Start work on rendering with ImageMagick

tools/cmd/icat/magick.go

@@ -0,0 +1,13 @@
+// License: GPLv3 Copyright: 2023, Kovid Goyal, <kovid at kovidgoyal.net>
+
+package icat
+
+import (
+	"fmt"
+)
+
+var _ = fmt.Print
+
+func render_image_with_magick(imgd *image_data, src *opened_input) error {
+	return nil
+}

tools/cmd/icat/process_images.go

@@ -253,11 +253,14 @@ func process_arg(arg input_arg) {
 	c, format, err := image.DecodeConfig(f.file)
 	f.Rewind()
 	imgd := image_data{source_name: arg.value}
-	if err != nil {
+	if !keep_going.Load() {
-		report_error(arg.value, "Unknown image format", err)
 		return
 	}
-	if !keep_going.Load() {
+	if err != nil {
+		err = render_image_with_magick(&imgd, &f)
+		if err != nil {
+			report_error(arg.value, "ImageMagick failed", err)
+		}
 		return
 	}
 	imgd.canvas_width = c.Width