image/jpeg: better pack APP0 structs

core/image/common.odin

@@ -610,19 +610,19 @@ JFIF_Unit :: enum byte {
 
 JFIF_APP0 :: struct {
 	version: u16be,
-	units: JFIF_Unit,
 	x_density: u16be,
 	y_density: u16be,
-	x_thumbnail: byte,
-	y_thumbnail: byte,
-	thumbnail: []RGB_Pixel `fmt:"-"`,
+	units: JFIF_Unit,
+	x_thumbnail: u8,
+	y_thumbnail: u8,
 	greyscale_thumbnail: bool,
+	thumbnail: []RGB_Pixel `fmt:"-"`,
 }
 
 JFXX_APP0 :: struct {
 	extension_code: JFXX_Extension_Code,
-	x_thumbnail: int,
-	y_thumbnail: int,
+	x_thumbnail: u8,
+	y_thumbnail: u8,
 	thumbnail: []byte `fmt:"-"`,
 }
 

core/image/jpeg/jpeg.odin

@@ -270,13 +270,13 @@ load_from_context :: proc(ctx: ^$C, options := Options{}, allocator := context.a
 							}
 							info.jfif_app0 = image.JFIF_APP0{
 								version,
-								units,
 								x_density,
 								y_density,
+								units,
 								cast(u8)x_thumbnail,
 								cast(u8)y_thumbnail,
-								thumbnail,
 								greyscale_thumbnail,
+								thumbnail,
 							}
 							img.metadata = info
 						}
@@ -330,8 +330,8 @@ load_from_context :: proc(ctx: ^$C, options := Options{}, allocator := context.a
 							}
 							info.jfxx_app0 = image.JFXX_APP0{
 								extension_code,
-								x_thumbnail,
-								y_thumbnail,
+								cast(u8)x_thumbnail,
+								cast(u8)y_thumbnail,
 								thumbnail,
 							}
 							img.metadata = info
@@ -359,8 +359,8 @@ load_from_context :: proc(ctx: ^$C, options := Options{}, allocator := context.a
 							}
 							info.jfxx_app0 = image.JFXX_APP0{
 								extension_code,
-								x_thumbnail,
-								y_thumbnail,
+								cast(u8)x_thumbnail,
+								cast(u8)y_thumbnail,
 								pixels,
 							}
 							img.metadata = info