virtual-file: add from TR2X

meson.build

@@ -46,10 +46,10 @@ endif
 
 sources = [
   'src/benchmark.c',
-  'src/filesystem.c',
   'src/engine/audio.c',
   'src/engine/audio_sample.c',
   'src/engine/audio_stream.c',
+  'src/filesystem.c',
   'src/json/bson_parse.c',
   'src/json/bson_write.c',
   'src/json/json_base.c',
@@ -59,6 +59,7 @@ sources = [
   'src/memory.c',
   'src/strings.c',
   'src/vector.c',
+  'src/virtual_file.c',
 ]
 
 dependencies = [

src/virtual_file.c

@@ -0,0 +1,83 @@
+#include "virtual_file.h"
+
+#include "memory.h"
+
+#include <assert.h>
+#include <string.h>
+
+VFILE *VFile_CreateFromBuffer(const char *data, size_t size)
+{
+    VFILE *const file = Memory_Alloc(sizeof(VFILE));
+    file->content = Memory_Dup(data, size);
+    file->size = size;
+    file->cur_ptr = file->content;
+    return file;
+}
+
+void VFile_Close(VFILE *file)
+{
+    Memory_FreePointer(&file->content);
+    Memory_FreePointer(&file);
+}
+
+size_t VFile_GetPos(const VFILE *file)
+{
+    return file->cur_ptr - file->content;
+}
+
+void VFile_Skip(VFILE *file, int32_t offset)
+{
+    const size_t cur_pos = VFile_GetPos(file);
+    assert(cur_pos + offset <= file->size);
+    file->cur_ptr += offset;
+}
+
+void VFile_Read(VFILE *file, void *target, size_t size)
+{
+    const size_t cur_pos = VFile_GetPos(file);
+    assert(cur_pos + size <= file->size);
+    memcpy(target, file->cur_ptr, size);
+    file->cur_ptr += size;
+}
+
+int8_t VFile_ReadS8(VFILE *file)
+{
+    int8_t result;
+    VFile_Read(file, &result, sizeof(result));
+    return result;
+}
+
+int16_t VFile_ReadS16(VFILE *file)
+{
+    int16_t result;
+    VFile_Read(file, &result, sizeof(result));
+    return result;
+}
+
+int32_t VFile_ReadS32(VFILE *file)
+{
+    int32_t result;
+    VFile_Read(file, &result, sizeof(result));
+    return result;
+}
+
+uint8_t VFile_ReadU8(VFILE *file)
+{
+    uint8_t result;
+    VFile_Read(file, &result, sizeof(result));
+    return result;
+}
+
+uint16_t VFile_ReadU16(VFILE *file)
+{
+    uint16_t result;
+    VFile_Read(file, &result, sizeof(result));
+    return result;
+}
+
+uint32_t VFile_ReadU32(VFILE *file)
+{
+    uint32_t result;
+    VFile_Read(file, &result, sizeof(result));
+    return result;
+}

src/virtual_file.h

@@ -0,0 +1,23 @@
+#pragma once
+
+#include <stdint.h>
+
+typedef struct {
+    char *content;
+    size_t size;
+    char *cur_ptr;
+} VFILE;
+
+VFILE *VFile_CreateFromBuffer(const char *data, size_t size);
+void VFile_Close(VFILE *file);
+
+size_t VFile_GetPos(const VFILE *file);
+void VFile_Skip(VFILE *file, int32_t offset);
+
+void VFile_Read(VFILE *file, void *target, size_t size);
+int8_t VFile_ReadS8(VFILE *file);
+int16_t VFile_ReadS16(VFILE *file);
+int32_t VFile_ReadS32(VFILE *file);
+uint8_t VFile_ReadU8(VFILE *file);
+uint16_t VFile_ReadU16(VFILE *file);
+uint32_t VFile_ReadU32(VFILE *file);