mirror of https://github.com/kivy/kivy.git
91 lines
2.5 KiB
Python
91 lines
2.5 KiB
Python
'''
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Plasma Shader
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=============
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This shader example have been taken from http://www.iquilezles.org/apps/shadertoy/
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with some adapation.
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This might become a Kivy widget when experimentation will be done.
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'''
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from kivy.clock import Clock
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from kivy.app import App
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from kivy.uix.floatlayout import FloatLayout
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from kivy.core.window import Window
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from kivy.graphics import RenderContext
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from kivy.properties import StringProperty
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# This header must be not changed, it contain the minimum information from Kivy.
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header = '''
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#ifdef GL_ES
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precision highp float;
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#endif
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/* Outputs from the vertex shader */
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varying vec4 frag_color;
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varying vec2 tex_coord0;
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/* uniform texture samplers */
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uniform sampler2D texture0;
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'''
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# Plasma shader
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plasma_shader = header + '''
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uniform vec2 resolution;
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uniform float time;
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void main(void)
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{
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float x = gl_FragCoord.x;
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float y = gl_FragCoord.y;
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float mov0 = x+y+cos(sin(time)*2.)*100.+sin(x/100.)*1000.;
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float mov1 = y / resolution.y / 0.2 + time;
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float mov2 = x / resolution.x / 0.2;
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float c1 = abs(sin(mov1+time)/2.+mov2/2.-mov1-mov2+time);
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float c2 = abs(sin(c1+sin(mov0/1000.+time)+sin(y/40.+time)+sin((x+y)/100.)*3.));
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float c3 = abs(sin(c2+cos(mov1+mov2+c2)+cos(mov2)+sin(x/1000.)));
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gl_FragColor = vec4( c1,c2,c3,1.0);
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}
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'''
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class ShaderWidget(FloatLayout):
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# property to set the source code for fragment shader
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fs = StringProperty(None)
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def __init__(self, **kwargs):
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# Instead of using Canvas, we will use a RenderContext,
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# and change the default shader used.
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self.canvas = RenderContext()
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# call the constructor of parent
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# if they are any graphics object, they will be added on our new canvas
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super(ShaderWidget, self).__init__(**kwargs)
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# We'll update our glsl variables in a clock
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Clock.schedule_interval(self.update_glsl, 1 / 60.)
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def on_fs(self, instance, value):
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# set the fragment shader to our source code
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shader = self.canvas.shader
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old_value = shader.fs
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shader.fs = value
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if not shader.success:
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shader.fs = old_value
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raise Exception('failed')
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def update_glsl(self, *largs):
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self.canvas['time'] = Clock.get_boottime()
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self.canvas['resolution'] = list(map(float, self.size))
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# This is needed for the default vertex shader.
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self.canvas['projection_mat'] = Window.render_context['projection_mat']
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class PlasmaApp(App):
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def build(self):
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return ShaderWidget(fs=plasma_shader)
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if __name__ == '__main__':
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PlasmaApp().run()
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