Fixed the bug of incorrect calculation of page height when resize gif…

… with vscale (#386)

Signed-off-by: songjiayang <[email protected]>

vips/arithmetic.go

@@ -40,7 +40,7 @@ func vipsDivide(left *C.VipsImage, right *C.VipsImage) (*C.VipsImage, error) {
 	return out, nil
 }
 
-//  https://libvips.github.io/libvips/API/current/libvips-arithmetic.html#vips-linear
+// https://libvips.github.io/libvips/API/current/libvips-arithmetic.html#vips-linear
 func vipsLinear(in *C.VipsImage, a, b []float64, n int) (*C.VipsImage, error) {
 	incOpCounter("linear")
 	var out *C.VipsImage
@@ -52,7 +52,7 @@ func vipsLinear(in *C.VipsImage, a, b []float64, n int) (*C.VipsImage, error) {
 	return out, nil
 }
 
-//  https://libvips.github.io/libvips/API/current/libvips-arithmetic.html#vips-linear1
+// https://libvips.github.io/libvips/API/current/libvips-arithmetic.html#vips-linear1
 func vipsLinear1(in *C.VipsImage, a, b float64) (*C.VipsImage, error) {
 	incOpCounter("linear1")
 	var out *C.VipsImage

vips/color.go

@@ -43,7 +43,7 @@ const (
 // Intent represents VIPS_INTENT type
 type Intent int
 
-//Intent enum
+// Intent enum
 const (
 	IntentPerceptual Intent = C.VIPS_INTENT_PERCEPTUAL
 	IntentRelative   Intent = C.VIPS_INTENT_RELATIVE

vips/image.go

@@ -1662,7 +1662,7 @@ func (r *ImageRef) ResizeWithVScale(hScale, vScale float64, kernel Kernel) error
 		if vScale != -1 {
 			scale = vScale
 		}
-		newPageHeight := int(float64(pageHeight) * scale)
+		newPageHeight := int(float64(pageHeight)*scale + 0.5)
 		if err := r.SetPageHeight(newPageHeight); err != nil {
 			return err
 		}

vips/image_gif_test.go

@@ -50,6 +50,19 @@ func TestImage_GIF_Animated_Resize(t *testing.T) {
 		nil)
 }
 
+func TestImage_GIF_Animated_ResizeWithVScale(t *testing.T) {
+	goldenAnimatedTest(t, resources+"gif-animated.gif",
+		3,
+		func(img *ImageRef) error {
+			return img.ResizeWithVScale(0.5, 0.78, KernelCubic)
+		},
+		func(img *ImageRef) {
+			assert.Equal(t, 3, img.Pages())
+			assert.Equal(t, 100, img.GetPageHeight())
+		},
+		nil)
+}
+
 func TestImage_GIF_Animated_Rotate90(t *testing.T) {
 	goldenAnimatedTest(t, resources+"gif-animated.gif",
 		-1,

vips/logging.go

@@ -33,6 +33,7 @@ var (
 // and called by glib and libvips for each logging message. It will call govipsLog
 // which in turn will filter based on verbosity and direct the messages to the
 // currently chosen LoggingHandlerFunction.
+//
 //export govipsLoggingHandler
 func govipsLoggingHandler(messageDomain *C.char, messageLevel C.int, message *C.char) {
 	govipsLog(C.GoString(messageDomain), LogLevel(messageLevel), C.GoString(message))