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"""This module provides functions to add to shaders."""
__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 Fog(event.Notifier, ProgramFunction):
"""Linear fog over the whole scene content.
The background of the viewport is used as fog color,
otherwise it defaults to white.
"""
# TODO: add more controls (set fog range), add more fog modes
_fragDecl = """
/* (1/(far - near) or 0, near) z in [0 (camera), -inf[ */
uniform vec2 fogExtentInfo;
/* Color to use as fog color */
uniform vec3 fogColor;
vec4 fog(vec4 color, vec4 cameraPosition) {
/* d = (pos - near) / (far - near) */
float distance = fogExtentInfo.x * (cameraPosition.z/cameraPosition.w - fogExtentInfo.y);
float fogFactor = clamp(distance, 0.0, 1.0);
vec3 rgb = mix(color.rgb, fogColor, fogFactor);
return vec4(rgb.r, rgb.g, rgb.b, color.a);
}
"""
_fragDeclNoop = """
vec4 fog(vec4 color, vec4 cameraPosition) {
return color;
}
"""
def __init__(self):
super(Fog, self).__init__()
self._isOn = True
@property
def isOn(self):
"""True to enable fog, False to disable (bool)"""
return self._isOn
@isOn.setter
def isOn(self, isOn):
isOn = bool(isOn)
if self._isOn != isOn:
self._isOn = bool(isOn)
self.notify()
@property
def fragDecl(self):
return self._fragDecl if self.isOn else self._fragDeclNoop
@property
def fragCall(self):
return "fog"
@staticmethod
def _zExtentCamera(viewport):
"""Return (far, near) planes Z in camera coordinates.
:param Viewport viewport:
:return: (far, near) position in camera coords (from 0 to -inf)
"""
# Provide scene z extent in camera coords
bounds = viewport.camera.extrinsic.transformBounds(
viewport.scene.bounds(transformed=True, dataBounds=True))
return bounds[:, 2]
[docs] def setupProgram(self, context, program):
if not self.isOn:
return
far, near = context.cache(key='zExtentCamera',
factory=self._zExtentCamera,
viewport=context.viewport)
extent = far - near
gl.glUniform2f(program.uniforms['fogExtentInfo'],
0.9/extent if extent != 0. else 0.,
near)
# Use background color as fog color
bgColor = context.viewport.background
if bgColor is None:
bgColor = 1., 1., 1.
gl.glUniform3f(program.uniforms['fogColor'], *bgColor[:3])
[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)
[docs]class Colormap(event.Notifier, ProgramFunction):
_declTemplate = string.Template("""
uniform sampler2D cmap_texture;
uniform int cmap_normalization;
uniform float cmap_parameter;
uniform float cmap_min;
uniform float cmap_oneOverRange;
uniform vec4 nancolor;
const float oneOverLog10 = 0.43429448190325176;
vec4 colormap(float value) {
float data = value; /* Keep original input value for isnan test */
if (cmap_normalization == 1) { /* Log10 mapping */
if (value > 0.0) {
value = clamp(cmap_oneOverRange *
(oneOverLog10 * log(value) - cmap_min),
0.0, 1.0);
} else {
value = 0.0;
}
} else if (cmap_normalization == 2) { /* Sqrt mapping */
if (value > 0.0) {
value = clamp(cmap_oneOverRange * (sqrt(value) - cmap_min),
0.0, 1.0);
} else {
value = 0.0;
}
} else if (cmap_normalization == 3) { /*Gamma correction mapping*/
value = pow(
clamp(cmap_oneOverRange * (value - cmap_min), 0.0, 1.0),
cmap_parameter);
} else if (cmap_normalization == 4) { /* arcsinh mapping */
/* asinh = log(x + sqrt(x*x + 1) for compatibility with GLSL 1.20 */
value = clamp(cmap_oneOverRange * (log(value + sqrt(value*value + 1.0)) - cmap_min), 0.0, 1.0);
} else { /* Linear mapping */
value = clamp(cmap_oneOverRange * (value - cmap_min), 0.0, 1.0);
}
$discard
vec4 color;
if (data != data) { /* isnan alternative for compatibility with GLSL 1.20 */
color = nancolor;
} else {
color = texture2D(cmap_texture, vec2(value, 0.5));
}
return color;
}
""")
_discardCode = """
if (value == 0.) {
discard;
}
"""
call = "colormap"
NORMS = 'linear', 'log', 'sqrt', 'gamma', 'arcsinh'
"""Tuple of supported normalizations."""
_COLORMAP_TEXTURE_UNIT = 1
"""Texture unit to use for storing the colormap"""
def __init__(self, colormap=None, norm='linear', gamma=0., 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: see :attr:`NORMS`.
:param float gamma: Gamma normalization parameter
: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._gamma = -1.
self._range = 1., 10.
self._displayValuesBelowMin = True
self._nancolor = numpy.array((1., 1., 1., 0.), dtype=numpy.float32)
self._texture = None
self._textureToDiscard = None
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 values through properties to perform asserts and updates
self.colormap = colormap
self.norm = norm
self.gamma = gamma
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
if self._texture is not None and self._texture.name is not None:
self._textureToDiscard = self._texture
data = numpy.empty(
(16, self._colormap.shape[0], self._colormap.shape[1]),
dtype=self._colormap.dtype)
data[:] = self._colormap
format_ = gl.GL_RGBA if data.shape[-1] == 4 else gl.GL_RGB
self._texture = _glutils.Texture(
format_, data, format_,
texUnit=self._COLORMAP_TEXTURE_UNIT,
minFilter=gl.GL_NEAREST,
magFilter=gl.GL_NEAREST,
wrap=gl.GL_CLAMP_TO_EDGE)
self.notify()
@property
def nancolor(self):
"""RGBA color to use for Not-A-Number values as 4 float in [0., 1.]"""
return self._nancolor
@nancolor.setter
def nancolor(self, color):
color = numpy.clip(numpy.array(color, dtype=numpy.float32), 0., 1.)
assert color.ndim == 1
assert len(color) == 4
if not numpy.array_equal(self._nancolor, color):
self._nancolor = color
self.notify()
@property
def norm(self):
"""Normalization to use for colormap mapping.
One of 'linear' (the default), 'log' for log10 mapping or 'sqrt'.
Invalid values (e.g., negative values with 'log' or 'sqrt') are mapped to 0.
"""
return self._norm
@norm.setter
def norm(self, norm):
if norm != self._norm:
assert norm in self.NORMS
self._norm = norm
if norm in ('log', 'sqrt'):
self.range_ = self.range_ # To test for positive range_
self.notify()
@property
def gamma(self):
"""Gamma correction normalization parameter (float >= 0.)"""
return self._gamma
@gamma.setter
def gamma(self, gamma):
if gamma != self._gamma:
assert gamma >= 0.
self._gamma = gamma
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)
elif self.norm == 'sqrt' and (range_[0] < 0. or range_[1] < 0.):
_logger.warning(
"Sqrt normalization and negative range: updating range.")
range_ = max(range_[0], 0.), max(range_[1], 0.)
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()
[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.
"""
self.prepareGL2(context) # TODO see how to handle
self._texture.bind()
gl.glUniform1i(program.uniforms['cmap_texture'],
self._texture.texUnit)
min_, max_ = self.range_
param = 0.
if self._norm == 'log':
min_, max_ = numpy.log10(min_), numpy.log10(max_)
normID = 1
elif self._norm == 'sqrt':
min_, max_ = numpy.sqrt(min_), numpy.sqrt(max_)
normID = 2
elif self._norm == 'gamma':
# Keep min_, max_ as is
param = self._gamma
normID = 3
elif self._norm == 'arcsinh':
min_, max_ = numpy.arcsinh(min_), numpy.arcsinh(max_)
normID = 4
else: # Linear
normID = 0
gl.glUniform1i(program.uniforms['cmap_normalization'], normID)
gl.glUniform1f(program.uniforms['cmap_parameter'], param)
gl.glUniform1f(program.uniforms['cmap_min'], min_)
gl.glUniform1f(program.uniforms['cmap_oneOverRange'],
(1. / (max_ - min_)) if max_ != min_ else 0.)
gl.glUniform4f(program.uniforms['nancolor'], *self._nancolor)
def prepareGL2(self, context):
if self._textureToDiscard is not None:
self._textureToDiscard.discard()
self._textureToDiscard = None
self._texture.prepare()
