1. How do I set the GL context to be 16 bit?

2. How do I set the GL context to be 32?

3. How do I set textures to be 16 bit or 32bit?


Ok does the context buffer simplt match the current screen depth?

AFAIK, however you setup your RC to OpenGL sets up your bit depth. I use SDL so I tell SDL to run in 32bit mode and OpenGL is good to go. Not sure what API your using? Cocoa or Carbon? If they are either of those two I can't help you. =)

When you request a pixel format, you can pass an option for color depth, choosing either 16 or 32-bit. I'm pretty sure you'll match the screen resolution anyway, though, regardless of what you say...

You can upload textures in 16-bit using GL_RGBA_1_5_5_5_REV_EXT as your format. I don't know if this is useful or not, though, since it seems likely that GL will downsample your textures to 16-bit for you if you've got a 16-bit context.

Quote:Originally posted by Mars_999
AFAIK, however you setup your RC to OpenGL sets up your bit depth. I use SDL so I tell SDL to run in 32bit mode and OpenGL is good to go. Not sure what API your using? Cocoa or Carbon? If they are either of those two I can't help you. =)

Im using AGL....
This is the Apple GL extension lib.
See the AGL PDF with the apple GL SDK.

I think this would be used only with carbon since
cocoa has its own classes for setting up GL.

Quote:Originally posted by OneSadCookie
When you request a pixel format, you can pass an option for color depth, choosing either 16 or 32-bit. I'm pretty sure you'll match the screen resolution anyway, though, regardless of what you say...

You can upload textures in 16-bit using GL_RGBA_1_5_5_5_REV_EXT as your format. I don't know if this is useful or not, though, since it seems likely that GL will downsample your textures to 16-bit for you if you've got a 16-bit context.

Pixel format....
I tired this short of thing....

// OpenGL compliant HWA renderer
GLint attrib[] = { AGL_RGBA, AGL_ACCELERATED, AGL_DOUBLEBUFFER, AGL_DEPTH_SIZE, 16, AGL_PIXEL_SIZE, 16, AGL_NONE };

Is this what you mean...

I can't tell if GL is giving 16 bit or not.

Maybe I can ask it what it gave me?

Quote:Originally posted by ChrisD
I can't tell if GL is giving 16 bit or not.

Maybe I can ask it what it gave me?

AFAIK, OpenGL gives you whatever the current screen depth is. If you want a 16bpp environment, you have to switch the screen to 16bpp. I believe Apple's SetupGL sample code does this.

You can indeed query the pixel format for its exact spec. Just look in agl.h, all that stuff's there and obvious.

I think maybe you want COLOR_SIZE rather than PIXEL_SIZE? Not quite sure...