Initial revision

1 files changed, 330 insertions, 0 deletions

diff --git a/ident.c b/ident.c
new file mode 100644
index 0000000..cfbe6c1
--- /dev/null
+++ b/ident.c
@@ -0,0 +1,330 @@
+/*
+  Copyright (c) 2003 by Juliusz Chroboczek
+
+  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 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.
+*/
+/* $XFree86: xc/programs/mkfontscale/ident.c,v 1.4 2003/10/24 20:38:13 tsi Exp $ */
+
+/* The function identifyBitmap returns -1 if filename is definitively not
+   a font file, 1 if it is a single-face bitmap font with a XLFD name,
+   and 0 if it should be processed normally.  identifyBitmap is
+   much faster than parsing the whole font. */
+
+#include <stdlib.h>
+#include <string.h>
+#include "zlib.h"
+
+#define PCF_VERSION (('p'<<24)|('c'<<16)|('f'<<8)|1)
+#define PCF_PROPERTIES (1 << 0)
+
+typedef struct _Prop {
+    unsigned name;
+    int isString;
+    unsigned value;
+} PropRec, *PropPtr;
+
+static int pcfIdentify(gzFile f, char **name);
+static int bdfIdentify(gzFile f, char **name);
+
+static int
+getLSB32(gzFile f)
+{
+    int rc;
+    unsigned char c[4];
+
+    rc = gzread(f, c, 4);
+    if(rc != 4)
+        return -1;
+    return (c[0]) | (c[1] << 8) | (c[2] << 16) | (c[3] << 24);
+}
+
+static int
+getInt8(gzFile f, int format)
+{
+    unsigned char c;
+    int rc;
+
+    rc = gzread(f, &c, 1);
+    if(rc != 1)
+        return -1;
+    return c;
+}
+
+static int
+getInt32(gzFile f, int format)
+{
+    int rc;
+    unsigned char c[4];
+
+    rc = gzread(f, c, 4);
+    if(rc != 4)
+        return -1;
+
+    if(format & (1 << 2)) {
+        return (c[0] << 24) | (c[1] << 16) | (c[2] << 8) | (c[3]);
+    } else {
+        return (c[0]) | (c[1] << 8) | (c[2] << 16) | (c[3] << 24);
+    }
+}
+
+static int
+pcfskip(gzFile f, int n)
+{
+    char buf[32];
+    int i, rc;
+    while(n > 0) {
+        i = (n > 32 ? 32 : n);
+        rc = gzread(f, buf, i);
+        if(rc != i)
+            return -1;
+        n -= rc;
+    }
+    return 1;
+}
+
+int 
+bitmapIdentify(char *filename, char **name)
+{
+    gzFile f;
+    int magic;
+
+    f = gzopen(filename, "rb");
+    if(f == NULL)
+        return -1;
+
+    magic = getLSB32(f);
+    if(magic == PCF_VERSION)
+        return pcfIdentify(f, name);
+    else if(magic == ('S' | ('T' << 8) | ('A' << 16) | ('R') << 24))
+        return bdfIdentify(f, name);
+
+    gzclose(f);
+    return 0;
+}
+
+static int
+pcfIdentify(gzFile f, char **name)
+{
+    int prop_position;
+    PropPtr props = NULL;
+    int format, count, nprops, i, string_size, rc;
+    char *strings = NULL, *s;
+
+    count = getLSB32(f);
+    if(count <= 0)
+        goto fail;
+
+    prop_position = -1;
+    for(i = 0; i < count; i++) {
+        int type, offset;
+        type = getLSB32(f);
+        (void) getLSB32(f);
+        (void) getLSB32(f);
+        offset = getLSB32(f);
+        if(type == PCF_PROPERTIES) {
+            prop_position = offset;
+            break;
+        }
+    }
+    if(prop_position < 0)
+        goto fail;
+
+    rc = gzseek(f, prop_position, SEEK_SET);
+    if(rc < 0)
+        goto fail;
+    
+    format = getLSB32(f);
+    if((format & 0xFFFFFF00) != 0)
+        goto fail;
+    nprops = getInt32(f, format);
+    if(nprops <= 0 || nprops > 1000)
+        goto fail;
+    props = malloc(nprops * sizeof(PropRec));
+    if(props == NULL)
+        goto fail;
+
+    for(i = 0; i < nprops; i++) {
+        props[i].name = getInt32(f, format);
+        props[i].isString = getInt8(f, format);
+        props[i].value = getInt32(f, format);
+    }
+    if(nprops & 3) {
+        rc = pcfskip(f, 4 - (nprops & 3));
+        if(rc < 0)
+            goto fail;
+    }
+
+    string_size = getInt32(f, format);
+    if(string_size < 0 || string_size > 100000)
+        goto fail;
+    strings = malloc(string_size);
+    if(!strings)
+        goto fail;
+
+    rc = gzread(f, strings, string_size);
+    if(rc != string_size)
+        goto fail;
+
+    for(i = 0; i < nprops; i++) {
+        if(!props[i].isString ||
+           props[i].name >= string_size - 4 ||
+           props[i].value >= string_size)
+            continue;
+        if(strcmp(strings + props[i].name, "FONT") == 0)
+            break;
+    }
+
+    if(i >= nprops)
+        goto fail;
+
+    s = malloc(strlen(strings + props[i].value) + 1);
+    if(s == NULL)
+        goto fail;
+    strcpy(s, strings + props[i].value);
+    *name = s;
+    free(strings);
+    free(props);
+    gzclose(f);
+    return 1;
+
+ fail:
+    if(strings) free(strings);
+    if(props) free(props);
+    gzclose(f);
+    return 0;
+}
+
+#define NKEY 20
+
+static char*
+getKeyword(gzFile *f, int *eol)
+{
+    static char keyword[NKEY + 1];
+    int c, i;
+    i = 0;
+    while(i < NKEY) {
+        c = gzgetc(f);
+        if(c == ' ' || c == '\n') {
+            if(i <= 0)
+                return NULL;
+            if(eol)
+                *eol = (c == '\n');
+            keyword[i] = '\0';
+            return keyword;
+        }
+        if(c < 'A' || c > 'Z')
+            return NULL;
+        keyword[i++] = c;
+    }
+    return NULL;
+}
+
+static int
+bdfskip(gzFile *f)
+{
+    int c;
+    do {
+        c = gzgetc(f);
+    } while(c >= 0 && c != '\n');
+    if(c < 0)
+        return -1;
+    return 1;
+}
+
+static char *
+bdfend(gzFile *f)
+{
+    int c;
+    char *buf = NULL;
+    int bufsize = 0;
+    int i = 0;
+
+    do {
+        c = gzgetc(f);
+    } while (c == ' ');
+
+    while(i < 1000) {
+        if(c < 0 || (c == '\n' && i == 0)) {
+            goto fail;
+        }
+        if(bufsize < i + 1) {
+            char *newbuf;
+            if(bufsize == 0) {
+                bufsize = 20;
+                newbuf = malloc(bufsize);
+            } else {
+                bufsize = 2 * bufsize;
+                newbuf = realloc(buf, bufsize);
+            }
+            if(newbuf == NULL)
+                goto fail;
+            buf = newbuf;
+        }
+        if(c == '\n') {
+            buf[i] = '\0';
+            return buf;
+        }
+        buf[i++] = c;
+        c = gzgetc(f);
+    }
+
+ fail:
+    if(buf)
+        free(buf);
+    return NULL;
+}
+
+static int
+bdfIdentify(gzFile f, char **name)
+{
+    char *k;
+    int rc;
+    int eol;
+    /* bitmapIdentify already read "STAR", so we need to check for
+       "TFONT" */
+    k = getKeyword(f, &eol);
+    if(k == NULL || eol)
+        goto fail;
+    if(strcmp(k, "TFONT") != 0)
+        goto fail;
+    while(1) {
+        if(!eol) {
+            rc = bdfskip(f);
+            if(rc < 0) 
+                goto fail;
+        }
+        k = getKeyword(f, &eol);
+        if(k == NULL)
+            goto fail;
+        else if(strcmp(k, "FONT") == 0) {
+            if(eol)
+                goto fail;
+            k = bdfend(f);
+            if(k == NULL)
+                goto fail;
+            *name = k;
+            gzclose(f);
+            return 1;
+        } else if(strcmp(k, "CHARS") == 0)
+            goto fail;
+    }
+ fail:
+    gzclose(f);
+    return 0;
+}