icat: allow specifying image ids

kittens/icat/main.py

@@ -138,6 +138,14 @@ Whether to surround graphics commands with escape sequences that allow them to p
 programs like tmux. The default is to detect when running inside tmux and automatically use
 the tmux passthrough escape codes. Note that when this option is enabled it implies
 :option:`--unicode-placeholder` as well.
+
+
+--image-id
+type=int
+default=0
+The graphics protocol id to use for the created image. Normally, a random id is created if needed.
+This option allows control of the id. When multiple images are sent, sequential ids starting from the specified id
+are used. Valid ids are from 1 to 4294967295. Numbers outside this range are automatically wrapped.
 '''
 
 help_text = (

tools/cmd/icat/main.go

@@ -240,8 +240,16 @@ func main(cmd *cli.Command, o *Options, args []string) (rc int, err error) {
 	if passthrough_mode != no_passthrough {
 		use_unicode_placeholder = true
 	}
+	base_id := uint32(opts.ImageId)
 	for num_of_items > 0 {
 		imgd := <-output_channel
+		if base_id != 0 {
+			imgd.image_id = base_id
+			base_id++
+			if base_id == 0 {
+				base_id++
+			}
+		}
 		imgd.use_unicode_placeholder = use_unicode_placeholder
 		imgd.passthrough_mode = passthrough_mode
 		num_of_items--

tools/cmd/icat/transmit.go

@@ -313,6 +313,7 @@ func transmit_image(imgd *image_data) {
 	if f == nil {
 		f = transmit_stream
 	}
+	if imgd.image_id == 0 {
 		if imgd.use_unicode_placeholder {
 			for imgd.image_id&0xFF000000 == 0 || imgd.image_id&0x00FFFF00 == 0 {
 				// Generate a 32-bit image id using rejection sampling such that the most
@@ -329,6 +330,7 @@ func transmit_image(imgd *image_data) {
 				}
 			}
 		}
+	}
 	place_cursor(imgd)
 	if imgd.use_unicode_placeholder && utils.Max(imgd.width_cells, imgd.height_cells) >= len(images.NumberToDiacritic) {
 		imgd.err = fmt.Errorf("Image too large to be displayed using Unicode placeholders. Maximum size is %dx%d cells", len(images.NumberToDiacritic), len(images.NumberToDiacritic))