# coding: utf-8
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"""This module provides functions to add to shaders."""
from __future__ import absolute_import, division, unicode_literals
__authors__ = ["T. Vincent"]
__license__ = "MIT"
__date__ = "17/07/2018"
import contextlib
import logging
import string
import numpy
from ... import _glutils
from ..._glutils import gl
from . import event
from . import utils
_logger = logging.getLogger(__name__)
[docs]class ProgramFunction(object):
"""Class providing a function to add to a GLProgram shaders.
"""
[docs] def setupProgram(self, context, program):
"""Sets-up uniforms of a program using this shader function.
:param RenderContext context: The current rendering context
:param GLProgram program: The program to set-up.
It MUST be in use and using this function.
"""
pass
[docs]class ClippingPlane(ProgramFunction):
"""Description of a clipping plane and rendering.
Convention: Clipping is performed in camera/eye space.
:param point: Local coordinates of a point on the plane.
:type point: numpy.ndarray-like of 3 float32
:param normal: Local coordinates of the plane normal.
:type normal: numpy.ndarray-like of 3 float32
"""
_fragDecl = """
/* Clipping plane */
/* as rx + gy + bz + a > 0, clipping all positive */
uniform vec4 planeEq;
/* Position is in camera/eye coordinates */
bool isClipped(vec4 position) {
vec4 tmp = planeEq * position;
float value = tmp.x + tmp.y + tmp.z + planeEq.a;
return (value < 0.0001);
}
void clipping(vec4 position) {
if (isClipped(position)) {
discard;
}
}
/* End of clipping */
"""
_fragDeclNoop = """
bool isClipped(vec4 position)
{
return false;
}
void clipping(vec4 position) {}
"""
def __init__(self, point=(0., 0., 0.), normal=(0., 0., 0.)):
self._plane = utils.Plane(point, normal)
@property
def plane(self):
"""Plane parameters in camera space."""
return self._plane
# GL2
@property
def fragDecl(self):
return self._fragDecl if self.plane.isPlane else self._fragDeclNoop
@property
def fragCall(self):
return "clipping"
[docs] def setupProgram(self, context, program):
"""Sets-up uniforms of a program using this shader function.
:param RenderContext context: The current rendering context
:param GLProgram program: The program to set-up.
It MUST be in use and using this function.
"""
if self.plane.isPlane:
gl.glUniform4f(program.uniforms['planeEq'], *self.plane.parameters)
[docs]class DirectionalLight(event.Notifier, ProgramFunction):
"""Description of a directional Phong light.
:param direction: The direction of the light or None to disable light
:type direction: ndarray of 3 floats or None
:param ambient: RGB ambient light
:type ambient: ndarray of 3 floats in [0, 1], default: (1., 1., 1.)
:param diffuse: RGB diffuse light parameter
:type diffuse: ndarray of 3 floats in [0, 1], default: (0., 0., 0.)
:param specular: RGB specular light parameter
:type specular: ndarray of 3 floats in [0, 1], default: (1., 1., 1.)
:param int shininess: The shininess of the material for specular term,
default: 0 which disables specular component.
"""
fragmentShaderFunction = """
/* Lighting */
struct DLight {
vec3 lightDir; // Direction of light in object space
vec3 ambient;
vec3 diffuse;
vec3 specular;
float shininess;
vec3 viewPos; // Camera position in object space
};
uniform DLight dLight;
vec4 lighting(vec4 color, vec3 position, vec3 normal)
{
normal = normalize(normal);
// 1-sided
float nDotL = max(0.0, dot(normal, - dLight.lightDir));
// 2-sided
//float nDotL = dot(normal, - dLight.lightDir);
//if (nDotL < 0.) {
// nDotL = - nDotL;
// normal = - normal;
//}
float specFactor = 0.;
if (dLight.shininess > 0. && nDotL > 0.) {
vec3 reflection = reflect(dLight.lightDir, normal);
vec3 viewDir = normalize(dLight.viewPos - position);
specFactor = max(0.0, dot(reflection, viewDir));
if (specFactor > 0.) {
specFactor = pow(specFactor, dLight.shininess);
}
}
vec3 enlightedColor = color.rgb * (dLight.ambient +
dLight.diffuse * nDotL) +
dLight.specular * specFactor;
return vec4(enlightedColor.rgb, color.a);
}
/* End of Lighting */
"""
fragmentShaderFunctionNoop = """
vec4 lighting(vec4 color, vec3 position, vec3 normal)
{
return color;
}
"""
def __init__(self, direction=None,
ambient=(1., 1., 1.), diffuse=(0., 0., 0.),
specular=(1., 1., 1.), shininess=0):
super(DirectionalLight, self).__init__()
self._direction = None
self.direction = direction # Set _direction
self._isOn = True
self._ambient = ambient
self._diffuse = diffuse
self._specular = specular
self._shininess = shininess
ambient = event.notifyProperty('_ambient')
diffuse = event.notifyProperty('_diffuse')
specular = event.notifyProperty('_specular')
shininess = event.notifyProperty('_shininess')
@property
def isOn(self):
"""True if light is on, False otherwise."""
return self._isOn and self._direction is not None
@isOn.setter
def isOn(self, isOn):
self._isOn = bool(isOn)
[docs] @contextlib.contextmanager
def turnOff(self):
"""Context manager to temporary turn off lighting during rendering.
>>> with light.turnOff():
... # Do some rendering without lighting
"""
wason = self._isOn
self._isOn = False
yield
self._isOn = wason
@property
def direction(self):
"""The direction of the light, or None if light is not on."""
return self._direction
@direction.setter
def direction(self, direction):
if direction is None:
self._direction = None
else:
assert len(direction) == 3
direction = numpy.array(direction, dtype=numpy.float32, copy=True)
norm = numpy.linalg.norm(direction)
assert norm != 0
self._direction = direction / norm
self.notify()
# GL2
@property
def fragmentDef(self):
"""Definition to add to fragment shader"""
if self.isOn:
return self.fragmentShaderFunction
else:
return self.fragmentShaderFunctionNoop
@property
def fragmentCall(self):
"""Function name to call in fragment shader"""
return "lighting"
[docs] def setupProgram(self, context, program):
"""Sets-up uniforms of a program using this shader function.
:param RenderContext context: The current rendering context
:param GLProgram program: The program to set-up.
It MUST be in use and using this function.
"""
if self.isOn and self._direction is not None:
# Transform light direction from camera space to object coords
lightdir = context.objectToCamera.transformDir(
self._direction, direct=False)
lightdir /= numpy.linalg.norm(lightdir)
gl.glUniform3f(program.uniforms['dLight.lightDir'], *lightdir)
# Convert view position to object coords
viewpos = context.objectToCamera.transformPoint(
numpy.array((0., 0., 0., 1.), dtype=numpy.float32),
direct=False,
perspectiveDivide=True)[:3]
gl.glUniform3f(program.uniforms['dLight.viewPos'], *viewpos)
gl.glUniform3f(program.uniforms['dLight.ambient'], *self.ambient)
gl.glUniform3f(program.uniforms['dLight.diffuse'], *self.diffuse)
gl.glUniform3f(program.uniforms['dLight.specular'], *self.specular)
gl.glUniform1f(program.uniforms['dLight.shininess'],
self.shininess)
class Colormap(event.Notifier, ProgramFunction):
_declTemplate = string.Template("""
uniform struct {
sampler2D texture;
bool isLog;
float min;
float oneOverRange;
} cmap;
const float oneOverLog10 = 0.43429448190325176;
vec4 colormap(float value) {
if (cmap.isLog) { /* Log10 mapping */
if (value > 0.0) {
value = clamp(cmap.oneOverRange *
(oneOverLog10 * log(value) - cmap.min),
0.0, 1.0);
} else {
value = 0.0;
}
} else { /* Linear mapping */
value = clamp(cmap.oneOverRange * (value - cmap.min), 0.0, 1.0);
}
$discard
vec4 color = texture2D(cmap.texture, vec2(value, 0.5));
return color;
}
""")
_discardCode = """
if (value == 0.) {
discard;
}
"""
call = "colormap"
NORMS = 'linear', 'log'
"""Tuple of supported normalizations."""
_COLORMAP_TEXTURE_UNIT = 1
"""Texture unit to use for storing the colormap"""
def __init__(self, colormap=None, norm='linear', range_=(1., 10.)):
"""Shader function to apply a colormap to a value.
:param colormap: RGB(A) color look-up table (default: gray)
:param colormap: numpy.ndarray of numpy.uint8 of dimension Nx3 or Nx4
:param str norm: Normalization to apply: 'linear' (default) or 'log'.
:param range_: Range of value to map to the colormap.
:type range_: 2-tuple of float (begin, end).
"""
super(Colormap, self).__init__()
# Init privates to default
self._colormap = None
self._norm = 'linear'
self._range = 1., 10.
self._displayValuesBelowMin = True
self._texture = None
self._update_texture = True
if colormap is None:
# default colormap
colormap = numpy.empty((256, 3), dtype=numpy.uint8)
colormap[:] = numpy.arange(256,
dtype=numpy.uint8)[:, numpy.newaxis]
# Set to param values through properties to go through asserts
self.colormap = colormap
self.norm = norm
self.range_ = range_
@property
def decl(self):
"""Source code of the function declaration"""
return self._declTemplate.substitute(
discard="" if self.displayValuesBelowMin else self._discardCode)
@property
def colormap(self):
"""Color look-up table to use."""
return numpy.array(self._colormap, copy=True)
@colormap.setter
def colormap(self, colormap):
colormap = numpy.array(colormap, copy=True)
assert colormap.ndim == 2
assert colormap.shape[1] in (3, 4)
self._colormap = colormap
self._update_texture = True
self.notify()
@property
def norm(self):
"""Normalization to use for colormap mapping.
Either 'linear' (the default) or 'log' for log10 mapping.
With 'log' normalization, values <= 0. are set to 1. (i.e. log == 0)
"""
return self._norm
@norm.setter
def norm(self, norm):
if norm != self._norm:
assert norm in self.NORMS
self._norm = norm
if norm == 'log':
self.range_ = self.range_ # To test for positive range_
self.notify()
@property
def range_(self):
"""Range of values to map to the colormap.
2-tuple of floats: (begin, end).
The begin value is mapped to the origin of the colormap and the
end value is mapped to the other end of the colormap.
The colormap is reversed if begin > end.
"""
return self._range
@range_.setter
def range_(self, range_):
assert len(range_) == 2
range_ = float(range_[0]), float(range_[1])
if self.norm == 'log' and (range_[0] <= 0. or range_[1] <= 0.):
_logger.warning(
"Log normalization and negative range: updating range.")
minPos = numpy.finfo(numpy.float32).tiny
range_ = max(range_[0], minPos), max(range_[1], minPos)
if range_ != self._range:
self._range = range_
self.notify()
@property
def displayValuesBelowMin(self):
"""True to display values below colormap min, False to discard them.
"""
return self._displayValuesBelowMin
@displayValuesBelowMin.setter
def displayValuesBelowMin(self, displayValuesBelowMin):
displayValuesBelowMin = bool(displayValuesBelowMin)
if self._displayValuesBelowMin != displayValuesBelowMin:
self._displayValuesBelowMin = displayValuesBelowMin
self.notify()
def setupProgram(self, context, program):
"""Sets-up uniforms of a program using this shader function.
:param RenderContext context: The current rendering context
:param GLProgram program: The program to set-up.
It MUST be in use and using this function.
"""
self.prepareGL2(context) # TODO see how to handle
if self._texture is None: # No colormap
return
self._texture.bind()
gl.glUniform1i(program.uniforms['cmap.texture'],
self._texture.texUnit)
gl.glUniform1i(program.uniforms['cmap.isLog'], self._norm == 'log')
min_, max_ = self.range_
if self._norm == 'log':
min_, max_ = numpy.log10(min_), numpy.log10(max_)
gl.glUniform1f(program.uniforms['cmap.min'], min_)
gl.glUniform1f(program.uniforms['cmap.oneOverRange'],
(1. / (max_ - min_)) if max_ != min_ else 0.)
def prepareGL2(self, context):
if self._texture is None or self._update_texture:
if self._texture is not None:
self._texture.discard()
colormap = numpy.empty(
(16, self._colormap.shape[0], self._colormap.shape[1]),
dtype=self._colormap.dtype)
colormap[:] = self._colormap
format_ = gl.GL_RGBA if colormap.shape[-1] == 4 else gl.GL_RGB
self._texture = _glutils.Texture(
format_, colormap, format_,
texUnit=self._COLORMAP_TEXTURE_UNIT,
minFilter=gl.GL_NEAREST,
magFilter=gl.GL_NEAREST,
wrap=gl.GL_CLAMP_TO_EDGE)
self._update_texture = False
