added scr_lvled, a bunch of libraries, and improved framework code

[raydungeon] / libs / goat3d / src / util.c

diff --git a/libs/goat3d/src/util.c b/libs/goat3d/src/util.c
new file mode 100644 (file)
index 0000000..9344e55
--- /dev/null
+++ b/libs/goat3d/src/util.c
@@ -0,0 +1,118 @@
+/*
+goat3d - 3D scene, and animation file format library.
+Copyright (C) 2013-2023  John Tsiombikas <nuclear@member.fsf.org>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program 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 Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include <stdlib.h>
+#include <string.h>
+#include "util.h"
+
+static int b64bits(int c);
+
+int calc_b64_size(const char *s)
+{
+       int len = strlen(s);
+       const char *end = s + len;
+       while(end > s && *--end == '=') len--;
+       return len * 3 / 4;
+}
+
+
+GOAT3DAPI void *goat3d_b64decode(const char *str, void *buf, int *bufsz)
+{
+       unsigned char *dest, *end;
+       unsigned char acc;
+       int bits, sz;
+       unsigned int gidx;
+
+       if(buf) {
+               sz = *bufsz;
+       } else {
+               sz = calc_b64_size(str);
+               if(!(buf = malloc(sz))) {
+                       return 0;
+               }
+               if(bufsz) *bufsz = sz;
+       }
+       dest = buf;
+       end = (unsigned char*)buf + sz;
+
+       sz = 0;
+       gidx = 0;
+       acc = 0;
+       while(*str) {
+               if((bits = b64bits(*str++)) == -1) {
+                       continue;
+               }
+
+               switch(gidx++ & 3) {
+               case 0:
+                       acc = bits << 2;
+                       break;
+               case 1:
+                       if(dest < end) *dest = acc | (bits >> 4);
+                       dest++;
+                       acc = bits << 4;
+                       break;
+               case 2:
+                       if(dest < end) *dest = acc | (bits >> 2);
+                       dest++;
+                       acc = bits << 6;
+                       break;
+               case 3:
+                       if(dest < end) *dest = acc | bits;
+                       dest++;
+               default:
+                       break;
+               }
+       }
+
+       if(gidx & 3) {
+               if(dest < end) *dest = acc;
+               dest++;
+       }
+
+       if(bufsz) *bufsz = dest - (unsigned char*)buf;
+       return buf;
+}
+
+static int b64bits(int c)
+{
+       if(c >= 'A' && c <= 'Z') {
+               return c - 'A';
+       }
+       if(c >= 'a' && c <= 'z') {
+               return c - 'a' + 26;
+       }
+       if(c >= '0' && c <= '9') {
+               return c - '0' + 52;
+       }
+       if(c == '+') return 62;
+       if(c == '/') return 63;
+
+       return -1;
+}
+
+GOAT3DAPI void goat3d_bswap32(void *buf, int count)
+{
+       int i;
+       register uint32_t x;
+       uint32_t *ptr = buf;
+
+       for(i=0; i<count; i++) {
+               x = *ptr;
+               *ptr++ = (x >> 24) | (x << 24) | ((x >> 8) & 0xff00) | ((x << 8) & 0xff0000);
+       }
+}