Started markers chapter

Author: rougier

08-markers.rst

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+# -----------------------------------------------------------------------------
+# Python & OpenGL for Scientific Visualization
+# www.labri.fr/perso/nrougier/python+opengl
+# Copyright (c) 2017, Nicolas P. Rougier
+# Distributed under the 2-Clause BSD License.
+# -----------------------------------------------------------------------------
+import numpy as np
+from glumpy import app, gl, gloo
+from glumpy.transforms import Position, OrthographicProjection, PanZoom
+
+# Create window
+window = app.Window(width=2*512, height=512, color=(1,1,1,1))
+
+# What to draw when necessary
+@window.event
+def on_draw(dt):
+    window.clear()
+    program.draw(gl.GL_POINTS)
+    program['orientation'][-1] += np.pi/1024.0
+
+# Setup some markers
+n = 500+1
+data = np.zeros(n, dtype=[('position',    np.float32, 2),
+                          ('fg_color',    np.float32, 4),
+                          ('bg_color',    np.float32, 4),
+                          ('size',        np.float32, 1),
+                          ('orientation', np.float32, 1),
+                          ('linewidth',   np.float32, 1)])
+data = data.view(gloo.VertexBuffer)
+data['linewidth'] = 1
+data['fg_color'] = 0, 0, 0, 1
+data['bg_color'] = 1, 1, 1, 0
+data['orientation'] = 0
+radius, theta, dtheta = 250.0, 0.0, 5.5 / 180.0 * np.pi
+for i in range(500):
+    theta += dtheta
+    x = 256 + radius * np.cos(theta)
+    y = 256 + radius * np.sin(theta)
+    r = 10.0 - i * 0.02
+    radius -= 0.45
+    data['orientation'][i] = theta - np.pi/2
+    data['position'][i] = x, y
+    data['size'][i] = 2 * r
+    data['linewidth'][i] = 1
+
+data['position'][-1]    = 512+256, 256
+data['size'][-1]        = 512/np.sqrt(2)
+data['linewidth'][-1]   = 3.0
+data['fg_color'][-1]    = 0, 0, 0, 1
+data['bg_color'][-1]    = .95, .95, .95, 1
+data['orientation'][-1] = 0
+
+program = gloo.Program("markers/marker.vert", "markers/marker.frag")
+program.bind(data)
+program['antialias'] = 1.00
+
+#  <marker> : "arrow", "asterisk", "chevron", "clover", "club",
+#             "cross", "diamond", "disc", "ellipse", "hbar",
+#             "heart", "infinity", "pin", "ring", "spade",
+#             "square", "tag", "triangle", "vbar"
+program['marker'] = "asterisk"
+
+#  <paint>  : "stroke", "filled" or "outline"
+program['paint'] = "outline"
+
+transform = OrthographicProjection(Position("position"))
+program['transform'] = transform
+window.attach(transform)
+
+app.run()

book.html

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+# -----------------------------------------------------------------------------
+# Python & OpenGL for Scientific Visualization
+# www.labri.fr/perso/nrougier/python+opengl
+# Copyright (c) 2017, Nicolas P. Rougier
+# Distributed under the 2-Clause BSD License.
+# -----------------------------------------------------------------------------
+import numpy as np
+from glumpy import app, gloo, gl
+
+vertex = """
+  uniform vec2 resolution;
+  // attribute vec2 position;
+  in vec2 position;
+  void main()
+  { gl_Position = vec4(2.0*position/resolution-1.0, 0.0, 1.0); }
+"""
+
+fragment = """
+  out vec4 color;
+  void main() { color = vec4(vec3(0.0), 1.0); }
+  // void main() { gl_FragColor = vec4(vec3(0.0), 1.0); }
+"""
+
+config = app.configuration.Configuration()
+config.samples = 6
+config.major_version = 3
+config.minor_version = 2
+config.profile = "core"
+GLSL_version = "150"
+window = app.Window(32, 8, color=(1,1,1,1), config=config)
+             
+triangle = gloo.Program(vertex, fragment, version=GLSL_version)
+V = np.zeros(3, dtype=[("position", np.float32,2)])
+V["position"] = (1.,3.), (7.,7.), (30., 1.)
+V = V.view(gloo.VertexArray)
+triangle.bind(V)
+             
+@window.event
+def on_resize(width, height):
+    triangle["resolution"] = width, height
+
+@window.event
+def on_init():
+    gl.glEnable(gl.GL_MULTISAMPLE)
+    pass
+    
+@window.event
+def on_draw(dt):
+    window.clear()
+    triangle.draw(gl.GL_TRIANGLE_STRIP)
+
+
+for i in range(window.config.samples):
+    print(gl.glGetMultisamplefv(gl.GL_SAMPLE_POSITION, i))
+
+app.run()