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np2100

OpenGL handling key presses

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np2100    102
Hello, I am very new to OpenGL and SDL and I've been playing around with it. I have been able so far to change the background color by pressing different keys. Now I am wondering how I can move a shape up or down by hitting a key. For example: case SDLK_1: glTranslatef( -1.5f, 0.0f, -6.0f ); break; This doesn't work. I expected it to move the shape in the drawGLScene but it didn't. Does anyone know another way of doing this?

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datalurkur    122
It might be better to put the glTranslate in your draw code and use a variable to communicate the amount of translation. In other words, your draw code (which is elsewhere) might look like this:

glPushMatrix();
glTranslatef(-1.5f, 0.0f, ztrans);
DrawStuff();
glPopMatrix();

and then in your SDL code:
case SDLK_1:
ztrans=-6.0f;
break;

This way you don't have to wonder where in the OGL stream the translate comes.

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np2100    102
I tried doing that but since they are in different functions it says ztrans is undeclared. So how do I get the key handling into the draw function to change it.

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