add rounded rectangle

README.md

@@ -3,6 +3,10 @@
 This version is forked from [Hopding/pdf-lib](https://github.com/Hopding/pdf-lib).  
 Incorporated several bug fixes and additional features into the original code.
 
+ <details>
+  <summary><a href="https://github.com/pdfme/pdf-lib/pull/9">2025/03/09 - Add `radius` option for drawRectangle. This enables to render rounded corner rectangles</a></summary>
+Draw rounded corners with the specified radius using the Bezier curve function. The radius must be a positive number. If it exceeds half of the width or height, it will be clipped.
+</details>
  <details>
   <summary><a href="https://github.com/cantoo-scribe/pdf-lib/pull/42">2023/12/22 - Incorporate @cantoo/pdf-lib Refactor drawSvg PR</a></summary>
 

apps/web/test9.html

@@ -98,6 +98,7 @@
           color: solarizedWhite,
           borderColor: solarizedGray,
           borderWidth: 3,
+          radius: 10.0,
         });
         page.setFont(ubuntuFont);
         page.setFontColor(solarizedGray);

src/api/PDFPage.ts

@@ -1354,6 +1354,7 @@ export default class PDFPage {
    *   color: rgb(0.75, 0.2, 0.2),
    *   opacity: 0.5,
    *   borderOpacity: 0.75,
+   *   radius: 0.1,
    * })
    * ```
    * @param options The options to be used when drawing the rectangle.
@@ -1390,6 +1391,7 @@ export default class PDFPage {
       1,
     );
     assertIsOneOfOrUndefined(options.blendMode, 'options.blendMode', BlendMode);
+    assertOrUndefined(options.radius, 'options.radius', ['number']);
 
     const graphicsStateKey = this.maybeEmbedGraphicsState({
       opacity: options.opacity,
@@ -1420,6 +1422,7 @@ export default class PDFPage {
         borderLineCap: options.borderLineCap ?? undefined,
         matrix: options.matrix,
         clipSpaces: options.clipSpaces,
+        radius: options.radius ?? 0,
       }),
     );
   }

src/api/PDFPageOptions.ts

@@ -112,6 +112,7 @@ export interface PDFPageDrawRectangleOptions extends SvgOptions {
   borderDashPhase?: number;
   borderLineCap?: LineCapStyle;
   blendMode?: BlendMode;
+  radius?: number;
 }
 
 export interface PDFPageDrawSquareOptions extends SvgOptions {

src/api/operations.ts

@@ -225,7 +225,41 @@ export const drawRectangle = (options: {
   graphicsState?: string | PDFName;
   matrix?: TransformationMatrix;
   clipSpaces?: Space[];
-}) => [
+  radius?: number | PDFNumber;
+}) => {
+  let ops = [];
+
+  if (!options.radius || asNumber(options.radius) <= 0) {
+    ops = [
+      moveTo(0, 0),
+      lineTo(0, options.height),
+      lineTo(options.width, options.height),
+      lineTo(options.width, 0),
+      closePath(),
+    ];
+  } else {
+    let radius = asNumber(options.radius);
+    const width = asNumber(options.width);
+    const height = asNumber(options.height);
+
+    if (radius > width / 2.0 || radius > height / 2.0) {
+      radius = Math.min(width / 2.0, height / 2.0);
+    }
+    const offset = KAPPA * radius;
+    ops = [
+      moveTo(0, radius),
+      appendBezierCurve(0, radius - offset, radius - offset, 0, radius, 0),
+      lineTo(width - radius, 0),
+      appendBezierCurve(width - radius + offset, 0, width, radius - offset, width, radius),
+      lineTo(width, height - radius),
+      appendBezierCurve(width, height - radius + offset, width - radius + offset, height, width - radius, height),
+      lineTo(radius, height),
+      appendBezierCurve(radius - offset, height, 0, height - radius + offset, 0, height - radius),
+      closePath(),
+    ];
+  }
+
+  return [
     pushGraphicsState(),
     options.graphicsState && setGraphicsState(options.graphicsState),
     options.color && setFillingColor(options.color),
@@ -238,11 +272,8 @@ export const drawRectangle = (options: {
     translate(options.x, options.y),
     rotateRadians(toRadians(options.rotate)),
     skewRadians(toRadians(options.xSkew), toRadians(options.ySkew)),
-    moveTo(0, 0),
-    lineTo(0, options.height),
-    lineTo(options.width, options.height),
-    lineTo(options.width, 0),
-    closePath(),
+
+    ...ops,
 
     // prettier-ignore
     options.color && options.borderWidth ? fillAndStroke()
@@ -252,6 +283,7 @@ export const drawRectangle = (options: {
 
     popGraphicsState(),
   ].filter(Boolean) as PDFOperator[];
+}
 
 const KAPPA = 4.0 * ((Math.sqrt(2) - 1.0) / 3.0);