Add xcursor sublibrary

3 files changed, 1291 insertions, 0 deletions

diff --git a/xcursor/meson.build b/xcursor/meson.build
new file mode 100644
index 00000000..570d1fe1
--- /dev/null
+++ b/xcursor/meson.build
@@ -0,0 +1,4 @@
+wlr_files += files(
+    'xcursor.c',
+    'wlr_cursor.c',
+)
diff --git a/xcursor/wlr_cursor.c b/xcursor/wlr_cursor.c
new file mode 100644
index 00000000..c42f3d02
--- /dev/null
+++ b/xcursor/wlr_cursor.c
@@ -0,0 +1,317 @@
+/*
+ * Copyright © 2012 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#define _XOPEN_SOURCE 500
+#include <wlr/render.h>
+#include <wlr/xcursor.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include "xcursor/xcursor.h"
+
+static void wlr_cursor_destroy(struct wlr_cursor *cursor) {
+	for (size_t i = 0; i < cursor->image_count; i++) {
+		free(cursor->images[i]->buffer);
+		free(cursor->images[i]);
+	}
+
+	free(cursor->images);
+	free(cursor->name);
+	free(cursor);
+}
+
+#include "xcursor/cursor_data.h"
+
+static struct wlr_cursor *wlr_cursor_create_from_data(
+		struct cursor_metadata *metadata, struct wlr_cursor_theme *theme) {
+	struct wlr_cursor *cursor;
+	struct wlr_cursor_image *image;
+	int size;
+
+	cursor = malloc(sizeof(*cursor));
+	if (!cursor) {
+		return NULL;
+	}
+
+	cursor->image_count = 1;
+	cursor->images = malloc(sizeof(*cursor->images));
+	if (!cursor->images) {
+		goto err_free_cursor;
+	}
+
+	cursor->name = strdup(metadata->name);
+	cursor->total_delay = 0;
+
+	image = malloc(sizeof(*image));
+	if (!image) {
+		goto err_free_images;
+	}
+
+	cursor->images[0] = image;
+	image->buffer = NULL;
+	image->width = metadata->width;
+	image->height = metadata->height;
+	image->hotspot_x = metadata->hotspot_x;
+	image->hotspot_y = metadata->hotspot_y;
+	image->delay = 0;
+
+	size = metadata->width * metadata->height * sizeof(uint32_t);
+	image->buffer = malloc(size);
+
+	if (!image->buffer) {
+		goto err_free_image;
+	}
+
+	memcpy(image->buffer, cursor_data + metadata->offset, size);
+
+	return cursor;
+
+err_free_image:
+	free(image);
+
+err_free_images:
+	free(cursor->name);
+	free(cursor->images);
+
+err_free_cursor:
+	free(cursor);
+	return NULL;
+}
+
+static void load_default_theme(struct wlr_cursor_theme *theme) {
+	uint32_t i;
+
+	free(theme->name);
+	theme->name = strdup("default");
+
+	theme->cursor_count = sizeof(cursor_metadata) / sizeof(cursor_metadata[0]);
+	theme->cursors = malloc(theme->cursor_count * sizeof(*theme->cursors));
+
+	if (theme->cursors == NULL) {
+		theme->cursor_count = 0;
+		return;
+	}
+
+	for (i = 0; i < theme->cursor_count; ++i) {
+		theme->cursors[i] =
+			wlr_cursor_create_from_data(&cursor_metadata[i], theme);
+
+		if (theme->cursors[i] == NULL) {
+			break;
+		}
+	}
+	theme->cursor_count = i;
+}
+
+static struct wlr_cursor *wlr_cursor_create_from_xcursor_images(
+		XcursorImages *images, struct wlr_cursor_theme *theme) {
+	struct wlr_cursor *cursor;
+	struct wlr_cursor_image *image;
+	int i, size;
+
+	cursor = malloc(sizeof(*cursor));
+	if (!cursor) {
+		return NULL;
+	}
+
+	cursor->images = malloc(images->nimage * sizeof(cursor->images[0]));
+	if (!cursor->images) {
+		free(cursor);
+		return NULL;
+	}
+
+	cursor->name = strdup(images->name);
+	cursor->total_delay = 0;
+
+	for (i = 0; i < images->nimage; i++) {
+		image = malloc(sizeof(*image));
+		if (image == NULL) {
+			break;
+		}
+
+		image->buffer = NULL;
+
+		image->width = images->images[i]->width;
+		image->height = images->images[i]->height;
+		image->hotspot_x = images->images[i]->xhot;
+		image->hotspot_y = images->images[i]->yhot;
+		image->delay = images->images[i]->delay;
+
+		size = image->width * image->height * 4;
+		image->buffer = malloc(size);
+		if (!image->buffer) {
+			free(image);
+			break;
+		}
+
+		/* copy pixels to shm pool */
+		memcpy(image->buffer, images->images[i]->pixels, size);
+		cursor->total_delay += image->delay;
+		cursor->images[i] = image;
+	}
+	cursor->image_count = i;
+
+	if (cursor->image_count == 0) {
+		free(cursor->name);
+		free(cursor->images);
+		free(cursor);
+		return NULL;
+	}
+
+	return cursor;
+}
+
+static void load_callback(XcursorImages *images, void *data) {
+	struct wlr_cursor_theme *theme = data;
+	struct wlr_cursor *cursor;
+
+	if (wlr_cursor_theme_get_cursor(theme, images->name)) {
+		XcursorImagesDestroy(images);
+		return;
+	}
+
+	cursor = wlr_cursor_create_from_xcursor_images(images, theme);
+
+	if (cursor) {
+		theme->cursor_count++;
+		theme->cursors =
+			realloc(theme->cursors,
+				theme->cursor_count * sizeof(theme->cursors[0]));
+
+		if (theme->cursors == NULL) {
+			theme->cursor_count--;
+			free(cursor);
+		} else {
+			theme->cursors[theme->cursor_count - 1] = cursor;
+		}
+	}
+
+	XcursorImagesDestroy(images);
+}
+
+struct wlr_cursor_theme *wlr_cursor_theme_load(const char *name, int size) {
+	struct wlr_cursor_theme *theme;
+
+	theme = malloc(sizeof(*theme));
+	if (!theme) {
+		return NULL;
+	}
+
+	if (!name) {
+		name = "default";
+	}
+
+	theme->name = strdup(name);
+	if (!theme->name) {
+		goto out_error_name;
+	}
+	theme->size = size;
+	theme->cursor_count = 0;
+	theme->cursors = NULL;
+
+	xcursor_load_theme(name, size, load_callback, theme);
+
+	if (theme->cursor_count == 0) {
+		load_default_theme(theme);
+	}
+
+	return theme;
+
+out_error_name:
+	free(theme);
+	return NULL;
+}
+
+void wlr_cursor_theme_destroy(struct wlr_cursor_theme *theme) {
+	unsigned int i;
+
+	for (i = 0; i < theme->cursor_count; i++) {
+		wlr_cursor_destroy(theme->cursors[i]);
+	}
+
+	free(theme->name);
+	free(theme->cursors);
+	free(theme);
+}
+
+struct wlr_cursor *wlr_cursor_theme_get_cursor(struct wlr_cursor_theme *theme,
+		   const char *name) {
+	unsigned int i;
+
+	for (i = 0; i < theme->cursor_count; i++) {
+		if (strcmp(name, theme->cursors[i]->name) == 0) {
+			return theme->cursors[i];
+		}
+	}
+
+	return NULL;
+}
+
+static int wlr_cursor_frame_and_duration(struct wlr_cursor *cursor,
+		uint32_t time, uint32_t *duration) {
+	uint32_t t;
+	int i;
+
+	if (cursor->image_count == 1) {
+		if (duration) {
+			*duration = 0;
+		}
+		return 0;
+	}
+
+	i = 0;
+	t = time % cursor->total_delay;
+
+	/* If there is a 0 delay in the image set then this
+	 * loop breaks on it and we display that cursor until
+	 * time % cursor->total_delay wraps again.
+	 * Since a 0 delay is silly, and we've never actually
+	 * seen one in a cursor file, we haven't bothered to
+	 * "fix" this.
+	 */
+	while (t - cursor->images[i]->delay < t) {
+		t -= cursor->images[i++]->delay;
+	}
+
+	if (!duration) {
+		return i;
+	}
+
+	/* Make sure we don't accidentally tell the caller this is
+	 * a static cursor image.
+	 */
+	if (t >= cursor->images[i]->delay) {
+		*duration = 1;
+	} else {
+		*duration = cursor->images[i]->delay - t;
+	}
+
+	return i;
+}
+
+int wlr_cursor_frame(struct wlr_cursor *_cursor, uint32_t time) {
+	return wlr_cursor_frame_and_duration(_cursor, time, NULL);
+}
diff --git a/xcursor/xcursor.c b/xcursor/xcursor.c
new file mode 100644
index 00000000..8dc35a7c
--- /dev/null
+++ b/xcursor/xcursor.c
@@ -0,0 +1,970 @@
+/*
+ * Copyright © 2002 Keith Packard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#define _DEFAULT_SOURCE
+#include "xcursor/xcursor.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dirent.h>
+
+/*
+ * From libXcursor/include/X11/extensions/Xcursor.h
+ */
+
+#define XcursorTrue	1
+#define XcursorFalse	0
+
+/*
+ * Cursor files start with a header.  The header
+ * contains a magic number, a version number and a
+ * table of contents which has type and offset information
+ * for the remaining tables in the file.
+ *
+ * File minor versions increment for compatible changes
+ * File major versions increment for incompatible changes (never, we hope)
+ *
+ * Chunks of the same type are always upward compatible.  Incompatible
+ * changes are made with new chunk types; the old data can remain under
+ * the old type.  Upward compatible changes can add header data as the
+ * header lengths are specified in the file.
+ *
+ *  File:
+ *	FileHeader
+ *	LISTofChunk
+ *
+ *  FileHeader:
+ *	CARD32		magic	    magic number
+ *	CARD32		header	    bytes in file header
+ *	CARD32		version	    file version
+ *	CARD32		ntoc	    number of toc entries
+ *	LISTofFileToc   toc	    table of contents
+ *
+ *  FileToc:
+ *	CARD32		type	    entry type
+ *	CARD32		subtype	    entry subtype (size for images)
+ *	CARD32		position    absolute file position
+ */
+
+#define XCURSOR_MAGIC	0x72756358  /* "Xcur" LSBFirst */
+
+/*
+ * Current Xcursor version number.  Will be substituted by configure
+ * from the version in the libXcursor configure.ac file.
+ */
+
+#define XCURSOR_LIB_MAJOR 1
+#define XCURSOR_LIB_MINOR 1
+#define XCURSOR_LIB_REVISION 13
+#define XCURSOR_LIB_VERSION	((XCURSOR_LIB_MAJOR * 10000) + \
+				 (XCURSOR_LIB_MINOR * 100) + \
+				 (XCURSOR_LIB_REVISION))
+
+/*
+ * This version number is stored in cursor files; changes to the
+ * file format require updating this version number
+ */
+#define XCURSOR_FILE_MAJOR	1
+#define XCURSOR_FILE_MINOR	0
+#define XCURSOR_FILE_VERSION	((XCURSOR_FILE_MAJOR << 16) | (XCURSOR_FILE_MINOR))
+#define XCURSOR_FILE_HEADER_LEN	(4 * 4)
+#define XCURSOR_FILE_TOC_LEN	(3 * 4)
+
+typedef struct _XcursorFileToc {
+    XcursorUInt	    type;	/* chunk type */
+    XcursorUInt	    subtype;	/* subtype (size for images) */
+    XcursorUInt	    position;	/* absolute position in file */
+} XcursorFileToc;
+
+typedef struct _XcursorFileHeader {
+    XcursorUInt	    magic;	/* magic number */
+    XcursorUInt	    header;	/* byte length of header */
+    XcursorUInt	    version;	/* file version number */
+    XcursorUInt	    ntoc;	/* number of toc entries */
+    XcursorFileToc  *tocs;	/* table of contents */
+} XcursorFileHeader;
+
+/*
+ * The rest of the file is a list of chunks, each tagged by type
+ * and version.
+ *
+ *  Chunk:
+ *	ChunkHeader
+ *	<extra type-specific header fields>
+ *	<type-specific data>
+ *
+ *  ChunkHeader:
+ *	CARD32	    header	bytes in chunk header + type header
+ *	CARD32	    type	chunk type
+ *	CARD32	    subtype	chunk subtype
+ *	CARD32	    version	chunk type version
+ */
+
+#define XCURSOR_CHUNK_HEADER_LEN    (4 * 4)
+
+typedef struct _XcursorChunkHeader {
+    XcursorUInt	    header;	/* bytes in chunk header */
+    XcursorUInt	    type;	/* chunk type */
+    XcursorUInt	    subtype;	/* chunk subtype (size for images) */
+    XcursorUInt	    version;	/* version of this type */
+} XcursorChunkHeader;
+
+/*
+ * Here's a list of the known chunk types
+ */
+
+/*
+ * Comments consist of a 4-byte length field followed by
+ * UTF-8 encoded text
+ *
+ *  Comment:
+ *	ChunkHeader header	chunk header
+ *	CARD32	    length	bytes in text
+ *	LISTofCARD8 text	UTF-8 encoded text
+ */
+
+#define XCURSOR_COMMENT_TYPE	    0xfffe0001
+#define XCURSOR_COMMENT_VERSION	    1
+#define XCURSOR_COMMENT_HEADER_LEN  (XCURSOR_CHUNK_HEADER_LEN + (1 *4))
+#define XCURSOR_COMMENT_COPYRIGHT   1
+#define XCURSOR_COMMENT_LICENSE	    2
+#define XCURSOR_COMMENT_OTHER	    3
+#define XCURSOR_COMMENT_MAX_LEN	    0x100000
+
+typedef struct _XcursorComment {
+    XcursorUInt	    version;
+    XcursorUInt	    comment_type;
+    char	    *comment;
+} XcursorComment;
+
+/*
+ * Each cursor image occupies a separate image chunk.
+ * The length of the image header follows the chunk header
+ * so that future versions can extend the header without
+ * breaking older applications
+ *
+ *  Image:
+ *	ChunkHeader	header	chunk header
+ *	CARD32		width	actual width
+ *	CARD32		height	actual height
+ *	CARD32		xhot	hot spot x
+ *	CARD32		yhot	hot spot y
+ *	CARD32		delay	animation delay
+ *	LISTofCARD32	pixels	ARGB pixels
+ */
+
+#define XCURSOR_IMAGE_TYPE    	    0xfffd0002
+#define XCURSOR_IMAGE_VERSION	    1
+#define XCURSOR_IMAGE_HEADER_LEN    (XCURSOR_CHUNK_HEADER_LEN + (5*4))
+#define XCURSOR_IMAGE_MAX_SIZE	    0x7fff	/* 32767x32767 max cursor size */
+
+typedef struct _XcursorFile XcursorFile;
+
+struct _XcursorFile {
+    void    *closure;
+    int	    (*read)  (XcursorFile *file, unsigned char *buf, int len);
+    int	    (*write) (XcursorFile *file, unsigned char *buf, int len);
+    int	    (*seek)  (XcursorFile *file, long offset, int whence);
+};
+
+typedef struct _XcursorComments {
+    int		    ncomment;	/* number of comments */
+    XcursorComment  **comments;	/* array of XcursorComment pointers */
+} XcursorComments;
+
+/*
+ * From libXcursor/src/file.c
+ */
+
+static XcursorImage *
+XcursorImageCreate (int width, int height)
+{
+    XcursorImage    *image;
+
+    image = malloc (sizeof (XcursorImage) +
+		    width * height * sizeof (XcursorPixel));
+    if (!image)
+	return NULL;
+    image->version = XCURSOR_IMAGE_VERSION;
+    image->pixels = (XcursorPixel *) (image + 1);
+    image->size = width > height ? width : height;
+    image->width = width;
+    image->height = height;
+    image->delay = 0;
+    return image;
+}
+
+static void
+XcursorImageDestroy (XcursorImage *image)
+{
+    free (image);
+}
+
+static XcursorImages *
+XcursorImagesCreate (int size)
+{
+    XcursorImages   *images;
+
+    images = malloc (sizeof (XcursorImages) +
+		     size * sizeof (XcursorImage *));
+    if (!images)
+	return NULL;
+    images->nimage = 0;
+    images->images = (XcursorImage **) (images + 1);
+    images->name = NULL;
+    return images;
+}
+
+void
+XcursorImagesDestroy (XcursorImages *images)
+{
+    int	n;
+
+    if (!images)
+        return;
+
+    for (n = 0; n < images->nimage; n++)
+	XcursorImageDestroy (images->images[n]);
+    if (images->name)
+	free (images->name);
+    free (images);
+}
+
+static void
+XcursorImagesSetName (XcursorImages *images, const char *name)
+{
+    char    *new;
+
+    if (!images || !name)
+        return;
+
+    new = malloc (strlen (name) + 1);
+
+    if (!new)
+	return;
+
+    strcpy (new, name);
+    if (images->name)
+	free (images->name);
+    images->name = new;
+}
+
+static XcursorBool
+_XcursorReadUInt (XcursorFile *file, XcursorUInt *u)
+{
+    unsigned char   bytes[4];
+
+    if (!file || !u)
+        return XcursorFalse;
+
+    if ((*file->read) (file, bytes, 4) != 4)
+	return XcursorFalse;
+    *u = ((bytes[0] << 0) |
+	  (bytes[1] << 8) |
+	  (bytes[2] << 16) |
+	  (bytes[3] << 24));
+    return XcursorTrue;
+}
+
+static void
+_XcursorFileHeaderDestroy (XcursorFileHeader *fileHeader)
+{
+    free (fileHeader);
+}
+
+static XcursorFileHeader *
+_XcursorFileHeaderCreate (int ntoc)
+{
+    XcursorFileHeader	*fileHeader;
+
+    if (ntoc > 0x10000)
+	return NULL;
+    fileHeader = malloc (sizeof (XcursorFileHeader) +
+			 ntoc * sizeof (XcursorFileToc));
+    if (!fileHeader)
+	return NULL;
+    fileHeader->magic = XCURSOR_MAGIC;
+    fileHeader->header = XCURSOR_FILE_HEADER_LEN;
+    fileHeader->version = XCURSOR_FILE_VERSION;
+    fileHeader->ntoc = ntoc;
+    fileHeader->tocs = (XcursorFileToc *) (fileHeader + 1);
+    return fileHeader;
+}
+
+static XcursorFileHeader *
+_XcursorReadFileHeader (XcursorFile *file)
+{
+    XcursorFileHeader	head, *fileHeader;
+    XcursorUInt		skip;
+    unsigned int	n;
+
+    if (!file)
+        return NULL;
+
+    if (!_XcursorReadUInt (file, &head.magic))
+	return NULL;
+    if (head.magic != XCURSOR_MAGIC)
+	return NULL;
+    if (!_XcursorReadUInt (file, &head.header))
+	return NULL;
+    if (!_XcursorReadUInt (file, &head.version))
+	return NULL;
+    if (!_XcursorReadUInt (file, &head.ntoc))
+	return NULL;
+    skip = head.header - XCURSOR_FILE_HEADER_LEN;
+    if (skip)
+	if ((*file->seek) (file, skip, SEEK_CUR) == EOF)
+	    return NULL;
+    fileHeader = _XcursorFileHeaderCreate (head.ntoc);
+    if (!fileHeader)
+	return NULL;
+    fileHeader->magic = head.magic;
+    fileHeader->header = head.header;
+    fileHeader->version = head.version;
+    fileHeader->ntoc = head.ntoc;
+    for (n = 0; n < fileHeader->ntoc; n++)
+    {
+	if (!_XcursorReadUInt (file, &fileHeader->tocs[n].type))
+	    break;
+	if (!_XcursorReadUInt (file, &fileHeader->tocs[n].subtype))
+	    break;
+	if (!_XcursorReadUInt (file, &fileHeader->tocs[n].position))
+	    break;
+    }
+    if (n != fileHeader->ntoc)
+    {
+	_XcursorFileHeaderDestroy (fileHeader);
+	return NULL;
+    }
+    return fileHeader;
+}
+
+static XcursorBool
+_XcursorSeekToToc (XcursorFile		*file,
+		   XcursorFileHeader	*fileHeader,
+		   int			toc)
+{
+    if (!file || !fileHeader || \
+        (*file->seek) (file, fileHeader->tocs[toc].position, SEEK_SET) == EOF)
+	return XcursorFalse;
+    return XcursorTrue;
+}
+
+static XcursorBool
+_XcursorFileReadChunkHeader (XcursorFile	*file,
+			     XcursorFileHeader	*fileHeader,
+			     int		toc,
+			     XcursorChunkHeader	*chunkHeader)
+{
+    if (!file || !fileHeader || !chunkHeader)
+        return XcursorFalse;
+    if (!_XcursorSeekToToc (file, fileHeader, toc))
+	return XcursorFalse;
+    if (!_XcursorReadUInt (file, &chunkHeader->header))
+	return XcursorFalse;
+    if (!_XcursorReadUInt (file, &chunkHeader->type))
+	return XcursorFalse;
+    if (!_XcursorReadUInt (file, &chunkHeader->subtype))
+	return XcursorFalse;
+    if (!_XcursorReadUInt (file, &chunkHeader->version))
+	return XcursorFalse;
+    /* sanity check */
+    if (chunkHeader->type != fileHeader->tocs[toc].type ||
+	chunkHeader->subtype != fileHeader->tocs[toc].subtype)
+	return XcursorFalse;
+    return XcursorTrue;
+}
+
+#define dist(a,b)   ((a) > (b) ? (a) - (b) : (b) - (a))
+
+static XcursorDim
+_XcursorFindBestSize (XcursorFileHeader *fileHeader,
+		      XcursorDim	size,
+		      int		*nsizesp)
+{
+    unsigned int n;
+    int		nsizes = 0;
+    XcursorDim	bestSize = 0;
+    XcursorDim	thisSize;
+
+    if (!fileHeader || !nsizesp)
+        return 0;
+
+    for (n = 0; n < fileHeader->ntoc; n++)
+    {
+	if (fileHeader->tocs[n].type != XCURSOR_IMAGE_TYPE)
+	    continue;
+	thisSize = fileHeader->tocs[n].subtype;
+	if (!bestSize || dist (thisSize, size) < dist (bestSize, size))
+	{
+	    bestSize = thisSize;
+	    nsizes = 1;
+	}
+	else if (thisSize == bestSize)
+	    nsizes++;
+    }
+    *nsizesp = nsizes;
+    return bestSize;
+}
+
+static int
+_XcursorFindImageToc (XcursorFileHeader	*fileHeader,
+		      XcursorDim	size,
+		      int		count)
+{
+    unsigned int	toc;
+    XcursorDim		thisSize;
+
+    if (!fileHeader)
+        return 0;
+
+    for (toc = 0; toc < fileHeader->ntoc; toc++)
+    {
+	if (fileHeader->tocs[toc].type != XCURSOR_IMAGE_TYPE)
+	    continue;
+	thisSize = fileHeader->tocs[toc].subtype;
+	if (thisSize != size)
+	    continue;
+	if (!count)
+	    break;
+	count--;
+    }
+    if (toc == fileHeader->ntoc)
+	return -1;
+    return toc;
+}
+
+static XcursorImage *
+_XcursorReadImage (XcursorFile		*file,
+		   XcursorFileHeader	*fileHeader,
+		   int			toc)
+{
+    XcursorChunkHeader	chunkHeader;
+    XcursorImage	head;
+    XcursorImage	*image;
+    int			n;
+    XcursorPixel	*p;
+
+    if (!file || !fileHeader)
+        return NULL;
+
+    if (!_XcursorFileReadChunkHeader (file, fileHeader, toc, &chunkHeader))
+	return NULL;
+    if (!_XcursorReadUInt (file, &head.width))
+	return NULL;
+    if (!_XcursorReadUInt (file, &head.height))
+	return NULL;
+    if (!_XcursorReadUInt (file, &head.xhot))
+	return NULL;
+    if (!_XcursorReadUInt (file, &head.yhot))
+	return NULL;
+    if (!_XcursorReadUInt (file, &head.delay))
+	return NULL;
+    /* sanity check data */
+    if (head.width >= 0x10000 || head.height > 0x10000)
+	return NULL;
+    if (head.width == 0 || head.height == 0)
+	return NULL;
+    if (head.xhot > head.width || head.yhot > head.height)
+	return NULL;
+
+    /* Create the image and initialize it */
+    image = XcursorImageCreate (head.width, head.height);
+    if (image == NULL)
+	    return NULL;
+    if (chunkHeader.version < image->version)
+	image->version = chunkHeader.version;
+    image->size = chunkHeader.subtype;
+    image->xhot = head.xhot;
+    image->yhot = head.yhot;
+    image->delay = head.delay;
+    n = image->width * image->height;
+    p = image->pixels;
+    while (n--)
+    {
+	if (!_XcursorReadUInt (file, p))
+	{
+	    XcursorImageDestroy (image);
+	    return NULL;
+	}
+	p++;
+    }
+    return image;
+}
+
+static XcursorImages *
+XcursorXcFileLoadImages (XcursorFile *file, int size)
+{
+    XcursorFileHeader	*fileHeader;
+    XcursorDim		bestSize;
+    int			nsize;
+    XcursorImages	*images;
+    int			n;
+    int			toc;
+
+    if (!file || size < 0)
+	return NULL;
+    fileHeader = _XcursorReadFileHeader (file);
+    if (!fileHeader)
+	return NULL;
+    bestSize = _XcursorFindBestSize (fileHeader, (XcursorDim) size, &nsize);
+    if (!bestSize)
+    {
+        _XcursorFileHeaderDestroy (fileHeader);
+	return NULL;
+    }
+    images = XcursorImagesCreate (nsize);
+    if (!images)
+    {
+        _XcursorFileHeaderDestroy (fileHeader);
+	return NULL;
+    }
+    for (n = 0; n < nsize; n++)
+    {
+	toc = _XcursorFindImageToc (fileHeader, bestSize, n);
+	if (toc < 0)
+	    break;
+	images->images[images->nimage] = _XcursorReadImage (file, fileHeader,
+							    toc);
+	if (!images->images[images->nimage])
+	    break;
+	images->nimage++;
+    }
+    _XcursorFileHeaderDestroy (fileHeader);
+    if (images->nimage != nsize)
+    {
+	XcursorImagesDestroy (images);
+	images = NULL;
+    }
+    return images;
+}
+
+static int
+_XcursorStdioFileRead (XcursorFile *file, unsigned char *buf, int len)
+{
+    FILE    *f = file->closure;
+    return fread (buf, 1, len, f);
+}
+
+static int
+_XcursorStdioFileWrite (XcursorFile *file, unsigned char *buf, int len)
+{
+    FILE    *f = file->closure;
+    return fwrite (buf, 1, len, f);
+}
+
+static int
+_XcursorStdioFileSeek (XcursorFile *file, long offset, int whence)
+{
+    FILE    *f = file->closure;
+    return fseek (f, offset, whence);
+}
+
+static void
+_XcursorStdioFileInitialize (FILE *stdfile, XcursorFile *file)
+{
+    file->closure = stdfile;
+    file->read = _XcursorStdioFileRead;
+    file->write = _XcursorStdioFileWrite;
+    file->seek = _XcursorStdioFileSeek;
+}
+
+static XcursorImages *
+XcursorFileLoadImages (FILE *file, int size)
+{
+    XcursorFile	f;
+
+    if (!file)
+        return NULL;
+
+    _XcursorStdioFileInitialize (file, &f);
+    return XcursorXcFileLoadImages (&f, size);
+}
+
+/*
+ * From libXcursor/src/library.c
+ */
+
+#ifndef ICONDIR
+#define ICONDIR "/usr/X11R6/lib/X11/icons"
+#endif
+
+#ifndef XCURSORPATH
+#define XCURSORPATH "~/.icons:/usr/share/icons:/usr/share/pixmaps:~/.cursors:/usr/share/cursors/xorg-x11:"ICONDIR
+#endif
+
+static const char *
+XcursorLibraryPath (void)
+{
+    static const char	*path;
+
+    if (!path)
+    {
+	path = getenv ("XCURSOR_PATH");
+	if (!path)
+	    path = XCURSORPATH;
+    }
+    return path;
+}
+
+static  void
+_XcursorAddPathElt (char *path, const char *elt, int len)
+{
+    int	    pathlen = strlen (path);
+
+    /* append / if the path doesn't currently have one */
+    if (path[0] == '\0' || path[pathlen - 1] != '/')
+    {
+	strcat (path, "/");
+	pathlen++;
+    }
+    if (len == -1)
+	len = strlen (elt);
+    /* strip leading slashes */
+    while (len && elt[0] == '/')
+    {
+	elt++;
+	len--;
+    }
+    strncpy (path + pathlen, elt, len);
+    path[pathlen + len] = '\0';
+}
+
+static char *
+_XcursorBuildThemeDir (const char *dir, const char *theme)
+{
+    const char	    *colon;
+    const char	    *tcolon;
+    char	    *full;
+    char	    *home;
+    int		    dirlen;
+    int		    homelen;
+    int		    themelen;
+    int		    len;
+
+    if (!dir || !theme)
+        return NULL;
+
+    colon = strchr (dir, ':');
+    if (!colon)
+	colon = dir + strlen (dir);
+
+    dirlen = colon - dir;
+
+    tcolon = strchr (theme, ':');
+    if (!tcolon)
+	tcolon = theme + strlen (theme);
+
+    themelen = tcolon - theme;
+
+    home = NULL;
+    homelen = 0;
+    if (*dir == '~')
+    {
+	home = getenv ("HOME");
+	if (!home)
+	    return NULL;
+	homelen = strlen (home);
+	dir++;
+	dirlen--;
+    }
+
+    /*
+     * add space for any needed directory separators, one per component,
+     * and one for the trailing null
+     */
+    len = 1 + homelen + 1 + dirlen + 1 + themelen + 1;
+
+    full = malloc (len);
+    if (!full)
+	return NULL;
+    full[0] = '\0';
+
+    if (home)
+	_XcursorAddPathElt (full, home, -1);
+    _XcursorAddPathElt (full, dir, dirlen);
+    _XcursorAddPathElt (full, theme, themelen);
+    return full;
+}
+
+static char *
+_XcursorBuildFullname (const char *dir, const char *subdir, const char *file)
+{
+    char    *full;
+
+    if (!dir || !subdir || !file)
+        return NULL;
+
+    full = malloc (strlen (dir) + 1 + strlen (subdir) + 1 + strlen (file) + 1);
+    if (!full)
+	return NULL;
+    full[0] = '\0';
+    _XcursorAddPathElt (full, dir, -1);
+    _XcursorAddPathElt (full, subdir, -1);
+    _XcursorAddPathElt (full, file, -1);
+    return full;
+}
+
+static const char *
+_XcursorNextPath (const char *path)
+{
+    char    *colon = strchr (path, ':');
+
+    if (!colon)
+	return NULL;
+    return colon + 1;
+}
+
+#define XcursorWhite(c)	((c) == ' ' || (c) == '\t' || (c) == '\n')
+#define XcursorSep(c) ((c) == ';' || (c) == ',')
+
+static char *
+_XcursorThemeInherits (const char *full)
+{
+    char    line[8192];
+    char    *result = NULL;
+    FILE    *f;
+
+    if (!full)
+        return NULL;
+
+    f = fopen (full, "r");
+    if (f)
+    {
+	while (fgets (line, sizeof (line), f))
+	{
+	    if (!strncmp (line, "Inherits", 8))
+	    {
+		char    *l = line + 8;
+		char    *r;
+		while (*l == ' ') l++;
+		if (*l != '=') continue;
+		l++;
+		while (*l == ' ') l++;
+		result = malloc (strlen (l) + 1);
+		if (result)
+		{
+		    r = result;
+		    while (*l)
+		    {
+			while (XcursorSep(*l) || XcursorWhite (*l)) l++;
+			if (!*l)
+			    break;
+			if (r != result)
+			    *r++ = ':';
+			while (*l && !XcursorWhite(*l) &&
+			       !XcursorSep(*l))
+			    *r++ = *l++;
+		    }
+		    *r++ = '\0';
+		}
+		break;
+	    }
+	}
+	fclose (f);
+    }
+    return result;
+}
+
+static FILE *
+XcursorScanTheme (const char *theme, const char *name)
+{
+    FILE	*f = NULL;
+    char	*full;
+    char	*dir;
+    const char  *path;
+    char	*inherits = NULL;
+    const char	*i;
+
+    if (!theme || !name)
+        return NULL;
+
+    /*
+     * Scan this theme
+     */
+    for (path = XcursorLibraryPath ();
+	 path && f == NULL;
+	 path = _XcursorNextPath (path))
+    {
+	dir = _XcursorBuildThemeDir (path, theme);
+	if (dir)
+	{
+	    full = _XcursorBuildFullname (dir, "cursors", name);
+	    if (full)
+	    {
+		f = fopen (full, "r");
+		free (full);
+	    }
+	    if (!f && !inherits)
+	    {
+		full = _XcursorBuildFullname (dir, "", "index.theme");
+		if (full)
+		{
+		    inherits = _XcursorThemeInherits (full);
+		    free (full);
+		}
+	    }
+	    free (dir);
+	}
+    }
+    /*
+     * Recurse to scan inherited themes
+     */
+    for (i = inherits; i && f == NULL; i = _XcursorNextPath (i))
+	f = XcursorScanTheme (i, name);
+    if (inherits != NULL)
+	free (inherits);
+    return f;
+}
+
+XcursorImages *
+XcursorLibraryLoadImages (const char *file, const char *theme, int size)
+{
+    FILE	    *f = NULL;
+    XcursorImages   *images = NULL;
+
+    if (!file)
+        return NULL;
+
+    if (theme)
+	f = XcursorScanTheme (theme, file);
+    if (!f)
+	f = XcursorScanTheme ("default", file);
+    if (f)
+    {
+	images = XcursorFileLoadImages (f, size);
+	if (images)
+	    XcursorImagesSetName (images, file);
+	fclose (f);
+    }
+    return images;
+}
+
+static void
+load_all_cursors_from_dir(const char *path, int size,
+			  void (*load_callback)(XcursorImages *, void *),
+			  void *user_data)
+{
+	FILE *f;
+	DIR *dir = opendir(path);
+	struct dirent *ent;
+	char *full;
+	XcursorImages *images;
+
+	if (!dir)
+		return;
+
+	for(ent = readdir(dir); ent; ent = readdir(dir)) {
+		if (ent->d_type != DT_UNKNOWN &&
+		    (ent->d_type != DT_REG && ent->d_type != DT_LNK))
+			continue;
+
+		full = _XcursorBuildFullname(path, "", ent->d_name);
+		if (!full)
+			continue;
+
+		f = fopen(full, "r");
+		if (!f) {
+			free(full);
+			continue;
+		}
+
+		images = XcursorFileLoadImages(f, size);
+
+		if (images) {
+			XcursorImagesSetName(images, ent->d_name);
+			load_callback(images, user_data);
+		}
+
+		fclose (f);
+		free(full);
+	}
+
+	closedir(dir);
+}
+
+/** Load all the cursor of a theme
+ *
+ * This function loads all the cursor images of a given theme and its
+ * inherited themes. Each cursor is loaded into an XcursorImages object
+ * which is passed to the caller's load callback. If a cursor appears
+ * more than once across all the inherited themes, the load callback
+ * will be called multiple times, with possibly different XcursorImages
+ * object which have the same name. The user is expected to destroy the
+ * XcursorImages objects passed to the callback with
+ * XcursorImagesDestroy().
+ *
+ * \param theme The name of theme that should be loaded
+ * \param size The desired size of the cursor images
+ * \param load_callback A callback function that will be called
+ * for each cursor loaded. The first parameter is the XcursorImages
+ * object representing the loaded cursor and the second is a pointer
+ * to data provided by the user.
+ * \param user_data The data that should be passed to the load callback
+ */
+void
+xcursor_load_theme(const char *theme, int size,
+		    void (*load_callback)(XcursorImages *, void *),
+		    void *user_data)
+{
+	char *full, *dir;
+	char *inherits = NULL;
+	const char *path, *i;
+
+	if (!theme)
+		theme = "default";
+
+	for (path = XcursorLibraryPath();
+	     path;
+	     path = _XcursorNextPath(path)) {
+		dir = _XcursorBuildThemeDir(path, theme);
+		if (!dir)
+			continue;
+
+		full = _XcursorBuildFullname(dir, "cursors", "");
+
+		if (full) {
+			load_all_cursors_from_dir(full, size, load_callback,
+						  user_data);
+			free(full);
+		}
+
+		if (!inherits) {
+			full = _XcursorBuildFullname(dir, "", "index.theme");
+			if (full) {
+				inherits = _XcursorThemeInherits(full);
+				free(full);
+			}
+		}
+
+		free(dir);
+	}
+
+	for (i = inherits; i; i = _XcursorNextPath(i))
+		xcursor_load_theme(i, size, load_callback, user_data);
+
+	if (inherits)
+		free(inherits);
+}