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(Said Max Horn on the SDL mailing list...) Hi folks, based on Eric Wing's patch, I created the attached patch which fixes the OpenGL coordinate inversion bug in SDL. It works fine over here on 10.3 with Ryan's test program (which I also attached). There is another change in it: I removed the "- 1" in the two lines using CGDisplayPixelsHigh()... while I understand from a logical point of view why they *should* be correct, I checked the actual values computed that way, and they were off-by-one. After removing the " - 1", the returned mouse coordinates are correct. I checked this by moving the mouse to the screen top/bottom in fullscreen mode, BTW. With the change, the proper values 0 and 479 are returned (in 640x480 mode). Sam, you may still want to test on 10.1, it's very simple using Ryan's minimal test code :-) Cheers, Max (Here is the reproduction case for revision history's sake...) /* * To compile: * gcc -o test test.c `sdl-config --cflags` `sdl-config --libs` -framework OpenGL * * --ryan. */ #include <stdio.h> #include "SDL.h" #include "SDL_opengl.h" int main(int argc, char **argv) { Uint32 flags = SDL_OPENGL /* | SDL_FULLSCREEN */; SDL_Surface *screen; SDL_Event event; int done = 0; GLfloat ratio; SDL_Init(SDL_INIT_VIDEO); SDL_ShowCursor(0); if ((argv[1]) && (strcmp(argv[1], "--grab") == 0)) SDL_WM_GrabInput(SDL_GRAB_ON); screen = SDL_SetVideoMode(640, 480, 0, flags); if (!screen) return(42); ratio = ((GLfloat) screen->w) / ((GLfloat) screen->h); glClearColor( 0.0f, 0.0f, 0.0f, 0.0f ); glClearDepth( 1.0f ); glEnable( GL_DEPTH_TEST ); glDepthFunc( GL_LEQUAL ); glViewport( 0, 0, screen->w, screen->h); glMatrixMode( GL_PROJECTION ); glLoadIdentity(); gluPerspective( 45.0f, ratio, 0.1f, 100.0f ); glMatrixMode( GL_MODELVIEW ); glLoadIdentity(); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); SDL_GL_SwapBuffers(); // eh, close enough. #define MAX_X 6.12 #define MAX_Y 4.50 while (!done) { int x, y; GLfloat glx, gly; if (!SDL_WaitEvent(&event)) break; switch (event.type) { case SDL_KEYUP: if (event.key.keysym.sym == SDLK_ESCAPE) done = 1; break; } SDL_GetMouseState(&x, &y); glx = ((((GLfloat) x) / ((GLfloat) screen->w)) - 0.5f) * MAX_X; gly = ((((GLfloat) y) / ((GLfloat) screen->h)) - 0.5f) * MAX_Y; glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); glTranslatef(glx,-gly,-6.0f); glBegin(GL_TRIANGLES); glColor3f(1,0,0); glVertex3f( 0.00f, 0.25f, 0.00f); glColor3f(0,1,0); glVertex3f(-0.25f, -0.25f, 0.00f); glColor3f(0,0,1); glVertex3f( 0.25f, -0.25f, 0.00f); glEnd(); SDL_GL_SwapBuffers(); } SDL_Quit(); return(0); } /* end of test.c ... */
author Ryan C. Gordon <icculus@icculus.org>
date Mon, 22 Mar 2004 09:38:20 +0000
parents 355632dca928
children
line wrap: on
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<HTML
><HEAD
><TITLE
>Joystick</TITLE
><META
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TITLE="SDL_JoystickEventState"
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><DIV
CLASS="CHAPTER"
><H1
><A
NAME="JOYSTICK"
></A
>Chapter 9. Joystick</H1
><DIV
CLASS="TOC"
><DL
><DT
><B
>Table of Contents</B
></DT
><DT
><A
HREF="sdlnumjoysticks.html"
>SDL_NumJoysticks</A
>&nbsp;--&nbsp;Count available joysticks.</DT
><DT
><A
HREF="sdljoystickname.html"
>SDL_JoystickName</A
>&nbsp;--&nbsp;Get joystick name.</DT
><DT
><A
HREF="sdljoystickopen.html"
>SDL_JoystickOpen</A
>&nbsp;--&nbsp;Opens a joystick for use.</DT
><DT
><A
HREF="sdljoystickopened.html"
>SDL_JoystickOpened</A
>&nbsp;--&nbsp;Determine if a joystick has been opened</DT
><DT
><A
HREF="sdljoystickindex.html"
>SDL_JoystickIndex</A
>&nbsp;--&nbsp;Get the index of an SDL_Joystick.</DT
><DT
><A
HREF="sdljoysticknumaxes.html"
>SDL_JoystickNumAxes</A
>&nbsp;--&nbsp;Get the number of joystick axes</DT
><DT
><A
HREF="sdljoysticknumballs.html"
>SDL_JoystickNumBalls</A
>&nbsp;--&nbsp;Get the number of joystick trackballs</DT
><DT
><A
HREF="sdljoysticknumhats.html"
>SDL_JoystickNumHats</A
>&nbsp;--&nbsp;Get the number of joystick hats</DT
><DT
><A
HREF="sdljoysticknumbuttons.html"
>SDL_JoystickNumButtons</A
>&nbsp;--&nbsp;Get the number of joysitck buttons</DT
><DT
><A
HREF="sdljoystickupdate.html"
>SDL_JoystickUpdate</A
>&nbsp;--&nbsp;Updates the state of all joysticks</DT
><DT
><A
HREF="sdljoystickgetaxis.html"
>SDL_JoystickGetAxis</A
>&nbsp;--&nbsp;Get the current state of an axis</DT
><DT
><A
HREF="sdljoystickgethat.html"
>SDL_JoystickGetHat</A
>&nbsp;--&nbsp;Get the current state of a joystick hat</DT
><DT
><A
HREF="sdljoystickgetbutton.html"
>SDL_JoystickGetButton</A
>&nbsp;--&nbsp;Get the current state of a given button on a given joystick</DT
><DT
><A
HREF="sdljoystickgetball.html"
>SDL_JoystickGetBall</A
>&nbsp;--&nbsp;Get relative trackball motion</DT
><DT
><A
HREF="sdljoystickclose.html"
>SDL_JoystickClose</A
>&nbsp;--&nbsp;Closes a previously opened joystick</DT
></DL
></DIV
><P
>Joysticks, and other similar input devices, have a very strong role in game playing and SDL provides comprehensive support for them. Axes, Buttons, POV Hats and trackballs are all supported.</P
><P
>Joystick support is initialized by passed the <TT
CLASS="LITERAL"
>SDL_INIT_JOYSTICK</TT
> flag to <A
HREF="sdlinit.html"
><TT
CLASS="FUNCTION"
>SDL_Init</TT
></A
>. Once initilized joysticks must be opened using <A
HREF="sdljoystickopen.html"
><TT
CLASS="FUNCTION"
>SDL_JoystickOpen</TT
></A
>.</P
><P
>While using the functions describe in this secton may seem like the best way to access and read from joysticks, in most cases they aren't. Ideally joysticks should be read using the <A
HREF="event.html"
>event</A
> system. To enable this, you must set the joystick event processing state with <A
HREF="sdljoystickeventstate.html"
><TT
CLASS="FUNCTION"
>SDL_JoystickEventState</TT
></A
>. Joysticks must be <A
HREF="sdljoystickopen.html"
>opened</A
> before they can be used of course.</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
>If you are <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>not</I
></SPAN
> handling the joystick via the event queue then you must explicitly request a joystick update by calling <A
HREF="sdljoystickupdate.html"
><TT
CLASS="FUNCTION"
>SDL_JoystickUpdate</TT
></A
>.</P
></BLOCKQUOTE
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
>Force Feedback is not yet support. Sam (slouken@libsdl.org) is soliciting suggestions from people with force-feedback experience on the best wat to desgin the API.</P
></BLOCKQUOTE
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