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Use FontMatrix of Type3 font during text chunks parsing #733

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Merged
MaximPlusov merged 1 commit into from
Jun 17, 2026
Merged

Use FontMatrix of Type3 font during text chunks parsing #733

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17 changes: 9 additions & 8 deletions wcag-validation/src/main/java/org/verapdf/gf/model/factory/chunks/ChunkParser.java
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Original file line number Diff line number Diff line change
Expand Up @@ -827,18 +827,18 @@ private void putChunk(Long mcid, IChunk chunk) {
}
}

private TextPieces parseTextShowArgument(COSBase argument) {
private TextPieces parseTextShowArgument(COSBase argument, double horizontalScalingFactor) {
TextPieces textPieces = new TextPieces();
if (argument.getType() == COSObjType.COS_STRING) {
parseString((COSString) argument.getDirectBase(), textPieces);
parseString((COSString) argument.getDirectBase(), textPieces, horizontalScalingFactor);
} else if (argument.getType() == COSObjType.COS_ARRAY) {
COSArray array = (COSArray) argument;
for (COSObject obj : array) {
if (obj != null) {
if (obj.getType() == COSObjType.COS_STRING) {
parseString((COSString) obj.getDirectBase(), textPieces);
parseString((COSString) obj.getDirectBase(), textPieces, horizontalScalingFactor);
} else if (obj.getType().isNumber()) {
double shift = - obj.getReal() / 1000 *
double shift = - obj.getReal() * horizontalScalingFactor *
graphicsState.getTextState().getTextFontSize() *
graphicsState.getTextState().getHorizontalScaling();
textPieces.shiftCurrentX(shift);
Expand All @@ -853,7 +853,7 @@ private TextPieces parseTextShowArgument(COSBase argument) {
return textPieces;
}

private void parseString(COSString string, TextPieces textPieces) {
private void parseString(COSString string, TextPieces textPieces, double horizontalScalingFactor) {
byte[] bytes = string.get();
try (InputStream inputStream = new ByteArrayInputStream(bytes)) {
while (inputStream.available() > 0) {
Expand All @@ -868,7 +868,7 @@ private void parseString(COSString string, TextPieces textPieces) {
graphicsState.getTextState().getWordSpacing() : 0)) *
graphicsState.getTextState().getHorizontalScaling();
width = width *
graphicsState.getTextState().getTextFontSize() / 1000 *
graphicsState.getTextState().getTextFontSize() * horizontalScalingFactor *
graphicsState.getTextState().getHorizontalScaling();
String value = graphicsState.getTextState().getTextFont().toUnicode(code);
String result = value;
Expand All @@ -892,7 +892,8 @@ private TextChunk createTextChunk(List<COSBase> arguments, String operatorType,
COSBase argument = TextChunksHelper.getArgument(arguments, operatorType);
if (font != null && argument != null && (argument.getType() == COSObjType.COS_STRING ||
argument.getType() == COSObjType.COS_ARRAY) && this.textMatrix != null) {
TextPieces textPieces = parseTextShowArgument(argument);
double horizontalScalingFactor = TextChunksHelper.getHorizontalScalingFactor(font);
TextPieces textPieces = parseTextShowArgument(argument, horizontalScalingFactor);
if (textPieces.isEmpty()) {
textMatrix.concatenate(Matrix.getTranslateInstance(textPieces.getCurrentX(), 0));
return null;
Expand All @@ -905,7 +906,7 @@ private TextChunk createTextChunk(List<COSBase> arguments, String operatorType,
PDFontDescriptor descriptor = font.getFontDescriptor();
String fontNameWithoutSubset = font.getNameWithoutSubset();
TextChunk textChunk = new TextChunk(TextChunksHelper.calculateTextBoundingBox(textRenderingMatrixBefore,
textRenderingMatrixAfter, font, pageNumber), textPieces.getValue(),
textRenderingMatrixAfter, font, pageNumber, horizontalScalingFactor), textPieces.getValue(),
fontNameWithoutSubset, TextChunksHelper.calculateTextSize(textRenderingMatrixAfter),
TextChunksHelper.calculateFontWeight(graphicsState.getTextState().getRenderingMode(), font),
descriptor.getItalicAngle(), TextChunksHelper.calculateTextBaseLine(textRenderingMatrixAfter),
Expand Down
56 changes: 39 additions & 17 deletions wcag-validation/src/main/java/org/verapdf/gf/model/factory/chunks/TextChunksHelper.java
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Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,7 @@
import org.verapdf.cos.COSBase;
import org.verapdf.model.tools.constants.Operators;
import org.verapdf.pd.font.PDFont;
import org.verapdf.pd.font.type3.PDType3Font;
import org.verapdf.wcag.algorithms.entities.geometry.BoundingBox;
import org.verapdf.wcag.algorithms.semanticalgorithms.utils.NodeUtils;

Expand All @@ -45,7 +46,7 @@ protected static COSBase getArgument(List<COSBase> arguments, String operatorTyp
}

protected static BoundingBox calculateTextBoundingBox(Matrix textRenderingMatrixBefore, Matrix textRenderingMatrixAfter,
PDFont font, Integer pageNumber) {
PDFont font, Integer pageNumber, double horizontalScalingFactor) {
double[] fontBoundingBox = font.getBoundingBox();
Double descent = font.getDescent();
if (descent == null) {
Expand All @@ -55,38 +56,59 @@ protected static BoundingBox calculateTextBoundingBox(Matrix textRenderingMatrix
if (ascent == null) {
ascent = fontBoundingBox[3];
}
double verticalScalingFactor = TextChunksHelper.getVerticalScalingFactor(font);
double x1;
double x2;
if (textRenderingMatrixBefore.getScaleX() >= 0 && textRenderingMatrixBefore.getShearX() >= 0) {
x1 = textRenderingMatrixBefore.getTranslateX() + descent * textRenderingMatrixBefore.getShearX() / 1000;
x2 = textRenderingMatrixAfter.getTranslateX() + ascent * textRenderingMatrixAfter.getShearX() / 1000;
x1 = textRenderingMatrixBefore.getTranslateX() + descent * textRenderingMatrixBefore.getShearX() * horizontalScalingFactor;
x2 = textRenderingMatrixAfter.getTranslateX() + ascent * textRenderingMatrixAfter.getShearX() * horizontalScalingFactor;
} else if (textRenderingMatrixBefore.getScaleX() < 0 && textRenderingMatrixBefore.getShearX() < 0) {
x1 = textRenderingMatrixAfter.getTranslateX() + ascent * textRenderingMatrixAfter.getShearX() / 1000;
x2 = textRenderingMatrixBefore.getTranslateX() + descent * textRenderingMatrixBefore.getShearX() / 1000;
x1 = textRenderingMatrixAfter.getTranslateX() + ascent * textRenderingMatrixAfter.getShearX() * horizontalScalingFactor;
x2 = textRenderingMatrixBefore.getTranslateX() + descent * textRenderingMatrixBefore.getShearX() * horizontalScalingFactor;
} else if (textRenderingMatrixBefore.getScaleX() >= 0) {
x1 = textRenderingMatrixBefore.getTranslateX() + ascent * textRenderingMatrixBefore.getShearX() / 1000;
x2 = textRenderingMatrixAfter.getTranslateX() + descent * textRenderingMatrixAfter.getShearX() / 1000;
x1 = textRenderingMatrixBefore.getTranslateX() + ascent * textRenderingMatrixBefore.getShearX() * horizontalScalingFactor;
x2 = textRenderingMatrixAfter.getTranslateX() + descent * textRenderingMatrixAfter.getShearX() * horizontalScalingFactor;
} else {
x1 = textRenderingMatrixAfter.getTranslateX() + descent * textRenderingMatrixAfter.getShearX() / 1000;
x2 = textRenderingMatrixBefore.getTranslateX() + ascent * textRenderingMatrixBefore.getShearX() / 1000;
x1 = textRenderingMatrixAfter.getTranslateX() + descent * textRenderingMatrixAfter.getShearX() * horizontalScalingFactor;
x2 = textRenderingMatrixBefore.getTranslateX() + ascent * textRenderingMatrixBefore.getShearX() * horizontalScalingFactor;
}
double y1;
double y2;
if (textRenderingMatrixBefore.getScaleY() >= 0 && textRenderingMatrixBefore.getShearY() >= 0) {
y1 = textRenderingMatrixBefore.getTranslateY() + descent * textRenderingMatrixBefore.getScaleY() / 1000;
y2 = textRenderingMatrixAfter.getTranslateY() + ascent * textRenderingMatrixAfter.getScaleY() / 1000;
y1 = textRenderingMatrixBefore.getTranslateY() + descent * textRenderingMatrixBefore.getScaleY() * verticalScalingFactor;
y2 = textRenderingMatrixAfter.getTranslateY() + ascent * textRenderingMatrixAfter.getScaleY() * verticalScalingFactor;
} else if (textRenderingMatrixBefore.getScaleY() < 0 && textRenderingMatrixBefore.getShearY() < 0) {
y1 = textRenderingMatrixAfter.getTranslateY() + ascent * textRenderingMatrixAfter.getScaleY() / 1000;
y2 = textRenderingMatrixBefore.getTranslateY() + descent * textRenderingMatrixBefore.getScaleY() / 1000;
y1 = textRenderingMatrixAfter.getTranslateY() + ascent * textRenderingMatrixAfter.getScaleY() * verticalScalingFactor;
y2 = textRenderingMatrixBefore.getTranslateY() + descent * textRenderingMatrixBefore.getScaleY() * verticalScalingFactor;
} else if (textRenderingMatrixBefore.getScaleY() >= 0) {
y1 = textRenderingMatrixAfter.getTranslateY() + descent * textRenderingMatrixAfter.getScaleY() / 1000;
y2 = textRenderingMatrixBefore.getTranslateY() + ascent * textRenderingMatrixBefore.getScaleY() / 1000;
y1 = textRenderingMatrixAfter.getTranslateY() + descent * textRenderingMatrixAfter.getScaleY() * verticalScalingFactor;
y2 = textRenderingMatrixBefore.getTranslateY() + ascent * textRenderingMatrixBefore.getScaleY() * verticalScalingFactor;
} else {
y1 = textRenderingMatrixBefore.getTranslateY() + ascent * textRenderingMatrixBefore.getScaleY() / 1000;
y2 = textRenderingMatrixAfter.getTranslateY() + descent * textRenderingMatrixAfter.getScaleY() / 1000;
y1 = textRenderingMatrixBefore.getTranslateY() + ascent * textRenderingMatrixBefore.getScaleY() * verticalScalingFactor;
y2 = textRenderingMatrixAfter.getTranslateY() + descent * textRenderingMatrixAfter.getScaleY() * verticalScalingFactor;
}
return new BoundingBox(pageNumber, x1, y1, x2, y2);
}

public static double getHorizontalScalingFactor(PDFont font) {
if (font instanceof PDType3Font) {
double[] fontMatrix = ((PDType3Font) font).getFontMatrix();
if (fontMatrix != null && fontMatrix.length > 0 && fontMatrix[0] != 0.0) {
return fontMatrix[0];
}
}
return 1.0 / 1000.0;
}

public static double getVerticalScalingFactor(PDFont font) {
if (font instanceof PDType3Font) {
double[] fontMatrix = ((PDType3Font) font).getFontMatrix();
if (fontMatrix != null && fontMatrix.length > 3 && fontMatrix[3] != 0.0) {
return fontMatrix[3];
}
}
return 1.0 / 1000.0;
}

protected static double calculateTextBaseLine(Matrix textMatrix) {
double rotationDegree = textMatrix.getRotationDegree();
Expand Down
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