1#!/usr/bin/env python
2
3
4#############################################################################
5##
6## Copyright (C) 2018 Riverbank Computing Limited.
7## Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
8## Contact: http://www.qt-project.org/legal
9##
10## This file is part of the documentation of the Qt Toolkit.
11##
12## $QT_BEGIN_LICENSE:BSD$
13## You may use this file under the terms of the BSD license as follows:
14##
15## "Redistribution and use in source and binary forms, with or without
16## modification, are permitted provided that the following conditions are
17## met:
18##   * Redistributions of source code must retain the above copyright
19##     notice, this list of conditions and the following disclaimer.
20##   * Redistributions in binary form must reproduce the above copyright
21##     notice, this list of conditions and the following disclaimer in
22##     the documentation and/or other materials provided with the
23##     distribution.
24##   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
25##     of its contributors may be used to endorse or promote products derived
26##     from this software without specific prior written permission.
27##
28##
29## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
30## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
31## LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
32## A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
33## OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
34## SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
35## LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36## DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37## THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38## (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
39## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
40## $QT_END_LICENSE$
41##
42#############################################################################
43
44
45import array
46
47from PyQt5.QtCore import QEvent
48from PyQt5.QtGui import (QGuiApplication, QMatrix4x4, QOpenGLContext,
49        QOpenGLShader, QOpenGLShaderProgram, QOpenGLVersionProfile,
50        QSurfaceFormat, QWindow)
51
52
53class OpenGLWindow(QWindow):
54    def __init__(self, parent=None):
55        super(OpenGLWindow, self).__init__(parent)
56
57        self.m_update_pending = False
58        self.m_animating = False
59        self.m_context = None
60        self.m_gl = None
61
62        self.setSurfaceType(QWindow.OpenGLSurface)
63
64    def initialize(self):
65        pass
66
67    def setAnimating(self, animating):
68        self.m_animating = animating
69
70        if animating:
71            self.renderLater()
72
73    def renderLater(self):
74        if not self.m_update_pending:
75            self.m_update_pending = True
76            QGuiApplication.postEvent(self, QEvent(QEvent.UpdateRequest))
77
78    def renderNow(self):
79        if not self.isExposed():
80            return
81
82        self.m_update_pending = False
83
84        needsInitialize = False
85
86        if self.m_context is None:
87            self.m_context = QOpenGLContext(self)
88            self.m_context.setFormat(self.requestedFormat())
89            self.m_context.create()
90
91            needsInitialize = True
92
93        self.m_context.makeCurrent(self)
94
95        if needsInitialize:
96            version_profile = QOpenGLVersionProfile()
97            version_profile.setVersion(2, 0)
98            self.m_gl = self.m_context.versionFunctions(version_profile)
99            self.m_gl.initializeOpenGLFunctions()
100
101            self.initialize()
102
103        self.render(self.m_gl)
104
105        self.m_context.swapBuffers(self)
106
107        if self.m_animating:
108            self.renderLater()
109
110    def event(self, event):
111        if event.type() == QEvent.UpdateRequest:
112            self.renderNow()
113            return True
114
115        return super(OpenGLWindow, self).event(event)
116
117    def exposeEvent(self, event):
118        self.renderNow()
119
120    def resizeEvent(self, event):
121        self.renderNow()
122
123
124class TriangleWindow(OpenGLWindow):
125    vertexShaderSource = '''
126attribute highp vec4 posAttr;
127attribute lowp vec4 colAttr;
128varying lowp vec4 col;
129uniform highp mat4 matrix;
130void main() {
131    col = colAttr;
132    gl_Position = matrix * posAttr;
133}
134'''
135
136    fragmentShaderSource = '''
137varying lowp vec4 col;
138void main() {
139    gl_FragColor = col;
140}
141'''
142
143    def __init__(self):
144        super(TriangleWindow, self).__init__()
145
146        self.m_program = 0
147        self.m_frame = 0
148
149        self.m_posAttr = 0
150        self.m_colAttr = 0
151        self.m_matrixUniform = 0
152
153    def initialize(self):
154        self.m_program = QOpenGLShaderProgram(self)
155
156        self.m_program.addShaderFromSourceCode(QOpenGLShader.Vertex,
157                self.vertexShaderSource)
158        self.m_program.addShaderFromSourceCode(QOpenGLShader.Fragment,
159                self.fragmentShaderSource)
160
161        self.m_program.link()
162
163        self.m_posAttr = self.m_program.attributeLocation('posAttr')
164        self.m_colAttr = self.m_program.attributeLocation('colAttr')
165        self.m_matrixUniform = self.m_program.uniformLocation('matrix')
166
167    def render(self, gl):
168        gl.glViewport(0, 0, self.width(), self.height())
169
170        gl.glClear(gl.GL_COLOR_BUFFER_BIT)
171
172        self.m_program.bind()
173
174        matrix = QMatrix4x4()
175        matrix.perspective(60, 4.0/3.0, 0.1, 100.0)
176        matrix.translate(0, 0, -2)
177        matrix.rotate(100.0 * self.m_frame / self.screen().refreshRate(),
178                0, 1, 0)
179
180        self.m_program.setUniformValue(self.m_matrixUniform, matrix)
181
182        vertices = array.array('f', [
183                 0.0,  0.707,
184                -0.5, -0.5,
185                 0.5, -0.5])
186
187        gl.glVertexAttribPointer(self.m_posAttr, 2, gl.GL_FLOAT, False, 0,
188                vertices)
189        gl.glEnableVertexAttribArray(self.m_posAttr)
190
191        colors = array.array('f', [
192                1.0, 0.0, 0.0,
193                0.0, 1.0, 0.0,
194                0.0, 0.0, 1.0])
195
196        gl.glVertexAttribPointer(self.m_colAttr, 3, gl.GL_FLOAT, False, 0,
197                colors)
198        gl.glEnableVertexAttribArray(self.m_colAttr)
199
200        gl.glDrawArrays(gl.GL_TRIANGLES, 0, 3)
201
202        self.m_program.release()
203
204        self.m_frame += 1
205
206
207if __name__ == '__main__':
208
209    import sys
210
211    app = QGuiApplication(sys.argv)
212
213    format = QSurfaceFormat()
214    format.setSamples(4)
215
216    window = TriangleWindow()
217    window.setFormat(format)
218    window.resize(640, 480)
219    window.show()
220
221    window.setAnimating(True)
222
223    sys.exit(app.exec_())
224