Implement RPck decompression.

dstien · Jan 9, 2024 · 2997ce5 · 2997ce5
1 parent d83b279
commit 2997ce5
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Showing 6 changed files with 180 additions and 6 deletions.
diff --git a/src/lib/Makefile b/src/lib/Makefile
@@ -1,5 +1,5 @@
 BIN = libstunpack$(LIBSUFFIX)
-SRCS = stunpack.c stunts.c stunts_huff.c stunts_rle.c util.c
+SRCS = rpck.c stunpack.c stunts.c stunts_huff.c stunts_rle.c util.c
 OBJS = $(SRCS:%.c=$(BUILDDIR)/%.o)
 
 all: $(BUILDDIR)/$(BIN)

diff --git a/src/lib/rpck.c b/src/lib/rpck.c
@@ -0,0 +1,107 @@
+/*
+ * stunpack - Stunts/4D [Sports] Driving game resource unpacker
+ * Copyright (C) 2008-2024 Daniel Stien <[email protected]>
+ *  
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software 
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include "rpck.h"
+
+#include "util.h"
+
+int rpck_isValid(stpk_Context *ctx)
+{
+    if (ctx->src.len < RPCK_SIZE_MIN) {
+		return 0;
+	}
+
+    uint32_t finalLength = rpck_peekLength(ctx->src.data, 4);
+    uint32_t savedLength = rpck_peekLength(ctx->src.data, 8);
+
+    return rpck_checkMagic(ctx)
+        && (finalLength - savedLength + RPCK_SIZE_MIN) == ctx->src.len;
+}
+
+unsigned int rpck_decompress(stpk_Context *ctx)
+{
+    if (ctx->src.len < RPCK_SIZE_MIN) {
+        UTIL_ERR("Unexpected EOF while reading RPck header.\n");
+		return 0;
+	}
+    if (!rpck_checkMagic(ctx)) {
+        unsigned char magic[5];
+        UTIL_ERR("Invalid magic bytes. Expected \"RPck\", got \"%s\"\n", magic, util_stringCharsSafe(ctx->src.data, magic, sizeof(magic)));
+        return 0;
+    }
+    ctx->src.offset += 4;
+    UTIL_VERBOSE1("Format: RPck\n");
+
+    uint32_t finalLength = rpck_readLength(&ctx->src);
+    UTIL_VERBOSE1("Final length  %d\n", finalLength);
+    UTIL_VERBOSE1("Source length %d\n", ctx->src.len);
+
+    uint32_t savedLength = rpck_readLength(&ctx->src);
+    UTIL_VERBOSE1("Saved length  %d\n", savedLength);
+    UTIL_VERBOSE1("Ratio %.2f\n", (float)finalLength / ctx->src.len);
+
+    ctx->dst.len = finalLength;
+    if (util_allocDst(ctx)) {
+        return 1;
+    }
+
+    while (ctx->src.offset < ctx->src.len) {
+        signed char ctrl = ctx->src.data[ctx->src.offset++];
+        UTIL_VERBOSE2("Offset %04X  Read ctrl %d ", ctx->src.offset - 1, ctrl);
+        if (ctrl < 0) {
+            if (ctx->src.offset - ctrl > ctx->src.len) {
+                UTIL_ERR("Attempted to read %d byte(s) past end of source buffer at offset %04X",
+                    (ctx->src.offset - ctrl) - ctx->src.len,
+                    ctx->src.offset);
+                return 1;
+            }
+            if (ctx->dst.offset - ctrl > ctx->dst.len) {
+                UTIL_ERR("Attempted to write %d byte(s) past end of destination buffer at offset %04X",
+                    (ctx->dst.offset - ctrl) - ctx->dst.len,
+                    ctx->dst.offset);
+                return 1;
+            }
+            for (; ctrl; ctrl++) {
+                UTIL_VERBOSE2(" %02X", ctx->src.data[ctx->src.offset]);
+                ctx->dst.data[ctx->dst.offset++] = ctx->src.data[ctx->src.offset++];
+            }
+            UTIL_VERBOSE2("\n");
+        }
+        else {
+            if (ctx->src.offset >= ctx->src.len) {
+                UTIL_ERR("Attempted to read 1 byte past end of source buffer at offset %04X",
+                    ctx->src.offset);
+                return 1;
+            }
+            unsigned char data = ctx->src.data[ctx->src.offset++];
+            if (ctx->dst.offset + ctrl + 1 > ctx->dst.len) {
+                UTIL_ERR("Attempted to write %d byte(s) past end of destination buffer at offset %04X",
+                    (ctx->dst.offset + ctrl + 1) - ctx->dst.len,
+                    ctx->dst.offset);
+                return 1;
+            }
+            UTIL_VERBOSE2(" x %02X\n", data);
+            for (int i = ctrl + 1; i; i--) {
+                ctx->dst.data[ctx->dst.offset++] = data;
+            }
+        }
+    }
+
+    return 0;
+}
diff --git a/src/lib/rpck.h b/src/lib/rpck.h
@@ -0,0 +1,56 @@
+/*
+ * stunpack - Stunts/4D [Sports] Driving game resource unpacker
+ * Copyright (C) 2008-2024 Daniel Stien <[email protected]>
+ *  
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software 
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef STPK_LIB_RPCK_H
+#define STPK_LIB_RPCK_H
+
+#include <stdint.h>
+#include <stunpack.h>
+
+#define RPCK_SIZE_MIN 14
+
+int rpck_isValid(stpk_Context *ctx);
+unsigned int rpck_decompress(stpk_Context *ctx);
+
+inline int rpck_checkMagic(stpk_Context *ctx)
+{
+    return ctx->src.data[0] == 'R'
+		&& ctx->src.data[1] == 'P'
+		&& ctx->src.data[2] == 'c'
+		&& ctx->src.data[3] == 'k';
+}
+
+// Peek at 32-bit big endian data length.
+inline uint32_t rpck_peekLength(unsigned char *data, unsigned offset)
+{
+    return data[offset + 0] << 24
+        | data[offset + 1] << 16
+        | data[offset + 2] << 8
+        | data[offset + 3];
+}
+
+// Read 32-bit big endian data length and advance buffer offset.
+inline uint32_t rpck_readLength(stpk_Buffer *buf)
+{
+    uint32_t len = rpck_peekLength(buf->data, buf->offset);
+    buf->offset += 4;
+    return len;
+}
+
+#endif
diff --git a/src/lib/stunpack.c b/src/lib/stunpack.c
@@ -19,6 +19,7 @@
 
 #include <stunpack.h>
 
+#include "rpck.h"
 #include "stunts.h"
 
 stpk_Context stpk_init(stpk_Format format, int verbosity, stpk_LogCallback logCallback, stpk_AllocCallback allocCallback, stpk_DeallocCallback deallocCallback)
@@ -63,6 +64,8 @@ void stpk_deinit(stpk_Context *ctx)
 unsigned int stpk_decompress(stpk_Context *ctx)
 {
 	switch (stpk_getFmtType(ctx)) {
+		case STPK_FMT_RPCK:
+			return rpck_decompress(ctx);
 		case STPK_FMT_STUNTS:
 			return stunts_decompress(ctx);
 		default:
@@ -74,11 +77,7 @@ unsigned int stpk_decompress(stpk_Context *ctx)
 stpk_FmtType stpk_getFmtType(stpk_Context *ctx)
 {
 	if (ctx->format.type == STPK_FMT_AUTO) {
-		// TODO: Check other header details, cleanup, move to rpck.c.
-		if (ctx->src.data[0] == 'R'
-		&& ctx->src.data[1] == 'P'
-		&& ctx->src.data[2] == 'c'
-		&& ctx->src.data[3] == 'k') {
+		if (rpck_isValid(ctx)) {
 			ctx->format.type = STPK_FMT_RPCK;
 		}
 		// TODO: Check other header details, cleanup, move to barchard.c.

diff --git a/src/lib/util.c b/src/lib/util.c
@@ -17,6 +17,7 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
+#include <ctype.h>
 #include <errno.h>
 #include <string.h>
 
@@ -54,6 +55,16 @@ char *util_stringBits16(unsigned short val)
 	return buf;
 }
 
+// Copy n-1 bytes from source to fixed destination buffer as printable ASCII characters.
+unsigned char *util_stringCharsSafe(const unsigned char *src, unsigned char *dst, unsigned int len)
+{
+    for (unsigned i = 0; i < len - 1; i++) {
+        dst[i] = isprint(src[i]) ? src[i] : '.';
+    }
+    dst[len] = 0;
+    return dst;
+}
+
 // Print formatted array. Used in verbose output.
 void util_printArray(const stpk_Context *ctx, const unsigned char *arr, unsigned int len, const char *name)
 {

diff --git a/src/lib/util.h b/src/lib/util.h
@@ -42,6 +42,7 @@ int util_allocDst(stpk_Context *ctx);
 void util_dst2src(stpk_Context *ctx);
 
 char *util_stringBits16(unsigned short val);
+unsigned char *util_stringCharsSafe(const unsigned char *src, unsigned char *dst, unsigned int len);
 void util_printArray(const stpk_Context *ctx, const unsigned char *arr, unsigned int len, const char *name);
 
 #endif