fix: maxWidth overflow paint_x position should power the scale ratio (#…

…603)

__test__/regression.spec.ts

@@ -1,10 +1,10 @@
 import { promises as fs } from 'fs'
+import { join } from 'path'
 
 import test from 'ava'
 
-import { createCanvas, loadImage } from '../index'
+import { createCanvas, loadImage, GlobalFonts } from '../index'
 import { snapshotImage } from './image-snapshot'
-import { join } from 'path'
 
 test('transform-with-state', async (t) => {
   const canvas = createCanvas(256, 256)
@@ -104,3 +104,23 @@ test('global-alpha-should-effect-drawImage', async (t) => {
   ctx.drawImage(await loadImage(image), 0, 0, 200, 100)
   await snapshotImage(t, { ctx, canvas }, 'png', 1)
 })
+
+test('draw-text-maxWidth', async (t) => {
+  GlobalFonts.registerFromPath(join(__dirname, 'fonts', 'iosevka-slab-regular.ttf'))
+  const canvas = createCanvas(150, 150)
+  const ctx = canvas.getContext('2d')
+  const pad = 10 // padding
+  ctx.textBaseline = 'top'
+  ctx.font = '50px Iosevka Slab'
+
+  ctx.fillRect(0, 0, canvas.width, canvas.height)
+
+  ctx.fillStyle = 'blue'
+  ctx.fillRect(pad, pad, canvas.width - pad * 2, canvas.height - pad * 2)
+
+  const maxWidth = canvas.width - pad * 2
+  ctx.fillStyle = 'white'
+  ctx.fillText('Short text', pad, 10, maxWidth)
+  ctx.fillText(`Very ${'long '.repeat(2)} text`, pad, 80, maxWidth)
+  await snapshotImage(t, { ctx, canvas })
+})

skia-c/skia_c.cpp

@@ -511,13 +511,14 @@ extern "C"
         break;
       };
       auto need_scale = line_width > max_width;
+      float ratio = need_scale ? max_width / line_width : 1.0;
       if (need_scale)
       {
         CANVAS_CAST->save();
-        CANVAS_CAST->scale(max_width / line_width, 1.0);
+        CANVAS_CAST->scale(ratio, 1.0);
       }
       auto paint_y = y + baseline_offset;
-      paragraph->paint(CANVAS_CAST, paint_x, paint_y);
+      paragraph->paint(CANVAS_CAST, need_scale ? paint_x / ratio : paint_x, paint_y);
       if (need_scale)
       {
         CANVAS_CAST->restore();