1 files changed, 125 insertions, 0 deletions

diff --git a/apps/plugins/sdl/progs/wolf3d/id_pm.c b/apps/plugins/sdl/progs/wolf3d/id_pm.c
new file mode 100644
index 0000000000..4b8d580b14
--- /dev/null
+++ b/apps/plugins/sdl/progs/wolf3d/id_pm.c
@@ -0,0 +1,125 @@
+#include "wl_def.h"
+
+int ChunksInFile;
+int PMSpriteStart;
+int PMSoundStart;
+
+bool PMSoundInfoPagePadded = false;
+
+// holds the whole VSWAP
+uint32_t *PMPageData;
+size_t PMPageDataSize;
+
+// ChunksInFile+1 pointers to page starts.
+// The last pointer points one byte after the last page.
+uint8_t **PMPages;
+
+void PM_Startup()
+{
+    char fname[13 + sizeof(DATADIR)] = DATADIR "vswap.";
+    strcat(fname,extension);
+
+    FILE *file = fopen(fname,"rb");
+    if(!file)
+        CA_CannotOpen(fname);
+
+    ChunksInFile = 0;
+    fread(&ChunksInFile, sizeof(word), 1, file);
+    PMSpriteStart = 0;
+    fread(&PMSpriteStart, sizeof(word), 1, file);
+    PMSoundStart = 0;
+    fread(&PMSoundStart, sizeof(word), 1, file);
+
+    uint32_t* pageOffsets = (uint32_t *) malloc((ChunksInFile + 1) * sizeof(int32_t));
+    CHECKMALLOCRESULT(pageOffsets);
+    fread(pageOffsets, sizeof(uint32_t), ChunksInFile, file);
+
+    word *pageLengths = (word *) malloc(ChunksInFile * sizeof(word));
+    CHECKMALLOCRESULT(pageLengths);
+    fread(pageLengths, sizeof(word), ChunksInFile, file);
+
+    fseek(file, 0, SEEK_END);
+    long fileSize = ftell(file);
+    long pageDataSize = fileSize - pageOffsets[0];
+    if(pageDataSize > (size_t) -1)
+        Quit("The page file \"%s\" is too large!", fname);
+
+    pageOffsets[ChunksInFile] = fileSize;
+
+    uint32_t dataStart = pageOffsets[0];
+    int i;
+
+    // Check that all pageOffsets are valid
+    for(i = 0; i < ChunksInFile; i++)
+    {
+        if(!pageOffsets[i]) continue;   // sparse page
+        if(pageOffsets[i] < dataStart || pageOffsets[i] >= (size_t) fileSize)
+            Quit("Illegal page offset for page %i: %u (filesize: %u)",
+                    i, pageOffsets[i], fileSize);
+    }
+
+    // Calculate total amount of padding needed for sprites and sound info page
+    int alignPadding = 0;
+    for(i = PMSpriteStart; i < PMSoundStart; i++)
+    {
+        if(!pageOffsets[i]) continue;   // sparse page
+        uint32_t offs = pageOffsets[i] - dataStart + alignPadding;
+        if(offs & 1)
+            alignPadding++;
+    }
+
+    if((pageOffsets[ChunksInFile - 1] - dataStart + alignPadding) & 1)
+        alignPadding++;
+
+    PMPageDataSize = (size_t) pageDataSize + alignPadding;
+    PMPageData = (uint32_t *) malloc(PMPageDataSize);
+    CHECKMALLOCRESULT(PMPageData);
+
+    PMPages = (uint8_t **) malloc((ChunksInFile + 1) * sizeof(uint8_t *));
+    CHECKMALLOCRESULT(PMPages);
+
+    // Load pages and initialize PMPages pointers
+    uint8_t *ptr = (uint8_t *) PMPageData;
+    for(i = 0; i < ChunksInFile; i++)
+    {
+        if(i >= PMSpriteStart && i < PMSoundStart || i == ChunksInFile - 1)
+        {
+            size_t offs = ptr - (uint8_t *) PMPageData;
+
+            // pad with zeros to make it 2-byte aligned
+            if(offs & 1)
+            {
+                *ptr++ = 0;
+                if(i == ChunksInFile - 1) PMSoundInfoPagePadded = true;
+            }
+        }
+
+        PMPages[i] = ptr;
+
+        if(!pageOffsets[i])
+            continue;               // sparse page
+
+        // Use specified page length, when next page is sparse page.
+        // Otherwise, calculate size from the offset difference between this and the next page.
+        uint32_t size;
+        if(!pageOffsets[i + 1]) size = pageLengths[i];
+        else size = pageOffsets[i + 1] - pageOffsets[i];
+
+        fseek(file, pageOffsets[i], SEEK_SET);
+        fread(ptr, 1, size, file);
+        ptr += size;
+    }
+
+    // last page points after page buffer
+    PMPages[ChunksInFile] = ptr;
+
+    free(pageLengths);
+    free(pageOffsets);
+    fclose(file);
+}
+
+void PM_Shutdown()
+{
+    free(PMPages);
+    free(PMPageData);
+}