1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
|
'''
Framebuffer scissoring.
Renders a fullscreen quad four times with different scissor
values filling each quadrant of the screen with a different color.
We swap between rendering geometry and using clear.
'''
import numpy as np
import moderngl
from _example import Example
class Scissor(Example):
gl_version = (3, 3)
title = "Scissor"
resizable = True
aspect_ratio = None
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.prog = self.ctx.program(
vertex_shader='''
#version 330
in vec2 in_vert;
void main() {
gl_Position = vec4(in_vert, 0.0, 1.0);
}
''',
fragment_shader='''
#version 330
out vec4 fragColor;
uniform vec4 color;
void main() {
fragColor = color;
}
''',
)
quad = [
-1.0, 1.0,
-1.0, -1.0,
1.0, 1.0,
1.0, -1.0,
]
vbo = self.ctx.buffer(np.array(quad, dtype='f4'))
self.vao = self.ctx.simple_vertex_array(self.prog, vbo, 'in_vert')
def render(self, time: float, frame_time: float):
"""Swap between rendering geometry and using clear"""
fb_width_half = self.wnd.buffer_width // 2
fb_height_half = self.wnd.buffer_height // 2
if self.wnd.frames % 2 == 0:
# upper left (red)
self.ctx.scissor = 0, fb_height_half, fb_width_half, fb_height_half
self.prog['color'].value = 1.0, 0.0, 0.0, 0.0
self.vao.render(mode=moderngl.TRIANGLE_STRIP)
# upper right (green)
self.ctx.scissor = fb_width_half, fb_height_half, fb_width_half, fb_height_half
self.prog['color'].value = 0.0, 1.0, 0.0, 0.0
self.vao.render(mode=moderngl.TRIANGLE_STRIP)
# Lower left
self.ctx.scissor = 0, 0, fb_width_half, fb_height_half
self.prog['color'].value = 0.0, 0.0, 1.0, 0.0
self.vao.render(mode=moderngl.TRIANGLE_STRIP)
# Lower right
self.ctx.scissor = fb_width_half, 0, fb_width_half, fb_height_half
self.prog['color'].value = 1.0, 1.0, 1.0, 1.0
self.vao.render(mode=moderngl.TRIANGLE_STRIP)
else:
# upper left (red)
self.ctx.scissor = 0, fb_height_half, fb_width_half, fb_height_half
self.ctx.clear(1.0, 0.0, 0.0, 0.0)
# upper right (green)
self.ctx.scissor = fb_width_half, fb_height_half, fb_width_half, fb_height_half
self.ctx.clear(0.0, 1.0, 0.0, 0.0)
# Lower left
self.ctx.scissor = 0, 0, fb_width_half, fb_height_half
self.ctx.clear(0.0, 0.0, 1.0, 0.0)
# Lower right
self.ctx.scissor = fb_width_half, 0, fb_width_half, fb_height_half
self.ctx.clear(1.0, 1.0, 1.0, 1.0)
# Reset scissor
self.ctx.scissor = None
if __name__ == '__main__':
Scissor.run()
|
