|
|
|
 |
Reply From: |
Zylann |
Here is an example script in Godot 2 that lets you paint ont a Control node:
Project: http://zylannprods.fr/dl/godot/ChalkBoard.zip
extends Control
var _pen = null
var _prev_mouse_pos = Vector2()
func _ready():
# Create the viewport
var viewport = Viewport.new()
# Make it so it renders on a texture
viewport.set_as_render_target(true)
# Set the size of it
var rect = get_rect()
viewport.set_rect(Rect2(0, 0, rect.size.x, rect.size.y))
# I tried to set the background color, but none of this worked...
# var world = World.new()
# var env = Environment.new()
# env.set_background(Environment.BG_COLOR)
# env.set_background_param(Environment.BG_PARAM_COLOR, Color(0,0,0))
# world.set_environment(env)
# viewport.set_world(world)
# viewport.set_use_own_world(true)
_pen = Node2D.new()
viewport.add_child(_pen)
_pen.connect("draw", self, "_on_draw")
# Don't clear the frame when it gets updated so it will accumulate drawings
viewport.set_render_target_clear_on_new_frame(false)
add_child(viewport)
# Use a TextureFrame to display the result texture (because pivot is top-left)
var rt = viewport.get_render_target_texture()
var board = TextureFrame.new()
board.set_texture(rt)
add_child(board)
set_process(true)
func _process(delta):
_pen.update()
func _on_draw():
var mouse_pos = get_local_mouse_pos()
if Input.is_mouse_button_pressed(BUTTON_LEFT):
_pen.draw_line(mouse_pos, _prev_mouse_pos, Color(1, 1, 0))
_prev_mouse_pos = mouse_pos
hi Zylann, your ChalkBoard demo is work well in godot 2.0 but how it works in godot 3.0?
zhengying | 2018-09-20 10:17
It’s almost the same, I managed to make it work in Godot 3 like this:
Project: http://zylannprods.fr/dl/godot/godot3/ChalkBoard.zip
extends Control
var _pen = null
var _prev_mouse_pos = Vector2()
func _ready():
var viewport = Viewport.new()
var rect = get_rect()
viewport.size = rect.size
viewport.usage = Viewport.USAGE_2D
# Note: I also tried CLEAR_MODE_NEVER but it doesn't draw anything.
# (see issue https://github.com/godotengine/godot/issues/20775)
viewport.render_target_clear_mode = Viewport.CLEAR_MODE_ONLY_NEXT_FRAME
viewport.render_target_v_flip = true
_pen = Node2D.new()
viewport.add_child(_pen)
_pen.connect("draw", self, "_on_draw")
add_child(viewport)
# Use a sprite to display the result texture
var rt = viewport.get_texture()
var board = TextureRect.new()
board.set_texture(rt)
add_child(board)
func _process(delta):
_pen.update()
func _on_draw():
var mouse_pos = get_local_mouse_position()
if Input.is_mouse_button_pressed(BUTTON_LEFT):
_pen.draw_line(mouse_pos, _prev_mouse_pos, Color(1, 1, 0))
_prev_mouse_pos = mouse_pos
Zylann | 2018-09-20 19:31
thanks Zylann.
It’s works well!
zhengying | 2018-09-21 02:18
Hi Zylann,
I saw you tried a few different methods to change the background for your chalkboard that were all unsuccesful. Have you found out a way to do it yet? I am creating a notepad type app in godot and wanted the ability to draw in a textbox. I tried overlaying a control node with your sample script over the textbox but then the text is covered up as well. Is there a way to make the background transparent?
kingpinpenguin | 2020-01-16 04:45
Hey kingpinpenguin,
Almost a year late and I’m not Zylann, but I’ve got a solution. Put this anywhere before adding “viewport” as a child in _ready():
viewport.set_transparent_background(true)
FakeSky | 2020-12-08 20:39
