Source code for silx.gui.plot3d.scene.text

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"""Primitive displaying a text field in the scene."""

__authors__ = ["T. Vincent"]
__license__ = "MIT"
__date__ = "24/04/2018"


import logging
import numpy

from silx.gui.colors import rgba

from ... import _glutils
from ..._glutils import gl

from ..._glutils import font as _font
from ...plot._utils import ticklayout

from . import event, primitives, core, transform


_logger = logging.getLogger(__name__)


[docs]class Font(event.Notifier): """Description of a font. :param str name: Family of the font :param int size: Size of the font in points :param int weight: Font weight :param bool italic: True for italic font, False (default) otherwise """ def __init__(self, name=None, size=-1, weight=-1, italic=False): self._name = name if name is not None else _font.getDefaultFontFamily() self._size = size self._weight = weight self._italic = italic super(Font, self).__init__() name = event.notifyProperty( '_name', doc="""Name of the font (str)""", converter=str) size = event.notifyProperty( '_size', doc="""Font size in points (int)""", converter=int) weight = event.notifyProperty( '_weight', doc="""Font size in points (int)""", converter=int) italic = event.notifyProperty( '_italic', doc="""True for italic (bool)""", converter=bool)
[docs]class Text2D(primitives.Geometry): """Text field as a 2D texture displayed with bill-boarding :param str text: Text to display :param Font font: The font to use """ # Text anchor values CENTER = 'center' LEFT = 'left' RIGHT = 'right' TOP = 'top' BASELINE = 'baseline' BOTTOM = 'bottom' _ALIGN = LEFT, CENTER, RIGHT _VALIGN = TOP, BASELINE, CENTER, BOTTOM _rasterTextCache = {} """Internal cache storing already rasterized text""" # TODO limit cache size and discard least recent used def __init__(self, text='', font=None): self._dirtyTexture = True self._dirtyAlign = True self._baselineOffset = 0 self._text = text self._font = font if font is not None else Font() self._foreground = 1., 1., 1., 1. self._background = 0., 0., 0., 0. self._overlay = False self._align = 'left' self._valign = 'baseline' self._devicePixelRatio = 1.0 # Store it to check for changes self._texture = None self._textureDirty = True super(Text2D, self).__init__( 'triangle_strip', copy=False, # Keep an array for position as it is bound to attr 0 and MUST # be active and an array at least on Mac OS X position=numpy.zeros((4, 3), dtype=numpy.float32), vertexID=numpy.arange(4., dtype=numpy.float32).reshape(4, 1), offsetInViewportCoords=(0., 0.)) @property def text(self): """Text displayed by this primitive (str)""" return self._text @text.setter def text(self, text): text = str(text) if text != self._text: self._dirtyTexture = True self._text = text self.notify() @property def font(self): """Font to use to raster text (Font)""" return self._font @font.setter def font(self, font): self._font.removeListener(self._fontChanged) self._font = font self._font.addListener(self._fontChanged) self._fontChanged(self) # Which calls notify and primitive as dirty def _fontChanged(self, source): """Listen for font change""" self._dirtyTexture = True self.notify() foreground = event.notifyProperty( '_foreground', doc="""RGBA color of the text: 4 float in [0, 1]""", converter=rgba) background = event.notifyProperty( '_background', doc="RGBA background color of the text field: 4 float in [0, 1]", converter=rgba) overlay = event.notifyProperty( '_overlay', doc="True to always display text on top of the scene (default: False)", converter=bool) def _setAlign(self, align): assert align in self._ALIGN self._align = align self._dirtyAlign = True self.notify() align = property( lambda self: self._align, _setAlign, doc="""Horizontal anchor position of the text field (str). Either 'left' (default), 'center' or 'right'.""") def _setVAlign(self, valign): assert valign in self._VALIGN self._valign = valign self._dirtyAlign = True self.notify() valign = property( lambda self: self._valign, _setVAlign, doc="""Vertical anchor position of the text field (str). Either 'top', 'baseline' (default), 'center' or 'bottom'""") def _raster(self, devicePixelRatio): """Raster current primitive to a bitmap :param float devicePixelRatio: The ratio between device and device-independent pixels :return: Corresponding image in grayscale and baseline offset from top :rtype: (HxW numpy.ndarray of uint8, int) """ params = (self.text, self.font.name, self.font.size, self.font.weight, self.font.italic, devicePixelRatio) if params not in self._rasterTextCache: # Add to cache self._rasterTextCache[params] = _font.rasterText(*params) array, offset = self._rasterTextCache[params] return array.copy(), offset def _bounds(self, dataBounds=False): return None
[docs] def prepareGL2(self, context): # Check if devicePixelRatio has changed since last rendering devicePixelRatio = context.glCtx.devicePixelRatio if self._devicePixelRatio != devicePixelRatio: self._devicePixelRatio = devicePixelRatio self._dirtyTexture = True if self._dirtyTexture: self._dirtyTexture = False if self._texture is not None: self._texture.discard() self._texture = None self._baselineOffset = 0 if self.text: image, self._baselineOffset = self._raster( self._devicePixelRatio) self._texture = _glutils.Texture( gl.GL_R8, image, gl.GL_RED, minFilter=gl.GL_NEAREST, magFilter=gl.GL_NEAREST, wrap=gl.GL_CLAMP_TO_EDGE) self._texture.prepare() self._dirtyAlign = True # To force update of offset if self._dirtyAlign: self._dirtyAlign = False if self._texture is not None: height, width = self._texture.shape if self._align == 'left': ox = 0. elif self._align == 'center': ox = - width // 2 elif self._align == 'right': ox = - width else: _logger.error("Unsupported align: %s", self._align) ox = 0. if self._valign == 'top': oy = 0. elif self._valign == 'baseline': oy = self._baselineOffset elif self._valign == 'center': oy = height // 2 elif self._valign == 'bottom': oy = height else: _logger.error("Unsupported valign: %s", self._valign) oy = 0. offsets = (ox, oy) + numpy.array( ((0., 0.), (width, 0.), (0., -height), (width, -height)), dtype=numpy.float32) self.setAttribute('offsetInViewportCoords', offsets) super(Text2D, self).prepareGL2(context)
[docs] def renderGL2(self, context): if not self.text: return # Nothing to render program = context.glCtx.prog(*self._shaders) program.use() program.setUniformMatrix('matrix', context.objectToNDC.matrix) gl.glUniform2f( program.uniforms['viewportSize'], *context.viewport.size) gl.glUniform4f(program.uniforms['foreground'], *self.foreground) gl.glUniform4f(program.uniforms['background'], *self.background) gl.glUniform1i(program.uniforms['texture'], self._texture.texUnit) gl.glUniform1i(program.uniforms['isOverlay'], 1 if self._overlay else 0) self._texture.bind() if not self._overlay or not gl.glGetBoolean(gl.GL_DEPTH_TEST): self._draw(program) else: # overlay and depth test currently enabled gl.glDisable(gl.GL_DEPTH_TEST) self._draw(program) gl.glEnable(gl.GL_DEPTH_TEST)
# TODO texture atlas + viewportSize as attribute to chain text rendering _shaders = ( """ attribute vec3 position; attribute vec2 offsetInViewportCoords; /* Offset in pixels (y upward) */ attribute float vertexID; /* Index of rectangle corner */ uniform mat4 matrix; uniform vec2 viewportSize; /* Width, height of the viewport */ uniform int isOverlay; varying vec2 texCoords; void main(void) { vec4 clipPos = matrix * vec4(position, 1.0); vec4 ndcPos = clipPos / clipPos.w; /* Perspective divide */ /* Align ndcPos with pixels in viewport-like coords (origin useless) */ vec2 viewportPos = floor((ndcPos.xy + vec2(1.0, 1.0)) * 0.5 * viewportSize); /* Apply offset in viewport coords */ viewportPos += offsetInViewportCoords; /* Convert back to NDC */ vec2 pointPos = 2.0 * viewportPos / viewportSize - vec2(1.0, 1.0); float z = (isOverlay != 0) ? -1.0 : ndcPos.z; gl_Position = vec4(pointPos, z, 1.0); /* Index : texCoords: * 0: (0., 0.) * 1: (1., 0.) * 2: (0., 1.) * 3: (1., 1.) */ texCoords = vec2(vertexID == 0.0 || vertexID == 2.0 ? 0.0 : 1.0, vertexID < 1.5 ? 0.0 : 1.0); } """, # noqa """ varying vec2 texCoords; uniform vec4 foreground; uniform vec4 background; uniform sampler2D texture; void main(void) { float value = texture2D(texture, texCoords).r; if (background.a != 0.0) { gl_FragColor = mix(background, foreground, value); } else { gl_FragColor = foreground; gl_FragColor.a *= value; if (gl_FragColor.a <= 0.01) { discard; } } } """)
[docs]class LabelledAxes(primitives.GroupBBox): """A group displaying a bounding box with axes labels around its children. """ def __init__(self): super(LabelledAxes, self).__init__() self._ticksForBounds = None self._font = Font() # TODO offset labels from anchor in pixels self._xlabel = Text2D(font=self._font) self._xlabel.align = 'center' self._xlabel.transforms = [self._boxTransforms, transform.Translate(tx=0.5)] self._children.append(self._xlabel) self._ylabel = Text2D(font=self._font) self._ylabel.align = 'center' self._ylabel.transforms = [self._boxTransforms, transform.Translate(ty=0.5)] self._children.append(self._ylabel) self._zlabel = Text2D(font=self._font) self._zlabel.align = 'center' self._zlabel.transforms = [self._boxTransforms, transform.Translate(tz=0.5)] self._children.append(self._zlabel) self._tickLines = primitives.Lines( # Init tick lines with dummy pos positions=((0., 0., 0.), (0., 0., 0.)), mode='lines') self._tickLines.visible = False self._children.append(self._tickLines) self._tickLabels = core.Group() self._children.append(self._tickLabels) @property def font(self): """Font of axes text labels (Font)""" return self._font @font.setter def font(self, font): self._font = font self._xlabel.font = font self._ylabel.font = font self._zlabel.font = font for label in self._tickLabels.children: label.font = font @property def xlabel(self): """Text label of the X axis (str)""" return self._xlabel.text @xlabel.setter def xlabel(self, text): self._xlabel.text = text @property def ylabel(self): """Text label of the Y axis (str)""" return self._ylabel.text @ylabel.setter def ylabel(self, text): self._ylabel.text = text @property def zlabel(self): """Text label of the Z axis (str)""" return self._zlabel.text @zlabel.setter def zlabel(self, text): self._zlabel.text = text def _updateTicks(self): """Check if ticks need update and update them if needed.""" bounds = self._group.bounds(transformed=False, dataBounds=True) if bounds is None: # No content if self._ticksForBounds is not None: self._ticksForBounds = None self._tickLines.visible = False self._tickLabels.children = [] # Reset previous labels elif (self._ticksForBounds is None or not numpy.all(numpy.equal(bounds, self._ticksForBounds))): self._ticksForBounds = bounds # Update ticks # TODO make ticks having a constant length on the screen ticklength = numpy.abs(bounds[1] - bounds[0]) / 20. xticks, xlabels = ticklayout.ticks(*bounds[:, 0]) yticks, ylabels = ticklayout.ticks(*bounds[:, 1]) zticks, zlabels = ticklayout.ticks(*bounds[:, 2]) # Update tick lines coords = numpy.empty( ((len(xticks) + len(yticks) + len(zticks)), 4, 3), dtype=numpy.float32) coords[:, :, :] = bounds[0, :] # account for offset from origin xcoords = coords[:len(xticks)] xcoords[:, :, 0] = numpy.asarray(xticks)[:, numpy.newaxis] xcoords[:, 1, 1] += ticklength[1] # X ticks on XY plane xcoords[:, 3, 2] += ticklength[2] # X ticks on XZ plane ycoords = coords[len(xticks):len(xticks) + len(yticks)] ycoords[:, :, 1] = numpy.asarray(yticks)[:, numpy.newaxis] ycoords[:, 1, 0] += ticklength[0] # Y ticks on XY plane ycoords[:, 3, 2] += ticklength[2] # Y ticks on YZ plane zcoords = coords[len(xticks) + len(yticks):] zcoords[:, :, 2] = numpy.asarray(zticks)[:, numpy.newaxis] zcoords[:, 1, 0] += ticklength[0] # Z ticks on XZ plane zcoords[:, 3, 1] += ticklength[1] # Z ticks on YZ plane self._tickLines.setAttribute('position', coords.reshape(-1, 3)) self._tickLines.visible = True # Update labels offsets = bounds[0] - ticklength labels = [] for tick, label in zip(xticks, xlabels): text = Text2D(text=label, font=self.font) text.align = 'center' text.transforms = [transform.Translate( tx=tick, ty=offsets[1], tz=offsets[2])] labels.append(text) for tick, label in zip(yticks, ylabels): text = Text2D(text=label, font=self.font) text.align = 'center' text.transforms = [transform.Translate( tx=offsets[0], ty=tick, tz=offsets[2])] labels.append(text) for tick, label in zip(zticks, zlabels): text = Text2D(text=label, font=self.font) text.align = 'center' text.transforms = [transform.Translate( tx=offsets[0], ty=offsets[1], tz=tick)] labels.append(text) self._tickLabels.children = labels # Reset previous labels
[docs] def prepareGL2(self, context): self._updateTicks() super(LabelledAxes, self).prepareGL2(context)