PDA

View Full Version : Scaling for a HUD



morello
06-01-2011, 10:42 AM
I am creating a HUD by drawing text and controls on a transparent BufferedImage, creating a texture from it and rendering it on a rectangle using orthographic projection.

It basically works, but I can't work out how to do the scaling. What I want ideally is to create an image the same pixel size as the window, and have it scaled so it exactly fills the window.

Here is the code (JOGL)


gl.glLoadIdentity();
gl.glTranslatef(0.0f, 0.0f, -5.0f);
gl.glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
gl.glOrtho(-1, 1, -1, 1, -1.0, 1.0);
getTexture(gl, 128, 128);
gl.glBegin(GL.GL_POLYGON);
gl.glTexCoord2d(0f, 0f);
gl.glVertex2f(-0.5f, -0.5f);
gl.glTexCoord2d(1, 0f);
gl.glVertex2f(-0.5f, 0.5f);
gl.glTexCoord2d(1, 1);
gl.glVertex2f(0.5f, 0.5f);
gl.glTexCoord2d(0f, 1);
gl.glVertex2f(0.5f, -0.5f);
gl.glEnd();

getTexture creates and binds the texture. Any hints on how to scale it?

I find that I need to do a translate in the negative z direction to see anything. The smaller that translation, the bigger the image except that for values smaller in magnitude than -5 the texture disappears.