src_gui_qopenglshaderprogram.cpp

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include <QColor>
#include <QString>
#include <QtOpenGL/QOpenGLShader>
 
namespace src_gui_qopenglshaderprogram {
QString code;
QObject *context = nullptr;
QRectF rect() { return QRectF(); }
 
void wrapper() {
//! [0]
QOpenGLShader shader(QOpenGLShader::Vertex);
shader.compileSourceCode(code);
 
QOpenGLShaderProgram program(context);
program.addShader(&shader);
program.link();
 
program.bind();
//! [0]
 
//! [1]
program.addShaderFromSourceCode(QOpenGLShader::Vertex,
    "attribute highp vec4 vertex;\n"
    "uniform highp mat4 matrix;\n"
    "void main(void)\n"
    "{\n"
    "   gl_Position = matrix * vertex;\n"
    "}");
program.addShaderFromSourceCode(QOpenGLShader::Fragment,
    "uniform mediump vec4 color;\n"
    "void main(void)\n"
    "{\n"
    "   gl_FragColor = color;\n"
    "}");
program.link();
program.bind();
 
int vertexLocation = program.attributeLocation("vertex");
int matrixLocation = program.uniformLocation("matrix");
int colorLocation = program.uniformLocation("color");
//! [1]
 
//! [2]
static GLfloat const triangleVertices[] = {
    60.0f,  10.0f,  0.0f,
    110.0f, 110.0f, 0.0f,
    10.0f,  110.0f, 0.0f
};
 
QColor color(0, 255, 0, 255);
 
QMatrix4x4 pmvMatrix;
pmvMatrix.ortho(rect());
 
program.enableAttributeArray(vertexLocation);
program.setAttributeArray(vertexLocation, triangleVertices, 3);
program.setUniformValue(matrixLocation, pmvMatrix);
program.setUniformValue(colorLocation, color);
 
glDrawArrays(GL_TRIANGLES, 0, 3);
 
program.disableAttributeArray(vertexLocation);
//! [2]
 
} // wrapper
} // src_gui_qopenglshaderprogram