92 lines
2.6 KiB
Python
92 lines
2.6 KiB
Python
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'''
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FBO Canvas
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==========
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This demonstrates a layout using an FBO (Frame Buffer Off-screen)
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instead of a plain canvas. You should see a black canvas with a
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button labelled 'FBO' in the bottom left corner. Clicking it
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animates the button moving right to left.
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'''
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__all__ = ('FboFloatLayout', )
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from kivy.graphics import Color, Rectangle, Canvas, ClearBuffers, ClearColor
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from kivy.graphics.fbo import Fbo
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from kivy.uix.floatlayout import FloatLayout
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from kivy.properties import ObjectProperty, NumericProperty
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from kivy.app import App
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from kivy.core.window import Window
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from kivy.animation import Animation
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from kivy.factory import Factory
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class FboFloatLayout(FloatLayout):
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texture = ObjectProperty(None, allownone=True)
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alpha = NumericProperty(1)
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def __init__(self, **kwargs):
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self.canvas = Canvas()
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with self.canvas:
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self.fbo = Fbo(size=self.size)
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self.fbo_color = Color(1, 1, 1, 1)
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self.fbo_rect = Rectangle()
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with self.fbo:
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ClearColor(0, 0, 0, 0)
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ClearBuffers()
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# wait that all the instructions are in the canvas to set texture
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self.texture = self.fbo.texture
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super(FboFloatLayout, self).__init__(**kwargs)
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def add_widget(self, *args, **kwargs):
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# trick to attach graphics instruction to fbo instead of canvas
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canvas = self.canvas
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self.canvas = self.fbo
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ret = super(FboFloatLayout, self).add_widget(*args, **kwargs)
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self.canvas = canvas
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return ret
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def remove_widget(self, *args, **kwargs):
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canvas = self.canvas
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self.canvas = self.fbo
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super(FboFloatLayout, self).remove_widget(*args, **kwargs)
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self.canvas = canvas
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def on_size(self, instance, value):
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self.fbo.size = value
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self.texture = self.fbo.texture
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self.fbo_rect.size = value
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def on_pos(self, instance, value):
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self.fbo_rect.pos = value
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def on_texture(self, instance, value):
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self.fbo_rect.texture = value
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def on_alpha(self, instance, value):
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self.fbo_color.rgba = (1, 1, 1, value)
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class ScreenLayerApp(App):
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def build(self):
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f = FboFloatLayout()
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b = Factory.Button(text="FBO", size_hint=(None, None))
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f.add_widget(b)
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def anim_btn(*args):
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if b.pos[0] == 0:
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Animation(x=f.width - b.width).start(b)
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else:
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Animation(x=0).start(b)
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b.bind(on_press=anim_btn)
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return f
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if __name__ == "__main__":
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ScreenLayerApp().run()
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