Problems with Qt OpenGL drawing a textured Quad

[Halcom]

Hallo,

i use Qt 4.7 and want to draw a textured quad, because glDrawPixels is to slow. The texture changed every time i want to redraw, because it cames from a framegrabber.

I Have read some tutorials, the problems is, that he only draw my first image, a gray 256x256 texture. The second one a 512x512 white not. The image buffers and sizes are changed correctly. So i miss something else.

It will be nice if someone could help me.

Here my paintGL method from my QGLWidget. A whole test project is attached.

thanks



void GUIGLView::glInit()
{

}

void GUIGLView::paintGL()
{
qglClearColor(QColor(Qt::black));
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_ACCUM_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

// only do something if image is availible
if(mImageData.imageBuffer == NULL)
return;

QString debugString = QString("paintGL called with buffer: 0x%1, size %2").arg((int)mImageData.imageBuffer,8,16,QChar('0')) .arg(mImageData.width);
qDebug(debugString.toAscii().data());

// set projection - disable z-axis
glMatrixMode(GL_PROJECTION);

//clear projection matrix
glLoadIdentity();

//Creating an orthoscopic view matrix going from -1 -> 1 in each
//dimension on the screen (x, y, z).
glOrtho(0, 640, 480, 0, -1, 1);

//Now editing the model-view matrix.
glMatrixMode(GL_MODELVIEW);

//Clearing the model-view matrix.
glLoadIdentity();

//Disabling the depth test (z will not be used to tell what object
//will be shown above another, only the order in which I draw them.)
glDisable(GL_DEPTH_TEST);

// generate a texture
glGenTextures(1, &mTextureID);

// enable texturing
glEnable(GL_TEXTURE_2D);

//specify texture to use
glBindTexture(GL_TEXTURE_2D, mTextureID);

// set texturing parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

// copy image to texture
glTexImage2D(GL_TEXTURE_2D, 0, mImageData.samplesPerPixel, mImageData.width, mImageData.height, 0, GL_RGB, GL_UNSIGNED_BYTE, mImageData.imageBuffer);

// draw a textured quad
glBegin(GL_QUADS);
glTexCoord2f(0,0); glVertex3f( 0, 0,0); //lo
glTexCoord2f(0,1); glVertex3f(256, 0,0); //lu
glTexCoord2f(1,1); glVertex3f(256, 256,0); //ru
glTexCoord2f(1,0); glVertex3f( 0, 256,0); //ro
glEnd;

glDeleteTextures(1, &mTextureID);
mTextureID = 0;
}

[Halcom]

One Problems solved, missing () behind glEnd(). Sometimes i hate compilers.

But the screen is not correctly cleared.