problem with bindTexture

**spud** · 6th January 2008, 13:57

Hi,
I' trying to do a minimal OpenGL Image Viewer. Here's the code:

Qt Code:

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class ImageWidget : public QGLWidget
{
	QPixmap pixmap;
public:
	ImageWidget(const QPixmap &_pixmap, const IO& _io, QWidget *parent=0)
		: QGLWidget(QGLFormat(QGL::SampleBuffers), parent)
		, pixmap(_pixmap)
	{
	}
	void resizeGL(int w, int h)
	{
		glViewport(0, 0, w, h);
	}
	void paintGL()
	{
		glClear(GL_COLOR_BUFFER_BIT| GL_DEPTH_BUFFER_BIT);
		glLoadIdentity();
 
		glMatrixMode(GL_PROJECTION);
		glPushMatrix();
		glLoadIdentity();
 
		glOrtho(0, width(), 0, height(), -1, 1);
		glMatrixMode(GL_MODELVIEW);
		glPushMatrix();
		glLoadIdentity();
 
		bindTexture ( pixmap, GL_TEXTURE_2D, GL_RGBA );
		glBegin (GL_QUADS);
			glTexCoord2f (0.0, 0.0);		glVertex3f (10.0,		10.0,		0.0);
			glTexCoord2f (1.0, 0.0);		glVertex3f (width()-10,	10.0,		0.0);
			glTexCoord2f (1.0, 1.0);		glVertex3f (width()-10,	height()-10,	0.0);
			glTexCoord2f (0.0, 1.0);		glVertex3f (10.0,		height()-10,	0.0);
		glEnd ();
		/*glBegin(GL_TRIANGLES);
			glColor3ub(255, 0, 0);
			glVertex2d(0, 0);
			glColor3ub(0, 255, 0);
			glVertex2d(width(),0);
			glColor3ub(0, 0, 255);
			glVertex2d(width()/2, height());
		glEnd();*/
	}
};

class ImageWidget : public QGLWidget
{
	QPixmap pixmap;
public:
	ImageWidget(const QPixmap &_pixmap, const IO& _io, QWidget *parent=0)
		: QGLWidget(QGLFormat(QGL::SampleBuffers), parent)
		, pixmap(_pixmap)
	{
	}
	void resizeGL(int w, int h)
	{
		glViewport(0, 0, w, h);
	}
	void paintGL()
	{
		glClear(GL_COLOR_BUFFER_BIT| GL_DEPTH_BUFFER_BIT);
		glLoadIdentity();

		glMatrixMode(GL_PROJECTION);
		glPushMatrix();
		glLoadIdentity();

		glOrtho(0, width(), 0, height(), -1, 1);
		glMatrixMode(GL_MODELVIEW);
		glPushMatrix();
		glLoadIdentity();

		bindTexture ( pixmap, GL_TEXTURE_2D, GL_RGBA );
		glBegin (GL_QUADS);
			glTexCoord2f (0.0, 0.0);		glVertex3f (10.0,		10.0,		0.0);
			glTexCoord2f (1.0, 0.0);		glVertex3f (width()-10,	10.0,		0.0);
			glTexCoord2f (1.0, 1.0);		glVertex3f (width()-10,	height()-10,	0.0);
			glTexCoord2f (0.0, 1.0);		glVertex3f (10.0,		height()-10,	0.0);
		glEnd ();
		/*glBegin(GL_TRIANGLES);
			glColor3ub(255, 0, 0);
			glVertex2d(0, 0);
			glColor3ub(0, 255, 0);
			glVertex2d(width(),0);
			glColor3ub(0, 0, 255);
			glVertex2d(width()/2, height());
		glEnd();*/
	}
};

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The problem is I just see a white rectangle instead of the image. The commented code draws a triangle just fine, so I seem to have set up the viewport correctly.
I'm probably making some very simple mistake, so I'm thankful for any suggestions!

btw. Should I move any code from paintGL() to initGL()? I'm not sure if I have to make all of these calls every time I render the scene.