Qt and OpenGL Primitives in mobile resolution

Dinesh Balu

Hi...

I'm new to OpenGL in Qt..
and I've been trying to draw points in screen corners... I'm using Nokia 900 simulator
by default the co-ordinate range in openGL is
X: -1 to 1
Y: -1 to 1

right?

But here in mobile resolution it changes and couldn't predict the change ratio....

how to solve this...?

I've set the ViewPort width and height to 360 and 640.

ZapB

Please post some compilable code that reproduces your problem.

Dinesh Balu

This is the OpenGL code..

@#include "gameplay.h"

GamePlay::GamePlay(QWidget *parent) :
QGLWidget(parent)
{
setFormat(QGLFormat(QGL::DoubleBuffer | QGL::DepthBuffer));
rotationX = -21.0;
rotationY = -57.0;
rotationZ = 0.0;
faceColors[0] = Qt::red;
faceColors[1] = Qt::green;
faceColors[2] = Qt::blue;
faceColors[3] = Qt::yellow;
}

void GamePlay::initializeGL()
{
qglClearColor(Qt::green);
glShadeModel(GL_FLAT);
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);
}

void GamePlay::resizeGL(int width,int height)
{
width=360;
height=640;
glViewport(0,0,width,height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
GLfloat x = GLfloat(width) / height;

glFrustum(-x, x, -1, 1, 2.0, 15);
glMatrixMode(GL_MODELVIEW);

}

void GamePlay::paintGL()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
draw();
}

void GamePlay::draw()
{
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0, 0, -10);

glPointSize(4.0);
glBegin(GL_POINTS);
glVertex3f(0,0,0);
glEnd();

}

@

The draw function should draw a point of size 4 at the center of the screen.... right?

I does draw a point but not in the Center of the screen(orgin).

minimoog77

Please try setting projection matrix with gluPerspective.

Dinesh Balu

No... I have tried that too... same effect...

Dinesh Balu

Is this because of the simulator banner added by the QT in the output in simulator?

minimoog77

What were the parameters for gluPerspective?