fpvectorial: Adds a SVG reader and adds a new convinience file reading function

git-svn-id: trunk@17385 -

.gitattributes

@@ -2598,6 +2598,7 @@ packages/fpvectorial/src/pdfvectorialreader.pas svneol=native#text/pascal
 packages/fpvectorial/src/pdfvrlexico.pas svneol=native#text/pascal
 packages/fpvectorial/src/pdfvrsemantico.pas svneol=native#text/pascal
 packages/fpvectorial/src/pdfvrsintatico.pas svneol=native#text/pascal
+packages/fpvectorial/src/svgvectorialreader.pas svneol=native#text/pascal
 packages/fpvectorial/src/svgvectorialwriter.pas svneol=native#text/pascal
 packages/fuse/Makefile svneol=native#text/plain
 packages/fuse/Makefile.fpc svneol=native#text/plain

packages/fpvectorial/src/fpvectorial.pas

@@ -38,6 +38,7 @@ const
   STR_SVG_EXTENSION = '.svg';
   STR_CORELDRAW_EXTENSION = '.cdr';
   STR_WINMETAFILE_EXTENSION = '.wmf';
+  STR_AUTOCAD_EXCHANGE_EXTENSION = '.dxf';
 
 type
   {@@ We need our own format because TFPColor is too big for our needs and TColor has no Alpha }
@@ -144,7 +145,6 @@ type
     Brush: TvBrush;
     constructor Create();
     procedure Assign(APath: TPath);
-    function Count(): TPathSegment;
     procedure PrepareForSequentialReading;
     function Next(): TPathSegment;
   end;
@@ -243,7 +243,8 @@ type
     procedure WriteToFile(AFileName: string; AFormat: TvVectorialFormat);
     procedure WriteToStream(AStream: TStream; AFormat: TvVectorialFormat);
     procedure WriteToStrings(AStrings: TStrings; AFormat: TvVectorialFormat);
-    procedure ReadFromFile(AFileName: string; AFormat: TvVectorialFormat);
+    procedure ReadFromFile(AFileName: string; AFormat: TvVectorialFormat); overload;
+    procedure ReadFromFile(AFileName: string); overload;
     procedure ReadFromStream(AStream: TStream; AFormat: TvVectorialFormat);
     procedure ReadFromStrings(AStrings: TStrings; AFormat: TvVectorialFormat);
     class function GetFormatFromExtension(AFileName: string): TvVectorialFormat;
@@ -261,7 +262,9 @@ type
     procedure RemoveAllTexts;
     { Data writing methods }
     procedure AddPath(APath: TPath);
-    procedure StartPath(AX, AY: Double);
+    procedure StartPath(AX, AY: Double); overload;
+    procedure StartPath(); overload;
+    procedure AddMoveToPath(AX, AY: Double);
     procedure AddLineToPath(AX, AY: Double); overload;
     procedure AddLineToPath(AX, AY: Double; AColor: TvColor); overload;
     procedure AddLineToPath(AX, AY, AZ: Double); overload;
@@ -551,6 +554,23 @@ begin
   FTmpPath.PointsEnd := segment;
 end;
 
+procedure TvVectorialDocument.StartPath();
+begin
+  ClearTmpPath();
+end;
+
+procedure TvVectorialDocument.AddMoveToPath(AX, AY: Double);
+var
+  segment: T2DSegment;
+begin
+  segment := T2DSegment.Create;
+  segment.SegmentType := stMoveTo;
+  segment.X := AX;
+  segment.Y := AY;
+
+  AppendSegmentToTmpPath(segment);
+end;
+
 {@@
   Adds one more point to the end of a Path being
   writing in multiple steps.
@@ -824,8 +844,17 @@ procedure TvVectorialDocument.AppendSegmentToTmpPath(ASegment: TPathSegment);
 var
   L: Integer;
 begin
+  // Check if we are the first segment in the tmp path
   if FTmpPath.PointsEnd = nil then
-    Exception.Create('[TvVectorialDocument.AppendSegmentToTmpPath]' + Str_Error_Nil_Path);
+  begin
+    if FTmpPath.Len <> 0 then
+      Exception.Create('[TvVectorialDocument.AppendSegmentToTmpPath]' + Str_Error_Nil_Path);
+
+    FTmpPath.Points := ASegment;
+    FTmpPath.PointsEnd := ASegment;
+    FTmpPath.Len := 1;
+    Exit;
+  end;
 
   L := FTmpPath.Len;
   Inc(FTmpPath.Len);
@@ -904,6 +933,22 @@ begin
   end;
 end;
 
+{@@
+  Reads the document from a file.  A variant that auto-detects the format from the extension.
+}
+procedure TvVectorialDocument.ReadFromFile(AFileName: string);
+var
+  lExt: string;
+begin
+  lExt := ExtractFileExt(AFileName);
+  if lExt = STR_PDF_EXTENSION then ReadFromFile(AFileName, vfPDF)
+  else if lExt = STR_POSTSCRIPT_EXTENSION then ReadFromFile(AFileName, vfPostScript)
+  else if lExt = STR_SVG_EXTENSION then ReadFromFile(AFileName, vfSVG)
+  else if lExt = STR_CORELDRAW_EXTENSION then ReadFromFile(AFileName, vfCorelDrawCDR)
+  else if lExt = STR_WINMETAFILE_EXTENSION then ReadFromFile(AFileName, vfWindowsMetafileWMF)
+  else if lExt = STR_AUTOCAD_EXCHANGE_EXTENSION then ReadFromFile(AFileName, vfDXF);
+end;
+
 {@@
   Reads the document from a stream.
 
@@ -1134,11 +1179,6 @@ begin
   Brush := APath.Brush;
 end;
 
-function TPath.Count(): TPathSegment;
-begin
-
-end;
-
 procedure TPath.PrepareForSequentialReading;
 begin
   CurPoint := nil;

packages/fpvectorial/src/svgvectorialreader.pas

@@ -0,0 +1,300 @@
+{
+Reads an SVG Document
+
+License: The same modified LGPL as the Free Pascal RTL
+         See the file COPYING.modifiedLGPL for more details
+
+AUTHORS: Felipe Monteiro de Carvalho
+}
+unit svgvectorialreader;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, math,
+  xmlread, dom, fgl,
+  fpvectorial, fpvutils;
+
+type
+  TSVGTokenType = (sttMoveTo, sttLineTo, sttBezierTo, sttFloatValue);
+
+  TSVGToken = class
+    TokenType: TSVGTokenType;
+    Value: Float;
+  end;
+
+  TSVGTokenList = specialize TFPGList<TSVGToken>;
+
+  { TSVGPathTokenizer }
+
+  TSVGPathTokenizer = class
+  public
+    FPointSeparator, FCommaSeparator: TFormatSettings;
+    Tokens: TSVGTokenList;
+    constructor Create;
+    Destructor Destroy; override;
+    procedure AddToken(AStr: string);
+    procedure TokenizePathString(AStr: string);
+  end;
+
+  { TvSVGVectorialReader }
+
+  TvSVGVectorialReader = class(TvCustomVectorialReader)
+  private
+    FPointSeparator, FCommaSeparator: TFormatSettings;
+    FSVGPathTokenizer: TSVGPathTokenizer;
+    procedure ReadPathFromNode(APath: TDOMNode; AData: TvVectorialDocument);
+    procedure ReadPathFromString(AStr: string; AData: TvVectorialDocument);
+  public
+    { General reading methods }
+    constructor Create; override;
+    Destructor Destroy; override;
+    procedure ReadFromStream(AStream: TStream; AData: TvVectorialDocument); override;
+  end;
+
+implementation
+
+const
+  // SVG requires hardcoding a DPI value
+
+  // The Opera Browser and Inkscape use 90 DPI, so we follow that
+
+  // 1 Inch = 25.4 milimiters
+  // 90 inches per pixel = (1 / 90) * 25.4 = 0.2822
+  // FLOAT_MILIMETERS_PER_PIXEL = 0.3528; // DPI 72 = 1 / 72 inches per pixel
+
+  FLOAT_MILIMETERS_PER_PIXEL = 0.2822; // DPI 90 = 1 / 90 inches per pixel
+  FLOAT_PIXELS_PER_MILIMETER = 3.5433; // DPI 90 = 1 / 90 inches per pixel
+
+{ TSVGPathTokenizer }
+
+constructor TSVGPathTokenizer.Create;
+begin
+  inherited Create;
+
+  FPointSeparator := DefaultFormatSettings;
+  FPointSeparator.DecimalSeparator := '.';
+  FPointSeparator.ThousandSeparator := '#';// disable the thousand separator
+
+  Tokens := TSVGTokenList.Create;
+end;
+
+destructor TSVGPathTokenizer.Destroy;
+begin
+  Tokens.Free;
+
+  inherited Destroy;
+end;
+
+procedure TSVGPathTokenizer.AddToken(AStr: string);
+var
+  lToken: TSVGToken;
+begin
+  lToken := TSVGToken.Create;
+
+  if AStr = 'm' then lToken.TokenType := sttMoveTo
+  else if AStr = 'l' then lToken.TokenType := sttLineTo
+  else if AStr = 'c' then lToken.TokenType := sttBezierTo
+  else
+  begin
+    lToken.TokenType := sttFloatValue;
+    lToken.Value := StrToFloat(AStr, FPointSeparator);
+    lToken.Value := lToken.Value * FLOAT_MILIMETERS_PER_PIXEL;
+  end;
+
+  Tokens.Add(lToken);
+end;
+
+procedure TSVGPathTokenizer.TokenizePathString(AStr: string);
+const
+  Str_Space: Char = ' ';
+  Str_Comma: Char = ',';
+var
+  i: Integer;
+  lTmpStr: string;
+  lState: Integer;
+  lCurChar: Char;
+begin
+  lState := 0;
+
+  i := 1;
+  while i <= Length(AStr) do
+  begin
+    case lState of
+    0: // Adding to the tmp string
+    begin
+      lCurChar := AStr[i];
+      if lCurChar = Str_Space then
+      begin
+        lState := 1;
+        AddToken(lTmpStr);
+        lTmpStr := '';
+      end
+      else if lCurChar = Str_Comma then
+      begin
+        AddToken(lTmpStr);
+        lTmpStr := '';
+      end
+      else
+        lTmpStr := lTmpStr + lCurChar;
+
+      Inc(i);
+    end;
+    1: // Removing spaces
+    begin
+      if AStr[i] <> Str_Space then lState := 0
+      else Inc(i);
+    end;
+    end;
+  end;
+end;
+
+{ Example of a supported SVG image:
+
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Created with fpVectorial (http://wiki.lazarus.freepascal.org/fpvectorial) -->
+
+<svg
+  xmlns:dc="http://purl.org/dc/elements/1.1/"
+  xmlns:cc="http://creativecommons.org/ns#"
+  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+  xmlns:svg="http://www.w3.org/2000/svg"
+  xmlns="http://www.w3.org/2000/svg"
+  xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+  width="100mm"
+  height="100mm"
+  id="svg2"
+  version="1.1"
+  sodipodi:docname="New document 1">
+  <g id="layer1">
+  <path
+    style="fill:none;stroke:#000000;stroke-width:10px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1"
+    d="m 0,283.486888731396 l 106.307583274274,-35.4358610914245 "
+  id="path0" />
+  <path
+    style="fill:none;stroke:#000000;stroke-width:10px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1"
+    d="m 0,354.358610914245 l 354.358610914245,0 l 0,-354.358610914245 l -354.358610914245,0 l 0,354.358610914245 "
+  id="path1" />
+  <path
+    style="fill:none;stroke:#000000;stroke-width:10px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1"
+    d="m 0,354.358610914245 l 35.4358610914245,-35.4358610914245 c 0,-35.4358610914246 35.4358610914245,-35.4358610914246 35.4358610914245,0 l 35.4358610914245,35.4358610914245 "
+  id="path2" />
+  </g>
+</svg>
+}
+
+{ TvSVGVectorialReader }
+
+procedure TvSVGVectorialReader.ReadPathFromNode(APath: TDOMNode;
+  AData: TvVectorialDocument);
+var
+  lNodeName, lStyleStr, lDStr: WideString;
+  i: Integer;
+begin
+  for i := 0 to APath.Attributes.Length - 1 do
+  begin
+    lNodeName := APath.Attributes.Item[i].NodeName;
+    if  lNodeName = 'style' then
+      lStyleStr := APath.Attributes.Item[i].NodeValue
+    else if lNodeName = 'd' then
+      lDStr := APath.Attributes.Item[i].NodeValue
+  end;
+
+  AData.StartPath();
+  ReadPathFromString(UTF8Encode(lDStr), AData);
+  AData.EndPath();
+end;
+
+procedure TvSVGVectorialReader.ReadPathFromString(AStr: string;
+  AData: TvVectorialDocument);
+var
+  i: Integer;
+  X, Y, CurX, CurY: Float;
+begin
+  FSVGPathTokenizer.Tokens.Clear;
+  FSVGPathTokenizer.TokenizePathString(AStr);
+  CurX := 0;
+  CurY := 0;
+
+  i := 0;
+  while i < FSVGPathTokenizer.Tokens.Count do
+  begin
+    if FSVGPathTokenizer.Tokens.Items[i].TokenType = sttMoveTo then
+    begin
+      CurX := FSVGPathTokenizer.Tokens.Items[i+1].Value;
+      CurY := FSVGPathTokenizer.Tokens.Items[i+2].Value;
+
+      AData.AddMoveToPath(CurX, CurY);
+
+      Inc(i, 3);
+    end
+    else if FSVGPathTokenizer.Tokens.Items[i].TokenType = sttLineTo then
+    begin
+      X := FSVGPathTokenizer.Tokens.Items[i+1].Value;
+      Y := FSVGPathTokenizer.Tokens.Items[i+2].Value;
+
+      // LineTo uses relative coordenates in SVG
+      CurX := CurX + X;
+      CurY := CurY + Y;
+
+      AData.AddLineToPath(CurX, CurY);
+
+      Inc(i, 3);
+    end
+    else
+    begin
+      Inc(i);
+    end;
+  end;
+end;
+
+constructor TvSVGVectorialReader.Create;
+begin
+  inherited Create;
+
+  FPointSeparator := DefaultFormatSettings;
+  FPointSeparator.DecimalSeparator := '.';
+  FPointSeparator.ThousandSeparator := '#';// disable the thousand separator
+
+  FSVGPathTokenizer := TSVGPathTokenizer.Create;
+end;
+
+destructor TvSVGVectorialReader.Destroy;
+begin
+  FSVGPathTokenizer.Free;
+
+  inherited Destroy;
+end;
+
+procedure TvSVGVectorialReader.ReadFromStream(AStream: TStream;
+  AData: TvVectorialDocument);
+var
+  Doc: TXMLDocument;
+  lFirstLayer, lCurNode: TDOMNode;
+begin
+  try
+    // Read in xml file from the stream
+    ReadXMLFile(Doc, AStream);
+
+    // Now process the elements inside the first layer
+    lFirstLayer := Doc.DocumentElement.FirstChild;
+    lCurNode := lFirstLayer.FirstChild;
+    while Assigned(lCurNode) do
+    begin
+      ReadPathFromNode(lCurNode, AData);
+      lCurNode := lCurNode.NextSibling;
+    end;
+  finally
+    // finally, free the document
+    Doc.Free;
+  end;
+end;
+
+initialization
+
+  RegisterVectorialReader(TvSVGVectorialReader, vfSVG);
+
+end.
+