add mouse capture and relative mouse movement

1 files changed, 170 insertions, 1 deletions

diff --git a/kon/konwinlib.h b/kon/konwinlib.h
index 0a1f365..1570931 100644
--- a/kon/konwinlib.h
+++ b/kon/konwinlib.h
@@ -110,6 +110,7 @@ typedef struct kon_event {
 	int key;
 	unsigned int codepoint; /* unicode codepoint, only set for KON_EVENT_TEXT */
 	int mouseX, mouseY;
+	int mouseDX, mouseDY; /* how far the mouse moved, set for KON_EVENT_MOUSE_MOVE. keeps working while the mouse is captured */
 	kon_mouseButton_t mouseButton;
 	int wheel; /* only set for KON_EVENT_MOUSE_WHEEL, 1 for each notch away from you and -1 towards you */
 } kon_event_t;
@@ -128,6 +129,11 @@ void kon_setWindowSize(kon_window_t *window, int width, int height);
 void kon_getWindowPos(kon_window_t *window, int *x, int *y);
 void kon_getWindowSize(kon_window_t *window, int *width, int *height);
 
+/* hides the cursor and keeps it in the window so the mouse can turn a camera, move events keep reporting mouseDX and mouseDY.
+   returns 1 when it worked. the window lets go by itself when it loses focus. on the web this has to be called from a click or key press */
+int kon_setMouseCapture(kon_window_t *window, bool captured);
+bool kon_isMouseCaptured(const kon_window_t *window);
+
 /*** window tricks ***/
 
 typedef enum kon_messageType {
@@ -182,7 +188,13 @@ static void kon_pushEvent_(kon_eventQueue_t *q, const kon_event_t *event) {
 	if (q->count > 0 && (event->type == KON_EVENT_MOUSE_MOVE || event->type == KON_EVENT_RESIZE)) {
 		kon_event_t *last = &q->events[(q->head + q->count - 1) % KON_EVENT_QUEUE_SIZE];
 		if (last->type == event->type) {
+			int dx = last->mouseDX + event->mouseDX, dy = last->mouseDY + event->mouseDY;
+
 			*last = *event;
+			if (event->type == KON_EVENT_MOUSE_MOVE) {
+				last->mouseDX = dx;
+				last->mouseDY = dy;
+			}
 			return;
 		}
 	}
@@ -212,6 +224,7 @@ struct kon_context {
 
 struct kon_window {
 	char canvasID[64];
+	bool captured;
 	bool shouldClose;
 	int exitKey;
 	kon_eventQueue_t queue;
@@ -369,6 +382,8 @@ static EM_BOOL kon_mouseCallback_(int eventType, const EmscriptenMouseEvent *e,
 
 	if (eventType == EMSCRIPTEN_EVENT_MOUSEMOVE) {
 		ev.type = KON_EVENT_MOUSE_MOVE;
+		ev.mouseDX = (int)e->movementX;
+		ev.mouseDY = (int)e->movementY;
 	} else {
 		if (e->button > KON_MOUSE_RIGHT) return EM_FALSE;
 		ev.type = (eventType == EMSCRIPTEN_EVENT_MOUSEDOWN) ? KON_EVENT_MOUSE_DOWN : KON_EVENT_MOUSE_UP;
@@ -428,9 +443,27 @@ kon_window_t *kon_createWindow(const char *title, int x, int y, int width, int h
 	return window;
 }
 
+int kon_setMouseCapture(kon_window_t *window, bool captured) {
+	if (!window) return 0;
+
+	if (captured) {
+		if (emscripten_request_pointerlock(window->canvasID, EM_TRUE) < 0) return 0;
+		window->captured = true;
+	} else {
+		emscripten_exit_pointerlock();
+		window->captured = false;
+	}
+	return 1;
+}
+
+bool kon_isMouseCaptured(const kon_window_t *window) {
+	return window && window->captured;
+}
+
 void kon_destroyWindow(kon_window_t *window) {
 	if (!window) return;
 
+	if (window->captured) emscripten_exit_pointerlock();
 	emscripten_set_keydown_callback(EMSCRIPTEN_EVENT_TARGET_WINDOW, NULL, EM_FALSE, NULL);
 	emscripten_set_keyup_callback(EMSCRIPTEN_EVENT_TARGET_WINDOW, NULL, EM_FALSE, NULL);
 	emscripten_set_keypress_callback(EMSCRIPTEN_EVENT_TARGET_WINDOW, NULL, EM_FALSE, NULL);
@@ -702,6 +735,9 @@ struct kon_window {
 	bool shouldClose;
 	int exitKey;
 	int width, height;
+	bool captured, hasLast;
+	int lastX, lastY;
+	Cursor blankCursor;
 	kon_eventQueue_t queue;
 };
 
@@ -802,7 +838,7 @@ kon_window_t *kon_createWindow(const char *title, int x, int y, int width, int h
 	}
 
 	XStoreName(kon_ctx->display, window->window, title);
-	XSelectInput(kon_ctx->display, window->window, ExposureMask | StructureNotifyMask | KeyPressMask | KeyReleaseMask | ButtonPressMask | ButtonReleaseMask | PointerMotionMask);
+	XSelectInput(kon_ctx->display, window->window, ExposureMask | StructureNotifyMask | KeyPressMask | KeyReleaseMask | ButtonPressMask | ButtonReleaseMask | PointerMotionMask | FocusChangeMask);
 
 	if (flags & KON_WINDOW_NO_DECOR) {
 		Atom motif_hints = XInternAtom(kon_ctx->display, "_MOTIF_WM_HINTS", False);
@@ -845,10 +881,51 @@ kon_window_t *kon_createWindow(const char *title, int x, int y, int width, int h
 	return window;
 }
 
+int kon_setMouseCapture(kon_window_t *window, bool captured) {
+	if (!window || !kon_ctx) return 0;
+
+	if (!captured) {
+		if (!window->captured) return 1;
+		XUngrabPointer(kon_ctx->display, CurrentTime);
+		if (window->blankCursor) XFreeCursor(kon_ctx->display, window->blankCursor);
+		window->blankCursor = 0;
+		window->captured = false;
+		window->hasLast = false;
+		XFlush(kon_ctx->display);
+		return 1;
+	}
+	if (window->captured) return 1;
+
+	{
+		char data[1] = {0};
+		XColor black = {0};
+		Pixmap blank = XCreateBitmapFromData(kon_ctx->display, window->window, data, 1, 1);
+
+		window->blankCursor = XCreatePixmapCursor(kon_ctx->display, blank, blank, &black, &black, 0, 0);
+		XFreePixmap(kon_ctx->display, blank);
+	}
+
+	if (XGrabPointer(kon_ctx->display, window->window, True, ButtonPressMask | ButtonReleaseMask | PointerMotionMask,
+			GrabModeAsync, GrabModeAsync, window->window, window->blankCursor, CurrentTime) != GrabSuccess) {
+		XFreeCursor(kon_ctx->display, window->blankCursor);
+		window->blankCursor = 0;
+		return 0;
+	}
+	window->captured = true;
+	XWarpPointer(kon_ctx->display, None, window->window, 0, 0, 0, 0, window->width / 2, window->height / 2);
+	XFlush(kon_ctx->display);
+	return 1;
+}
+
+bool kon_isMouseCaptured(const kon_window_t *window) {
+	return window && window->captured;
+}
+
 void kon_destroyWindow(kon_window_t *window) {
 	if (!window) return;
 	if (!kon_ctx) { free(window); return; }
 
+	kon_setMouseCapture(window, false);
 	if (window->gc) XFreeGC(kon_ctx->display, window->gc);
 	if (window->window) XDestroyWindow(kon_ctx->display, window->window);
 	if (window->owns_colormap && window->colormap) XFreeColormap(kon_ctx->display, window->colormap);
@@ -990,9 +1067,28 @@ static void kon_pumpX11_(kon_window_t *window) {
 			ev.type = KON_EVENT_MOUSE_MOVE;
 			ev.mouseX = xev.xmotion.x;
 			ev.mouseY = xev.xmotion.y;
+			if (window->captured) {
+				/* the cursor gets put back in the middle every time, so how far it got from there is how far it moved */
+				int cx = window->width / 2, cy = window->height / 2;
+
+				ev.mouseDX = ev.mouseX - cx;
+				ev.mouseDY = ev.mouseY - cy;
+				if (ev.mouseDX == 0 && ev.mouseDY == 0) break;
+				XWarpPointer(kon_ctx->display, None, window->window, 0, 0, 0, 0, cx, cy);
+			} else if (window->hasLast) {
+				ev.mouseDX = ev.mouseX - window->lastX;
+				ev.mouseDY = ev.mouseY - window->lastY;
+			}
+			window->lastX = ev.mouseX;
+			window->lastY = ev.mouseY;
+			window->hasLast = true;
 			kon_pushEvent_(&window->queue, &ev);
 			break;
 
+		case FocusOut:
+			if (xev.xfocus.mode != NotifyGrab && xev.xfocus.mode != NotifyUngrab) kon_setMouseCapture(window, false);
+			break;
+
 		default:
 			break;
 		}
@@ -1499,6 +1595,8 @@ struct kon_window {
 	unsigned char alpha;
 	int exitKey;
 	unsigned short highSurrogate;
+	bool captured, hasLast;
+	int lastX, lastY;
 	kon_mainLoopFn liveFn;
 	void *liveData;
 	bool inLive;
@@ -1688,9 +1786,32 @@ LRESULT CALLBACK kon_wndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
 			ev.type = KON_EVENT_MOUSE_MOVE;
 			ev.mouseX = (int)(short)LOWORD(lParam);
 			ev.mouseY = (int)(short)HIWORD(lParam);
+			if (window->captured) {
+				/* the cursor gets put back in the middle every time, so how far it got from there is how far it moved */
+				RECT area;
+				POINT middle;
+
+				GetClientRect(hwnd, &area);
+				middle.x = (area.right - area.left) / 2;
+				middle.y = (area.bottom - area.top) / 2;
+				ev.mouseDX = ev.mouseX - (int)middle.x;
+				ev.mouseDY = ev.mouseY - (int)middle.y;
+				if (ev.mouseDX == 0 && ev.mouseDY == 0) break;
+				ClientToScreen(hwnd, &middle);
+				SetCursorPos(middle.x, middle.y);
+			} else if (window->hasLast) {
+				ev.mouseDX = ev.mouseX - window->lastX;
+				ev.mouseDY = ev.mouseY - window->lastY;
+			}
+			window->lastX = ev.mouseX;
+			window->lastY = ev.mouseY;
+			window->hasLast = true;
 			kon_pushEvent_(&window->queue, &ev);
 		}
 		break;
+	case WM_KILLFOCUS:
+		if (window) kon_setMouseCapture(window, false);
+		break;
 	case WM_CLOSE:
 		if (window) {
 			kon_event_t ev = {0};
@@ -1823,8 +1944,56 @@ kon_window_t *kon_createWindow(const char *title, int x, int y, int width, int h
 	return window;
 }
 
+int kon_setMouseCapture(kon_window_t *window, bool captured) {
+	if (!window || !window->hwnd) return 0;
+
+	if (!captured) {
+		if (!window->captured) return 1;
+		window->captured = false;
+		window->hasLast = false;
+		ClipCursor(NULL);
+		ReleaseCapture();
+		ShowCursor(TRUE);
+		return 1;
+	}
+	if (window->captured) return 1;
+	if (GetForegroundWindow() != window->hwnd) return 0;
+
+	{
+		RECT area;
+		POINT topLeft, bottomRight, middle;
+
+		GetClientRect(window->hwnd, &area);
+		topLeft.x = area.left;
+		topLeft.y = area.top;
+		bottomRight.x = area.right;
+		bottomRight.y = area.bottom;
+		ClientToScreen(window->hwnd, &topLeft);
+		ClientToScreen(window->hwnd, &bottomRight);
+		area.left = topLeft.x;
+		area.top = topLeft.y;
+		area.right = bottomRight.x;
+		area.bottom = bottomRight.y;
+		ClipCursor(&area);
+
+		middle.x = (area.right - area.left) / 2;
+		middle.y = (area.bottom - area.top) / 2;
+		ClientToScreen(window->hwnd, &middle);
+		SetCursorPos(middle.x, middle.y);
+	}
+	SetCapture(window->hwnd);
+	ShowCursor(FALSE);
+	window->captured = true;
+	return 1;
+}
+
+bool kon_isMouseCaptured(const kon_window_t *window) {
+	return window && window->captured;
+}
+
 void kon_destroyWindow(kon_window_t *window) {
 	if (!window) return;
+	kon_setMouseCapture(window, false);
 	if (window->hwnd) DestroyWindow(window->hwnd);
 	free(window);
 }