import itertools
import numpy as np
from ... import mesh
from .internal import GLPrimitive, GLShapeDecorator
from ... import draw
from ..internal import ShapeAttribute
[docs]@GLShapeDecorator
class Lines(draw.Lines, GLPrimitive):
__doc__ = draw.Lines.__doc__
shaders = {}
shaders['vertex'] = """
uniform mat4 camera;
uniform vec4 rotation;
uniform vec3 translation;
uniform int cap_mode;
uniform int transparency_mode;
attribute vec4 color;
attribute vec3 start_point;
attribute vec3 end_point;
attribute vec3 image;
attribute float width;
attribute vec4 shape_id;
varying vec4 v_color;
varying vec3 v_normal;
varying float v_width;
varying vec3 v_position;
varying vec4 v_shape_id;
vec3 rotate(vec3 point, vec4 quat)
{
vec3 result = (quat.x*quat.x - dot(quat.yzw, quat.yzw))*point;
result += 2.0*quat.x*cross(quat.yzw, point);
result += 2.0*dot(quat.yzw, point)*quat.yzw;
return result;
}
vec4 quatquat(vec4 a, vec4 b)
{
float real = a.x*b.x - dot(a.yzw, b.yzw);
vec3 imag = a.x*b.yzw + b.x*a.yzw + cross(a.yzw, b.yzw);
return vec4(real, imag);
}
void main()
{
vec3 startPos = rotate(start_point, rotation) + translation;
vec3 endPos = rotate(end_point, rotation) + translation;
vec3 deltaPos = endPos - startPos;
vec2 normDisplacement = normalize(deltaPos.xy);
vec3 delta = vec3(normDisplacement.y, -normDisplacement.x, 0.0)*width*image.x;
vec3 normal = normalize(cross(deltaPos, delta)*sign(image.x));
vec3 vertexPos = (1.0 - image.y)*startPos + image.y*endPos;
vec3 core = vertexPos;
vertexPos += delta;
if(cap_mode != 0)
{
vertexPos += image.z*width*vec3(normDisplacement, 0.0)*sign(image.y - 0.5)*sqrt(1.5);
vertexPos -= image.z*delta;
}
vec4 screenPosition = camera * vec4(vertexPos, 1.0);
int should_discard = 0;
should_discard += int(transparency_mode < 0 && color.a < 1.0);
should_discard += int(transparency_mode > 0 && color.a >= 1.0);
if(should_discard > 0)
screenPosition = vec4(2.0, 2.0, 2.0, 2.0);
gl_Position = screenPosition;
v_color = color;
v_normal = normal;
v_width = width;
v_position = (vertexPos - core)/width*2.0;
v_shape_id = shape_id;
}
"""
shaders['fragment'] = """
varying float v_width;
varying vec3 v_position;
varying vec4 v_color;
varying vec3 v_normal;
uniform mat4 camera;
// base light level
uniform float ambientLight;
// (x, y, z) direction*intensity
uniform vec3 diffuseLight[NUM_DIFFUSELIGHT];
uniform int transparency_mode;
void main()
{
vec4 color = v_color;
vec3 normal = v_position;
float rsq = dot(normal.xy, normal.xy);
if(rsq > 1.0)
discard;
normal.z = sqrt(1.0 - rsq);
float light = ambientLight;
for(int i = 0; i < NUM_DIFFUSELIGHT; ++i)
light += max(0.0, -dot(normal, diffuseLight[i]));
color.xyz *= light;
float alpha = color.a;
float weight = alpha*max(3e3*pow(
(1.0 - gl_FragCoord.z), 3.0), 1e-2);
#ifndef WEBGL
gl_FragDepth = gl_FragCoord.z + normal.z*v_width*camera[2][2];
#endif
if(transparency_mode < 1)
gl_FragColor = vec4(color.xyz, color.w);
else if(transparency_mode == 1)
gl_FragColor = vec4(color.rgb*alpha, alpha)*weight;
else
gl_FragColor = vec4(alpha);
}
"""
shaders['fragment_pick'] = """
uniform mat4 camera;
uniform vec4 pick_prim_index;
varying float v_width;
varying vec3 v_position;
varying vec3 v_normal;
varying vec4 v_shape_id;
void main()
{
vec3 normal = v_position;
float rsq = dot(normal.xy, normal.xy);
if(rsq > 1.0)
discard;
normal.z = sqrt(1.0 - rsq);
#ifndef WEBGL
gl_FragDepth = gl_FragCoord.z + normal.z*v_width*camera[2][2];
#endif
gl_FragColor = pick_prim_index + v_shape_id;
}
"""
_vertex_attribute_names = ['shape_id', 'start_point', 'end_point', 'color', 'width', 'image']
_GL_UNIFORMS = list(itertools.starmap(ShapeAttribute, [
('camera', np.float32, np.eye(4), 2, False,
'Internal: 4x4 Camera matrix for world projection'),
('cap_mode', np.int32, 0, 0, False,
'Cap mode for lines (0: default, 1: round)'),
('ambientLight', np.float32, .25, 0, False,
'Internal: Ambient (minimum) light level for all surfaces'),
('diffuseLight[]', np.float32, (0, 0, 0), 2, False,
'Internal: Diffuse light direction*magnitude'),
('rotation', np.float32, (1, 0, 0, 0), 1, False,
'Internal: Rotation to be applied to each scene as a quaternion'),
('translation', np.float32, (0, 0, 0), 1, False,
'Internal: Translation to be applied to the scene'),
('transparency_mode', np.int32, 0, 0, False,
'Internal: Transparency stage (<0: opaque, 0: all, 1: '
'translucency stage 1, 2: translucency stage 2)')
]))
def __init__(self, *args, **kwargs):
GLPrimitive.__init__(self)
draw.Lines.__init__(self, *args, **kwargs)
def update_arrays(self):
try:
for name in self._dirty_attributes:
self._gl_vertex_arrays[name][:] = self._attributes[name]
self._dirty_vertex_attribs.add(name)
except (ValueError, KeyError):
# vertices for a unit square. This square will be
# transformed in order for us to draw our line. x and y
# correspond to the square, z gives the pieces at the end
# that will potentially be turned into rounded caps
vertices = np.array([
[-1/2, 0, 0],
[1/2, 0, 0],
[1/2, 1.0, 0],
[-1/2, 1.0, 0],
[1/2, 0, 1],
[1/2, 1, 1],
], dtype=np.float32)
shape_ids = np.arange(len(self), dtype=np.uint32).view(np.uint8).reshape((-1, 4))
shape_ids = shape_ids.astype(np.float32)/255
vertex_arrays = mesh.unfoldProperties(
[shape_ids, self.start_points, self.end_points, self.colors, self.widths],
[vertices])
unfolded_shape = vertex_arrays[0].shape[:-1]
indices = (np.arange(unfolded_shape[0])[:, np.newaxis, np.newaxis]*unfolded_shape[1] +
np.array([[0, 1, 2], [2, 3, 0], [0, 4, 1], [2, 5, 3]], dtype=np.uint32))
indices = indices.reshape((-1, 3))
self._finalize_array_updates(indices, vertex_arrays)
self._dirty_attributes.clear()
def render_planes(self):
# Not currently supported, but we shouldn't error out in the middle of rendering
pass
def render_positions(self):
# Not currently supported, but we shouldn't error out in the middle of rendering
pass