else if(elem is PdfArray)
{
OpTJ(((PdfArray)elem));
OpTextPutMultiple(((PdfArray)elem));
}
}
}
@@ -311,37 +368,78 @@ namespace VAR.PdfTools
{
foreach (PdfContentAction action in _page.ContentActions)
{
if (action.Token == "BT")
// Graphics Operations
if (action.Token == "q")
{
OpBT();
OpPushGraphState();
}
else if (action.Token == "Q")
{
OpPopGraphState();
}
else if (action.Token == "cm")
{
double a = PdfElement_GetReal(action.Parameters[0], 0);
double b = PdfElement_GetReal(action.Parameters[1], 0);
double c = PdfElement_GetReal(action.Parameters[2], 0);
double d = PdfElement_GetReal(action.Parameters[3], 0);
double e = PdfElement_GetReal(action.Parameters[4], 0);
double f = PdfElement_GetReal(action.Parameters[5], 0);
OpSetGraphMatrix(a, b, c, d, e, f);
}
// Text Operations
else if (action.Token == "BT")
{
OpBeginText();
}
else if (action.Token == "ET")
{
OpET();
OpEndText();
}
else if (action.Token == "Tc")
{
// FIXME: Char spacing
}
else if (action.Token == "Tw")
{
// FIXME: Word spacing
}
else if (action.Token == "Tz")
{
// FIXME: Horizontal Scale
}
else if (action.Token == "Tf")
{
string fontName = ((PdfName)action.Parameters[0]).Value;
double fontSize = PdfElement_GetReal(action.Parameters[1], 0);
OpTf(fontName, fontSize);
OpTextFont(fontName, fontSize);
}
else if (action.Token == "TL")
{
double leading = PdfElement_GetReal(action.Parameters[0], 0);
OpTL(leading);
OpTextLeading(leading);
}
else if (action.Token == "Tr")
{
// FIXME: Rendering mode
}
else if (action.Token == "Ts")
{
// FIXME: Text rise
}
else if (action.Token == "Td")
{
double x = PdfElement_GetReal(action.Parameters[0], 0);
double y = PdfElement_GetReal(action.Parameters[1], 0);
OpTd(x, y);
OpTesDisplace(x, y);
}
else if (action.Token == "TD")
{
double x = PdfElement_GetReal(action.Parameters[0], 0);
double y = PdfElement_GetReal(action.Parameters[1], 0);
OpTL(-y);
OpTd(x, y);
OpTextLeading(-y);
OpTesDisplace(x, y);
}
else if (action.Token == "Tm")
{
@@ -351,30 +449,30 @@ namespace VAR.PdfTools
double d = PdfElement_GetReal(action.Parameters[3], 0);
double e = PdfElement_GetReal(action.Parameters[4], 0);
double f = PdfElement_GetReal(action.Parameters[5], 0);
OpTm(a, b, c, d, e, f);
OpSetTextMatrix(a, b, c, d, e, f);
}
else if (action.Token == "T*")
{
OpTStar();
OpTextLineFeed();
}
else if (action.Token == "Tj")
{
OpTj(((PdfString)action.Parameters[0]).Value);
OpTextPut(((PdfString)action.Parameters[0]).Value);
}
else if (action.Token == "'")
{
OpTStar();
OpTj(((PdfString)action.Parameters[0]).Value);
OpTextLineFeed();
OpTextPut(((PdfString)action.Parameters[0]).Value);
}
else if (action.Token == "\"")
{
double wordSpacing = PdfElement_GetReal(action.Parameters[0], 0);
double charSpacing = PdfElement_GetReal(action.Parameters[1], 0);
OpTj(((PdfString)action.Parameters[2]).Value);
OpTextPut(((PdfString)action.Parameters[2]).Value);
}
else if (action.Token == "TJ")
{
OpTJ(((PdfArray)action.Parameters[0]));
OpTextPutMultiple(((PdfArray)action.Parameters[0]));
}
}
FlushTextElement();