fix:opt atlas code.

packages/core/src/2d/sprite/Sprite.ts

@@ -64,12 +64,9 @@ export class Sprite extends RefObject {
 
   set atlasRegion(value: Rect) {
     const atlasRegion = this._atlasRegion;
-    atlasRegion.setValue(
-      MathUtil.clamp(value.x, 0, 1),
-      MathUtil.clamp(value.y, 0, 1),
-      MathUtil.clamp(value.width, 0, 1 - atlasRegion.x),
-      MathUtil.clamp(value.height, 0, 1 - atlasRegion.y)
-    );
+    const x = MathUtil.clamp(value.x, 0, 1);
+    const y = MathUtil.clamp(value.y, 0, 1);
+    atlasRegion.setValue(x, y, MathUtil.clamp(value.width, 0, 1 - x), MathUtil.clamp(value.height, 0, 1 - y));
     this._setDirtyFlagTrue(DirtyFlag.positions);
   }
 
@@ -106,12 +103,9 @@ export class Sprite extends RefObject {
 
   set region(value: Rect) {
     const region = this._region;
-    region.setValue(
-      MathUtil.clamp(value.x, 0, 1),
-      MathUtil.clamp(value.y, 0, 1),
-      MathUtil.clamp(value.width, 0, 1 - region.x),
-      MathUtil.clamp(value.height, 0, 1 - region.y)
-    );
+    const x = MathUtil.clamp(value.x, 0, 1);
+    const y = MathUtil.clamp(value.y, 0, 1);
+    region.setValue(x, y, MathUtil.clamp(value.width, 0, 1 - x), MathUtil.clamp(value.height, 0, 1 - y));
     this._setDirtyFlagTrue(DirtyFlag.positions | DirtyFlag.uv);
   }
 
@@ -182,24 +176,24 @@ export class Sprite extends RefObject {
 
       // Get the distance between the anchor point and the four sides.
       const lx = (-pivot.x + atlasRegionOffset.x) * unitWidth;
-      const ty = (-pivot.y + atlasRegionOffset.y) * unitHeight;
+      const by = (-pivot.y + atlasRegionOffset.y) * unitHeight;
       const rx = unitWidth + lx;
-      const by = unitHeight + ty;
+      const ty = unitHeight + by;
 
       // Assign values ​​to _positions
       const positions = this._positions;
       // Top-left.
-      positions[0].setValue(lx, by);
+      positions[0].setValue(lx, ty);
       // Top-right.
-      positions[1].setValue(rx, by);
+      positions[1].setValue(rx, ty);
       // Bottom-right.
-      positions[2].setValue(rx, ty);
+      positions[2].setValue(rx, by);
       // Bottom-left.
-      positions[3].setValue(lx, ty);
+      positions[3].setValue(lx, by);
 
       // Update bounds.
-      bounds.min.setValue(lx, ty, 0);
-      bounds.max.setValue(rx, by, 0);
+      bounds.min.setValue(lx, by, 0);
+      bounds.max.setValue(rx, ty, 0);
     } else {
       // Update bounds.
       bounds.min.setValue(0, 0, 0);
@@ -217,12 +211,11 @@ export class Sprite extends RefObject {
 
     if (this._isContainDirtyFlag(DirtyFlag.uv)) {
       const { _region: region, _atlasRegion: atlasRegion, _uv: uv } = this;
-      const realWidth = atlasRegion.width * region.width;
-      const realHeight = atlasRegion.height * region.height;
-      const left = atlasRegion.x + realWidth * region.x;
-      const top = atlasRegion.y + realHeight * region.y;
-      const right = left + realWidth;
-      const bottom = top + realHeight;
+      const { width: atlasRegionWidth, height: atlasRegionHeight } = atlasRegion;
+      const left = atlasRegion.x + atlasRegionWidth * region.x;
+      const top = atlasRegion.y + atlasRegionHeight * region.y;
+      const right = left + atlasRegionWidth * region.width;
+      const bottom = top + atlasRegionHeight * region.height;
 
       // Top-left.
       uv[0].setValue(left, top);

packages/loader/src/SpriteAtlasLoader.ts

@@ -51,16 +51,12 @@ class SpriteAtlasLoader extends Loader<SpriteAtlas> {
               for (let j = sprites.length - 1; j >= 0; j--) {
                 const atlasSprite = sprites[j];
                 const { region, pivot, atlasRegionOffset, atlasRegion } = atlasSprite;
-
-                tempRect.setValue(region.x, region.y, region.w, region.h);
-                tempPivot.setValue(pivot.x, pivot.y);
-
                 const sprite = new Sprite(
                   engine,
                   texture,
-                  tempRect,
-                  tempPivot,
-                  atlasSprite.pixelsPerUnit,
+                  region ? tempRect.setValue(region.x, region.y, region.w, region.h) : undefined,
+                  pivot ? tempPivot.setValue(pivot.x, pivot.y) : undefined,
+                  atlasSprite.pixelsPerUnit || undefined,
                   atlasSprite.name
                 );
                 sprite.atlasRegion.setValue(
@@ -69,7 +65,7 @@ class SpriteAtlasLoader extends Loader<SpriteAtlas> {
                   atlasRegion.w * sourceWidthReciprocal,
                   atlasRegion.h * sourceHeightReciprocal
                 );
-                sprite.atlasRegionOffset.setValue(atlasRegionOffset.x, atlasRegionOffset.y);
+                atlasRegionOffset && sprite.atlasRegionOffset.setValue(atlasRegionOffset.x, atlasRegionOffset.y);
                 /** @ts-ignore */
                 spriteAtlas._addSprite(sprite);
               }