README by Mike Gorchak <mike@malva.ua>, <lestat@i.com.ua>

Last changed at 30 Sep 2003.

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Table of Contents:

1. OpenGL.

2. Wheel and multi-button mouses.

3. CDROM handling issues.

4. Hardware video overlays.

5. Shared library building.

6. Some building issues.

7. Environment variables.

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OpenGL:

OpenGL works well and is stable, but fullscreen mode has not been

heavily tested yet.

If you have QNX RtP version 6.1.0 or above you must download the

Photon3D runtime from http://developers.qnx.com or install it from the

public repository or the public CD, available with QNX. OS versions

below 6.1.0 are not supported.

When creating an OpenGL context, software renderer mode is artifi-

cially selected (QSSL made acceleration only for Voodoo boards in

fullscreen mode, sorry but I don't have this board to test OpenGL -

maybe it works or maybe not :)). If you want acceleration - you can

remove one line in the source code: find the file SDL_ph_image.c and

remove the following

OGLAttrib[OGLargc++]=PHOGL_ATTRIB_FORCE_SW;

line in the ph_SetupOpenGLContext() function or change the argument to

PHOGL_ATTRIB_FORCE_HW or PHOGL_ATTRIB_FAVOR_HW.

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Wheel and multi-button mouses:

Photon emits keyboard events (key up and down) when the mouse

wheel is moved. The key_scan field appears valid, and it contains zero.

That is a basic method of detecting mouse wheel events under Photon.

It looks like a hack, but it works for me :) on various PC configura-

tions.

I've tested it on:

1. Genius Optical NetScroll/+ (1 wheel)

2. A4Tech Optical GreatEye WheelMouse, model: WOP-35. (2 wheels + 2

additional buttons). The wheel for vertical scrolling works as usu-

al, but the second wheel for horizontal scrolling emits two sequen-

tial events up or down, so it can provide faster scrolling than the

first wheel. Additional buttons don't emit any events, but it looks

like they're handled by photon in an unusual way - like click to

front, but works not with any window, looks like bug-o-feature :).

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CDROM handling issues:

Access to CDROM can only be provided with 'root' privileges. I

can't do anything about that, /dev/cd0 has brw------- permissions and

root:root rights.

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Hardware video overlays:

Overlays can flicker during window movement, resizing, etc. It

happens because the photon driver updates the real window contents be-

hind the overlay, then draws the temporary chroma key color over the

window contents. It can be done without using the chroma key but that

causes the overlay to always be on top. So flickering during window

movement is preferred instead.

Double buffering code is temporarily disabled in the photon driver

code, because on my GF2-MX it can accidentally cause a buffer switch,

which causes the old frame to show. S3 Savage4 has the same problem,

but ATI Rage 128 doesn't. I think it can be fixed later. Current code

works very well, so maybe double buffering is not needed right now.

Something strange happens when you try to move the window with the

overlay beyond the left border of the screen. The overlay tries to

stay at position x=0, but when attempting to move it a bit more it

jumps to position x=-60 (on GF2-MX, on ATI Rage128 this value a bit

smaller). It's really strange, looks like the overlay doesn't like

negative coordinates.

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Shared library building:

A shared library can be built, but before running the autogen.sh

script you must manually delete the libtool.m4 stuff from the acinclu-

de.m4 file (it comes after the ESD detection code up to the end of the

file), because the libtool stuff in the acinclude.m4 file is very old

in SDL distribution before the version 1.2.7 and doesn't know anything

about QNX. SDL 1.2.7 distribution contain the new libtool.m4 script,

but anyway it is broken :), Just remove it, then run "libtoolize

--force --copy", delete the file aclocal.m4 and after that run the

autogen.sh script.

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Some building issues:

Feel free to not use the --disable-shared configure option if you'

ve read the above comment about 'Shared library building'. Otherwise

this option is strongly recommended, as without it the sdl-config

script will be broken.

Run the configure script without x11 support, e.g.:

a) for OpenGL support:

./configure --prefix=/usr \

--disable-video-x11 \

--disable-shared

b) without OpenGL support:

./configure --prefix=/usr \

--disable-video-x11 \

--disable-shared \

--disable-video-opengl

In the test directory also run the ./configure script without

x11 support, e.g.:

./configure --with-sdl-prefix=/usr \

--with-sdl-exec-prefix=/usr \

--prefix=/usr --without-x

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Environment variables:

Please note that the photon driver is sensible to the following

environmental variables:

* SDL_VIDEO_WINDOW_POS - can be set in the "X,Y" format. If X and Y

coordinates are bigger than the current desktop resolution, then win-

dow positioning across virtual consoles is activated. If X and Y are

smaller than the desktop resolution then window positioning in the

current console is activated. The word "center" can be used instead of

coordinates, it produces the same behavior as SDL_VIDEO_CENTERED

environmental variable.

* SDL_VIDEO_CENTERED - if this environmental variable exists then the

window centering is perfomed in the current virtual console.

The SDL_VIDEO_CENTERED enviromental variable has greater priority

than the SDL_VIDEO_WINDOW_POS in case if both variables are supplied

to the application.