.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "gallery/gloo/gl/quad.py" .. LINE NUMBERS ARE GIVEN BELOW. .. only:: html .. note:: :class: sphx-glr-download-link-note :ref:`Go to the end ` to download the full example code .. rst-class:: sphx-glr-example-title .. _sphx_glr_gallery_gloo_gl_quad.py: Drawing a simple quad ===================== .. GENERATED FROM PYTHON SOURCE LINES 13-121 .. code-block:: Python import numpy as np from vispy import app from vispy.gloo import gl vertex_code = """ uniform float scale; attribute vec4 color; attribute vec2 position; varying vec4 v_color; void main() { gl_Position = vec4(scale*position, 0.0, 1.0); v_color = color; } """ fragment_code = """ varying vec4 v_color; void main() { gl_FragColor = v_color; } """ class Canvas(app.Canvas): def __init__(self): app.Canvas.__init__(self, size=(512, 512), title='Quad (GL)', keys='interactive') def on_initialize(self, event): # Build data self.data = np.zeros(4, [("position", np.float32, 2), ("color", np.float32, 4)]) self.data['color'] = [(1, 0, 0, 1), (0, 1, 0, 1), (0, 0, 1, 1), (1, 1, 0, 1)] self.data['position'] = [(-1, -1), (-1, +1), (+1, -1), (+1, +1)] # Build & activate program # Request a program and shader slots from GPU program = gl.glCreateProgram() vertex = gl.glCreateShader(gl.GL_VERTEX_SHADER) fragment = gl.glCreateShader(gl.GL_FRAGMENT_SHADER) # Set shaders source gl.glShaderSource(vertex, vertex_code) gl.glShaderSource(fragment, fragment_code) # Compile shaders gl.glCompileShader(vertex) gl.glCompileShader(fragment) # Attach shader objects to the program gl.glAttachShader(program, vertex) gl.glAttachShader(program, fragment) # Build program gl.glLinkProgram(program) # Get rid of shaders (no more needed) gl.glDetachShader(program, vertex) gl.glDetachShader(program, fragment) # Make program the default program gl.glUseProgram(program) # Build buffer # Request a buffer slot from GPU buf = gl.glCreateBuffer() # Make this buffer the default one gl.glBindBuffer(gl.GL_ARRAY_BUFFER, buf) # Upload data gl.glBufferData(gl.GL_ARRAY_BUFFER, self.data, gl.GL_DYNAMIC_DRAW) # Bind attributes stride = self.data.strides[0] offset = 0 loc = gl.glGetAttribLocation(program, "position") gl.glEnableVertexAttribArray(loc) gl.glBindBuffer(gl.GL_ARRAY_BUFFER, buf) gl.glVertexAttribPointer(loc, 3, gl.GL_FLOAT, False, stride, offset) offset = self.data.dtype["position"].itemsize loc = gl.glGetAttribLocation(program, "color") gl.glEnableVertexAttribArray(loc) gl.glBindBuffer(gl.GL_ARRAY_BUFFER, buf) gl.glVertexAttribPointer(loc, 4, gl.GL_FLOAT, False, stride, offset) # Bind uniforms # -------------------------------------- loc = gl.glGetUniformLocation(program, "scale") gl.glUniform1f(loc, 1.0) def on_draw(self, event): gl.glClear(gl.GL_COLOR_BUFFER_BIT) gl.glDrawArrays(gl.GL_TRIANGLE_STRIP, 0, 4) def on_resize(self, event): gl.glViewport(0, 0, *event.physical_size) if __name__ == '__main__': c = Canvas() c.show() app.run() .. rst-class:: sphx-glr-timing **Total running time of the script:** (0 minutes 0.078 seconds) .. _sphx_glr_download_gallery_gloo_gl_quad.py: .. only:: html .. container:: sphx-glr-footer sphx-glr-footer-example .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: quad.ipynb ` .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: quad.py ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_