all repos — mgba @ 657bcec87942b5583c983a1d375bc3c5dd3f8a4e

mGBA Game Boy Advance Emulator

src/platform/sdl/sdl-events.c (view raw)

  1/* Copyright (c) 2013-2014 Jeffrey Pfau
  2 *
  3 * This Source Code Form is subject to the terms of the Mozilla Public
  4 * License, v. 2.0. If a copy of the MPL was not distributed with this
  5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
  6#include "sdl-events.h"
  7
  8#include "debugger/debugger.h"
  9#include "gba/io.h"
 10#include "gba/supervisor/rr.h"
 11#include "gba/serialize.h"
 12#include "gba/video.h"
 13#include "gba/renderers/video-software.h"
 14#include "util/configuration.h"
 15#include "util/vfs.h"
 16
 17#if SDL_VERSION_ATLEAST(2, 0, 0) && defined(__APPLE__)
 18#define GUI_MOD KMOD_GUI
 19#else
 20#define GUI_MOD KMOD_CTRL
 21#endif
 22
 23#define GYRO_STEPS 100
 24
 25static void _GBASDLSetRumble(struct GBARumble* rumble, int enable);
 26static int32_t _GBASDLReadTiltX(struct GBARotationSource* rumble);
 27static int32_t _GBASDLReadTiltY(struct GBARotationSource* rumble);
 28static int32_t _GBASDLReadGyroZ(struct GBARotationSource* rumble);
 29static void _GBASDLRotationSample(struct GBARotationSource* source);
 30
 31bool GBASDLInitEvents(struct GBASDLEvents* context) {
 32	int subsystem = SDL_INIT_JOYSTICK;
 33#if SDL_VERSION_ATLEAST(2, 0, 0)
 34	subsystem |= SDL_INIT_HAPTIC;
 35#endif
 36	if (SDL_InitSubSystem(subsystem) < 0) {
 37		return false;
 38	}
 39
 40	SDL_JoystickEventState(SDL_ENABLE);
 41	int nJoysticks = SDL_NumJoysticks();
 42	if (nJoysticks > 0) {
 43		context->nJoysticks = nJoysticks;
 44		context->joysticks = calloc(context->nJoysticks, sizeof(SDL_Joystick*));
 45#if SDL_VERSION_ATLEAST(2, 0, 0)
 46		context->haptic = calloc(context->nJoysticks, sizeof(SDL_Haptic*));
 47#endif
 48		size_t i;
 49		for (i = 0; i < context->nJoysticks; ++i) {
 50			context->joysticks[i] = SDL_JoystickOpen(i);
 51#if SDL_VERSION_ATLEAST(2, 0, 0)
 52			context->haptic[i] = SDL_HapticOpenFromJoystick(context->joysticks[i]);
 53#endif
 54		}
 55	} else {
 56		context->nJoysticks = 0;
 57		context->joysticks = 0;
 58	}
 59
 60	context->playersAttached = 0;
 61
 62	size_t i;
 63	for (i = 0; i < MAX_PLAYERS; ++i) {
 64		context->preferredJoysticks[i] = 0;
 65		context->joysticksClaimed[i] = SIZE_MAX;
 66	}
 67
 68#if !SDL_VERSION_ATLEAST(2, 0, 0)
 69	SDL_EnableKeyRepeat(SDL_DEFAULT_REPEAT_DELAY, SDL_DEFAULT_REPEAT_INTERVAL);
 70#endif
 71	return true;
 72}
 73
 74void GBASDLDeinitEvents(struct GBASDLEvents* context) {
 75	size_t i;
 76	for (i = 0; i < context->nJoysticks; ++i) {
 77#if SDL_VERSION_ATLEAST(2, 0, 0)
 78		SDL_HapticClose(context->haptic[i]);
 79#endif
 80		SDL_JoystickClose(context->joysticks[i]);
 81	}
 82
 83	SDL_QuitSubSystem(SDL_INIT_JOYSTICK);
 84}
 85
 86void GBASDLEventsLoadConfig(struct GBASDLEvents* context, const struct Configuration* config) {
 87	context->preferredJoysticks[0] = GBAInputGetPreferredDevice(config, SDL_BINDING_BUTTON, 0);
 88	context->preferredJoysticks[1] = GBAInputGetPreferredDevice(config, SDL_BINDING_BUTTON, 1);
 89	context->preferredJoysticks[2] = GBAInputGetPreferredDevice(config, SDL_BINDING_BUTTON, 2);
 90	context->preferredJoysticks[3] = GBAInputGetPreferredDevice(config, SDL_BINDING_BUTTON, 3);
 91}
 92
 93void GBASDLInitBindings(struct GBAInputMap* inputMap) {
 94#ifdef BUILD_PANDORA
 95	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_PAGEDOWN, GBA_KEY_A);
 96	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_END, GBA_KEY_B);
 97	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_RSHIFT, GBA_KEY_L);
 98	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_RCTRL, GBA_KEY_R);
 99	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_LALT, GBA_KEY_START);
100	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_LCTRL, GBA_KEY_SELECT);
101	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_UP, GBA_KEY_UP);
102	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_DOWN, GBA_KEY_DOWN);
103	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_LEFT, GBA_KEY_LEFT);
104	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_RIGHT, GBA_KEY_RIGHT);
105#elif SDL_VERSION_ATLEAST(2, 0, 0)
106	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_X, GBA_KEY_A);
107	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_Z, GBA_KEY_B);
108	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_A, GBA_KEY_L);
109	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_S, GBA_KEY_R);
110	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_RETURN, GBA_KEY_START);
111	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_BACKSPACE, GBA_KEY_SELECT);
112	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_UP, GBA_KEY_UP);
113	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_DOWN, GBA_KEY_DOWN);
114	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_LEFT, GBA_KEY_LEFT);
115	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_RIGHT, GBA_KEY_RIGHT);
116#else
117	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_x, GBA_KEY_A);
118	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_z, GBA_KEY_B);
119	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_a, GBA_KEY_L);
120	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_s, GBA_KEY_R);
121	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_RETURN, GBA_KEY_START);
122	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_BACKSPACE, GBA_KEY_SELECT);
123	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_UP, GBA_KEY_UP);
124	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_DOWN, GBA_KEY_DOWN);
125	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_LEFT, GBA_KEY_LEFT);
126	GBAInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_RIGHT, GBA_KEY_RIGHT);
127#endif
128
129	GBAInputBindKey(inputMap, SDL_BINDING_BUTTON, 13, GBA_KEY_A);
130	GBAInputBindKey(inputMap, SDL_BINDING_BUTTON, 14, GBA_KEY_B);
131	GBAInputBindKey(inputMap, SDL_BINDING_BUTTON, 10, GBA_KEY_L);
132	GBAInputBindKey(inputMap, SDL_BINDING_BUTTON, 11, GBA_KEY_R);
133	GBAInputBindKey(inputMap, SDL_BINDING_BUTTON, 3, GBA_KEY_START);
134	GBAInputBindKey(inputMap, SDL_BINDING_BUTTON, 0, GBA_KEY_SELECT);
135	GBAInputBindKey(inputMap, SDL_BINDING_BUTTON, 4, GBA_KEY_UP);
136	GBAInputBindKey(inputMap, SDL_BINDING_BUTTON, 6, GBA_KEY_DOWN);
137	GBAInputBindKey(inputMap, SDL_BINDING_BUTTON, 7, GBA_KEY_LEFT);
138	GBAInputBindKey(inputMap, SDL_BINDING_BUTTON, 5, GBA_KEY_RIGHT);
139
140	struct GBAAxis description = { GBA_KEY_RIGHT, GBA_KEY_LEFT, 0x4000, -0x4000 };
141	GBAInputBindAxis(inputMap, SDL_BINDING_BUTTON, 0, &description);
142	description = (struct GBAAxis) { GBA_KEY_DOWN, GBA_KEY_UP, 0x4000, -0x4000 };
143	GBAInputBindAxis(inputMap, SDL_BINDING_BUTTON, 1, &description);
144}
145
146bool GBASDLAttachPlayer(struct GBASDLEvents* events, struct GBASDLPlayer* player) {
147	player->joystick = 0;
148	player->joystickIndex = SIZE_MAX;
149
150#if SDL_VERSION_ATLEAST(2, 0, 0)
151	player->rumble.d.setRumble = _GBASDLSetRumble;
152	player->rumble.p = player;
153#endif
154
155	player->rotation.d.readTiltX = _GBASDLReadTiltX;
156	player->rotation.d.readTiltY = _GBASDLReadTiltY;
157	player->rotation.d.readGyroZ = _GBASDLReadGyroZ;
158	player->rotation.d.sample = _GBASDLRotationSample;
159	player->rotation.axisX = 2;
160	player->rotation.axisY = 3;
161	player->rotation.gyroSensitivity = 2.2e9f;
162	player->rotation.gyroX = 0;
163	player->rotation.gyroY = 1;
164	player->rotation.zDelta = 0;
165	CircleBufferInit(&player->rotation.zHistory, sizeof(float) * GYRO_STEPS);
166	player->rotation.p = player;
167
168	if (events->playersAttached >= MAX_PLAYERS) {
169		return false;
170	}
171
172	player->playerId = events->playersAttached;
173	size_t firstUnclaimed = SIZE_MAX;
174
175	size_t i;
176	for (i = 0; i < events->nJoysticks; ++i) {
177		bool claimed = false;
178
179		int p;
180		for (p = 0; p < events->playersAttached; ++p) {
181			if (events->joysticksClaimed[p] == i) {
182				claimed = true;
183				break;
184			}
185		}
186		if (claimed) {
187			continue;
188		}
189
190		if (firstUnclaimed == SIZE_MAX) {
191			firstUnclaimed = i;
192		}
193
194		const char* joystickName;
195#if SDL_VERSION_ATLEAST(2, 0, 0)
196		joystickName = SDL_JoystickName(events->joysticks[i]);
197#else
198		joystickName = SDL_JoystickName(SDL_JoystickIndex(events->joysticks[i]));
199#endif
200		if (events->preferredJoysticks[player->playerId] && strcmp(events->preferredJoysticks[player->playerId], joystickName) == 0) {
201			player->joystickIndex = i;
202			break;
203		}
204	}
205
206	if (player->joystickIndex == SIZE_MAX && firstUnclaimed != SIZE_MAX) {
207		player->joystickIndex = firstUnclaimed;
208	}
209
210	if (player->joystickIndex != SIZE_MAX) {
211		player->joystick = events->joysticks[player->joystickIndex];
212		events->joysticksClaimed[player->playerId] = player->joystickIndex;
213
214#if SDL_VERSION_ATLEAST(2, 0, 0)
215		player->haptic = events->haptic[player->joystickIndex];
216		if (player->haptic) {
217			SDL_HapticRumbleInit(player->haptic);
218		}
219#endif
220	}
221
222	++events->playersAttached;
223	return true;
224}
225
226void GBASDLDetachPlayer(struct GBASDLEvents* events, struct GBASDLPlayer* player) {
227	events->joysticksClaimed[player->playerId] = SIZE_MAX;
228	CircleBufferDeinit(&player->rotation.zHistory);
229}
230
231void GBASDLPlayerLoadConfig(struct GBASDLPlayer* context, const struct Configuration* config) {
232	GBAInputMapLoad(context->bindings, SDL_BINDING_KEY, config);
233	if (context->joystick) {
234		GBAInputMapLoad(context->bindings, SDL_BINDING_BUTTON, config);
235#if SDL_VERSION_ATLEAST(2, 0, 0)
236		GBAInputProfileLoad(context->bindings, SDL_BINDING_BUTTON, config, SDL_JoystickName(context->joystick));
237#else
238		GBAInputProfileLoad(context->bindings, SDL_BINDING_BUTTON, config, SDL_JoystickName(SDL_JoystickIndex(context->joystick)));
239#endif
240	}
241}
242
243void GBASDLPlayerChangeJoystick(struct GBASDLEvents* events, struct GBASDLPlayer* player, size_t index) {
244	if (player->playerId > MAX_PLAYERS || index >= events->nJoysticks) {
245		return;
246	}
247	events->joysticksClaimed[player->playerId] = index;
248	player->joystickIndex = index;
249	player->joystick = events->joysticks[index];
250#if SDL_VERSION_ATLEAST(2, 0, 0)
251	player->haptic = events->haptic[index];
252#endif
253}
254
255static void _pauseAfterFrame(struct GBAThread* context) {
256	context->frameCallback = 0;
257	GBAThreadPauseFromThread(context);
258}
259
260static void _GBASDLHandleKeypress(struct GBAThread* context, struct GBASDLPlayer* sdlContext, const struct SDL_KeyboardEvent* event) {
261	enum GBAKey key = GBA_KEY_NONE;
262	if (!event->keysym.mod) {
263#if !defined(BUILD_PANDORA) && SDL_VERSION_ATLEAST(2, 0, 0)
264		key = GBAInputMapKey(sdlContext->bindings, SDL_BINDING_KEY, event->keysym.scancode);
265#else
266		key = GBAInputMapKey(sdlContext->bindings, SDL_BINDING_KEY, event->keysym.sym);
267#endif
268	}
269	if (key != GBA_KEY_NONE) {
270		if (event->type == SDL_KEYDOWN) {
271			context->activeKeys |= 1 << key;
272		} else {
273			context->activeKeys &= ~(1 << key);
274		}
275		return;
276	}
277	if (event->keysym.sym == SDLK_TAB) {
278		context->sync.audioWait = event->type != SDL_KEYDOWN;
279		return;
280	}
281	if (event->type == SDL_KEYDOWN) {
282		switch (event->keysym.sym) {
283		case SDLK_F11:
284			if (context->debugger) {
285				ARMDebuggerEnter(context->debugger, DEBUGGER_ENTER_MANUAL, 0);
286			}
287			return;
288#ifdef USE_PNG
289		case SDLK_F12:
290			GBAThreadInterrupt(context);
291			GBAThreadTakeScreenshot(context);
292			GBAThreadContinue(context);
293			return;
294#endif
295		case SDLK_BACKSLASH:
296			GBAThreadPause(context);
297			context->frameCallback = _pauseAfterFrame;
298			GBAThreadUnpause(context);
299			return;
300		case SDLK_BACKQUOTE:
301			GBAThreadInterrupt(context);
302			GBARewind(context, 10);
303			GBAThreadContinue(context);
304			return;
305#ifdef BUILD_PANDORA
306		case SDLK_ESCAPE:
307			GBAThreadEnd(context);
308			return;
309#endif
310		default:
311			if ((event->keysym.mod & GUI_MOD) && (event->keysym.mod & GUI_MOD) == event->keysym.mod) {
312				switch (event->keysym.sym) {
313#if SDL_VERSION_ATLEAST(2, 0, 0)
314				case SDLK_f:
315					SDL_SetWindowFullscreen(sdlContext->window, sdlContext->fullscreen ? 0 : SDL_WINDOW_FULLSCREEN_DESKTOP);
316					sdlContext->fullscreen = !sdlContext->fullscreen;
317					sdlContext->windowUpdated = 1;
318					break;
319#endif
320				case SDLK_p:
321					GBAThreadTogglePause(context);
322					break;
323				case SDLK_n:
324					GBAThreadPause(context);
325					context->frameCallback = _pauseAfterFrame;
326					GBAThreadUnpause(context);
327					break;
328				case SDLK_r:
329					GBAThreadReset(context);
330					break;
331				default:
332					break;
333				}
334			}
335			if (event->keysym.mod & KMOD_SHIFT) {
336				switch (event->keysym.sym) {
337				case SDLK_F1:
338				case SDLK_F2:
339				case SDLK_F3:
340				case SDLK_F4:
341				case SDLK_F5:
342				case SDLK_F6:
343				case SDLK_F7:
344				case SDLK_F8:
345				case SDLK_F9:
346					GBAThreadInterrupt(context);
347					GBASaveState(context, context->stateDir, event->keysym.sym - SDLK_F1 + 1, true);
348					GBAThreadContinue(context);
349					break;
350				default:
351					break;
352				}
353			} else {
354				switch (event->keysym.sym) {
355				case SDLK_F1:
356				case SDLK_F2:
357				case SDLK_F3:
358				case SDLK_F4:
359				case SDLK_F5:
360				case SDLK_F6:
361				case SDLK_F7:
362				case SDLK_F8:
363				case SDLK_F9:
364					GBAThreadInterrupt(context);
365					GBALoadState(context, context->stateDir, event->keysym.sym - SDLK_F1 + 1);
366					GBAThreadContinue(context);
367					break;
368				default:
369					break;
370				}
371			}
372			return;
373		}
374	}
375}
376
377static void _GBASDLHandleJoyButton(struct GBAThread* context, struct GBASDLPlayer* sdlContext, const struct SDL_JoyButtonEvent* event) {
378	enum GBAKey key = 0;
379	key = GBAInputMapKey(sdlContext->bindings, SDL_BINDING_BUTTON, event->button);
380	if (key == GBA_KEY_NONE) {
381		return;
382	}
383
384	if (event->type == SDL_JOYBUTTONDOWN) {
385		context->activeKeys |= 1 << key;
386	} else {
387		context->activeKeys &= ~(1 << key);
388	}
389}
390
391static void _GBASDLHandleJoyHat(struct GBAThread* context, const struct SDL_JoyHatEvent* event) {
392	enum GBAKey key = 0;
393
394	if (event->value & SDL_HAT_UP) {
395		key |= 1 << GBA_KEY_UP;
396	}
397	if (event->value & SDL_HAT_LEFT) {
398		key |= 1 << GBA_KEY_LEFT;
399	}
400	if (event->value & SDL_HAT_DOWN) {
401		key |= 1 << GBA_KEY_DOWN;
402	}
403	if (event->value & SDL_HAT_RIGHT) {
404		key |= 1 << GBA_KEY_RIGHT;
405	}
406
407	context->activeKeys &= ~((1 << GBA_KEY_UP) | (1 << GBA_KEY_LEFT) | (1 << GBA_KEY_DOWN) | (1 << GBA_KEY_RIGHT));
408	context->activeKeys |= key;
409}
410
411static void _GBASDLHandleJoyAxis(struct GBAThread* context, struct GBASDLPlayer* sdlContext, const struct SDL_JoyAxisEvent* event) {
412	int keys = context->activeKeys;
413
414	keys = GBAInputClearAxis(sdlContext->bindings, SDL_BINDING_BUTTON, event->axis, keys);
415	enum GBAKey key = GBAInputMapAxis(sdlContext->bindings, SDL_BINDING_BUTTON, event->axis, event->value);
416	if (key != GBA_KEY_NONE) {
417		keys |= 1 << key;
418	}
419
420	context->activeKeys = keys;
421}
422
423#if SDL_VERSION_ATLEAST(2, 0, 0)
424static void _GBASDLHandleWindowEvent(struct GBAThread* context, struct GBASDLPlayer* sdlContext, const struct SDL_WindowEvent* event) {
425	UNUSED(context);
426	switch (event->event) {
427	case SDL_WINDOWEVENT_SIZE_CHANGED:
428		sdlContext->windowUpdated = 1;
429		break;
430	}
431}
432#endif
433
434void GBASDLHandleEvent(struct GBAThread* context, struct GBASDLPlayer* sdlContext, const union SDL_Event* event) {
435	switch (event->type) {
436	case SDL_QUIT:
437		GBAThreadEnd(context);
438		break;
439#if SDL_VERSION_ATLEAST(2, 0, 0)
440	case SDL_WINDOWEVENT:
441		_GBASDLHandleWindowEvent(context, sdlContext, &event->window);
442		break;
443#endif
444	case SDL_KEYDOWN:
445	case SDL_KEYUP:
446		_GBASDLHandleKeypress(context, sdlContext, &event->key);
447		break;
448	case SDL_JOYBUTTONDOWN:
449	case SDL_JOYBUTTONUP:
450		_GBASDLHandleJoyButton(context, sdlContext, &event->jbutton);
451		break;
452	case SDL_JOYHATMOTION:
453		_GBASDLHandleJoyHat(context, &event->jhat);
454		break;
455	case SDL_JOYAXISMOTION:
456		_GBASDLHandleJoyAxis(context, sdlContext, &event->jaxis);
457		break;
458	}
459}
460
461#if SDL_VERSION_ATLEAST(2, 0, 0)
462static void _GBASDLSetRumble(struct GBARumble* rumble, int enable) {
463	struct GBASDLRumble* sdlRumble = (struct GBASDLRumble*) rumble;
464	if (!sdlRumble->p->haptic || !SDL_HapticRumbleSupported(sdlRumble->p->haptic)) {
465		return;
466	}
467	if (enable) {
468		SDL_HapticRumblePlay(sdlRumble->p->haptic, 1.0f, 20);
469	} else {
470		SDL_HapticRumbleStop(sdlRumble->p->haptic);
471	}
472}
473#endif
474
475static int32_t _readTilt(struct GBASDLPlayer* player, int axis) {
476	return SDL_JoystickGetAxis(player->joystick, axis) * 0x3800;
477}
478
479static int32_t _GBASDLReadTiltX(struct GBARotationSource* source) {
480	struct GBASDLRotation* rotation = (struct GBASDLRotation*) source;
481	return _readTilt(rotation->p, rotation->axisX);
482}
483
484static int32_t _GBASDLReadTiltY(struct GBARotationSource* source) {
485	struct GBASDLRotation* rotation = (struct GBASDLRotation*) source;
486	return _readTilt(rotation->p, rotation->axisY);
487}
488
489static int32_t _GBASDLReadGyroZ(struct GBARotationSource* source) {
490	struct GBASDLRotation* rotation = (struct GBASDLRotation*) source;
491	float z = rotation->zDelta;
492	return z * rotation->gyroSensitivity;
493}
494
495static void _GBASDLRotationSample(struct GBARotationSource* source) {
496	struct GBASDLRotation* rotation = (struct GBASDLRotation*) source;
497	SDL_JoystickUpdate();
498
499	int x = SDL_JoystickGetAxis(rotation->p->joystick, rotation->gyroX);
500	int y = SDL_JoystickGetAxis(rotation->p->joystick, rotation->gyroY);
501	float theta = atan2f(y, x) - atan2f(rotation->oldY, rotation->oldX);
502	if (isnan(theta)) {
503		theta = 0.0f;
504	} else if (theta > M_PI) {
505		theta -= 2.0f * M_PI;
506	} else if (theta < -M_PI) {
507		theta += 2.0f * M_PI;
508	}
509	rotation->oldX = x;
510	rotation->oldY = y;
511
512	float oldZ = 0;
513	if (CircleBufferSize(&rotation->zHistory) == GYRO_STEPS * sizeof(float)) {
514		CircleBufferRead32(&rotation->zHistory, (int32_t*) &oldZ);
515	}
516	CircleBufferWrite32(&rotation->zHistory, *(int32_t*) &theta);
517	rotation->zDelta += theta - oldZ;
518}