hgl 0.1.3

Simple OpenGL helper library for testing code and writting examples with minimal fuss

#+PROPERTY: header-args :cache yes
HGL - Python Helper GL library

This is a simple library used for writing quick tests and examples programs while avoiding some of the boiler plate code you normally require.
It has also been designed to be used nicely in emacs org-mode so you can do literate programming, quickly testing and annotate code as you go.

Currently only tested on linux, but will likely work on other platforms dependant on the context you use to render.

Current contexts supported are:
+ pySDL2 context
+ pygame-sdl2 context (its a pain to install no pip)
+ gtkglarea context
+ glut context

* Installation
You install this using pip.
#+BEGIN_SRC bash
pip install hgl
#+END_SRC

Alternatively you can use the commend below to install directly from the downloaded source.
#+BEGIN_SRC bash
python3 setup.py develop
#+END_SRC

* Development

To work on this library run setup.py in develop mode to create a symlink to your checked out project.
#+BEGIN_SRC bash
python3 setup.py develop
#+END_SRC

* Testing
To run the test suite you should be able to use pytest in the project root
#+BEGIN_SRC bash
pytest
#+END_SRC

#+RESULTS:
| ============================= | test | session | starts | ============================== | | | |
| platform | linux2 | -- | Python | 2.7.13, | pytest-3.0.6, | py-1.4.32, | pluggy-0.4.0 |
| rootdir: | /home/oly/repos/hgl, | inifile: | | | | | |
| plugins: | mock-1.3.0, | cov-2.4.0, | Inomaly-0.1.0 | | | | |
| collected | 56 | items | | | | | |
| | | | | | | | |
| tests/test_calculate/test_calculations_angles.py | ... | | | | | | |
| tests/test_calculate/test_calculations_boxes.py | ... | | | | | | |
| tests/test_calculate/test_calculations_circles.py | .... | | | | | | |
| tests/test_calculate/test_calculations_curves.py | 0 | | | | | | |
| tests/test_calculate/test_calculations_grid.py | ... | | | | | | |
| tests/test_calculate/test_calculations_intersection.py | .. | | | | | | |
| tests/test_calculate/test_calculations_misc.py | .. | | | | | | |
| tests/test_calculate/test_calculations_origin.py | .. | | | | | | |
| tests/test_extend_context/test_change_shaders.py | ............ | | | | | | |
| tests/test_extend_context/test_change_vertex_array.py | ............ | | | | | | |
| tests/test_gl_contexts/test_context.py | ............ | | | | | | |
| | | | | | | | |
| ========================== | 56 | passed | in | 29.46 | seconds | ========================== | |

* Examples
Below are a few examples of using this library to knock up some quick examples.
** Using different rendering contexts
*** Using gtkglarea context
#+BEGIN_SRC python :results file :exports both
from hgl.context.gtkglarea_context import context
return context(version=(4, 3)).save(filename='./docs/gtkglarea_context_example.png')
#+END_SRC

#+RESULT
#version 330
out vec4 fragColor;
void main()
{
fragColor = vec4(1.0, 1.0, 0.0, 1.0);
}"""]

my_ctx = custom_context(version=(4,3))
return my_ctx.save(filename='./docs/overriden_context.png')
#+END_SRC

#+RESULTS:
[[file:./docs/overriden_context.png]]

** Texturing
#+BEGIN_SRC python :results file :exports both
import os
from OpenGL import GL
import numpy as np
from hgl.context.gtkglarea_context import context
from hgl.libs.textures import load_texture

from hgl.helpers.defaults import simple_texture_fs
from hgl.helpers.defaults import simple_texture_vs
from hgl.helpers.defaults import square_uv, triangle_uv

class custom_context(context):
vertex_list = triangle_uv
vertex_size = 5
vertex_stride = 4 * vertex_size

default_vertex_shader = simple_texture_vs
default_fragment_shader = simple_texture_fs

def update(self):
self.texture_id = load_texture(filename='./tests/textures/testing.png')
super(custom_context, self).update()

my_ctx = custom_context(version=(4,3))
return my_ctx.save(filename='./docs/texture_context.png')
#+END_SRC

#+RESULTS:
[[file:./docs/texture_context.png]]

** Various Examples
*** Draw a square and shade with the uv cordinate
#+BEGIN_SRC python :results file :exports both
import os
from OpenGL import GL
import numpy as np
from hgl.context.gtkglarea_context import context

from hgl.helpers.defaults import point_texture_fs, simple_texture_fs
from hgl.helpers.defaults import point_texture_vs, simple_texture_vs
from hgl.helpers.defaults import square, square_uv

class custom_context(context):
texture_id = 1
vertex_list = square_uv
vertex_size = 5
vertex_stride = 4 * vertex_size

default_vertex_shader = point_texture_vs
default_fragment_shader = point_texture_fs

def draw_data(self):
GL.glBindVertexArray(self.vertex_array_object)
GL.glDrawArrays(GL.GL_TRIANGLE_STRIP, 0, 4)
GL.glBindVertexArray(0)

my_ctx = custom_context(version=(4,3))
return my_ctx.save(filename='./docs/texture_shaded_point.png')
#+END_SRC

#+RESULTS:
[[file:./docs/texture_shaded_point.png]]



*** Draw multiple squares using an index array
#+BEGIN_SRC python :results file :exports both
import random
from OpenGL import GL
import numpy as np
from hgl.context.gtkglarea_context import context
from hgl.calculate.box import plane_from_width_and_height

class custom_context(context):
points = 0
count = 0
box_vertex_list = []
box_index_list = []

def __init__(self, shader_programs=None, version=(4, 5)):
self.add_squares()
super(custom_context, self).__init__(shader_programs=shader_programs, version=version)

def add_point(self, pos):
offset = 4 * self.points
self.box_vertex_list += plane_from_width_and_height(
centre=(pos[0], pos[1], pos[2]), plane_width_centre=0.1, plane_height_centre=0.1)
self.box_index_list += 0+offset, 1+offset, 2+offset, 2+offset, 1+offset, 3+offset
self.points += 1

def add_squares(self, count=20):
for b in range(0, count):
pos_x, pos_y = random.uniform(-1.0,1.0), random.uniform(-1.0,1.0)
self.add_point((pos_x,pos_y,0.0))
self.vertex_list = np.array(self.box_vertex_list, dtype=np.float32)
self.index_list = np.array(self.box_index_list, dtype=np.uint32)

my_ctx = custom_context(version=(4,3))
return my_ctx.save(filename='./docs/indexed_quads.png')
#+END_SRC

#+RESULTS:
[[file:./docs/indexed_quads.png]]


*** Example font rendering
#+BEGIN_SRC python :results file :exports both
import freetype as ft
import numpy as np
from hgl.context.gtkglarea_context import context
from hgl.calculate.box import plane_from_width_and_height
from hgl.calculate.box import box_from_line
from hgl.calculate.font_outline import (
generate_text, step_text_points, step_text_lines)


class custom_context(context):
points = 0
count = 0
box_vertex_list = []
box_index_list = []

location = (0.0,0.0,-100.0)

model_view_matrix = np.array([
1.0, 0.0, 0.0, 0.0,
0.0, 1.0, 0.0, 0.0,
0.0, 0.0, 1.0, 0.0,
0.0, 0.0, location[2],1.0
], np.float32)


def __init__(self, shader_programs=None, version=(4, 5), points=None, lines=None):
if points is not None:
self.add_point_list(points)
if lines is not None:
self.add_line_list(lines)
self.load_point_buffer()
super(custom_context, self).__init__(shader_programs=shader_programs, version=version)

def add_line_list(self, lines):
for p1, p2 in step_text_lines(lines):
offset = 4 * self.points
self.box_vertex_list += box_from_line(
line_start=p1, line_end=p2, width=0.1)
self.box_index_list += 0+offset, 1+offset, 2+offset, 2+offset, 1+offset, 3+offset
self.points += 1

def add_point_list(self, points):
for p in points:
self.add_point(p)

def add_point(self, pos):
offset = 4 * self.points
self.box_vertex_list += plane_from_width_and_height(
centre=(pos[0], pos[1], pos[2]), plane_width_centre=0.3, plane_height_centre=0.3)
self.box_index_list += 0+offset, 1+offset, 2+offset, 2+offset, 1+offset, 3+offset
self.points += 1

def load_point_buffer(self):
self.vertex_list = np.array(self.box_vertex_list, dtype=np.float32)
self.index_list = np.array(self.box_index_list, dtype=np.uint32)


face = ft.Face('/usr/share/fonts/truetype/ubuntu-font-family/UbuntuMono-B.ttf')
face.set_char_size(12)
face.load_char('S')
point_list = generate_text(face, 'TESTING... :)')
points = []
for letter, segments, point in step_text_points(point_list):
points.append(point_list[letter][segments][point])

my_ctx = custom_context(version=(4,3), points=[], lines=point_list)
my_ctx.save(filename='./docs/font_outline.png')
#+END_SRC

#+RESULTS[add2ec6701393536f94eefb6f23ed47861f99092]:
[[file:None]]



*** Draw a line example
#+BEGIN_SRC python :results file :exports both
import numpy as np
from hgl.context.gtkglarea_context import context
from hgl.helpers.defaults import point_texture_fs, point_texture_vs
from hgl.calculate.box import box_from_line


class custom_context(context):
box_index_list = []
box_vertex_list = []
points = 0

def __init__(self, shader_programs=None, version=(4, 5), points=None, lines=None):
if lines is not None:
self.add_line_list(lines)
self.load_point_buffer()
super(custom_context, self).__init__(shader_programs=shader_programs, version=version)

def add_line_list(self, lines):
for p1, p2 in lines:
offset = 4 * self.points
self.box_vertex_list += box_from_line(
line_start=p1, line_end=p2, width=0.1)
self.box_index_list += 0+offset, 1+offset, 2+offset, 2+offset, 1+offset, 3+offset
self.points += 1

def load_point_buffer(self):
self.vertex_list = np.array(self.box_vertex_list, dtype=np.float32)
self.index_list = np.array(self.box_index_list, dtype=np.uint32)

lines = [((0.5,0.5,0.0),(-0.5,-0.5,0.0),)]
my_ctx = custom_context(version=(4,3), lines=lines)
return my_ctx.save(filename='./docs/draw_line_example.png')
#+END_SRC

#+RESULTS[b1685a840741aaef88b1f292ee836a0e2b195487]:
[[file:./docs/draw_line_example.png]]

*** Bezier curve
#+BEGIN_SRC python :results file :exports both
import numpy as np
from hgl.context.gtkglarea_context import context
from hgl.helpers.defaults import point_texture_fs, point_texture_vs
from hgl.calculate.box import box_from_line
from hgl.calculate.curve import generate_quadratic_bezier_curve_points, generate_bezier


class custom_context(context):
box_index_list = []
box_vertex_list = []
points = 0
location = (0.0, 0.0, -10.0)

def __init__(self, shader_programs=None, version=(4, 5), points=None, lines=None):
if lines is not None:
self.add_line_list(lines)
self.load_point_buffer()
super(custom_context, self).__init__(shader_programs=shader_programs, version=version)

def add_line_list(self, lines):
for p1, p2 in lines:
offset = 4 * self.points
self.box_vertex_list += box_from_line(
line_start=p1, line_end=p2, width=0.035)
self.box_index_list += 0+offset, 1+offset, 2+offset, 2+offset, 1+offset, 3+offset
self.points += 1

def load_point_buffer(self):
self.vertex_list = np.array(self.box_vertex_list, dtype=np.float32)
self.index_list = np.array(self.box_index_list, dtype=np.uint32)

lines = [
((1.0, 0.0, 0.0), (1.0, 1.0, 0.0),),
((-1.0, 1.0, 0.0), (-1.0, 0.0, 0.0),),
]
lines = [
((1.0, 2.5, 0.0), (1.5, 1.0, 0.0),),
((3.5, 1.0, 0.0), (4.0, 2.5, 0.0),),
]
line_points = [p for lp in lines for p in lp]
#results = generate_quadratic_bezier_curve_points(line_points, 10)
results = generate_bezier(line_points, 8)
#results = generate_quadratic_bezier_curve_points(lines[0], 10)
results = [(results[p], results[p+1]) for p in range(0, len(results)-1, 1)]
my_ctx = custom_context(version=(4,3), lines=results)
return my_ctx.save(filename='./docs/draw_bezier_example.png')
#return results
#+END_SRC

#+RESULTS[8b063fc305e53231b6c80c76bb5f3566b7be81bb]:
[[file:./docs/draw_bezier_example.png]]





#+BEGIN_SRC python

import numpy as np
from hgl.context.gtkglarea_context import context
from hgl.helpers.defaults import point_texture_fs, point_texture_vs
from hgl.calculate.box import box_from_line
from hgl.calculate.curve import generate_quadratic_bezier_curve_points, generate_bezier



lines = [
((1.0, 0.0, 0.0), (1.0, 1.0, 0.0),),
((-1.0, 0.0, 0.0), (-1.0, 1.0, 0.0),),
]
line_points = [p for lp in lines for p in lp]
#results = generate_quadratic_bezier_curve_points(line_points, 10)
results = generate_bezier(line_points, 10)
# results = [(results[p], results[p+1]) for p in range(0, len(results)-1, 2)]
return lines+results
#+END_SRC

#+RESULTS[8567e92e6e2095450741903dcf5602d5217599c4]:
| (1.0 0.0 0.0) | (1.0 1.0 0.0) | |
| (-1.0 0.0 0.0) | (-1.0 1.0 0.0) | |
| (1.0 0.1 0.0) | (0.8 0.9 0.0) | (-1.0 0.1 0.0) |
| (1.0 0.2 0.0) | (0.6000000000000001 0.8 0.0) | (-1.0 0.2 0.0) |
| (1.0 0.3 0.0) | (0.39999999999999997 0.7 0.0) | (-1.0 0.3 0.0) |
| (1.0 0.4 0.0) | (0.19999999999999996 0.6 0.0) | (-1.0 0.4 0.0) |
| (1.0 0.5 0.0) | (0.0 0.5 0.0) | (-1.0 0.5 0.0) |
| (1.0 0.6 0.0) | (-0.19999999999999996 0.4 0.0) | (-1.0 0.6 0.0) |
| (1.0 0.7 0.0) | (-0.3999999999999999 0.30000000000000004 0.0) | (-1.0 0.7 0.0) |
| (1.0 0.8 0.0) | (-0.6000000000000001 0.19999999999999996 0.0) | (-1.0 0.8 0.0) |
| (1.0 0.9 0.0) | (-0.8 0.09999999999999998 0.0) | (-1.0 0.9 0.0) |


#+BEGIN_SRC python :results file :exports both
from hgl.context.gtkglarea_context import context
from hgl.helpers.context import simple_primitive_context
from hgl.calculate.curve import generate_quadratic_bezier_curve_points, generate_bezier

lines = [
((1.0, 0.0, 0.0), (1.0, 1.0, 0.0),),
((-1.0, 1.0, 0.0), (-1.0, 0.0, 0.0),),
]

line_points = [p for lp in lines for p in lp]
results = generate_bezier(line_points, 8)
results = [(results[p], results[p+1]) for p in range(0, len(results)-1, 1)]
my_ctx = simple_primitive_context(inherited_context=context)(version=(4,3), lines=results)
return my_ctx.save(filename='./docs/draw_bezier_example.png')
#+END_SRC

#+RESULTS[94c9037cab1ecbd014f164d78576c0d59efa4906]:
[[file:./docs/draw_bezier_example.png]]






#+BEGIN_SRC python :exports both
from hgl.context.gtkglarea_context import context
from hgl.helpers.context import simple_primitive_context
from hgl.calculate.curve import generate_quadratic_bezier_curve_points, generate_bezier

lines = [
((1.0, 0.0, 0.0), (1.0, 1.0, 0.0),),
((-1.0, 1.0, 0.0), (-1.0, 0.0, 0.0),),
]

line_points = [p for lp in lines for p in lp]
results = generate_bezier(line_points, 8)
results = [(results[p], results[p+1]) for p in range(0, len(results)-1, 1)]
my_ctx = simple_primitive_context(inherited_context=context, version=(4,3), lines=results)
return results
#+END_SRC

#+RESULTS[1cf9e020722b36572275afe45d62f56f232cd3af]:
| (0.9140625 0.328125 0.0) | (0.6875 0.5625 0.0) |
| (0.6875 0.5625 0.0) | (0.3671875 0.703125 0.0) |
| (0.3671875 0.703125 0.0) | (0.0 0.75 0.0) |
| (0.0 0.75 0.0) | (-0.3671875 0.703125 0.0) |
| (-0.3671875 0.703125 0.0) | (-0.6875 0.5625 0.0) |
| (-0.6875 0.5625 0.0) | (-0.9140625 0.328125 0.0) |