QGLFrameBuffer useage resulting in distorted images

[Ankit.Jain]

Hi,
I was trying the use of QGLFrameBuffer, I found that the resultant image was a distorted image of what I get without using a frame buffer.
Framebuffer usage code:

QGLFramebufferObject fbObject(1500, 1500);
    fbObject.bind();
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
	glMatrixMode(GL_PROJECTION);					// Select Projection
	glPushMatrix();							// Push The Matrix
	glLoadIdentity();						// Reset The Matrix
	glOrtho( 0, 1500 , 0 , 1500, -1, 1 );				// Select Ortho Mode 
	glMatrixMode(GL_MODELVIEW);					// Select Modelview Matrix
	glPushMatrix();							// Push The Matrix
	glLoadIdentity();						// Reset The Matrix
    //Set transparency [currently hardcoded]
    const int transparency = 255;	//0-255 0->completely transparent; 255->completely opaque

    //Initialize variables
    SPointData point1, point2, point3, point4;
    for (int itrX = 0; itrX < heatmapPointsData.fragmentsX - 1; ++itrX)
    {
        for (int itrY = 0; itrY < heatmapPointsData.fragmentsY - 1; ++itrY)
        {
            point1 = heatmapPointsData.pointData[itrX][itrY][0];
            point2 = heatmapPointsData.pointData[itrX + 1][itrY][0];
            point3 = heatmapPointsData.pointData[itrX + 1][itrY + 1][0];
            point4 = heatmapPointsData.pointData[itrX][itrY + 1][0];
            glBegin(GL_QUADS);
            glColor4ub(point1.color.red(), point1.color.green(), point1.color.blue(), transparency);
            glVertex2d(point1.xCood, point1.yCood);
            glColor4ub(point2.color.red(), point2.color.green(), point2.color.blue(), transparency);
            glVertex2d(point2.xCood, point2.yCood);
            glColor4ub(point3.color.red(), point3.color.green(), point3.color.blue(), transparency);
            glVertex2d(point3.xCood, point3.yCood);
            glColor4ub(point4.color.red(), point4.color.green(), point4.color.blue(), transparency);
            glVertex2d(point4.xCood, point4.yCood);
            glEnd();
        }
    }
    glDisable(GL_BLEND);
    glMatrixMode(GL_PROJECTION);					// Select Projection
    glPopMatrix();							// Pop The Matrix
    glMatrixMode(GL_MODELVIEW);					// Select Modelview
    glPopMatrix();							// Pop The Matrix
    fbObject.toImage().save("C:/Users/<name>/Desktop/3.png");
    fbObject.release();
    return fbObject.toImage();

Output:

The same [w/o the QGLFrameBuffer] use does not cause any problems.
Output:

Could some suggest me how my usage might be incorrect? [P.S. same data was used and the overall image size is 1500x1500 (I hardcoded for testing).

[SGaist]

Hi,

Please don't post the same question multiple times.One is enough

Duplicates

Closing this one.