gnujpdf gradient transparency

2026-05-25 04:24:50 +00:00 · 2021-03-21 15:12:35 +01:00
parent cea421a54e
commit 5a4c9f34cc
4 changed files with 139 additions and 1 deletions
--- a/libsrc/gnujpdf/src/gnu/jpdf/PdfGradientShading.java
+++ b/libsrc/gnujpdf/src/gnu/jpdf/PdfGradientShading.java
@@ -0,0 +1,95 @@
+package gnu.jpdf;
+
+import java.awt.LinearGradientPaint;
+import java.awt.MultipleGradientPaint;
+import java.awt.RadialGradientPaint;
+import java.awt.geom.Point2D;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.text.DecimalFormat;
+import java.text.DecimalFormatSymbols;
+import java.util.Locale;
+
+/**
+ *
+ * @author JPEXS
+ */
+public class PdfGradientShading extends PDFObject {
+
+    private final MultipleGradientPaint fgrad;
+    private static final DecimalFormat matDf = new DecimalFormat("0", new DecimalFormatSymbols(Locale.ENGLISH));
+
+    static {
+        matDf.setMaximumFractionDigits(340);
+    }
+    private final double flen;
+    private final boolean useFunctionShading;
+    private final PDFObject function3;
+    private final PDFObject radialFunction;
+
+    public PdfGradientShading(MultipleGradientPaint fgrad,
+            double flen, boolean useFunctionShading, PDFObject function3,
+            PDFStream radialFunction) {
+        super(null);
+        this.fgrad = fgrad;
+        this.flen = flen;
+        this.useFunctionShading = useFunctionShading;
+        this.function3 = function3;
+        this.radialFunction = radialFunction;
+    }
+
+    @Override
+    public void write(OutputStream os) throws IOException {
+        writeStart(os);
+
+        if (fgrad instanceof LinearGradientPaint) {
+            LinearGradientPaint linGrad = (LinearGradientPaint) fgrad;
+
+            MyDoubleRect coords;
+
+            if (linGrad.getCycleMethod() == MultipleGradientPaint.CycleMethod.NO_CYCLE) {
+                Point2D startPointTrans = new Point2D.Double();
+                Point2D endPointTrans = new Point2D.Double();
+                startPointTrans = linGrad.getStartPoint();
+                endPointTrans = linGrad.getEndPoint();
+
+                coords = new MyDoubleRect(startPointTrans.getX(),
+                        startPointTrans.getY(),
+                        endPointTrans.getX(),
+                        endPointTrans.getY());
+
+            } else {
+                coords = new MyDoubleRect(0, 0, 0, flen);
+            }
+
+            os.write(("/ShadingType 2 /ColorSpace /DeviceRGB "
+                    + "/Coords [" + matDf.format(coords.xMin) + " " + matDf.format(coords.yMin) + " " + matDf.format(coords.xMax) + " " + matDf.format(coords.yMax) + "] "
+                    + "/Domain [0 1] "
+                    + "/Function " + function3.getSerialID() + " 0 R /Extend [true true]\n").getBytes());
+            writeEnd(os);
+        }
+        if (fgrad instanceof RadialGradientPaint) {
+
+            if (useFunctionShading) {
+                os.write("/ShadingType 1\n".getBytes());
+                os.write("/ColorSpace /DeviceRGB\n".getBytes());
+                os.write(("/Function " + radialFunction.getSerialID() + " 0 R\n").getBytes());
+            } else {
+                RadialGradientPaint radGrad = (RadialGradientPaint) fgrad;
+                os.write(("/ShadingType 3 /ColorSpace /DeviceRGB "
+                        + "/Coords ["
+                        + radGrad.getFocusPoint().getX() + " "
+                        + radGrad.getFocusPoint().getY() + " "
+                        + "0 "
+                        + radGrad.getCenterPoint().getX() + " "
+                        + radGrad.getCenterPoint().getY() + " "
+                        + radGrad.getRadius()
+                        + "] "
+                        + "/Domain [0 1] "
+                        + "/Function " + function3.getSerialID() + " 0 R /Extend [true true]\n").getBytes());
+            }
+            writeEnd(os);
+        }
+    }
+
+}