from OpenGL.GL import * # noqa
from OpenGL.GL import shaders # noqa
try:
from OpenGL import NullFunctionError
except ImportError:
from OpenGL.error import NullFunctionError
import numpy as np
import re
## For centralizing and managing vertex/fragment shader programs.
def initShaders():
global Shaders
Shaders = [
ShaderProgram(None, []),
## increases fragment alpha as the normal turns orthogonal to the view
## this is useful for viewing shells that enclose a volume (such as isosurfaces)
ShaderProgram('balloon', [
VertexShader("""
varying vec3 normal;
void main() {
// compute here for use in fragment shader
normal = normalize(gl_NormalMatrix * gl_Normal);
gl_FrontColor = gl_Color;
gl_BackColor = gl_Color;
gl_Position = ftransform();
}
"""),
FragmentShader("""
varying vec3 normal;
void main() {
vec4 color = gl_Color;
color.w = min(color.w + 2.0 * color.w * pow(normal.x*normal.x + normal.y*normal.y, 5.0), 1.0);
gl_FragColor = color;
}
""")
]),
## colors fragments based on face normals relative to view
## This means that the colors will change depending on how the view is rotated
ShaderProgram('viewNormalColor', [
VertexShader("""
varying vec3 normal;
void main() {
// compute here for use in fragment shader
normal = normalize(gl_NormalMatrix * gl_Normal);
gl_FrontColor = gl_Color;
gl_BackColor = gl_Color;
gl_Position = ftransform();
}
"""),
FragmentShader("""
varying vec3 normal;
void main() {
vec4 color = gl_Color;
color.x = (normal.x + 1.0) * 0.5;
color.y = (normal.y + 1.0) * 0.5;
color.z = (normal.z + 1.0) * 0.5;
gl_FragColor = color;
}
""")
]),
## colors fragments based on absolute face normals.
ShaderProgram('normalColor', [
VertexShader("""
varying vec3 normal;
void main() {
// compute here for use in fragment shader
normal = normalize(gl_Normal);
gl_FrontColor = gl_Color;
gl_BackColor = gl_Color;
gl_Position = ftransform();
}
"""),
FragmentShader("""
varying vec3 normal;
void main() {
vec4 color = gl_Color;
color.x = (normal.x + 1.0) * 0.5;
color.y = (normal.y + 1.0) * 0.5;
color.z = (normal.z + 1.0) * 0.5;
gl_FragColor = color;
}
""")
]),
## very simple simulation of lighting.
## The light source position is always relative to the camera.
ShaderProgram('shaded', [
VertexShader("""
varying vec3 normal;
void main() {
// compute here for use in fragment shader
normal = normalize(gl_NormalMatrix * gl_Normal);
gl_FrontColor = gl_Color;
gl_BackColor = gl_Color;
gl_Position = ftransform();
}
"""),
FragmentShader("""
varying vec3 normal;
void main() {
float p = dot(normal, normalize(vec3(1.0, -1.0, -1.0)));
p = p < 0. ? 0. : p * 0.8;
vec4 color = gl_Color;
color.x = color.x * (0.2 + p);
color.y = color.y * (0.2 + p);
color.z = color.z * (0.2 + p);
gl_FragColor = color;
}
""")
]),
## colors get brighter near edges of object
ShaderProgram('edgeHilight', [
VertexShader("""
varying vec3 normal;
void main() {
// compute here for use in fragment shader
normal = normalize(gl_NormalMatrix * gl_Normal);
gl_FrontColor = gl_Color;
gl_BackColor = gl_Color;
gl_Position = ftransform();
}
"""),
FragmentShader("""
varying vec3 normal;
void main() {
vec4 color = gl_Color;
float s = pow(normal.x*normal.x + normal.y*normal.y, 2.0);
color.x = color.x + s * (1.0-color.x);
color.y = color.y + s * (1.0-color.y);
color.z = color.z + s * (1.0-color.z);
gl_FragColor = color;
}
""")
]),
## colors fragments by z-value.
## This is useful for coloring surface plots by height.
## This shader uses a uniform called "colorMap" to determine how to map the colors:
## red = pow(colorMap[0]*(z + colorMap[1]), colorMap[2])
## green = pow(colorMap[3]*(z + colorMap[4]), colorMap[5])
## blue = pow(colorMap[6]*(z + colorMap[7]), colorMap[8])
## (set the values like this: shader['uniformMap'] = array([...])
ShaderProgram('heightColor', [
VertexShader("""
varying vec4 pos;
void main() {
gl_FrontColor = gl_Color;
gl_BackColor = gl_Color;
pos = gl_Vertex;
gl_Position = ftransform();
}
"""),
FragmentShader("""
uniform float colorMap[9];
varying vec4 pos;
//out vec4 gl_FragColor; // only needed for later glsl versions
//in vec4 gl_Color;
void main() {
vec4 color = gl_Color;
color.x = colorMap[0] * (pos.z + colorMap[1]);
if (colorMap[2] != 1.0)
color.x = pow(color.x, colorMap[2]);
color.x = color.x < 0. ? 0. : (color.x > 1. ? 1. : color.x);
color.y = colorMap[3] * (pos.z + colorMap[4]);
if (colorMap[5] != 1.0)
color.y = pow(color.y, colorMap[5]);
color.y = color.y < 0. ? 0. : (color.y > 1. ? 1. : color.y);
color.z = colorMap[6] * (pos.z + colorMap[7]);
if (colorMap[8] != 1.0)
color.z = pow(color.z, colorMap[8]);
color.z = color.z < 0. ? 0. : (color.z > 1. ? 1. : color.z);
color.w = 1.0;
gl_FragColor = color;
}
"""),
], uniforms={'colorMap': [1, 1, 1, 1, 0.5, 1, 1, 0, 1]}),
ShaderProgram('pointSprite', [ ## allows specifying point size using normal.x
## See:
##
## http://stackoverflow.com/questions/9609423/applying-part-of-a-texture-sprite-sheet-texture-map-to-a-point-sprite-in-ios
## http://stackoverflow.com/questions/3497068/textured-points-in-opengl-es-2-0
##
##
VertexShader("""
void main() {
gl_FrontColor=gl_Color;
gl_PointSize = gl_Normal.x;
gl_Position = ftransform();
}
"""),
#FragmentShader("""
##version 120
#uniform sampler2D texture;
#void main ( )
#{
#gl_FragColor = texture2D(texture, gl_PointCoord) * gl_Color;
#}
#""")
]),
]
CompiledShaderPrograms = {}
def getShaderProgram(name):
return ShaderProgram.names[name]
class Shader(object):
def __init__(self, shaderType, code):
self.shaderType = shaderType
self.code = code
self.compiled = None
def shader(self):
if self.compiled is None:
try:
self.compiled = shaders.compileShader(self.code, self.shaderType)
except NullFunctionError:
raise Exception("This OpenGL implementation does not support shader programs; many OpenGL features in pyqtgraph will not work.")
except RuntimeError as exc:
## Format compile errors a bit more nicely
if len(exc.args) == 3:
err, code, typ = exc.args
if not err.startswith('Shader compile failure'):
raise
code = code[0].decode('utf_8').split('\n')
err, c, msgs = err.partition(':')
err = err + '\n'
msgs = re.sub('b\'','',msgs)
msgs = re.sub('\'$','',msgs)
msgs = re.sub('\\\\n','\n',msgs)
msgs = msgs.split('\n')
errNums = [()] * len(code)
for i, msg in enumerate(msgs):
msg = msg.strip()
if msg == '':
continue
m = re.match(r'(\d+\:)?\d+\((\d+)\)', msg)
if m is not None:
line = int(m.groups()[1])
errNums[line-1] = errNums[line-1] + (str(i+1),)
#code[line-1] = '%d\t%s' % (i+1, code[line-1])
err = err + "%d %s\n" % (i+1, msg)
errNums = [','.join(n) for n in errNums]
maxlen = max(map(len, errNums))
code = [errNums[i] + " "*(maxlen-len(errNums[i])) + line for i, line in enumerate(code)]
err = err + '\n'.join(code)
raise Exception(err)
else:
raise
return self.compiled
class VertexShader(Shader):
def __init__(self, code):
Shader.__init__(self, GL_VERTEX_SHADER, code)
class FragmentShader(Shader):
def __init__(self, code):
Shader.__init__(self, GL_FRAGMENT_SHADER, code)
class ShaderProgram(object):
names = {}
def __init__(self, name, shaders, uniforms=None):
self.name = name
ShaderProgram.names[name] = self
self.shaders = shaders
self.prog = None
self.blockData = {}
self.uniformData = {}
## parse extra options from the shader definition
if uniforms is not None:
for k,v in uniforms.items():
self[k] = v
def setBlockData(self, blockName, data):
if data is None:
del self.blockData[blockName]
else:
self.blockData[blockName] = data
def setUniformData(self, uniformName, data):
if data is None:
del self.uniformData[uniformName]
else:
self.uniformData[uniformName] = data
def __setitem__(self, item, val):
self.setUniformData(item, val)
def __delitem__(self, item):
self.setUniformData(item, None)
def program(self):
if self.prog is None:
try:
compiled = [s.shader() for s in self.shaders] ## compile all shaders
self.prog = shaders.compileProgram(*compiled) ## compile program
except:
self.prog = -1
raise
return self.prog
def __enter__(self):
if len(self.shaders) > 0 and self.program() != -1:
glUseProgram(self.program())
try:
## load uniform values into program
for uniformName, data in self.uniformData.items():
loc = self.uniform(uniformName)
if loc == -1:
raise Exception('Could not find uniform variable "%s"' % uniformName)
glUniform1fv(loc, len(data), np.array(data, dtype=np.float32))
### bind buffer data to program blocks
#if len(self.blockData) > 0:
#bindPoint = 1
#for blockName, data in self.blockData.items():
### Program should have a uniform block declared:
###
### layout (std140) uniform blockName {
### vec4 diffuse;
### };
### pick any-old binding point. (there are a limited number of these per-program
#bindPoint = 1
### get the block index for a uniform variable in the shader
#blockIndex = glGetUniformBlockIndex(self.program(), blockName)
### give the shader block a binding point
#glUniformBlockBinding(self.program(), blockIndex, bindPoint)
### create a buffer
#buf = glGenBuffers(1)
#glBindBuffer(GL_UNIFORM_BUFFER, buf)
#glBufferData(GL_UNIFORM_BUFFER, size, data, GL_DYNAMIC_DRAW)
### also possible to use glBufferSubData to fill parts of the buffer
### bind buffer to the same binding point
#glBindBufferBase(GL_UNIFORM_BUFFER, bindPoint, buf)
except:
glUseProgram(0)
raise
def __exit__(self, *args):
if len(self.shaders) > 0:
glUseProgram(0)
def uniform(self, name):
"""Return the location integer for a uniform variable in this program"""
return glGetUniformLocation(self.program(), name.encode('utf_8'))
#def uniformBlockInfo(self, blockName):
#blockIndex = glGetUniformBlockIndex(self.program(), blockName)
#count = glGetActiveUniformBlockiv(self.program(), blockIndex, GL_UNIFORM_BLOCK_ACTIVE_UNIFORMS)
#indices = []
#for i in range(count):
#indices.append(glGetActiveUniformBlockiv(self.program(), blockIndex, GL_UNIFORM_BLOCK_ACTIVE_UNIFORM_INDICES))
class HeightColorShader(ShaderProgram):
def __enter__(self):
## Program should have a uniform block declared:
##
## layout (std140) uniform blockName {
## vec4 diffuse;
## vec4 ambient;
## };
## pick any-old binding point. (there are a limited number of these per-program
bindPoint = 1
## get the block index for a uniform variable in the shader
blockIndex = glGetUniformBlockIndex(self.program(), "blockName")
## give the shader block a binding point
glUniformBlockBinding(self.program(), blockIndex, bindPoint)
## create a buffer
buf = glGenBuffers(1)
glBindBuffer(GL_UNIFORM_BUFFER, buf)
glBufferData(GL_UNIFORM_BUFFER, size, data, GL_DYNAMIC_DRAW)
## also possible to use glBufferSubData to fill parts of the buffer
## bind buffer to the same binding point
glBindBufferBase(GL_UNIFORM_BUFFER, bindPoint, buf)
initShaders()