comparison pytouhou/ui/shader.py @ 370:74471afbac37

Add a programmable pipeline renderer, and a --fixed-pipeline switch to use the old one.
author Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
date Fri, 27 Jul 2012 18:43:48 +0200
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children 0537af9125a7
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369:f305cdd6f6c5 370:74471afbac37
1 #
2 # Copyright Tristam Macdonald 2008.
3 # Copyright Emmanuel Gil Peyrot 2012.
4 #
5 # Distributed under the Boost Software License, Version 1.0
6 # (see http://www.boost.org/LICENSE_1_0.txt)
7 #
8 # Source: https://swiftcoder.wordpress.com/2008/12/19/simple-glsl-wrapper-for-pyglet/
9 #
10
11 from pyglet.gl import *
12
13
14 class GLSLException(Exception):
15 pass
16
17
18 class Shader(object):
19 # vert and frag take arrays of source strings the arrays will be
20 # concattenated into one string by OpenGL
21 def __init__(self, vert=None, frag=None):
22 # create the program handle
23 self.handle = glCreateProgram()
24 # we are not linked yet
25 self.linked = False
26
27 # cache the uniforms location
28 self.location_cache = {}
29
30 # create the vertex shader
31 self.createShader(vert, GL_VERTEX_SHADER)
32 # create the fragment shader
33 self.createShader(frag, GL_FRAGMENT_SHADER)
34
35 # attempt to link the program
36 self.link()
37
38 def load_source(self, path):
39 with open(path, 'rb') as file:
40 source = file.read()
41 return source
42
43 def createShader(self, strings, type):
44 count = len(strings)
45 # if we have no source code, ignore this shader
46 if count < 1:
47 return
48
49 # create the shader handle
50 shader = glCreateShader(type)
51
52 # convert the source strings into a ctypes pointer-to-char array, and upload them
53 # this is deep, dark, dangerous black magick - don't try stuff like this at home!
54 src = (c_char_p * count)(*strings)
55 glShaderSource(shader, count, cast(byref(src), POINTER(POINTER(c_char))), None)
56
57 # compile the shader
58 glCompileShader(shader)
59
60 temp = c_int(0)
61 # retrieve the compile status
62 glGetShaderiv(shader, GL_COMPILE_STATUS, byref(temp))
63
64 # if compilation failed, print the log
65 if not temp:
66 # retrieve the log length
67 glGetShaderiv(shader, GL_INFO_LOG_LENGTH, byref(temp))
68 # create a buffer for the log
69 buffer = create_string_buffer(temp.value)
70 # retrieve the log text
71 glGetShaderInfoLog(shader, temp, None, buffer)
72 # print the log to the console
73 raise GLSLException(buffer.value)
74 else:
75 # all is well, so attach the shader to the program
76 glAttachShader(self.handle, shader);
77
78 def link(self):
79 # link the program
80 glLinkProgram(self.handle)
81
82 temp = c_int(0)
83 # retrieve the link status
84 glGetProgramiv(self.handle, GL_LINK_STATUS, byref(temp))
85
86 # if linking failed, print the log
87 if not temp:
88 # retrieve the log length
89 glGetProgramiv(self.handle, GL_INFO_LOG_LENGTH, byref(temp))
90 # create a buffer for the log
91 buffer = create_string_buffer(temp.value)
92 # retrieve the log text
93 glGetProgramInfoLog(self.handle, temp, None, buffer)
94 # print the log to the console
95 raise GLSLException(buffer.value)
96 else:
97 # all is well, so we are linked
98 self.linked = True
99
100 def bind(self):
101 # bind the program
102 glUseProgram(self.handle)
103
104 @classmethod
105 def unbind(self):
106 # unbind whatever program is currently bound
107 glUseProgram(0)
108
109 def get_uniform_location(self, name):
110 try:
111 return self.location_cache[name]
112 except KeyError:
113 loc = glGetUniformLocation(self.handle, name)
114 if loc == -1:
115 raise GLSLException #TODO
116 self.location_cache[name] = loc
117 return loc
118
119 # upload a floating point uniform
120 # this program must be currently bound
121 def uniformf(self, name, *vals):
122 # check there are 1-4 values
123 if len(vals) in range(1, 5):
124 # select the correct function
125 { 1 : glUniform1f,
126 2 : glUniform2f,
127 3 : glUniform3f,
128 4 : glUniform4f
129 # retrieve the uniform location, and set
130 }[len(vals)](self.get_uniform_location(name), *vals)
131
132 # upload an integer uniform
133 # this program must be currently bound
134 def uniformi(self, name, *vals):
135 # check there are 1-4 values
136 if len(vals) in range(1, 5):
137 # select the correct function
138 { 1 : glUniform1i,
139 2 : glUniform2i,
140 3 : glUniform3i,
141 4 : glUniform4i
142 # retrieve the uniform location, and set
143 }[len(vals)](self.get_uniform_location(name), *vals)
144
145 # upload a uniform matrix
146 # works with matrices stored as lists,
147 # as well as euclid matrices
148 def uniform_matrixf(self, name, mat):
149 # obtian the uniform location
150 loc = self.get_uniform_location(name)
151 # uplaod the 4x4 floating point matrix
152 glUniformMatrix4fv(loc, 1, False, mat)
153