def on_paint(self, event):
# Technically, we would only need to set u_time on every draw,
# because the program is enabled at the beginning and never disabled.
# In vispy, the program is re-enabled at each draw though and we
# want to keep the code similar.
gl.glClear(gl.GL_COLOR_BUFFER_BIT | gl.GL_DEPTH_BUFFER_BIT)
# Activate program and texture
gl.glUseProgram(self._prog_handle)
gl.glBindTexture(gl.GL_TEXTURE_2D, self._tex_handle)
# Update VBO
gl.glBindBuffer(gl.GL_ARRAY_BUFFER, self._vbo_handle)
gl.glBufferData(gl.GL_ARRAY_BUFFER, vertex_data.nbytes, vertex_data,
gl.GL_DYNAMIC_DRAW)
# Set attributes (again, the loc can be cached)
loc = gl.glGetAttribLocation(self._prog_handle,
'a_lifetime'.encode('utf-8'))
gl.glEnableVertexAttribArray(loc)
gl.glVertexAttribPointer(loc, 1, gl.GL_FLOAT, False, 7 * 4,
ctypes.c_voidp(0))
#
loc = gl.glGetAttribLocation(self._prog_handle,
'a_startPosition'.encode('utf-8'))
gl.glEnableVertexAttribArray(loc)
gl.glVertexAttribPointer(loc, 3, gl.GL_FLOAT, False, 7 * 4,
ctypes.c_voidp(1 * 4))
#
loc = gl.glGetAttribLocation(self._prog_handle,
'a_endPosition'.encode('utf-8'))
gl.glEnableVertexAttribArray(loc)
gl.glVertexAttribPointer(loc, 3, gl.GL_FLOAT, False, 7 * 4,
ctypes.c_voidp(4 * 4))
#
loc = gl.glGetUniformLocation(self._prog_handle,
'u_color'.encode('utf-8'))
gl.glUniform4f(loc, *self._color)
# Set unforms
loc = gl.glGetUniformLocation(self._prog_handle,
'u_time'.encode('utf-8'))
gl.glUniform1f(loc, time.time() - self._starttime)
#
loc = gl.glGetUniformLocation(self._prog_handle,
'u_centerPosition'.encode('utf-8'))
gl.glUniform3f(loc, *self._centerpos)
# Draw
gl.glDrawArrays(gl.GL_POINTS, 0, N)
# New explosion?
if time.time() - self._starttime > 1.5:
self._new_explosion()
# Redraw as fast as we can
self.update()
def on_timer(self, event):
self.elapsed_time += 1. / 60.
if self.elapsed_time > 1.5:
self.new_explosion()
self.elapsed_time = 0.0
loc = gl.glGetUniformLocation(self.program, "time")
gl.glUniform1f(loc, self.elapsed_time)
self.update()
def on_paint(self, event):
# Technically, we would only need to set u_time on every draw,
# because the program is enabled at the beginning and never disabled.
# In vispy, the program is re-enabled at each draw though and we
# want to keep the code similar.
gl.glClear(gl.GL_COLOR_BUFFER_BIT | gl.GL_DEPTH_BUFFER_BIT)
# Activate program and texture
gl.glUseProgram(self._prog_handle)
gl.glBindTexture(gl.GL_TEXTURE_2D, self._tex_handle)
# Update VBO
gl.glBindBuffer(gl.GL_ARRAY_BUFFER, self._vbo_handle)
gl.glBufferData(gl.GL_ARRAY_BUFFER, vertex_data.nbytes, vertex_data, gl.GL_DYNAMIC_DRAW)
# Set attributes (again, the loc can be cached)
loc = gl.glGetAttribLocation(self._prog_handle, 'a_lifetime'.encode('utf-8'))
gl.glEnableVertexAttribArray(loc)
gl.glVertexAttribPointer(loc, 1, gl.GL_FLOAT, False, 7*4, ctypes.c_voidp(0))
#
loc = gl.glGetAttribLocation(self._prog_handle, 'a_startPosition'.encode('utf-8'))
gl.glEnableVertexAttribArray(loc)
gl.glVertexAttribPointer(loc, 3, gl.GL_FLOAT, False, 7*4, ctypes.c_voidp(1*4))
#
loc = gl.glGetAttribLocation(self._prog_handle, 'a_endPosition'.encode('utf-8'))
gl.glEnableVertexAttribArray(loc)
gl.glVertexAttribPointer(loc, 3, gl.GL_FLOAT, False, 7*4, ctypes.c_voidp(4*4))
#
loc = gl.glGetUniformLocation(self._prog_handle, 'u_color'.encode('utf-8'))
gl.glUniform4f(loc, *self._color)
# Set unforms
loc = gl.glGetUniformLocation(self._prog_handle, 'u_time'.encode('utf-8'))
gl.glUniform1f(loc, time.time()-self._starttime)
#
loc = gl.glGetUniformLocation(self._prog_handle, 'u_centerPosition'.encode('utf-8'))
gl.glUniform3f(loc, *self._centerpos)
# Draw
gl.glDrawArrays(gl.GL_POINTS, 0, N)
# New explosion?
if time.time() - self._starttime > 1.5:
self._new_explosion()
# Redraw as fast as we can
self.update()
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_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)
