From f8626e3670734baf06c3274b6cd5d47ac3c5e147 Mon Sep 17 00:00:00 2001
From: hrj <harshad.rj@gmail.com>
Date: Sun, 3 Apr 2022 23:22:45 +0530
Subject: [PATCH] shadow text: adapt text to size dynamically

---
 src/main/java/lc/captchas/ShadowTextCaptcha.java | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/main/java/lc/captchas/ShadowTextCaptcha.java b/src/main/java/lc/captchas/ShadowTextCaptcha.java
index 16bbdc1..cdc314f 100644
--- a/src/main/java/lc/captchas/ShadowTextCaptcha.java
+++ b/src/main/java/lc/captchas/ShadowTextCaptcha.java
@@ -47,14 +47,18 @@ public class ShadowTextCaptcha implements ChallengeProvider {
 
   private byte[] shadowText(final int width, final int height, String text) {
     BufferedImage img = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
-    Font font = new Font("Arial", Font.ROMAN_BASELINE, 48);
+    final int fontHeight = (int) (height * 0.5f);
+    Font font = new Font("Arial", Font.PLAIN, fontHeight);
     Graphics2D graphics2D = img.createGraphics();
     HelperFunctions.setRenderingHints(graphics2D);
     graphics2D.setPaint(Color.WHITE);
     graphics2D.fillRect(0, 0, width, height);
     graphics2D.setPaint(Color.BLACK);
     graphics2D.setFont(font);
-    graphics2D.drawString(text, 15, 50);
+    final var stringWidth = graphics2D.getFontMetrics().stringWidth(text);
+    final var scaleX = (stringWidth > width) ? width/((double) stringWidth) : 1d;
+    graphics2D.scale(scaleX, 1d);
+    graphics2D.drawString(text, 0, fontHeight*1.1f);
     graphics2D.dispose();
     final int kernelSize = (int) Math.ceil((Math.min(width, height) / 50.0));
     ConvolveOp op = new ConvolveOp(new Kernel(kernelSize, kernelSize, makeKernel(kernelSize)), ConvolveOp.EDGE_NO_OP, null);
@@ -62,8 +66,9 @@ public class ShadowTextCaptcha implements ChallengeProvider {
     Graphics2D g2d = img2.createGraphics();
     HelperFunctions.setRenderingHints(g2d);
     g2d.setPaint(Color.WHITE);
+    g2d.scale(scaleX, 1d);
     g2d.setFont(font);
-    g2d.drawString(text, 13, 50);
+    g2d.drawString(text, -kernelSize, fontHeight*1.1f);
     g2d.dispose();
     ByteArrayOutputStream baos = new ByteArrayOutputStream();
     try {