update example

common/nori/export.go

@@ -38,14 +38,18 @@ func (n *Nori) ExportAnimation(num int) (*apng.APNG, error) {
 	for _, frame := range n.Animations[num].Frames {
 		planes := frame.Planes
 		var canvasRect image.Rectangle
-		for _, plane := range planes {
+		for i, plane := range planes {
 			if int(plane.BitmapId) >= len(n.Gawi.Images) {
 				log.Printf("could not find bitmap %d, only have %d", plane.BitmapId, len(n.Gawi.Images))
 			}
 			bitmap := n.Gawi.Images[plane.BitmapId]
 			pt := image.Pt(int(plane.PlaneX), int(plane.PlaneY)) // where to put the point
-			rc := bitmap.Img.Bounds()
-			canvasRect = canvasRect.Union(rc.Add(pt))
+			rc := bitmap.Img.Bounds().Add(pt)                    // translate rectangle to put in the global canvas
+			if i == 0 {
+				canvasRect = rc
+			} else {
+				canvasRect = canvasRect.Union(rc)
+			}
 		}
 		img := image.NewNRGBA64(canvasRect)
 		for _, plane := range planes {
@@ -63,9 +67,8 @@ func (n *Nori) ExportAnimation(num int) (*apng.APNG, error) {
 			}
 			_ = transparent
 			pt := image.Pt(int(plane.PlaneX), int(plane.PlaneY)) // where to put the point
+			rc := bitmap.Img.Bounds().Add(pt)
 			src := bitmap.Img
-			sr := src.Bounds()
-			r := image.Rectangle{pt, pt.Add(sr.Size())}
 			switch plane.Blend {
 			case BlendMode_Alpha:
 			case BlendMode_Mul, BlendMode_Mul7:
@@ -78,10 +81,11 @@ func (n *Nori) ExportAnimation(num int) (*apng.APNG, error) {
 			default:
 				return nil, fmt.Errorf("unknown blend mode: %d", plane.Blend)
 			}
-			draw.Draw(img,
-				r,
+			draw.Draw(
+				img,
+				rc,
 				src,
-				sr.Min,
+				src.Bounds().Min,
 				draw.Src,
 			)
 		}
@@ -95,12 +99,14 @@ func (n *Nori) ExportAnimation(num int) (*apng.APNG, error) {
 		return nil, fmt.Errorf("no frames found for animation")
 	}
 	for i, realFrame := range images {
+		log.Info().Int("frame", num).Interface("rect", or).Interface("frame", realFrame.Bounds()).Msg("")
+		src := realFrame
 		big := image.NewNRGBA64(or)
 		draw.Draw(
 			big,
-			big.Rect,
-			realFrame,
-			realFrame.Bounds().Min,
+			src.Bounds(),
+			src,
+			src.Bounds().Min,
 			draw.Src,
 		)
 		fr := apng.Frame{
@@ -112,6 +118,5 @@ func (n *Nori) ExportAnimation(num int) (*apng.APNG, error) {
 		}
 		a.Frames = append(a.Frames, fr)
 	}
-	log.Println(num, len(a.Frames))
 	return a, nil
 }

common/nori/nori_test.go

@@ -75,7 +75,7 @@ func writeApng(nori *Nori, name string) error {
 		if err != nil {
 			return err
 		}
-		err = os.WriteFile(fmt.Sprintf("./nori_test/%s%s/animation_%d.apng", name, postfix, i), out.Bytes(), 0740)
+		err = os.WriteFile(fmt.Sprintf("./nori_test/%s%s/animation_%d.png", name, postfix, i), out.Bytes(), 0740)
 		if err != nil {
 			return err
 		}