Use VisualServer viewport for applying shader

This comes with the benefit that we no longer need a Viewport node in the ShaderEffect dialog, which lets us have the Preview TextureRect at a fixed size. Previously, the preview was scaled based on the image's size, which would make applying shaders to large images very inconvenient, since the dialog would be way too big.

src/UI/Dialogs/ImageEffects/ShaderEffect.gd

@@ -2,19 +2,16 @@ extends ConfirmationDialog
 
 
 var current_cel : Image
+var shader : Shader
+var params := [] # String[]
 
-onready var viewport : Viewport = $VBoxContainer/ViewportContainer/Viewport
+onready var preview : TextureRect = $VBoxContainer/Preview
-onready var preview : TextureRect = viewport.get_node("Preview")
 onready var shader_loaded_label : Label = $VBoxContainer/ShaderLoadedLabel
 onready var shader_params : BoxContainer = $VBoxContainer/ShaderParams
 
 
 func _on_ShaderEffect_about_to_show() -> void:
 	current_cel = Global.current_project.frames[Global.current_project.current_frame].cels[Global.current_project.current_layer].image
-	current_cel.unlock()
-	viewport.size = Global.current_project.size
-#	var viewport_texture = viewport.get_texture().get_data()
-#	viewport_texture.convert(Image.FORMAT_RGBA8)
 
 	var preview_image := Image.new()
 	preview_image.copy_from(current_cel)
@@ -24,26 +21,53 @@ func _on_ShaderEffect_about_to_show() -> void:
 
 
 func _on_ShaderEffect_confirmed() -> void:
-	var viewport_texture := Image.new()
+	if !shader:
-	viewport_texture.copy_from(viewport.get_texture().get_data())
-	var viewport_texture_size = viewport_texture.get_size()
-	if viewport_texture_size == Vector2.ZERO:
 		return
-	viewport_texture.flip_y()
+	current_cel.unlock()
+	var viewport_texture := Image.new()
+	var size : Vector2 = Global.current_project.size
+	var vp = VisualServer.viewport_create()
+	var canvas = VisualServer.canvas_create()
+	VisualServer.viewport_attach_canvas(vp, canvas)
+	VisualServer.viewport_set_size(vp, size.x, size.y)
+	VisualServer.viewport_set_disable_3d(vp, true)
+	VisualServer.viewport_set_usage(vp, VisualServer.VIEWPORT_USAGE_2D)
+	VisualServer.viewport_set_hdr(vp, true)
+	VisualServer.viewport_set_active(vp, true)
+	VisualServer.viewport_set_transparent_background(vp, true)
+
+	var ci_rid = VisualServer.canvas_item_create()
+	VisualServer.viewport_set_canvas_transform(vp, canvas, Transform())
+	VisualServer.canvas_item_set_parent(ci_rid, canvas)
+	var texture = ImageTexture.new()
+	texture.create_from_image(current_cel)
+	VisualServer.canvas_item_add_texture_rect(ci_rid, Rect2(Vector2(0, 0), size), texture)
+
+	var mat_rid = VisualServer.material_create()
+	VisualServer.material_set_shader(mat_rid, shader.get_rid())
+	VisualServer.canvas_item_set_material(ci_rid, mat_rid)
+	for param in params:
+		var param_data = preview.material.get_shader_param(param)
+		VisualServer.material_set_param(mat_rid, param, param_data)
+
+	VisualServer.viewport_set_update_mode(vp, VisualServer.VIEWPORT_UPDATE_ONCE)
+	VisualServer.viewport_set_vflip(vp, true)
+	VisualServer.force_draw(false)
+	viewport_texture = VisualServer.texture_get_data(VisualServer.viewport_get_texture(vp))
+	VisualServer.free_rid(vp)
+	VisualServer.free_rid(canvas)
+	VisualServer.free_rid(ci_rid)
+	VisualServer.free_rid(mat_rid)
+	print(viewport_texture.data)
 	viewport_texture.convert(Image.FORMAT_RGBA8)
-	print(viewport_texture.get_size())
 	Global.canvas.handle_undo("Draw")
 	current_cel.copy_from(viewport_texture)
 	Global.canvas.handle_redo("Draw")
+	current_cel.lock()
 
 
 func _on_ShaderEffect_popup_hide() -> void:
-	current_cel.lock()
 	Global.dialog_open(false)
-	yield(get_tree().create_timer(0.2), "timeout")
-	preview.texture = null
-	viewport.size = Vector2.ONE
-	rect_size = Vector2.ONE
 
 
 func _on_ChooseShader_pressed() -> void:
@@ -54,15 +78,17 @@ func _on_ChooseShader_pressed() -> void:
 
 
 func _on_FileDialog_file_selected(path : String) -> void:
-	var shader = load(path)
+	var _shader = load(path)
-	if !shader is Shader:
+	if !_shader is Shader:
 		return
-	change_shader(shader, path.get_file().get_basename())
+	change_shader(_shader, path.get_file().get_basename())
 
 
-func change_shader(shader : Shader, name : String) -> void:
+func change_shader(_shader : Shader, name : String) -> void:
-	preview.material.shader = shader
+	shader = _shader
+	preview.material.shader = _shader
 	shader_loaded_label.text = tr("Shader loaded:") + " " + name
+	params.clear()
 	for child in shader_params.get_children():
 		child.queue_free()
 
@@ -88,6 +114,7 @@ func change_shader(shader : Shader, name : String) -> void:
 		var u_init = u_left_side[0].split(" ")
 		var u_type = u_init[1]
 		var u_name = u_init[2]
+		params.append(u_name)
 
 		if u_type == "float":
 			var label := Label.new()

src/UI/Dialogs/ImageEffects/ShaderEffect.tscn

@@ -32,58 +32,46 @@ margin_bottom = 31.0
 text = "This is an experimental feature and may not be included in the stable version"
 autowrap = true
 
-[node name="ViewportContainer" type="ViewportContainer" parent="VBoxContainer"]
+[node name="Preview" type="TextureRect" parent="VBoxContainer"]
+material = SubResource( 1 )
 margin_top = 35.0
 margin_right = 384.0
-margin_bottom = 36.0
+margin_bottom = 235.0
-__meta__ = {
+rect_min_size = Vector2( 200, 200 )
-"_edit_use_anchors_": false
+expand = true
-}
+stretch_mode = 6
-
-[node name="Viewport" type="Viewport" parent="VBoxContainer/ViewportContainer"]
-size = Vector2( 1, 1 )
-transparent_bg = true
-handle_input_locally = false
-disable_3d = true
-usage = 0
-render_target_update_mode = 0
-gui_disable_input = true
-
-[node name="Preview" type="TextureRect" parent="VBoxContainer/ViewportContainer/Viewport"]
-material = SubResource( 1 )
-anchor_right = 1.0
-anchor_bottom = 1.0
 
 [node name="ChooseShader" type="Button" parent="VBoxContainer"]
-margin_top = 40.0
+margin_top = 239.0
 margin_right = 384.0
-margin_bottom = 60.0
+margin_bottom = 259.0
 mouse_default_cursor_shape = 2
 text = "Choose Shader"
 
 [node name="ShaderLoadedLabel" type="Label" parent="VBoxContainer"]
-margin_top = 64.0
+margin_top = 263.0
 margin_right = 384.0
-margin_bottom = 78.0
+margin_bottom = 277.0
 text = "No shader loaded!"
 autowrap = true
 
 [node name="ShaderParams" type="VBoxContainer" parent="VBoxContainer"]
-margin_right = 40.0
+margin_top = 281.0
-margin_bottom = 40.0
+margin_right = 384.0
+margin_bottom = 281.0
 
 [node name="FileDialog" type="FileDialog" parent="."]
 margin_left = 8.0
 margin_top = 8.0
 margin_right = 392.0
-margin_bottom = 264.0
+margin_bottom = 289.0
 window_title = "Open a File"
 resizable = true
 mode = 0
 access = 2
 filters = PoolStringArray( "*shader" )
-current_dir = "/Users/Overloaded/Dropbox/Orama Founding Members/εταιρικα αρχεια/Godot Projects/Pixelorama"
+current_dir = "/Users/manos/Dropbox/Orama Founding Members/εταιρικα αρχεια/Godot Projects/Pixelorama"
-current_path = "/Users/Overloaded/Dropbox/Orama Founding Members/εταιρικα αρχεια/Godot Projects/Pixelorama/"
+current_path = "/Users/manos/Dropbox/Orama Founding Members/εταιρικα αρχεια/Godot Projects/Pixelorama/"
 [connection signal="about_to_show" from="." to="." method="_on_ShaderEffect_about_to_show"]
 [connection signal="confirmed" from="." to="." method="_on_ShaderEffect_confirmed"]
 [connection signal="popup_hide" from="." to="." method="_on_ShaderEffect_popup_hide"]