48 lines
1.3 KiB
Python
48 lines
1.3 KiB
Python
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'''
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This is an example of creating your own effect by writing a glsl string.
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'''
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from kivy.base import runTouchApp
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from kivy.lang import Builder
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from kivy.uix.effectwidget import EffectWidget, EffectBase
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# The effect string is glsl code defining an effect function.
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effect_string = '''
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vec4 effect(vec4 color, sampler2D texture, vec2 tex_coords, vec2 coords)
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{
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// Note that time is a uniform variable that is automatically
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// provided to all effects.
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float red = color.x * abs(sin(time*2.0));
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float green = color.y; // No change
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float blue = color.z * (1.0 - abs(sin(time*2.0)));
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return vec4(red, green, blue, color.w);
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}
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'''
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class DemoEffect(EffectWidget):
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def __init__(self, *args, **kwargs):
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self.effect_reference = EffectBase(glsl=effect_string)
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super(DemoEffect, self).__init__(*args, **kwargs)
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widget = Builder.load_string('''
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DemoEffect:
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effects: [self.effect_reference] if checkbox.active else []
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orientation: 'vertical'
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Button:
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text: 'Some text so you can see what happens.'
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BoxLayout:
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size_hint_y: None
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height: dp(50)
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Label:
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text: 'Enable effect?'
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CheckBox:
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id: checkbox
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active: True
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''')
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runTouchApp(widget)
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