--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/include/mupdf/fitz/transition.h	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,76 @@
+// Copyright (C) 2004-2021 Artifex Software, Inc.
+//
+// This file is part of MuPDF.
+//
+// MuPDF is free software: you can redistribute it and/or modify it under the
+// terms of the GNU Affero General Public License as published by the Free
+// Software Foundation, either version 3 of the License, or (at your option)
+// any later version.
+//
+// MuPDF is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+// details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>
+//
+// Alternative licensing terms are available from the licensor.
+// For commercial licensing, see <https://www.artifex.com/> or contact
+// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,
+// CA 94129, USA, for further information.
+
+#ifndef MUPDF_FITZ_TRANSITION_H
+#define MUPDF_FITZ_TRANSITION_H
+
+#include "mupdf/fitz/system.h"
+#include "mupdf/fitz/pixmap.h"
+
+/* Transition support */
+enum {
+	FZ_TRANSITION_NONE = 0, /* aka 'R' or 'REPLACE' */
+	FZ_TRANSITION_SPLIT,
+	FZ_TRANSITION_BLINDS,
+	FZ_TRANSITION_BOX,
+	FZ_TRANSITION_WIPE,
+	FZ_TRANSITION_DISSOLVE,
+	FZ_TRANSITION_GLITTER,
+	FZ_TRANSITION_FLY,
+	FZ_TRANSITION_PUSH,
+	FZ_TRANSITION_COVER,
+	FZ_TRANSITION_UNCOVER,
+	FZ_TRANSITION_FADE
+};
+
+typedef struct
+{
+	int type;
+	float duration; /* Effect duration (seconds) */
+
+	/* Parameters controlling the effect */
+	int vertical; /* 0 or 1 */
+	int outwards; /* 0 or 1 */
+	int direction; /* Degrees */
+	/* Potentially more to come */
+
+	/* State variables for use of the transition code */
+	int state0;
+	int state1;
+} fz_transition;
+
+/**
+	Generate a frame of a transition.
+
+	tpix: Target pixmap
+	opix: Old pixmap
+	npix: New pixmap
+	time: Position within the transition (0 to 256)
+	trans: Transition details
+
+	Returns 1 if successfully generated a frame.
+
+	Note: Pixmaps must include alpha.
+*/
+int fz_generate_transition(fz_context *ctx, fz_pixmap *tpix, fz_pixmap *opix, fz_pixmap *npix, int time, fz_transition *trans);
+
+#endif