QQuickWidget With QOpenGLFunctions is displaying white sceen
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I am using the following code but i am getting nothing error but displaying white screen instad of white screen.
#include "squircle.h"
#include <QtQuick/qquickwindow.h>
#include <QtGui/QOpenGLShaderProgram>
#include <QtGui/QOpenGLContext>
#include <QOpenGLFramebufferObjectFormat>
#include <QVector2D>
#include <QVector3D>struct VertexData
{
QVector3D position;
QVector2D texCoord;
};
Squircle::Squircle()
: m_t(0)
, m_renderer(nullptr)
{
this->setAcceptedMouseButtons(Qt::AllButtons);
connect(this, &QQuickItem::windowChanged, this, &Squircle::handleWindowChanged);
}void Squircle::setT(qreal t)
{
if (t == m_t)
return;
m_t = t;
emit tChanged();
if (window())
window()->update();
}void Squircle::handleWindowChanged(QQuickWindow *win)
{
if (win) {
connect(win, &QQuickWindow::beforeSynchronizing, this, &Squircle::sync, Qt::DirectConnection);
connect(win, &QQuickWindow::sceneGraphInvalidated, this, &Squircle::cleanup, Qt::DirectConnection);
// If we allow QML to do the clearing, they would clear what we paint
// and nothing would show.
win->setClearBeforeRendering(false);
}
}void Squircle::cleanup()
{
if (m_renderer) {
delete m_renderer;
m_renderer = nullptr;
}
}
void Squircle::mousePressEvent(QMouseEvent *event)
{
// m_color = Qt::black;
//update(); //changing an attribute of the qquickitem and updating the scenegraph
qDebug() << "mouse press";
}
void Squircle::mouseReleaseEvent(QMouseEvent *event)
{
// m_color = Qt::black;
//update(); //changing an attribute of the qquickitem and updating the scenegraph
qDebug() << "mouse release";
}
SquircleRenderer::~SquircleRenderer()
{
delete m_program;
}void Squircle::sync()
{
if (!m_renderer) {
m_renderer = new SquircleRenderer();
connect(window(), &QQuickWindow::beforeRendering, m_renderer, &SquircleRenderer::paint, Qt::DirectConnection);
}
m_renderer->setViewportSize(window()->size() * window()->devicePixelRatio());
m_renderer->setT(m_t);
m_renderer->setWindow(window());
}void SquircleRenderer::paint()
{
initializeOpenGLFunctions();arrayBuf.create(); indexBuf.create(); if (!m_program) { m_program = new QOpenGLShaderProgram(); m_program->addCacheableShaderFromSourceCode(QOpenGLShader::Vertex, "#ifdef GL_ES\n" "precision mediump int;" "precision mediump float;" "#endif\n" "uniform mat4 mvp_matrix;" "uniform mediump vec4 color;" "attribute vec4 a_position;" "attribute vec2 a_texcoord;" "varying vec2 v_texcoord;" "void main() {" " gl_Position = mvp_matrix * a_position;" " v_texcoord = a_texcoord;" "}"); m_program->addCacheableShaderFromSourceCode(QOpenGLShader::Fragment, "#ifdef GL_ES\n" "precision mediump int;" "precision mediump float;" "#endif\n" "uniform sampler2D texture;" "uniform mediump vec4 color;" "varying vec2 v_texcoord;" "void main() {" "gl_FragColor = color;" "}"); //m_program->bindAttributeLocation("vertices", 0); m_program->link(); glEnable(GL_DEPTH_TEST); glEnable(GL_CULL_FACE); } m_program->bind();glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
QMatrix4x4 matrix;
matrix.translate(0.0, 0.0, -5.0);
m_program->setUniformValue("mvp_matrix", matrix);// m_program->enableAttributeArray(0); VertexData values[] ={ // Vertex data for face 0 {QVector3D(-1.0f, -1.0f, 1.0f), QVector2D(0.0f, 0.0f)}, // v0 {QVector3D( 1.0f, -1.0f, 1.0f), QVector2D(0.33f, 0.0f)}, // v1 {QVector3D(-1.0f, 1.0f, 1.0f), QVector2D(0.0f, 0.5f)}, // v2 {QVector3D( 1.0f, 1.0f, 1.0f), QVector2D(0.33f, 0.5f)}, // v3 // Vertex data for face 1 {QVector3D( 1.0f, -1.0f, 1.0f), QVector2D( 0.0f, 0.5f)}, // v4 {QVector3D( 1.0f, -1.0f, -1.0f), QVector2D(0.33f, 0.5f)}, // v5 {QVector3D( 1.0f, 1.0f, 1.0f), QVector2D(0.0f, 1.0f)}, // v6 {QVector3D( 1.0f, 1.0f, -1.0f), QVector2D(0.33f, 1.0f)}, // v7 // Vertex data for face 2 {QVector3D( 1.0f, -1.0f, -1.0f), QVector2D(0.66f, 0.5f)}, // v8 {QVector3D(-1.0f, -1.0f, -1.0f), QVector2D(1.0f, 0.5f)}, // v9 {QVector3D( 1.0f, 1.0f, -1.0f), QVector2D(0.66f, 1.0f)}, // v10 {QVector3D(-1.0f, 1.0f, -1.0f), QVector2D(1.0f, 1.0f)}, // v11 // Vertex data for face 3 {QVector3D(-1.0f, -1.0f, -1.0f), QVector2D(0.66f, 0.0f)}, // v12 {QVector3D(-1.0f, -1.0f, 1.0f), QVector2D(1.0f, 0.0f)}, // v13 {QVector3D(-1.0f, 1.0f, -1.0f), QVector2D(0.66f, 0.5f)}, // v14 {QVector3D(-1.0f, 1.0f, 1.0f), QVector2D(1.0f, 0.5f)}, // v15 // Vertex data for face 4 {QVector3D(-1.0f, -1.0f, -1.0f), QVector2D(0.33f, 0.0f)}, // v16 {QVector3D( 1.0f, -1.0f, -1.0f), QVector2D(0.66f, 0.0f)}, // v17 {QVector3D(-1.0f, -1.0f, 1.0f), QVector2D(0.33f, 0.5f)}, // v18 {QVector3D( 1.0f, -1.0f, 1.0f), QVector2D(0.66f, 0.5f)}, // v19 // Vertex data for face 5 {QVector3D(-1.0f, 1.0f, 1.0f), QVector2D(0.33f, 0.5f)}, // v20 {QVector3D( 1.0f, 1.0f, 1.0f), QVector2D(0.66f, 0.5f)}, // v21 {QVector3D(-1.0f, 1.0f, -1.0f), QVector2D(0.33f, 1.0f)}, // v22 {QVector3D( 1.0f, 1.0f, -1.0f), QVector2D(0.66f, 1.0f)} // v23 }; GLushort indices[] = { 0, 1, 2, 3, 3, // Face 0 - triangle strip ( v0, v1, v2, v3) 4, 4, 5, 6, 7, 7, // Face 1 - triangle strip ( v4, v5, v6, v7) 8, 8, 9, 10, 11, 11, // Face 2 - triangle strip ( v8, v9, v10, v11) 12, 12, 13, 14, 15, 15, // Face 3 - triangle strip (v12, v13, v14, v15) 16, 16, 17, 18, 19, 19, // Face 4 - triangle strip (v16, v17, v18, v19) 20, 20, 21, 22, 23 // Face 5 - triangle strip (v20, v21, v22, v23) }; arrayBuf.bind(); arrayBuf.allocate(values, 24 * sizeof(VertexData)); indexBuf.bind(); indexBuf.allocate(indices, 34 * sizeof(GLushort)); arrayBuf.bind(); indexBuf.bind(); quintptr offset = 0; // Tell OpenGL programmable pipeline how to locate vertex position data int vertexLocation = m_program->attributeLocation("a_position"); m_program->enableAttributeArray(vertexLocation); m_program->setAttributeBuffer(vertexLocation, GL_FLOAT, offset, 3, sizeof(VertexData)); // Offset for texture coordinate offset += sizeof(QVector3D); // Tell OpenGL programmable pipeline how to locate vertex texture coordinate data int texcoordLocation = m_program->attributeLocation("a_texcoord"); m_program->enableAttributeArray(texcoordLocation); m_program->setAttributeBuffer(texcoordLocation, GL_FLOAT, offset, 2, sizeof(VertexData)); int colorLocation = m_program->uniformLocation("color"); QColor color(0, 255, 0, 255); m_program->setUniformValue(colorLocation, color); glDrawElements(GL_TRIANGLE_STRIP, 34, GL_UNSIGNED_SHORT, 0); //m_program->setAttributeArray(0, GL_FLOAT, values, 2); //m_program->setUniformValue("t", (float) m_t); //glViewport(0, 0, m_viewportSize.width(), m_viewportSize.height()); //m_program->disableAttributeArray(0); //m_program->release(); // Not strictly needed for this example, but generally useful for when // mixing with raw OpenGL. //m_window->resetOpenGLState(); // Restore the matrix state //glPopMatrix();}
can anyone help me out in these
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I think you should:
- write a minimal test program to show the problem in the title - nobody should be expected to read, understand and debug your long code
- describe your mobile or embedded system and its configuration and your Qt version and its configuration - someone might notice something in either
