FEAT: codecs/dds/size? function for resolving dds image size without need of decoding

Author: Oldes

src/mezz/codec-image-ext.reb

@@ -163,8 +163,17 @@ if find codecs 'gif [
 if find codecs 'bmp [
 	extend codecs/bmp 'size? function ["Return BMP image size or none" img [file! url! binary!]][
 		unless binary? img [img: read/binary/part img 32]
-		unless find/tail img #{424D} [return none]
+		unless find/match img #{424D} [return none]
 		try [return to pair! binary/read img [SKIP 18 UI32LE UI32LE]]
 		none
 	]
 ]
+
+if find codecs 'dds [
+	extend codecs/dds 'size? function ["Return DDS image size or none" img [file! url! binary!]][
+		unless binary? img [img: read/binary/part img 32]
+		unless find/match img #{444453207C000000} [return none]
+		try [return to pair! reverse binary/read img [SKIP 12 UI32LE UI32LE]]
+		none
+	]
+]

src/mezz/codec-image-win.reb

@@ -29,7 +29,7 @@ register-codec [
 
 	decode:   func [data [binary!]][lib/image/load/as data 'DDS]
 	encode:   func [data [image! ]][lib/image/save/as none data 'DDS]
-	identify: func [data [binary!]][parse data [#{444453} to end]]
+	identify: func [data [binary!]][parse data [#{444453207C000000} to end]]
 ]
 
 register-codec [

src/tests/units/codecs-test.r3

@@ -430,6 +430,14 @@ if find codecs 'BMP [
 	===end-group===
 ]
 
+if find codecs 'DDS [
+	===start-group=== "DDS codec"
+	--test-- "dds/size?"
+		--assert 256x256 = codecs/dds/size? %units/files/flower.dds
+		--assert none?     codecs/dds/size? %units/files/test.aar
+	===end-group===
+]
+
 if find codecs 'XML [
 	===start-group=== "XML codec"
 	--test-- "XML decode test1"