import

DSTexCompress/FreeImage/Examples/Generic/LoadFromMemory.cpp

@@ -0,0 +1,113 @@
+// ==========================================================
+// Load From Memory Example
+//
+// Design and implementation by Floris van den Berg
+//
+// This file is part of FreeImage 3
+//
+// Use at own risk!
+// ==========================================================
+//
+//  This example shows how to load a bitmap from memory
+//  rather than from a file. To do this we make use of the
+//  FreeImage_LoadFromHandle functions where we override
+//  the i/o functions to simulate FILE* access in memory.
+//
+//  For seeking purposes the fi_handle passed to the i/o
+//  functions contain the start of the data block where the
+//  bitmap is stored.
+//
+// ==========================================================
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "FreeImage.h"
+
+// ----------------------------------------------------------
+
+fi_handle g_load_address;
+
+// ----------------------------------------------------------
+
+inline unsigned _stdcall
+_ReadProc(void *buffer, unsigned size, unsigned count, fi_handle handle) {
+	BYTE *tmp = (BYTE *)buffer;
+
+	for (unsigned c = 0; c < count; c++) {
+		memcpy(tmp, g_load_address, size);
+
+		g_load_address = (BYTE *)g_load_address + size;
+
+		tmp += size;
+	}
+
+	return count;
+}
+
+inline unsigned _stdcall
+_WriteProc(void *buffer, unsigned size, unsigned count, fi_handle handle) {
+	// there's not much use for saving the bitmap into memory now, is there?
+
+	return size;
+}
+
+inline int _stdcall
+_SeekProc(fi_handle handle, long offset, int origin) {
+	assert(origin != SEEK_END);
+
+	if (origin == SEEK_SET) {
+		g_load_address = (BYTE *)handle + offset;
+	} else {
+		g_load_address = (BYTE *)g_load_address + offset;
+	}
+
+	return 0;
+}
+
+inline long _stdcall
+_TellProc(fi_handle handle) {
+	assert((int)handle > (int)g_load_address);
+
+	return ((int)g_load_address - (int)handle);
+}
+
+// ----------------------------------------------------------
+
+int 
+main(int argc, char *argv[]) {
+	FreeImageIO io;
+
+	io.read_proc  = _ReadProc;
+	io.write_proc = _WriteProc;
+	io.tell_proc  = _TellProc;
+	io.seek_proc  = _SeekProc;
+
+	// allocate some memory for the bitmap
+
+	BYTE *test = new BYTE[159744];
+
+	if (test != NULL) {
+		// load the bitmap into memory. ofcourse you can do this any way you want
+
+		FILE *file = fopen("e:\\projects\\images\\money-256.tif", "rb");
+		fread(test, 159744, 1, file);
+		fclose(file);
+
+		// we store the load address of the bitmap for internal reasons
+
+		g_load_address = test;
+
+		// convert the bitmap
+		
+		FIBITMAP *dib = FreeImage_LoadFromHandle(FIF_TIFF, &io, (fi_handle)test);
+
+		// don't forget to free the dib !
+		FreeImage_Unload(dib);
+
+		delete [] test;
+	}
+
+	return 0;
+}