def paint():
n = 100
data = np.hstack(
(.2 * np.random.randn(n, 2), np.random.rand(n, 4))).astype(np.float32)
vs = compile_shader(VS, gl.GL_VERTEX_SHADER)
fs = compile_shader(FS, gl.GL_FRAGMENT_SHADER)
shaders_program = link_shader_program(vs, fs)
buffer = gl.glGenBuffers(1)
gl.glBindBuffer(gl.GL_ARRAY_BUFFER, buffer)
gl.glBufferData(gl.GL_ARRAY_BUFFER, data, gl.GL_STATIC_DRAW)
l = gl.glGetAttribLocation(shaders_program, "position")
gl.glVertexAttribPointer(l, 2, gl.GL_FLOAT, gl.GL_FALSE, 0, None)
gl.glEnableVertexAttribArray(l)
lc = gl.glGetAttribLocation(shaders_program, "color")
gl.glVertexAttribPointer(lc, 4, gl.GL_FLOAT, gl.GL_FALSE, 2 * 4, None)
gl.glEnableVertexAttribArray(lc)
gl.glUseProgram(shaders_program)
gl.glViewport(0, 0, 500, 500)
gl.glClearColor(0., 0., 0., 1.)
gl.glClear(gl.GL_COLOR_BUFFER_BIT | gl.GL_DEPTH_BUFFER_BIT)
gl.glEnable(gl.GL_BLEND)
gl.glBlendFunc(gl.GL_SRC_ALPHA, gl.GL_ONE)
gl.glBindBuffer(gl.GL_ARRAY_BUFFER, buffer)
gl.glDrawArrays(gl.GL_TRIANGLE_STRIP, 0, data.shape[0])
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_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 paint():
n = 100
data = np.hstack((
.2 * np.random.randn(n, 2),
np.random.rand(n, 4)
)).astype(np.float32)
vs = compile_shader(VS, gl.GL_VERTEX_SHADER)
fs = compile_shader(FS, gl.GL_FRAGMENT_SHADER)
shaders_program = link_shader_program(vs, fs)
buffer = gl.glGenBuffers(1)
gl.glBindBuffer(gl.GL_ARRAY_BUFFER, buffer)
gl.glBufferData(gl.GL_ARRAY_BUFFER, data, gl.GL_STATIC_DRAW)
l = gl.glGetAttribLocation(shaders_program, "position")
gl.glVertexAttribPointer(l, 2, gl.GL_FLOAT, gl.GL_FALSE, 0, None)
gl.glEnableVertexAttribArray(l);
lc = gl.glGetAttribLocation(shaders_program, "color")
gl.glVertexAttribPointer(lc, 4, gl.GL_FLOAT, gl.GL_FALSE, 2 * 4, None)
gl.glEnableVertexAttribArray(lc);
gl.glUseProgram(shaders_program)
gl.glViewport(0, 0, 500, 500)
gl.glClearColor(0., 0., 0., 1.)
gl.glClear(gl.GL_COLOR_BUFFER_BIT | gl.GL_DEPTH_BUFFER_BIT)
gl.glEnable(gl.GL_BLEND)
gl.glBlendFunc(gl.GL_SRC_ALPHA, gl.GL_ONE)
gl.glBindBuffer(gl.GL_ARRAY_BUFFER, buffer)
gl.glDrawArrays(gl.GL_TRIANGLE_STRIP, 0, data.shape[0])
def draw_arrays(self, mode, first=0, count=None):
""" Draw the attribute arrays in the specified mode.
Only call when the program is enabled.
Parameters
----------
mode : GL_ENUM
GL_POINTS, GL_LINES, GL_LINE_STRIP, GL_LINE_LOOP,
GL_TRIANGLES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN
first : int
The starting vertex index in the vertex array. Default 0.
count : int
The number of vertices to draw. Default all.
"""
# Check
if not self._active:
raise ProgramError('ShaderProgram must be active when drawing.')
# Upload any attributes and uniforms if necessary
for variable in (self.attributes + self.uniforms):
if variable.active:
variable.upload(self)
# Prepare
refcount = self._get_vertex_count()
if count is None:
count = refcount
elif refcount:
if count > refcount:
raise ValueError(
'Count is larger than known number of vertices.')
# Check if we know count
if count is None:
raise ProgramError("Could not determine element count for draw.")
# Draw
gl.glDrawArrays(mode, first, count)
def draw_arrays(self, mode, first=0, count=None):
""" Draw the attribute arrays in the specified mode.
Only call when the program is enabled.
Parameters
----------
mode : GL_ENUM
GL_POINTS, GL_LINES, GL_LINE_STRIP, GL_LINE_LOOP,
GL_TRIANGLES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN
first : int
The starting vertex index in the vertex array. Default 0.
count : int
The number of vertices to draw. Default all.
"""
# Check
if not self._active:
raise ProgramError('ShaderProgram must be active when drawing.')
# Upload any attributes and uniforms if necessary
for variable in (self.attributes + self.uniforms):
if variable.active:
variable.upload(self)
# Prepare
refcount = self._get_vertex_count()
if count is None:
count = refcount
elif refcount:
if count > refcount:
raise ValueError('Count is larger than known number of vertices.')
# Check if we know count
if count is None:
raise ProgramError("Could not determine element count for draw.")
# Draw
gl.glDrawArrays(mode, first, count)
def draw(self, mode, subset=None):
""" Draw the vertices in the specified mode.
If the program is not active, it is activated to do the
drawing and then deactivated.
Parameters
----------
mode : str
POINTS, LINES, LINE_STRIP, LINE_LOOP, TRIANGLES, TRIANGLE_STRIP,
TRIANGLE_FAN. Case insensitive. Alternatively, the real GL enum
can also be given.
subset : {ElementBuffer, tuple}
The subset of vertices to draw. This can be an ElementBuffer
that specifies the indices of the vertices to draw, or a
tuple that specifies the slice: (start, end). The second
element in this tuple can be None to specify the maximum
length. If the subset is not given or None, all vertices
are drawn.
"""
# Check if active. If not, call recursively, but activated
if not self._active:
if self._error_enter:
# An error message has already been shown, we stop here
# because if we would continue we would very likely
# just spew messages for spin-off errors.
return
with self:
return self.draw(mode, subset)
# Check mode
mode = convert_to_enum(mode)
if mode not in [gl.GL_POINTS, gl.GL_LINES, gl.GL_LINE_STRIP,
gl.GL_LINE_LOOP, gl.GL_TRIANGLES, gl.GL_TRIANGLE_STRIP,
gl.GL_TRIANGLE_FAN]:
raise ValueError('Given mode is invalid: %r.' % mode)
# Allow subset None
if subset is None:
subset = (0, None)
# Upload any attributes and uniforms if necessary
for variable in (self.attributes + self.uniforms):
if variable.active:
variable.upload(self)
if isinstance(subset, ElementBuffer):
# Draw elements
# Prepare pointer or offset
if isinstance(subset, ClientElementBuffer):
ptr = subset.data
else:
ptr = None # Note that this can also be a ctypes.pointer offset
# Activate
self.activate_object(subset)
# Prepare
gltype = ElementBuffer.DTYPE2GTYPE[subset.dtype.name]
if gltype == gl.GL_UNSIGNED_INT and not ext_available('element_index_uint'):
raise ValueError('element_index_uint extension needed for uint32 ElementBuffer.')
# Draw
gl.glDrawElements(mode, subset.count, gltype, ptr)
elif isinstance(subset, tuple):
# Draw arrays
# Check tuple
ok = [isinstance(i, (int, type(None))) for i in subset]
if len(subset) != 2 or not all(ok):
raise ValueError('Subset must be a two-element tuple with '
'interegers or None.')
# Get start, end, refcount
start, end = subset
start = start or 0
refcount = self._get_vertex_count()
# Determine count
if end is None:
count = refcount
if count is None:
raise ProgramError("Could not determine element count for draw.")
else:
count = end - start
if refcount and count > refcount:
raise ValueError('Count is larger than known number of vertices.')
# Draw
gl.glDrawArrays(mode, start, count)
else:
raise ValueError('Given subset is of invalid type: %r.' % type(subset))
