Source code for opengl.shader

##  This file is part of pyFormex 1.0.7  (Mon Jun 17 12:20:39 CEST 2019)
##  pyFormex is a tool for generating, manipulating and transforming 3D
##  geometrical models by sequences of mathematical operations.
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##  Copyright 2004-2019 (C) Benedict Verhegghe (
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##  but WITHOUT ANY WARRANTY; without even the implied warranty of
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"""OpenGL shader programs

Python OpenGL framework for pyFormex

This module is responsible for loading the shader programs
and its data onto the graphics system.

(C) 2013 Benedict Verhegghe and the pyFormex project.

from __future__ import absolute_import, division, print_function

from OpenGL import GL
from OpenGL.GL import shaders
import pyformex as pf

[docs]def defaultShaders(): """Determine the default shader programs""" from pyformex.opengl import canvas from pyformex.gui import viewport from import SaneVersion glversion = canvas.glVersion() vendor = glversion['vendor'] renderer = glversion['renderer'] version = glversion['version'] vmajor, vminor = version.split('.')[:2] fmt = viewport.opengl_format major, minor = fmt.majorVersion(), fmt.minorVersion() availversion = "%s.%s" % (vmajor, vminor) activeversion = "%s.%s" % (major, minor) pf.debug("Vendor: %s; Renderer: %s; Available version: %s; Active version %s" % (vendor, renderer, availversion, activeversion), pf.DEBUG.OPENGL) #shortversion = "%s.%s" % (major,minor) # Default shaders dirname = pf.pyformexdir / 'glsl' vertexshader = str(dirname / "vertex_shader") fragmentshader = str(dirname / "fragment_shader") if not pf.options.shader: if pf.options.opengl is not None: if SaneVersion(pf.options.opengl) >= SaneVersion('3.3'): pf.options.shader = '330' # Default shaders for some hardware pf.debug("Selecting best default shader", pf.DEBUG.OPENGL) if 'Mesa' in renderer or 'Mesa' in version: pf.options.shader = 'mesa' # For Radeon, select 330 if available if 'Radeon' in renderer and SaneVersion(availversion) >= SaneVersion('3.3'): pf.options.shader = '330' if pf.options.shader: vertexshader += '_%s' % pf.options.shader fragmentshader += '_%s' % pf.options.shader vertexshader += '.c' fragmentshader += '.c' return vertexshader, fragmentshader
[docs]class Shader(object): """An OpenGL shader consisting of a vertex and a fragment shader pair. Class attributes: - `_vertexshader` : the vertex shader source. By default, a basic shader supporting vertex positions and vertex colors is defined - `_fragmentshader` : the fragment shader source. By default, a basic shader supporting fragment colors is defined. - `attributes`: the shaders' vertex attributes. - `uniforms`: the shaders' uniforms. """ # Default attributes and uniforms attributes = [ 'vertexCoords', 'vertexNormal', 'vertexColor', 'vertexTexturePos', 'vertexScalar', 'vertexOffset', ] # int and bool uniforms uniforms_int = [ 'highlight', 'useObjectColor', 'rgbamode', 'useTexture', 'texmode', 'rendertype', 'alphablend', 'drawface', 'lighting', 'nlights', ] uniforms_float = [ 'pointsize', 'ambient', 'diffuse', 'specular', 'shininess', 'alpha', 'bkalpha', ] uniforms_vec3 = [ 'objectColor', 'objectBkColor', 'ambicolor', 'diffcolor', 'speccolor', 'lightdir', 'offset3', 'highlightColor', ] uniforms = uniforms_int + uniforms_float + uniforms_vec3 + [ 'modelview', 'projection', 'modelviewprojection', 'normalstransform', 'pickmat', 'picking', ] def __init__(self, vshader=None, fshader=None, attributes=None, uniforms=None): _vertexshader, _fragmentshader = defaultShaders() if vshader is None: vshader = _vertexshader pf.debug("Using vertex shader %s" % vshader, pf.DEBUG.OPENGL) with open(vshader) as f: VertexShader = if fshader is None: fshader = _fragmentshader pf.debug("Using fragment shader %s" % fshader, pf.DEBUG.OPENGL) with open(fshader) as f: FragmentShader = if attributes is None: attributes = Shader.attributes if uniforms is None: uniforms = Shader.uniforms vertex_shader = shaders.compileShader(VertexShader, GL.GL_VERTEX_SHADER) fragment_shader = shaders.compileShader(FragmentShader, GL.GL_FRAGMENT_SHADER) self.shader = shaders.compileProgram(vertex_shader, fragment_shader) self.attribute = self.locations(GL.glGetAttribLocation, attributes) self.uniform = self.locations(GL.glGetUniformLocation, uniforms) self.picking = 0 # Default render mode
[docs] def locations(self, func, keys): """Create a dict with the locations of the specified keys""" return dict([(k, func(self.shader, k)) for k in keys])
[docs] def uniformInt(self, name, value): """Load a uniform integer or boolean into the shader""" loc = self.uniform[name] GL.glUniform1i(loc, value)
[docs] def uniformFloat(self, name, value): """Load a uniform float into the shader""" loc = self.uniform[name] GL.glUniform1f(loc, value)
## def uniformVec3(self,name,value): ## """Load a uniform vec3 into the shader""" ## loc = self.uniform[name] ## GL.glUniform3fv(loc,1,value)
[docs] def uniformVec3(self, name, value): """Load a uniform vec3[n] into the shader The value should be a 1D array or list. """ loc = self.uniform[name] n = len(value) // 3 GL.glUniform3fv(loc, n, value)
[docs] def uniformMat4(self, name, value): """Load a uniform mat4 into the shader""" loc = self.uniform[name] GL.glUniformMatrix4fv(loc, 1, False, value)
[docs] def uniformMat3(self, name, value): """Load a uniform mat3 into the shader""" loc = self.uniform[name] GL.glUniformMatrix3fv(loc, 1, False, value)
[docs] def bind(self, picking=False): """Bind the shader program""" shaders.glUseProgram(self.shader) self.uniformInt('picking', picking)
[docs] def unbind(self): """Unbind the shader program""" shaders.glUseProgram(0)
[docs] def loadUniforms(self, D): """Load the uniform attributes defined in D D is a dict with uniform attributes to be loaded into the shader program. The attributes can be of type int, float, or vec3. """ for attribs, func in [ (self.uniforms_int, self.uniformInt), (self.uniforms_float, self.uniformFloat), (self.uniforms_vec3, self.uniformVec3), ]: for a in attribs: v = D[a] if v is not None: func(a, v)
def __del__(self): """Delete a shader instance. This will unbinf the shader program before deleting it. """ self.unbind()
# End