src/main/java/org/saturnclient/ui/RenderScope.java

@@ -3,6 +3,7 @@ package org.saturnclient.ui;
 import java.io.ByteArrayInputStream;
 import java.io.InputStream;
 import java.nio.charset.StandardCharsets;
+import java.util.Locale;
 
 import org.saturnclient.common.ref.asset.IdentifierRef;
 import org.saturnclient.common.ref.asset.SpriteRef;
@@ -36,19 +37,66 @@ public interface RenderScope {
         radius = Math.min(radius, width / 2);
         radius = Math.min(radius, height / 2);
 
-        String svg = String.format(
+        String rect = String.format(
-                "<svg xmlns='http://www.w3.org/2000/svg' width='%d' height='%d'>" +
+                "<rect width='%d' height='%d' rx='%d' ry='%d' fill='white'/>",
-                        "<rect width='%d' height='%d' rx='%d' ry='%d' fill='white'/>" +
-                        "</svg>",
-                width, height,
                 width, height,
                 radius, radius);
 
+        drawSvgShape(rect, "rounded_" + width + "_" + height + "_" + radius, x, y, width, height, color);
+    }
+
+    /**
+     * Draws a rounded outline that stays inside the given bounds, so it lines up
+     * with a {@link #drawRoundedRectangle} of the same size and radius.
+     */
+    default void drawRoundedBorder(int x, int y, int width, int height, int radius, int thickness, int color) {
+        if (color == 0 || thickness <= 0)
+            return;
+
+        radius = Math.min(radius, width / 2);
+        radius = Math.min(radius, height / 2);
+        thickness = Math.min(thickness, Math.min(width, height) / 2);
+
+        // The stroke is centered on the path, so inset it by half its width.
+        float inset = thickness / 2f;
+        float innerRadius = Math.max(0, radius - inset);
+
+        String rect = String.format(Locale.ROOT,
+                "<rect x='%.1f' y='%.1f' width='%.1f' height='%.1f' rx='%.1f' ry='%.1f' " +
+                        "fill='none' stroke='white' stroke-width='%d'/>",
+                inset, inset,
+                width - (float) thickness, height - (float) thickness,
+                innerRadius, innerRadius,
+                thickness);
+
+        drawSvgShape(rect, "rounded_border_" + width + "_" + height + "_" + radius + "_" + thickness,
+                x, y, width, height, color);
+    }
+
+    /**
+     * Draws a rounded rectangle filled with {@code background} and outlined with
+     * {@code border}. Either color can be 0 to skip that part.
+     */
+    default void drawRoundedRectangle(int x, int y, int width, int height, int radius, int thickness,
+            int background, int border) {
+        drawRoundedRectangle(x, y, width, height, radius, background);
+        drawRoundedBorder(x, y, width, height, radius, thickness, border);
+    }
+
+    /**
+     * Renders {@code shape} (SVG elements in a {@code width} x {@code height}
+     * canvas, drawn in white) to a cached texture and draws it tinted with
+     * {@code color}.
+     */
+    private void drawSvgShape(String shape, String cacheKey, int x, int y, int width, int height, int color) {
+        String svg = String.format(
+                "<svg xmlns='http://www.w3.org/2000/svg' width='%d' height='%d'>%s</svg>",
+                width, height, shape);
+
         InputStream svgStream = new ByteArrayInputStream(svg.getBytes(StandardCharsets.UTF_8));
 
         drawTexture(SvgTexture.getSvg(svgStream,
-                IdentifierRef.ofSaturn(
+                IdentifierRef.ofSaturn("textures/gui/tmp_rect/" + cacheKey),
-                        "textures/gui/tmp_rect/rounded_" + width + "_" + height + "_" + radius),
                 width * 4, height * 4), x, y, 0, 0, width, height, color);
     }