#!/usr/bin/env python
 
 
#############################################################################
##
## Copyright (C) 2013 Riverbank Computing Limited.
## Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
## All rights reserved.
##
## This file is part of the examples of PyQt.
##
## $QT_BEGIN_LICENSE:BSD$
## You may use this file under the terms of the BSD license as follows:
##
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## modification, are permitted provided that the following conditions are
## met:
##   * Redistributions of source code must retain the above copyright
##     notice, this list of conditions and the following disclaimer.
##   * Redistributions in binary form must reproduce the above copyright
##     notice, this list of conditions and the following disclaimer in
##     the documentation and/or other materials provided with the
##     distribution.
##   * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
##     the names of its contributors may be used to endorse or promote
##     products derived from this software without specific prior written
##     permission.
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## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
## $QT_END_LICENSE$
##
#############################################################################
 
 
import sys
 
from PyQt5.QtCore import pyqtSignal, QPoint, QSize, Qt, QTimer
from PyQt5.QtGui import (QColor, QMatrix4x4, QOpenGLShader,
        QOpenGLShaderProgram, QPixmap)
from PyQt5.QtWidgets import QApplication, QGridLayout, QMessageBox, QWidget
from PyQt5.QtOpenGL import QGLWidget
 
try:
    from OpenGL.GL import *
except ImportError:
    app = QApplication(sys.argv)
    QMessageBox.critical(None, "OpenGL textures",
            "PyOpenGL must be installed to run this example.")
    sys.exit(1)
 
import textures_rc
 
 
class GLWidget(QGLWidget):
 
    clicked = pyqtSignal()
 
    PROGRAM_VERTEX_ATTRIBUTE, PROGRAM_TEXCOORD_ATTRIBUTE = range(2)
 
    vsrc = """
attribute highp vec4 vertex;
attribute mediump vec4 texCoord;
varying mediump vec4 texc;
uniform mediump mat4 matrix;
void main(void)
{
    gl_Position = matrix * vertex;
    texc = texCoord;
}
"""
 
    fsrc = """
uniform sampler2D texture;
varying mediump vec4 texc;
void main(void)
{
    gl_FragColor = texture2D(texture, texc.st);
}
"""
 
    coords = (
        (( +1, -1, -1 ), ( -1, -1, -1 ), ( -1, +1, -1 ), ( +1, +1, -1 )),
        (( +1, +1, -1 ), ( -1, +1, -1 ), ( -1, +1, +1 ), ( +1, +1, +1 )),
        (( +1, -1, +1 ), ( +1, -1, -1 ), ( +1, +1, -1 ), ( +1, +1, +1 )),
        (( -1, -1, -1 ), ( -1, -1, +1 ), ( -1, +1, +1 ), ( -1, +1, -1 )),
        (( +1, -1, +1 ), ( -1, -1, +1 ), ( -1, -1, -1 ), ( +1, -1, -1 )),
        (( -1, -1, +1 ), ( +1, -1, +1 ), ( +1, +1, +1 ), ( -1, +1, +1 ))
    )
 
    def __init__(self, parent=None, shareWidget=None):
        super(GLWidget, self).__init__(parent, shareWidget)
 
        self.clearColor = Qt.black
        self.xRot = 0
        self.yRot = 0
        self.zRot = 0
 
        self.clearColor = QColor()
        self.lastPos = QPoint()
 
        self.program = None
 
    def minimumSizeHint(self):
        return QSize(50, 50)
 
    def sizeHint(self):
        return QSize(200, 200)
 
    def rotateBy(self, xAngle, yAngle, zAngle):
        self.xRot += xAngle
        self.yRot += yAngle
        self.zRot += zAngle
        self.updateGL()
 
    def setClearColor(self, color):
        self.clearColor = color
        self.updateGL()
 
    def initializeGL(self):
        self.makeObject()
 
        glEnable(GL_DEPTH_TEST)
        glEnable(GL_CULL_FACE)
 
        vshader = QOpenGLShader(QOpenGLShader.Vertex, self)
        vshader.compileSourceCode(self.vsrc)
 
        fshader = QOpenGLShader(QOpenGLShader.Fragment, self)
        fshader.compileSourceCode(self.fsrc)
 
        self.program = QOpenGLShaderProgram(self)
        self.program.addShader(vshader)
        self.program.addShader(fshader)
        self.program.bindAttributeLocation('vertex',
                self.PROGRAM_VERTEX_ATTRIBUTE)
        self.program.bindAttributeLocation('texCoord',
                self.PROGRAM_TEXCOORD_ATTRIBUTE)
        self.program.link()
 
        self.program.bind()
        self.program.setUniformValue('texture', 0)
 
        self.program.enableAttributeArray(self.PROGRAM_VERTEX_ATTRIBUTE)
        self.program.enableAttributeArray(self.PROGRAM_TEXCOORD_ATTRIBUTE)
        self.program.setAttributeArray(self.PROGRAM_VERTEX_ATTRIBUTE,
                self.vertices)
        self.program.setAttributeArray(self.PROGRAM_TEXCOORD_ATTRIBUTE,
                self.texCoords)
 
    def paintGL(self):
        self.qglClearColor(self.clearColor)
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
 
        m = QMatrix4x4()
        m.ortho(-0.5, 0.5, 0.5, -0.5, 4.0, 15.0)
        m.translate(0.0, 0.0, -10.0)
        m.rotate(self.xRot / 16.0, 1.0, 0.0, 0.0)
        m.rotate(self.yRot / 16.0, 0.0, 1.0, 0.0)
        m.rotate(self.zRot / 16.0, 0.0, 0.0, 1.0)
 
        self.program.setUniformValue('matrix', m)
 
        for i in range(6):
            glBindTexture(GL_TEXTURE_2D, self.textures[i])
            glDrawArrays(GL_TRIANGLE_FAN, i * 4, 4)
 
    def resizeGL(self, width, height):
        side = min(width, height)
        glViewport((width - side) // 2, (height - side) // 2, side, side)
 
    def mousePressEvent(self, event):
        self.lastPos = event.pos()
 
    def mouseMoveEvent(self, event):
        dx = event.x() - self.lastPos.x()
        dy = event.y() - self.lastPos.y()
 
        if event.buttons() & Qt.LeftButton:
            self.rotateBy(8 * dy, 8 * dx, 0)
        elif event.buttons() & Qt.RightButton:
            self.rotateBy(8 * dy, 0, 8 * dx)
 
        self.lastPos = event.pos()
 
    def mouseReleaseEvent(self, event):
        self.clicked.emit()
 
    def makeObject(self):
        self.textures = []
        self.texCoords = []
        self.vertices = []
 
        for i in range(6):
            self.textures.append(
                    self.bindTexture(QPixmap(':/images/side%d.png' % (i + 1))))
 
            for j in range(4):
                self.texCoords.append(((j == 0 or j == 3), (j == 0 or j == 1)))
 
                x, y, z = self.coords[i][j]
                self.vertices.append((0.2 * x, 0.2 * y, 0.2 * z))
 
 
class Window(QWidget):
    NumRows = 2
    NumColumns = 3
 
    def __init__(self):
        super(Window, self).__init__()
 
        mainLayout = QGridLayout()
        self.glWidgets = []
 
        for i in range(Window.NumRows):
            row = []
 
            for j in range(Window.NumColumns):
                clearColor = QColor()
                clearColor.setHsv(((i * Window.NumColumns) + j) * 255
                                  / (Window.NumRows * Window.NumColumns - 1),
                                  255, 63)
 
                widget = GLWidget(None, None)
                widget.setClearColor(clearColor)
                widget.rotateBy(+42 * 16, +42 * 16, -21 * 16)
                mainLayout.addWidget(widget, i, j)
 
                widget.clicked.connect(self.setCurrentGlWidget)
 
                row.append(widget)
 
            self.glWidgets.append(row)
 
        self.setLayout(mainLayout)
 
        self.currentGlWidget = self.glWidgets[0][0]
 
        timer = QTimer(self)
        timer.timeout.connect(self.rotateOneStep)
        timer.start(20)
 
        self.setWindowTitle("Textures")
 
    def setCurrentGlWidget(self):
        self.currentGlWidget = self.sender()
 
    def rotateOneStep(self):
        if self.currentGlWidget:
            self.currentGlWidget.rotateBy(+2 * 16, +2 * 16, -1 * 16)
 
 
if __name__ == '__main__':
 
    app = QApplication(sys.argv)
    window = Window()
    window.show()
    sys.exit(app.exec_())