23 lines
650 B
GDScript
23 lines
650 B
GDScript
extends Sprite2D
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@export var size := 512
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@export var export_path = ""
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func _ready() -> void:
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var image = Image.create_empty(size, size, false, Image.FORMAT_RGBA8)
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# 放射性 point light，圆心 alpha 通道为 1，随半径增加逐渐接近 0
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var r = size / 2.0
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for x in range(size):
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for y in range(size):
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var rate = pow(pow(x - r, 2) + pow(y - r, 2), 0.5) / r
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if rate > 1:
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image.set_pixel(x, y, Color.TRANSPARENT)
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else:
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# var a = 1 - rate
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var a = smoothstep(1.0, 0.0, rate)
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image.set_pixel(x, y, Color(1, 1, 1, a))
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if export_path:
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image.save_png(export_path)
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texture = ImageTexture.create_from_image(image)
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