view test/testjoystick.c @ 4384:6800e2560310 SDL-1.2

Fixed bugs #882 and 865, re-opening bug #634 Ronald Lamprecht to SDL Hi, Sam Lantinga wrote: The problem with that fix is that it breaks IME events again. Maybe we can handle keyboard events differently to prevent this issue? Spending an hour reading MSDN, analysing SDL and another hour testing the reality on XP I am really wondering how patch r4990 could have ever worked in any situation. It's main effect is to break the unicode translation and causing spurious activation events! Why does TranslateMessage(&msg) nothing useful? Simply because it does not affect "msg" at all! All keyboard events are dispatched without the slightest change (see MSDN). TranslateMessage() just appends additional WM_CHAR, WM_DEADCHAR, WM_SYSCHAR, WM_SYSDEADCHAR event messages to the queue. But I could not find any SDL event handling routine that catches these events and transforms them to proper SDL keyevents while eliminating the corresponding WM_KEYDOWN, etc. events. Thus any IME input like the '@' generated by "Alt + 6(Numpad) + 4(Numpad)" is simply lost. But the situation is even worse! Up to r4990 the TranslateKey()/ToUnicode() calls did evaluate dead keys and did deliver proper key events for subsequent key strokes like '´' + 'e' resulting in 'é'. ToUnicode() needs proper key state informations to be able to handle these substitutions. But unfortunatly TranslateMessage() needs the same state information and eats it up while generating the WM_CHAR messages :-( Thus the current 1.2.14 breakes the partial IME support of previous releases, too. The key state race condition between ToUnicode() and TranslateMessage() requires to avoid any ToUnicode() usage for receiving proper WM_CHAR, etc. messages generated by TranslateMessage(). (Yes - the '@' and 'é' appear as WM_CHAR messages when unicode is switched off). The spurious SDL activation events are *not* caused by additional WM_ACTIVATE Windows messages! Besides DIB_HandleMessage() SDL_PrivateAppActive() is called by another source which I am not yet aware of - any hints? Thus I do strongly recommend the deletion of the TranslateMessage(&msg) call as a quick fix. A proper support of unicode and IME requires a clean SDL keyboard input concept first. Which SDL keyboards events should be transmitted to the app when the user presses '´' + 'e' ? Within the current unicode handling the first key stroke is hidden. Even though ToUnicode() delivers the proper key SDL does ignore it in TranslateKey(). Just the composed key event is transmitted to the app. That is what you expect for text input, but the app can no longer use keys like '^' as a key button because it will never receive a key event for it! With a given concept it seems to be necessary to regenerate SDL key events out of the WM_CHAR, etc. events and to drop all related direct WM_KEYDOWN, etc. events while the remaining basic WM_KEYDOWN, etc. events would still have to result in SDL key events. Anyway the source of the spurious WM_ACTIVATE should be located to avoid future trouble. Greets, Ronald
author Sam Lantinga <slouken@libsdl.org>
date Tue, 17 Nov 2009 04:59:13 +0000
parents 0dd0ca51d941
children
line wrap: on
line source


/* Simple program to test the SDL joystick routines */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "SDL.h"

#define SCREEN_WIDTH	640
#define SCREEN_HEIGHT	480

void WatchJoystick(SDL_Joystick *joystick)
{
	SDL_Surface *screen;
	const char *name;
	int i, done;
	SDL_Event event;
	int x, y, draw;
	SDL_Rect axis_area[2];

	/* Set a video mode to display joystick axis position */
	screen = SDL_SetVideoMode(SCREEN_WIDTH, SCREEN_HEIGHT, 16, 0);
	if ( screen == NULL ) {
		fprintf(stderr, "Couldn't set video mode: %s\n",SDL_GetError());
		return;
	}

	/* Print info about the joystick we are watching */
	name = SDL_JoystickName(SDL_JoystickIndex(joystick));
	printf("Watching joystick %d: (%s)\n", SDL_JoystickIndex(joystick),
	       name ? name : "Unknown Joystick");
	printf("Joystick has %d axes, %d hats, %d balls, and %d buttons\n",
	       SDL_JoystickNumAxes(joystick), SDL_JoystickNumHats(joystick),
	       SDL_JoystickNumBalls(joystick),SDL_JoystickNumButtons(joystick));

	/* Initialize drawing rectangles */
	memset(axis_area, 0, (sizeof axis_area));
	draw = 0;

	/* Loop, getting joystick events! */
	done = 0;
	while ( ! done ) {
		while ( SDL_PollEvent(&event) ) {
			switch (event.type) {
			    case SDL_JOYAXISMOTION:
				printf("Joystick %d axis %d value: %d\n",
				       event.jaxis.which,
				       event.jaxis.axis,
				       event.jaxis.value);
				break;
			    case SDL_JOYHATMOTION:
				printf("Joystick %d hat %d value:",
				       event.jhat.which,
				       event.jhat.hat);
				if ( event.jhat.value == SDL_HAT_CENTERED )
					printf(" centered");
				if ( event.jhat.value & SDL_HAT_UP )
					printf(" up");
				if ( event.jhat.value & SDL_HAT_RIGHT )
					printf(" right");
				if ( event.jhat.value & SDL_HAT_DOWN )
					printf(" down");
				if ( event.jhat.value & SDL_HAT_LEFT )
					printf(" left");
				printf("\n");
				break;
			    case SDL_JOYBALLMOTION:
				printf("Joystick %d ball %d delta: (%d,%d)\n",
				       event.jball.which,
				       event.jball.ball,
				       event.jball.xrel,
				       event.jball.yrel);
				break;
			    case SDL_JOYBUTTONDOWN:
				printf("Joystick %d button %d down\n",
				       event.jbutton.which,
				       event.jbutton.button);
				break;
			    case SDL_JOYBUTTONUP:
				printf("Joystick %d button %d up\n",
				       event.jbutton.which,
				       event.jbutton.button);
				break;
			    case SDL_KEYDOWN:
				if ( event.key.keysym.sym != SDLK_ESCAPE ) {
					break;
				}
				/* Fall through to signal quit */
			    case SDL_QUIT:
				done = 1;
				break;
			    default:
				break;
			}
		}
		/* Update visual joystick state */
		for ( i=0; i<SDL_JoystickNumButtons(joystick); ++i ) {
			SDL_Rect area;

			area.x = i*34;
			area.y = SCREEN_HEIGHT-34;
			area.w = 32;
			area.h = 32;
			if (SDL_JoystickGetButton(joystick, i) == SDL_PRESSED) {
				SDL_FillRect(screen, &area, 0xFFFF);
			} else {
				SDL_FillRect(screen, &area, 0x0000);
			}
			SDL_UpdateRects(screen, 1, &area);
		}

		/* Erase previous axes */
		SDL_FillRect(screen, &axis_area[draw], 0x0000);

		/* Draw the X/Y axis */
		draw = !draw;
		x = (((int)SDL_JoystickGetAxis(joystick, 0))+32768);
		x *= SCREEN_WIDTH;
		x /= 65535;
		if ( x < 0 ) {
			x = 0;
		} else
		if ( x > (SCREEN_WIDTH-16) ) {
			x = SCREEN_WIDTH-16;
		}
		y = (((int)SDL_JoystickGetAxis(joystick, 1))+32768);
		y *= SCREEN_HEIGHT;
		y /= 65535;
		if ( y < 0 ) {
			y = 0;
		} else
		if ( y > (SCREEN_HEIGHT-16) ) {
			y = SCREEN_HEIGHT-16;
		}
		axis_area[draw].x = (Sint16)x;
		axis_area[draw].y = (Sint16)y;
		axis_area[draw].w = 16;
		axis_area[draw].h = 16;
		SDL_FillRect(screen, &axis_area[draw], 0xFFFF);

		SDL_UpdateRects(screen, 2, axis_area);
	}
}

int main(int argc, char *argv[])
{
	const char *name;
	int i;
	SDL_Joystick *joystick;

	/* Initialize SDL (Note: video is required to start event loop) */
	if ( SDL_Init(SDL_INIT_VIDEO|SDL_INIT_JOYSTICK) < 0 ) {
		fprintf(stderr, "Couldn't initialize SDL: %s\n",SDL_GetError());
		exit(1);
	}

	/* Print information about the joysticks */
	printf("There are %d joysticks attached\n", SDL_NumJoysticks());
	for ( i=0; i<SDL_NumJoysticks(); ++i ) {
		name = SDL_JoystickName(i);
		printf("Joystick %d: %s\n",i,name ? name : "Unknown Joystick");
		joystick = SDL_JoystickOpen(i);
		if (joystick == NULL) {
			fprintf(stderr, "SDL_JoystickOpen(%d) failed: %s\n", i, SDL_GetError());
		} else {
			printf("       axes: %d\n", SDL_JoystickNumAxes(joystick));
			printf("      balls: %d\n", SDL_JoystickNumBalls(joystick));
			printf("       hats: %d\n", SDL_JoystickNumHats(joystick));
			printf("    buttons: %d\n", SDL_JoystickNumButtons(joystick));
			SDL_JoystickClose(joystick);
		}
	}

	if ( argv[1] ) {
		joystick = SDL_JoystickOpen(atoi(argv[1]));
		if ( joystick == NULL ) {
			printf("Couldn't open joystick %d: %s\n", atoi(argv[1]),
			       SDL_GetError());
		} else {
			WatchJoystick(joystick);
			SDL_JoystickClose(joystick);
		}
	}
	SDL_QuitSubSystem(SDL_INIT_VIDEO|SDL_INIT_JOYSTICK);

	return(0);
}