add a (completely untested) decoder for voobly mod SLPs

based on algorithm in https://github.com/withmorten/vooblyslpdecode

CMakeLists.txt

@@ -234,6 +234,7 @@ set(EXTRACT_SRC src/tools/extract/datextract.cpp)
 set(DRSTOOL_SRC src/tools/drstool/drstool.cpp)
 set(CPXTOOL_SRC src/tools/cpxtool/cpxtool.cpp)
 set(PCRIOTOOL_SRC src/tools/pcriotool/pcriotool.cpp)
+set(VOOBLYDECODER_SRC src/tools/vooblydecoder/main.cpp)
 
 set(BINCOMP_SRC src/tools/bincompare/bincomp.cpp
                 src/tools/bincompare/main.cpp)
@@ -305,6 +306,9 @@ if (GUTILS_TOOLS)
 
   add_executable(genie-bindiff ${BINCOMP_SRC})
   install(TARGETS genie-bindiff)
+
+  add_executable(genie-vooblydecoder ${VOOBLYDECODER_SRC})
+  install(TARGETS genie-vooblydecoder)
 endif (GUTILS_TOOLS)
 
 #------------------------------------------------------------------------------#

src/resource/SlpFile.cpp

@@ -227,6 +227,7 @@ int SlpFile::frameWidth(const size_t frame)
 void SlpFile::serializeHeader()
 {
     serialize(version, 4);
+
     serializeSize<uint32_t>(num_frames_, frames_.size());
     serialize(comment, 24);
 }

src/tools/vooblydecoder/main.cpp

@@ -0,0 +1,70 @@
+#include <cstdio>
+#include <filesystem>
+#include <vector>
+#include <cstdint>
+#include <unistd.h>
+#include <cstring>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+int main(int argc, char *argv[])
+{
+    if (argc < 2) {
+        printf("Usage: %s <filename.slp>\n", argv[0]);
+        return 1;
+    }
+    if (!std::filesystem::exists(argv[1])) {
+        printf("Usage: %s <filename.slp>\n", argv[0]);
+        return 1;
+    }
+    int fd = open(argv[1], O_RDONLY);
+    if (fd < 0) {
+        perror("Failed to open filename");
+        return 1;
+    }
+    ssize_t size = lseek(fd, 0, SEEK_END) - 4; // 4 bytes header
+    if (size <= 0) {
+        perror("Failed to get size or too small");
+        close(fd);
+        return 1;
+    }
+
+    static const uint8_t vooblyHeader[4] = { 0xBE, 0xEF, 0x13, 0x37 };
+    uint8_t header[4];
+    read(fd, header, 4);
+    if (memcmp(header, vooblyHeader, 4) != 0) {
+        puts("Not a voobly encoded SLP");
+        close(fd);
+        return 1;
+    }
+
+    std::vector<uint8_t> buffer(size);
+    if (read(fd, buffer.data(), buffer.size()) != size) {
+        perror("Failed to read entire file");
+        close(fd);
+        return 1;
+    }
+    close(fd);
+
+    for (uint8_t &c : buffer) {
+        c = ' ' * ((c - 0x11) ^ '#') | (uint8_t((c - 0x11) ^ '#') >> 3);
+    }
+    const std::string outFile = std::filesystem::path(argv[1]).stem().string() + "-decoded.slp";
+    fd = open(outFile.c_str(), O_WRONLY);
+    if (fd < 0) {
+        perror("Failed to open filename");
+        return 1;
+    }
+
+    if (write(fd, buffer.data(), buffer.size()) != size) {
+        perror("Failed to write entire file");
+        close(fd);
+        return 1;
+    }
+    close(fd);
+
+    puts("Done.");
+
+    return 0;
+}
+