void exposeEvent(QExposeEvent *)
{
if (!isExposed())
return;
if (!gl) {
gl = new QOpenGLContext();
gl->setFormat(requestedFormat());
gl->create();
}
gl->makeCurrent(this);
QOpenGLShaderProgram prog;
prog.addShaderFromSourceCode(QOpenGLShader::Vertex,
"attribute highp vec4 a_Pos;"
"attribute lowp vec4 a_Color;"
"varying lowp vec4 v_Color;"
"void main() {"
" gl_Position = a_Pos;"
" v_Color = a_Color;"
"}");
prog.addShaderFromSourceCode(QOpenGLShader::Fragment,
"varying lowp vec4 v_Color;"
"void main() {"
" gl_FragColor = v_Color;"
"}");
prog.bind();
glClearColor(0, 0, 0, 1);
glClear(GL_COLOR_BUFFER_BIT);
glViewport(0, 0, width(), height());
prog.enableAttributeArray("a_Pos");
prog.enableAttributeArray("a_Color");
float coords[] = { -0.7f, 0.7f,
0.8f, 0.8f,
-0.8f, -0.8f,
0.7f, -0.7f
};
float colors[] = { 1, 0, 0, 1,
0, 1, 0, 1,
0, 0, 1, 1,
0, 0, 0, 0
};
prog.setAttributeArray("a_Pos", GL_FLOAT, coords, 2, 0);
prog.setAttributeArray("a_Color", GL_FLOAT, colors, 4, 0);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
prog.disableAttributeArray("a_Pos");
prog.disableAttributeArray("a_Color");
gl->swapBuffers(this);
}
void VideoSurface::paintGL()
{
mutex.lock();
VideoFrame currFrame = frame;
frame.invalidate();
mutex.unlock();
if (currFrame.isValid() && res != currFrame.resolution)
{
res = currFrame.resolution;
// delete old texture
if (textureId != 0)
glDeleteTextures(1, &textureId);
// a texture used to render the pbo (has the match the pixelformat of the source)
glGenTextures(1,&textureId);
glBindTexture(GL_TEXTURE_2D, textureId);
glTexImage2D(GL_TEXTURE_2D,0, GL_RGB, res.width(), res.height(), 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
}
if (currFrame.isValid())
{
pboIndex = (pboIndex + 1) % 2;
int nextPboIndex = (pboIndex + 1) % 2;
if (pboAllocSize != currFrame.frameData.size())
{
qDebug() << "VideoSurface: Resize pbo " << currFrame.frameData.size() << "(" << currFrame.resolution << ")" << "bytes (before" << pboAllocSize << ")";
pbo[0]->bind();
pbo[0]->allocate(currFrame.frameData.size());
pbo[0]->release();
pbo[1]->bind();
pbo[1]->allocate(currFrame.frameData.size());
pbo[1]->release();
pboAllocSize = currFrame.frameData.size();
}
pbo[pboIndex]->bind();
glBindTexture(GL_TEXTURE_2D, textureId);
glTexSubImage2D(GL_TEXTURE_2D,0,0,0, res.width(), res.height(), GL_RGB, GL_UNSIGNED_BYTE, 0);
pbo[pboIndex]->unmap();
pbo[pboIndex]->release();
// transfer data
pbo[nextPboIndex]->bind();
void* ptr = pbo[nextPboIndex]->map(QOpenGLBuffer::WriteOnly);
if (ptr)
memcpy(ptr, currFrame.frameData.data(), currFrame.frameData.size());
pbo[nextPboIndex]->unmap();
pbo[nextPboIndex]->release();
}
// background
glClearColor(0, 0, 0, 1);
glClear(GL_COLOR_BUFFER_BIT);
// keep aspect ratio
float aspectRatio = float(res.width()) / float(res.height());
if (width() < float(height()) * aspectRatio)
{
float h = float(width()) / aspectRatio;
glViewport(0, (height() - h)*0.5f, width(), h);
}
else
{
float w = float(height()) * float(aspectRatio);
glViewport((width() - w)*0.5f, 0, w, height());
}
QOpenGLShaderProgram* programm = nullptr;
switch (frame.format)
{
case VideoFrame::YUV:
programm = yuvProgramm;
break;
case VideoFrame::BGR:
programm = bgrProgramm;
break;
default:
break;
}
if (programm)
{
// render pbo
static float values[] = {
-1, -1,
1, -1,
-1, 1,
1, 1
};
programm->bind();
programm->setAttributeArray(0, GL_FLOAT, values, 2);
programm->enableAttributeArray(0);
}
glBindTexture(GL_TEXTURE_2D, textureId);
//draw fullscreen quad
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
glBindTexture(GL_TEXTURE_2D, 0);
if (programm)
{
programm->disableAttributeArray(0);
programm->release();
}
}
