Source code for fury.shaders.base

from functools import partial
import os

import fury
from fury.decorators import warn_on_args_to_kwargs
from fury.io import load_text
from fury.lib import (
    VTK_OBJECT,
    Command,
    DataObject,
    Shader,
    calldata_type,
    numpy_support,
)

SHADERS_DIR = os.path.join(os.path.dirname(__file__))

SHADERS_EXTS = [
    ".glsl",
    ".vert",
    ".tesc",
    ".tese",
    ".geom",
    ".frag",
    ".comp",
]

SHADERS_TYPE = {
    "vertex": Shader.Vertex,
    "geometry": Shader.Geometry,
    "fragment": Shader.Fragment,
}

REPLACEMENT_SHADERS_TYPES = {"vertex": Shader.Vertex, "fragment": Shader.Fragment}

SHADERS_BLOCK = {
    "position": "//VTK::PositionVC",  # frag position in VC
    "normal": "//VTK::Normal",  # optional normal declaration
    "light": "//VTK::Light",  # extra lighting parameters
    "tcoord": "//VTK::TCoord",  # Texture coordinates
    "color": "//VTK::Color",  # material property values
    "clip": "//VTK::Clip",  # clipping plane vars
    "camera": "//VTK::Camera",  # camera and actor matrix values
    "prim_id": "//VTK::PrimID",  # Apple Bug
    "valuepass": "//VTK::ValuePass",  # Value raster
    "output": "//VTK::Output",  # only for geometry shader
    "coincident": "//VTK::Coincident",  # handle coincident offsets
    "zbufer": "//VTK::ZBuffer",
    "depth_peeling": "//VTK::DepthPeeling",  # Depth Peeling Support
    "picking": "//VTK::Picking",  # picking support
}

# See [1] for a more extensive list of OpenGL constants
# [1] https://docs.factorcode.org/content/vocab-opengl.gl.html
GL_NUMBERS = {
    "GL_ONE": 1,
    "GL_ZERO": 0,
    "GL_BLEND": 3042,
    "GL_ONE_MINUS_SRC_ALPHA": 771,
    "GL_SRC_ALPHA": 770,
    "GL_DEPTH_TEST": 2929,
    "GL_DST_COLOR": 774,
    "GL_FUNC_SUBTRACT": 3277,
    "GL_CULL_FACE": 2884,
    "GL_ALPHA_TEST": 3008,
    "GL_CW": 2304,
    "GL_CCW": 2305,
    "GL_ONE_MINUS_SRC_COLOR": 769,
    "GL_SRC_COLOR": 768,
}


[docs] def compose_shader(glsl_code): """Merge GLSL shader code from a list of strings. Parameters ---------- glsl_code : list of str (code or filenames). Returns ------- code : str GLSL shader code. """ if not glsl_code: return "" if not all(isinstance(i, str) for i in glsl_code): raise IOError("The only supported format are string.") if isinstance(glsl_code, str): return glsl_code code = "" for content in glsl_code: code += "\n" code += content return code
[docs] def import_fury_shader(shader_file): """Import a Fury shader. Parameters ---------- shader_file : str Filename of shader. The file must be in the fury/shaders directory and must have the one of the supported extensions specified by the Khronos Group (https://github.com/KhronosGroup/glslang#execution-of-standalone-wrapper). Returns ------- code : str GLSL shader code. """ shader_fname = os.path.join(SHADERS_DIR, shader_file) return load_shader(shader_fname)
[docs] def load_shader(shader_file): """Load a shader from a file. Parameters ---------- shader_file : str Full path to a shader file ending with one of the file extensions defined by the Khronos Group (https://github.com/KhronosGroup/glslang#execution-of-standalone-wrapper). Returns ------- code : str GLSL shader code. """ file_ext = os.path.splitext(os.path.basename(shader_file))[1] if file_ext not in SHADERS_EXTS: raise IOError( 'Shader file "{}" does not have one of the supported ' "extensions: {}.".format(shader_file, SHADERS_EXTS) ) return load_text(shader_file)
[docs] @warn_on_args_to_kwargs() def shader_to_actor( actor, shader_type, *, impl_code="", decl_code="", block="valuepass", keep_default=True, replace_first=True, replace_all=False, debug=False, ): """Apply your own substitutions to the shader creation process. A set of string replacements is applied to a shader template. This function let's apply custom string replacements. Parameters ---------- actor : vtkActor Fury actor you want to set the shader code to. shader_type : str Shader type: vertex, fragment impl_code : str, optional Shader implementation code, should be a string or filename. Default None. decl_code : str, optional Shader declaration code, should be a string or filename. Default None. block : str, optional Section name to be replaced. VTK use of heavy string replacements to insert shader and make it flexible. Each section of the shader template have a specific name. For more information: https://vtk.org/Wiki/Shaders_In_VTK. The possible values are: position, normal, light, tcoord, color, clip, camera, prim_id, valuepass. by default valuepass keep_default : bool, optional Keep the default block tag to let VTK replace it with its default behavior. Default True. replace_first : bool, optional If True, apply this change before the standard VTK replacements. Default True. replace_all : bool, optional [description], by default False debug : bool, optional Introduce a small error to debug shader code. Default False. """ shader_type = shader_type.lower() shader_type = REPLACEMENT_SHADERS_TYPES.get(shader_type, None) if shader_type is None: msg = "Invalid Shader Type. Please choose between " msg += ", ".join(REPLACEMENT_SHADERS_TYPES.keys()) raise ValueError(msg) block = block.lower() block = SHADERS_BLOCK.get(block, None) if block is None: msg = "Invalid Shader Type. Please choose between " msg += ", ".join(SHADERS_BLOCK.keys()) raise ValueError(msg) block_dec = block + "::Dec" block_impl = block + "::Impl" if keep_default: decl_code = block_dec + "\n" + decl_code impl_code = block_impl + "\n" + impl_code if debug: fury.enable_warnings() error_msg = "\n\n--- DEBUG: THIS LINE GENERATES AN ERROR ---\n\n" impl_code += error_msg sp = actor.GetShaderProperty() sp.AddShaderReplacement( shader_type, block_dec, replace_first, decl_code, replace_all ) sp.AddShaderReplacement( shader_type, block_impl, replace_first, impl_code, replace_all )
[docs] def replace_shader_in_actor(actor, shader_type, code): """Set and replace the shader template with a new one. Parameters ---------- actor : vtkActor Fury actor you want to set the shader code to. shader_type : str Shader type: vertex, geometry, fragment. code : str New shader template code. """ function_name = { "vertex": "SetVertexShaderCode", "fragment": "SetFragmentShaderCode", "geometry": "SetGeometryShaderCode", } shader_type = shader_type.lower() function = function_name.get(shader_type, None) if function is None: msg = "Invalid Shader Type. Please choose between " msg += ", ".join(function_name.keys()) raise ValueError(msg) sp = actor.GetShaderProperty() getattr(sp, function)(code)
[docs] @warn_on_args_to_kwargs() def add_shader_callback(actor, callback, *, priority=0.0): """Add a shader callback to the actor. Parameters ---------- actor : vtkActor Fury actor you want to add the callback to. callback : callable Function or class that contains 3 parameters: caller, event, calldata. This callback will be trigger at each `UpdateShaderEvent` event. priority : float, optional Commands with a higher priority are called first. Returns ------- id_observer : int An unsigned Int tag which can be used later to remove the event or retrieve the vtkCommand used in the observer. See more at: https://vtk.org/doc/nightly/html/classvtkObject.html Examples -------- .. code-block:: python add_shader_callback(actor, func_call1) id_observer = add_shader_callback(actor, func_call2) actor.GetMapper().RemoveObserver(id_observer) Priority calls .. code-block:: python test_values = [] def callbackLow(_caller, _event, calldata=None): program = calldata if program is not None: test_values.append(0) def callbackHigh(_caller, _event, calldata=None): program = calldata if program is not None: test_values.append(999) def callbackMean(_caller, _event, calldata=None): program = calldata if program is not None: test_values.append(500) fs.add_shader_callback( actor, callbackHigh, priority=999) fs.add_shader_callback( actor, callbackLow, priority=0) id_mean = fs.add_shader_callback( actor, callbackMean, priority=500) showm.start() # test_values = [999, 500, 0, 999, 500, 0, ...] """ if not isinstance(priority, (float, int)): raise ValueError( """ add_shader_callback priority argument should be a float/int""" ) # @warn_on_args_to_kwargs() @calldata_type(VTK_OBJECT) def cbk(caller, event, calldata=None): callback(caller, event, calldata=calldata) mapper = actor.GetMapper() id_observer = mapper.AddObserver(Command.UpdateShaderEvent, cbk, priority) return id_observer
[docs] @warn_on_args_to_kwargs() def shader_apply_effects(window, actor, effects, *, priority=0): """This applies a specific opengl state (effect) or a list of effects just before the actor's shader is executed. Parameters ---------- window : RenderWindow For example, this is provided by the ShowManager.window attribute. actor : actor effects : a function or a list of functions priority : float, optional Related with the shader callback command. Effects with a higher priority are applied first and can be override by the others. Returns ------- id_observer : int An unsigned Int tag which can be used later to remove the event or retrieve the vtkCommand used in the observer. See more at: https://vtk.org/doc/nightly/html/classvtkObject.html """ if not isinstance(effects, list): effects = [effects] @warn_on_args_to_kwargs() def callback(_caller, _event, *, calldata=None, effects=None, window=None): program = calldata glState = window.GetState() if program is not None: for func in effects: func(glState) id_observer = add_shader_callback( actor, partial(callback, effects=effects, window=window), priority=priority ) return id_observer
[docs] @warn_on_args_to_kwargs() def attribute_to_actor(actor, arr, attr_name, *, deep=True): """Link a numpy array with vertex attribute. Parameters ---------- actor : vtkActor Fury actor you want to add the vertex attribute to. arr : ndarray Array to link to vertices. attr_name : str Vertex attribute name. The vtk array will take the same name as the attribute. deep : bool, optional If True a deep copy is applied, otherwise a shallow copy is applied. Default True. """ nb_components = arr.shape[1] if arr.ndim > 1 else arr.ndim vtk_array = numpy_support.numpy_to_vtk(arr, deep=deep) vtk_array.SetNumberOfComponents(nb_components) vtk_array.SetName(attr_name) actor.GetMapper().GetInput().GetPointData().AddArray(vtk_array) mapper = actor.GetMapper() mapper.MapDataArrayToVertexAttribute( attr_name, attr_name, DataObject.FIELD_ASSOCIATION_POINTS, -1 )