Improve handling of supported image formats and file extensions, Update README with more information about supported formats

README.md

@@ -24,6 +24,15 @@ You can find the latest release ...
 - [here (remotebranch.eu)](https://remotebranch.eu/ChaoticByte/Pigment/releases/latest)
 
 
+## Supported Image Formats
+
+| Format | Import | Export | Notes |
+| ------ | :----: | :----: | ----- |
+| PNG    | ✔      | ✔      | exports to 8-bit RGBA |
+| JPEG   | ✔      |        |       |
+| WEBP   | ✔      |        |       |
+
+
 ## Usage
 
 With Pigment, you process images by writing Shader code using Godot's GLSL dialect: GDShader.  

src/Filesystem.gd

@@ -1,5 +1,9 @@
 extends Node
 
+const SUPPORTED_INPUT_EXT = [
+	".jpeg", ".jpg", ".png", ".webp"
+]
+
 var cwd = "."
 
 var shader_path = "":
@@ -31,16 +35,22 @@ func get_absolute_path(p: String) -> String:
 	return p
 
 func load_image() -> String: # returns an error message
-	print("Load ", input_image_path)
+	var supported = false
+	for e in SUPPORTED_INPUT_EXT:
+		if self.input_image_path.ends_with(e):
+			supported = true
+	if not supported:
+		return "File extension not supported."
+	print("Load ", self.input_image_path)
 	var img = Image.new()
-	var err = img.load(input_image_path)
+	var err = img.load(self.input_image_path)
 	if err == OK:
 		input_image_texture = ImageTexture.create_from_image(img)
-		if self.last_image_savepath == "" or input_image_path != self.last_input_image_path:
-			self.last_image_savepath = input_image_path
-		self.last_input_image_path = input_image_path
+		if self.last_image_savepath == "" or self.input_image_path != self.last_input_image_path:
+			self.last_image_savepath = self.input_image_path
+		self.last_input_image_path = self.input_image_path
 		return ""
-	return error_string(err) + " " + input_image_path
+	return error_string(err) + " " + self.input_image_path
 
 func save_result(path: String):
 	print("Export ", path)

src/Main.gd

@@ -1,9 +1,5 @@
 extends Node
 
-const BATCH_MODE_SUPPORTED_EXTS = [
-	".bmp", ".dds", ".exr", ".hdr", ".jpeg", ".jpg", ".ktx", ".png", ".svg", ".webp"
-]
-
 @onready var app_name = ProjectSettings.get_setting("application/config/name")
 
 func show_help():
@@ -75,7 +71,7 @@ func cli(args: PackedStringArray):
 		var out_dir_path: String = kwargs["--output"].rstrip("/")
 		for f in load_image_dir.get_files():
 			var supported = false
-			for e in BATCH_MODE_SUPPORTED_EXTS:
+			for e in Filesystem.SUPPORTED_INPUT_EXT:
 				if f.ends_with(e):
 					supported = true
 					break

src/MainUI.gd

@@ -26,7 +26,7 @@ enum Status {OKAY, ERROR, UNKNOWN = -1}
 
 func _ready() -> void:
 	var exts = []
-	for e in main.BATCH_MODE_SUPPORTED_EXTS:
+	for e in Filesystem.SUPPORTED_INPUT_EXT:
 		exts.append("*" + e)
 	open_image_dialog.add_filter(", ".join(exts), "Image")
 	open_shader_dialog.add_filter("*.gdshader", "Shader")
@@ -74,7 +74,10 @@ func _on_apply_shader_button_pressed():
 func _on_save_image_button_pressed():
 	if Filesystem.result != null:
 		set_buttons_disabled(true)
-		save_image_dialog.current_path = Filesystem.last_image_savepath
+		var p = Filesystem.last_image_savepath
+		for ext in Filesystem.SUPPORTED_INPUT_EXT:
+			p = p.trim_suffix(ext)
+		save_image_dialog.current_path = p + ".png"
 		save_image_dialog.show()
 
 #