--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/leptonica/src/fhmtgen.1.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,173 @@
+/*====================================================================*
+ -  Copyright (C) 2001 Leptonica.  All rights reserved.
+ -
+ -  Redistribution and use in source and binary forms, with or without
+ -  modification, are permitted provided that the following conditions
+ -  are met:
+ -  1. Redistributions of source code must retain the above copyright
+ -     notice, this list of conditions and the following disclaimer.
+ -  2. Redistributions in binary form must reproduce the above
+ -     copyright notice, this list of conditions and the following
+ -     disclaimer in the documentation and/or other materials
+ -     provided with the distribution.
+ -
+ -  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ -  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ -  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ -  A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL ANY
+ -  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ -  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ -  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ -  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ -  OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ -  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ -  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *====================================================================*/
+
+/*!
+ *      Top-level fast hit-miss transform with auto-generated sels
+ *
+ *             PIX     *pixHMTDwa_1()
+ *             PIX     *pixFHMTGen_1()
+ */
+
+#include <string.h>
+#include "allheaders.h"
+
+PIX *pixHMTDwa_1(PIX *pixd, PIX *pixs, const char *selname);
+PIX *pixFHMTGen_1(PIX *pixd, PIX *pixs, const char *selname);
+l_int32 fhmtgen_low_1(l_uint32 *datad, l_int32 w,
+                      l_int32 h, l_int32 wpld,
+                      l_uint32 *datas, l_int32 wpls,
+                      l_int32 index);
+
+static l_int32   NUM_SELS_GENERATED = 10;
+static char  SEL_NAMES[][80] = {
+                             "sel_3hm",
+                             "sel_3de",
+                             "sel_3ue",
+                             "sel_3re",
+                             "sel_3le",
+                             "sel_sl1",
+                             "sel_ulc",
+                             "sel_urc",
+                             "sel_llc",
+                             "sel_lrc"};
+
+/*!
+ * \brief  pixHMTDwa_1()
+ *
+ * \param[in]    pixd      usual 3 choices: null, == pixs, != pixs
+ * \param[in]    pixs      1 bpp
+ * \param[in]    sel       name
+ * \return   pixd
+ *
+ * <pre>
+ * Notes:
+ *      (1) This simply adds a 32 pixel border, calls the appropriate
+ *          pixFHMTGen_*(), and removes the border.
+ *          See notes below for that function.
+ * </pre>
+ */
+PIX *
+pixHMTDwa_1(PIX         *pixd,
+            PIX         *pixs,
+            const char  *selname)
+{
+PIX  *pixt1, *pixt2, *pixt3;
+
+    if (!pixs)
+        return (PIX *)ERROR_PTR("pixs not defined", __func__, pixd);
+    if (pixGetDepth(pixs) != 1)
+        return (PIX *)ERROR_PTR("pixs must be 1 bpp", __func__, pixd);
+
+    pixt1 = pixAddBorder(pixs, 32, 0);
+    pixt2 = pixFHMTGen_1(NULL, pixt1, selname);
+    pixt3 = pixRemoveBorder(pixt2, 32);
+    pixDestroy(&pixt1);
+    pixDestroy(&pixt2);
+
+    if (!pixd)
+        return pixt3;
+
+    pixCopy(pixd, pixt3);
+    pixDestroy(&pixt3);
+    return pixd;
+}
+
+
+/*!
+ * \brief  pixFHMTGen_1()
+ *
+ * \param[in]    pixd     usual 3 choices: null, == pixs, != pixs
+ * \param[in]    pixs     1 bpp
+ * \param[in]    sel      name
+ * \return   pixd
+ *
+ * <pre>
+ * Notes:
+ *      (1) This is a dwa implementation of the hit-miss transform
+ *          on pixs by the sel.
+ *      (2) The sel must be limited in size to not more than 31 pixels
+ *          about the origin.  It must have at least one hit, and it
+ *          can have any number of misses.
+ *      (3) This handles all required setting of the border pixels
+ *          before erosion and dilation.
+ * </pre>
+ */
+PIX *
+pixFHMTGen_1(PIX         *pixd,
+             PIX         *pixs,
+             const char  *selname)
+{
+l_int32    i, index, found, w, h, wpls, wpld;
+l_uint32  *datad, *datas, *datat;
+PIX       *pixt;
+
+    if (!pixs)
+        return (PIX *)ERROR_PTR("pixs not defined", __func__, pixd);
+    if (pixGetDepth(pixs) != 1)
+        return (PIX *)ERROR_PTR("pixs must be 1 bpp", __func__, pixd);
+
+    found = FALSE;
+    for (i = 0; i < NUM_SELS_GENERATED; i++) {
+        if (strcmp(selname, SEL_NAMES[i]) == 0) {
+            found = TRUE;
+            index = i;
+            break;
+        }
+    }
+    if (found == FALSE)
+        return (PIX *)ERROR_PTR("sel index not found", __func__, pixd);
+
+    if (!pixd) {
+        if ((pixd = pixCreateTemplate(pixs)) == NULL)
+            return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+    }
+    else  /* for in-place or pre-allocated */
+        pixResizeImageData(pixd, pixs);
+    wpls = pixGetWpl(pixs);
+    wpld = pixGetWpl(pixd);
+
+        /*  The images must be surrounded with 32 additional border
+         *  pixels, that we'll read from.  We fabricate a "proper"
+         *  image as the subimage within the border, having the
+         *  following parameters:  */
+    w = pixGetWidth(pixs) - 64;
+    h = pixGetHeight(pixs) - 64;
+    datas = pixGetData(pixs) + 32 * wpls + 1;
+    datad = pixGetData(pixd) + 32 * wpld + 1;
+
+    if (pixd == pixs) {  /* need temp image if in-place */
+        if ((pixt = pixCopy(NULL, pixs)) == NULL)
+            return (PIX *)ERROR_PTR("pixt not made", __func__, pixd);
+        datat = pixGetData(pixt) + 32 * wpls + 1;
+        fhmtgen_low_1(datad, w, h, wpld, datat, wpls, index);
+        pixDestroy(&pixt);
+    }
+    else {  /* not in-place */
+        fhmtgen_low_1(datad, w, h, wpld, datas, wpls, index);
+    }
+
+    return pixd;
+}